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Sample search results for: palapa b2r satellite

 

1

Modeling And Simulation Of Prolate Dual-Spin Satellite Dynamics In An Inclined Elliptical Orbit: Case Study Of Palapa B2R Satellite

  CERN Preprints

Summary: In response to the interest to re-use Palapa B2R satellite nearing its End of Life (EOL) time, an idea to incline the satellite orbit in order to cover a new region has emerged in the recent years. As a prolate dual-spin vehicle, Palapa B2R has to be stabilized against its internal energy dissipation effect. This work is focused on analyzing the dynamics of the reusable satellite in its inclined orbit. The study discusses in particular the stability of the prolate dual-spin satellite under the effect of perturbed field of gravitation due to the inclination of its elliptical orbit. Palapa B2R physical data was substituted into the dual-spin's equation of motion. The coefficient of zonal harmonics J2 was induced into the gravity-gradient moment term that affects the satellite attitude. The satellite's motion and attitude were then simulated in the perturbed gravitational field by J2, with the variation of orbit's eccentricity and inclination. The analysis of the satellite dynamics and its stability was conducte...

Muliadi, J; Budiyono, A
2008-01-01

2

Solutions to Home-work 11 1. (a) Notice that if B2(R3) and x, y R3 are arbitrary, and

  Mathematics Websites

Summary: define ij = (ei, ej), then (x, y) = (x, 3 j=1 ej (y)ej) = 3 j=1 ej (y)(x, ej) = 3 j=1 ej (y)( 3 i=1 ei (x)ei, ej) = 3 i=1 3 j=1 ei (x)ej (y)(ei, ej) = 3 i=1 3 j=1 (ei, ej)ei ej (x, y) , thereby showing that {ei ej : 1 i, j 3} is a spanning set for B2(R3). The above string of equations can also be used

Sunder, V S

3

Equalizers for communications satellites

  MIT - DSpace

Summary: This thesis investigates equalization for advanced protected satellite communications systems in development at MIT Lincoln Laboratory. Equalizers facilitate high data rate communication by correcting dispersion in the ...

Fay, Leon
2008-01-01

4

Equalizers for communications satellites .

  Open Access Theses and Dissertations

Summary: ??This thesis investigates equalization for advanced protected satellite communications systems in development at MIT Lincoln Laboratory. Equalizers facilitate high data rate communication by correcting dispersion… (more)

Fay, Leon
2008-01-01

5

Satellite Umts Network Architecture

  CiteSeer

Summary: This paper presents Race Monet's UMTS network architecture, concentrating on the features specific to the support of satellite access networks. It shows how this architecture is capable of supporting all the proposed terrestrial and satellite systems and those anticipated for the future

R.J. Finean; A. El-Hoiydi
1996-01-01

6

Experimental Satellite Quantum Communications

  Quantum Physics (arXiv)

Summary: Quantum Communications on planetary scale require complementary channels including ground and satellite links. The former have progressed up to commercial stage using fiber-cables, while for satellite links, the absence of terminals in orbit has impaired theirs development. However, the demonstration of the feasibility of such links is crucial for designing space payloads and to eventually enable the realization of protocols such as quantum-key-distribution (QKD) and quantum teleportation along satellite-to-ground or intersatellite links. We demonstrated the faithful transmission of qubits from space to ground by exploiting satellite corner cube retroreflectors acting as transmitter in orbit, obtaining a low error rate suitable for QKD. We also propose a two-way QKD protocol exploiting modulated retroreflectors that necessitates a minimal payload on satellite, thus facilitating the expansion of Space Quantum Communications.

Giuseppe Vallone; Davide Bacco; Daniele Dequal; Simone Gaiarin; Vincenza Luceri; Giuseppe Bianco; Paolo Villoresi
2014-06-16

7

Optimization of Satellite Constellation Reconfiguration

  Engineering Websites

Summary: Optimization of Satellite Constellation Reconfiguration by Uriel Scialom Submitted Students #12;2 #12;Optimization of Satellite Constellation Reconfiguration by Uriel Scialom Submitted for the degree of Master of Science in Aeronautics and Astronautics Abstract Traditional satellite constellation


8

Destriping Satellite Images

  MIT - DSpace

Summary: Before satellite images obtained with multiple image sensors can be used in image analysis, corrections must be introduced for the differences in transfer functions on these sensors. Methods are here presented for ...

Horn, B.K.P.
1978-03-01

9

On satellites in arbitrary categories

  CERN Preprints

Summary: We generalize the definition of satellites with respect to presheaves (and copresheaves) with trace in the sense of Inassaridze; a presheaf with trace is replaced by a graph with a pair of diagrams defined on it. We show that the right satellite functor is left adjoint to the left satellite functor, and that a functor having a right (left) adjoint preserves right (left) satellites. In particular cases the construction of satellites is given.

Janelidze, George
2008-01-01

10

the Satellites Infrastructure

  CiteSeer

Summary: Abstract:- The current researches and industries are looking forward to integrate different technologies to get a global technology that offers all of the intended services in a simple way. In this paper, a new communications system is proposed to integrate the use of GSM over the available satellites infrastructures. The proposed communications system could be used to facilitates and get benefits of both systems (the GSM and Satellites) to achieve competitive services over the world. The proposed system is concentrated on a global communications system that served all over the world and gives some specialization and privacy for each country. Furthermore, this paper shows an algorithm on how to implement the GSM over satellite systems in an efficient, flexible, and cost-effective manner.

Muzhir Sh. Al-ani; Basil M. Al-kasasbeh; Rafa E. Al-qutaish; Mohammad I. Muhairat; Muzhir Sh. Al-ani; Basil M. Al-kasasbeh; Rafa E. Al-qutaish; Mohammad I. Muhairat

11

Correspondence Satellites: make data

  Biology and Medicine Websites

Summary: is hampering the widespread application of satellite monitoring, a vital tool for controlling deforestation (Jim Lynch et al. Nature 496, 293­294; 2013) and for biodiversity assessments. We urge government Union for Conservation of Nature (IUCN), aims to help biodiversity conservation efforts worldwide (see

Courchamp, Franck

12

6, 79457958, 2006 Satellite monitoring

  Physics Websites

Summary: ACPD 6, 7945­7958, 2006 Satellite monitoring of vegetation by DOAS T. Wagner et al. Title Page Chemistry and Physics Discussions Satellite monitoring of different vegetation types by differential optical.wagner@iup.uni-heidelberg.de) 7945 #12;ACPD 6, 7945­7958, 2006 Satellite monitoring of vegetation by DOAS T. Wagner et al. Title Page

Paris-Sud XI, Université de

13

Satellite data networks

  CiteSeer

Summary: OWADAYS we take the availability of worldwide communications for granted; communication satellites bring us live coverage of events from around the world and undersea fiber-optic cables are used to provide global telephony service. However, as recent as the 1950s transatlantic communications were limited to a few dozen voice circuits, and real-time communication with much of the world was not even possible. The potential of man-made

Eytan Modiano
2004-01-01

14

Binary Satellite Galaxies

  CERN Preprints

Summary: Suggestions have appeared in the literature that the following five pairs of Milky Way and Andromeda satellite galaxies are gravitationally bound: Draco and Ursa Minor, Leo IV and V, Andromeda I and III, NGC 147 and 185, and the Magellanic clouds. Under the assumption that a given pair is gravitationally bound, the Virial theorem provides an estimate of its total mass and so its instantaneous tidal radius. For all of these pairs except for the Magellanic clouds the resulting total mass is 2 to 4 orders of magnitude higher than that within the half light radius. Furthermore in the case of each pair except for Leo IV and Leo V, the estimated tidal radius is inferior to the separation between the two satellites. Therefore all or almost all of these systems are not gravitationally bound. We note several possible explanations for the proximities and similar radial velocities of the satellites in each pair, for example they may have condensed from the same infalling structure or they may be bound by a nongravitatio...

Evslin, Jarah
2013-01-01

15

Satellite Meteorology and Climatology Division Roadmap

  Environmental Sciences and Ecology Websites

Summary: Satellite Meteorology and Climatology Division Roadmap NOAA NESDIS Center for Satellite Applications and Research #12;SMCD Roadmap 2 NOAA/NESDIS/STAR Satellite Meteorology and Climatology Division.............................................................................................. 7 Overview of The Satellite Meteorology and Climatology Division

Kuligowski, Bob

16

Dynamical friction on satellite galaxies

  Astrophysics (arXiv)

Summary: For a rigid model satellite, Chandrasekhar's dynamical friction formula describes the orbital evolution quite accurately, when the Coulomb logarithm is chosen appropriately. However, it is not known if the orbital evolution of a real satellite with the internal degree of freedom can be described by the dynamical friction formula. We performed N-body simulation of the orbital evolution of a self-consistent satellite galaxy within a self-consistent parent galaxy. We found that the orbital decay of the simulated satellite is significantly faster than the estimate from the dynamical friction formula. The main cause of this discrepancy is that the stars stripped out of the satellite are still close to the satellite, and increase the drag force on the satellite through two mechanisms. One is the direct drag force from particles in the trailing tidal arm, a non-axisymmetric force that slows the satellite down. The other is the indirect effect that is caused by the particles remaining close to the satellite after escape. The force from them enhances the wake caused in the parent galaxy by dynamical friction, and this larger wake in turn slows the satellite down more than expected from the contribution of its bound mass. We found these two have comparable effects, and the combined effect can be as large as 20% of the total drag force on the satellite.

Michiko Fujii; Yoko Funato; Junichiro Makino
2005-11-22

17

REZA RABIEI, PhD 2444 Benny Crescent ~ Montreal, Quebec H4B 2R3

  Engineering Websites

Summary: digital image correlation (SSDIC) method in fracture mechanics." Society for Experimental Mechanics Annual. Rabiei. "Micromechanics of fracture in sheet and columnar nacre." Society for Experimental Mechanics.rabiei@mail.mcgill.ca EDUCATION PhD, Mechanical Engineering Sep. 2007 ­ May 2011 McGill University, Montreal, GPA: 4

Barthelat, Francois

18

Interferometric Observations of Geosynchronous Satellites

  CERN Preprints

Summary: In recent years, a large number of geosynchronous satellites are being planned to provide augmentation services for enhancing the precision to global positioning systems, e.g., GPS, in applications such as aircraft landing. In this paper, we present a scheme for co-locating passive satellite observational facilities with a radio astronomy facility to open a new possibility of providing valuable data for radio astronomical imaging, ionospheric studies and satellite orbit estimation.

Subrahmanya, C R; Somashekar, R
2011-01-01

19

SATELLITE-BASED INTERNET TECHNOLOGY AND SERVICES

  CiteSeer

Summary: In a satellite-based Internet system, satellites are used to interconnect heterogeneous network segments and to provide ubiquitous direct Internet access to homes and businesses. This article presents satellite-based Internet architectures and discusses multiple access control, routing, satellite transport, and integrating satellite networks into the global Internet.

Yurong Hu; Victor O. K. Li; Hong Kong

20

On board computers for satellites

  CERN Preprints

Summary: The paper is concerned with stored program general purpose digital computers for use on satellites. Environmental and other constraints which render satellite computers different from equivalent ground machines are discussed and several approaches to the realization of such computers are briefly illustrated where three representative architectures are described. Finally the architecture of an on board computer under development by ESRO is described. (14 refs).

Perry, M A
1972-01-01

21

Packet Satellite Technology Reference Sources

  CiteSeer

Summary: This paper describes briefly the packet satellite technology developed by the Defense Advanced Research Projects Agency and several other participating organizations in the U.K. and Norway and provides a biblography of relevant papers for researchers interested in experimental and operational experience with this dynamic satellite-sharing technique.

Vinton G Cerf
1982-01-01

22

1 Introduction to Satellite Communications

  CiteSeer

Summary: A communications satellite is an orbiting artificial earth satellite that receives a communications signal from a transmitting ground station, amplifies and possibly processes it, then transmits it back to the earth for reception by one or more receiving ground stations. Communications

unknown authors

23

2, 135, 2005 Satellite observations

  Physics Websites

Summary: -year satellite observations of instability waves in the Tropical Atlantic Ocean A. C. V. Caltabiano1 , I. SOSD 2, 1­35, 2005 Satellite observations of TIW in the Atlantic Ocean A. C. V. Caltabiano et al Print Version Interactive Discussion EGU Ocean Science Discussions, 2, 1­35, 2005 www.ocean

Paris-Sud XI, Université de

24

PASSIVE ATTITUDE STABILIZATION FOR SMALL SATELLITES.

  Open Access Theses and Dissertations

Summary: ??This thesis addresses the problem of designing and evaluating passive satellite attitude control systems for small satellites. Passive stabilization techniques such as Gravity Gradient stabilization,… (more)

Rawashdeh, Samir Ahmed
2010-01-01

25

MAE Seminar Series Satellite Formations

  Engineering Websites

Summary: of Aerospace Engineering Texas A&M University, College Station Abstract This talk will introduce a method-satellite fuel balancing using continuous as well as a two-impulse-per-orbit scheme will be presented. An example

Krovi, Venkat

26

Biogeography based Satellite Image Classification

  CERN Preprints

Summary: Biogeography is the study of the geographical distribution of biological organisms. The mindset of the engineer is that we can learn from nature. Biogeography Based Optimization is a burgeoning nature inspired technique to find the optimal solution of the problem. Satellite image classification is an important task because it is the only way we can know about the land cover map of inaccessible areas. Though satellite images have been classified in past by using various techniques, the researchers are always finding alternative strategies for satellite image classification so that they may be prepared to select the most appropriate technique for the feature extraction task in hand. This paper is focused on classification of the satellite image of a particular land cover using the theory of Biogeography based Optimization. The original BBO algorithm does not have the inbuilt property of clustering which is required during image classification. Hence modifications have been proposed to the original algorithm and...

Panchal, V K; Kaur, Navdeep; Kundra, Harish
2009-01-01

27

Modern Digital Satellite Television: How It Works

  Computer Technologies and Information Sciences Websites

Summary: Modern Digital Satellite Television: How It Works Matthew C. Valenti Lane Department of Computer #12;Outline 1 Satellite Television Standards 2 DVB-S2 Modulation 3 LDPC Coding 4 Tricks for Improving Virginia UniverLDPC Codes Nov. 7, 2011 2 / 33 #12;Satellite Television Standards Outline 1 Satellite

Valenti, Matthew C.

28

Quasioptimal bandwidth allocation for multispot MFTDMA satellites

  Computer Technologies and Information Sciences Websites

Summary: Quasi­optimal bandwidth allocation for multi­spot MFTDMA satellites Sara Alouf # , Eitan Altman@osdp.is.tsukuba.ac.jp Abstract--- This paper presents an algorithm for resource allocation in satellite networks 1 . It deals a multi­spot geostationary satellite system for which a manager assigns satellite uplink MFTDMA (Multi

Bermond, Jean-Claude

29

Realizing Future Broadband Satellite Network Services

  Computer Technologies and Information Sciences Websites

Summary: @cis.ohio-state.edu ABSTRACT Future satellite communication systems proposed use geosynchronous (GEO) satellites, medium earth challenges before telecommunications industry in the 21st century. Satellite communication networks canRealizing Future Broadband Satellite Network Services Sastri Kota Arjan Durresi, Raj Jain Lockheed

Jain, Raj

30

A networking perspective on satellite constellations

  Engineering Websites

Summary: A networking perspective on satellite constellations Ecole d'Hiver des Télécommunications de Sophia networking perspective on satellite constellations - Lloyd Wood 2 We aim to build up a picture of satellite constellations and how we can simulate them as networks. To do that, we'll cover: · orbital geometry of satellite

Wood, Lloyd

31

Satellite Luminosities in Galaxy Groups

  Astrophysics (arXiv)

Summary: Halo model interpretations of the luminosity dependence of galaxy clustering assume that there is a central galaxy in every sufficiently massive halo, and that this central galaxy is very different from all the others in the halo. The halo model decomposition makes the remarkable prediction that the mean luminosity of the non-central galaxies in a halo should be almost independent of halo mass: the predicted increase is about 20% while the halo mass increases by a factor of more than 20. In contrast, the luminosity of the central object is predicted to increase approximately linearly with halo mass at low to intermediate masses, and logarithmically at high masses. We show that this weak, almost non-existent mass-dependence of the satellites is in excellent agreement with the satellite population in group catalogs constructed by two different collaborations. This is remarkable, because the halo model prediction was made without ever identifying groups and clusters. The halo model also predicts that the number of satellites in a halo is drawn from a Poisson distribution with mean which depends on halo mass. This, combined with the weak dependence of satellite luminosity on halo mass, suggests that the Scott effect, such that the luminosities of very bright galaxies are merely the statistically extreme values of a general luminosity distribution, may better apply to the most luminous satellite galaxy in a halo than to BCGs. If galaxies are identified with halo substructure at the present time, then central galaxies should be about 4 times more massive than satellite galaxies of the same luminosity, whereas the differences between the stellar M/L ratios should be smaller. Therefore, a comparison of the weak lensing signal from central and satellite galaxies should provide useful constraints. [abridged

Ramin A. Skibba; Ravi K. Sheth; Matthew C. Martino
2008-05-05

32

Gaussian Entanglement Distribution via Satellite

  Quantum Physics (arXiv)

Summary: In this work we analyse three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the trade-off between space-based engineering complexity and the rate of ground-station entanglement generation.

Nedasadat Hosseinidehaj; Robert Malaney
2014-10-06

33

The Stromlo Missing Satellites Survey

  CERN Preprints

Summary: The Stromlo Missing Satellites (SMS) program is a critical endeavor to investigate whether cold dark matter cosmology is flawed in its ability to describe the matter distribution on galaxy scales or proves itself once again as a powerful theory to make observational predictions. The project will deliver unprecedented results on Milky Way satellite numbers, their distribution and physical properties. It is the deepest, most extended survey for optically elusive dwarf satellite galaxies to date, covering the entire 20,000 sq deg of the Southern hemisphere. 150TB of CCD images will be analysed in six photometric bands, 0.5-1.0 mag fainter than SDSS produced by the ANU SkyMapper telescope over the next five years. (For more details see: http://msowww.anu.edu.au/~jerjen/SMS_Survey.html)

Jerjen, Helmut
2008-01-01

34

The Stromlo Missing Satellites Survey

  Astrophysics (arXiv)

Summary: The Stromlo Missing Satellites (SMS) program is a critical endeavor to investigate whether cold dark matter cosmology is flawed in its ability to describe the matter distribution on galaxy scales or proves itself once again as a powerful theory to make observational predictions. The project will deliver unprecedented results on Milky Way satellite numbers, their distribution and physical properties. It is the deepest, most extended survey for optically elusive dwarf satellite galaxies to date, covering the entire 20,000 sq deg of the Southern hemisphere. 150TB of CCD images will be analysed in six photometric bands, 0.5-1.0 mag fainter than SDSS produced by the ANU SkyMapper telescope over the next five years. (For more details see: http://msowww.anu.edu.au/~jerjen/SMS_Survey.html)

Helmut Jerjen
2008-11-06

35

Gaussian Entanglement Distribution via Satellite

  Quantum Physics (arXiv)

Summary: In this work we analyse three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the trade-off between space-based engineering complexity and the rate of ground-station entanglement generation.

Nedasadat Hosseinidehaj; Robert Malaney
2015-02-05

36

Dark Matter tested with satellites

  CERN Preprints

Summary: Recently, the distribution of velocity dispersion as far as 400kpc around red isolated galaxies was derived from statistical studies of satellites in the SDSS (Klypin & Prada 2009). This could help to constrain dark matter models at intermediate scales. We compare the predictions of different DM distributions, LCDM with NFW or cored profiles, and also modified gravity models, with observations. It is shown how the freedom in the various parameters (radial distribution of satellites, velocity anisotropy, external field effect), prevents to disentangle the models, which all can give pretty good fits to the data. In all cases, realistic radial variations of velocity anisotropy are used for the satellites, and a constant stellar-mass to light ratio for the host galaxies.

Combes, F
2009-01-01

37

Gaussian Entanglement Distribution via Satellite

  CERN Preprints

Summary: In this work we analyse three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the trade-off between space-based engineering complexity and the rate of ground-station entanglement generation...

Hosseinidehaj, Nedasadat
2014-01-01

38

SOLAR POWER SATELLITES: RECENT DEVELOPMENTS

  CiteSeer

Summary: Solar power is a reality. Today, increasing numbers of photovoltaic and other solar-powered installations are in service around the world and in space. The Solar Power Satellite has been hailed by proponents as the answer to future global energy security and dismissed by detractors as impractical and uneconomic. This paper reviews recent design and feasibility studies, advances made in enabling technologies (particularly wireless power transmission) and the development of supporting infrastructure. It identifies current progress towards practical demonstrations of space solar power technology that could lead to an economically viable Solar Power Satellite system.

Frank E. Little

39

Chameleon gravity and satellite geodesy

  CERN Preprints

Summary: We consider the possibility of the detection of a chameleon effect by an earth orbiting satellite such as LAGEOS, and possible constraints that might be placed on chameleon model parameters. Approximate constraints presented here result from using a simple monopole approximation for the gravitational field of the earth, along with results from the Khoury-Weltman chameleon model, solar system constraints obtained from the Cassini mission, and parameter bounds obtained from the LAGEOS satellite. It is furthermore suggested that a comparison of ground-based and space-based multipole moments of the geopotential could reveal a possible chameleon effect.

Morris, J R
2014-01-01

40

Chameleon gravity and satellite geodesy

  HEP - Theory (arXiv)

Summary: We consider the possibility of the detection of a chameleon effect by an earth orbiting satellite such as LAGEOS, and possible constraints that might be placed on chameleon model parameters. Approximate constraints presented here result from using a simple monopole approximation for the gravitational field of the earth, along with results from the Khoury-Weltman chameleon model, solar system constraints obtained from the Cassini mission, and parameter bounds obtained from the LAGEOS satellite. It is furthermore suggested that a comparison of ground-based and space-based multipole moments of the geopotential could reveal a possible chameleon effect.

J. R. Morris
2014-09-29

41

Avec 44 satellites lancer, Arianespace

  Geosciences Websites

Summary: ESPACE Avec 44 satellites à lancer, Arianespace affiche un carnet de commandes record LA SOCI�T� EUROP�ENNE Arianespa- cedevrait conclurelasemaine duSalonde l'aéronautique et de l'espace du Bourget niveau local. Pour lui, les maires sont « les premiers acteurs et les meilleurs prescripteurs du

Lapeyre, Guillaume

42

Autonomous Orbit Estimation For Near Earth Satellites Using Horizon Scanners.

  Open Access Theses and Dissertations

Summary: ??Autonomous navigation is the determination of satellites position and velocity vectors onboard the satellite, using the measurements available onboard. The orbital information of a satellite… (more)

Nagarajan, N
1994-01-01

43

Satellite altimeter remote sensing of ice caps 

  Edinburgh, University of - Research Archive

Summary: This thesis investigates the use of satellite altimetry techniques for measuring surface elevation changes of ice caps. Two satellite altimeters, Radar Altimeter 2 (RA-2) and Geoscience Laser Altimeter System (GLAS) are ...

Rinne, Eero Juhani
2011-11-24

44

Helios: Heterogeneous Multiprocessing with Satellite Kernels

  Computer Technologies and Information Sciences Websites

Summary: Helios: Heterogeneous Multiprocessing with Satellite Kernels Edmund B. Nightingale Microsoft Research Galen Hunt Microsoft Research ABSTRACT Helios is an operating system designed to simplify the task of writ- ing, deploying, and tuning applications for heterogeneous platforms. Helios introduces satellite

Brown, Angela Demke

45

Satellite atmospheres Melissa A. McGrath

  Physics Websites

Summary: 19 Satellite atmospheres Melissa A. McGrath Space Telescope Science Institute Emmanuel Lellouch University of Virginia 19.1 INTRODUCTION Study of the Galilean satellite atmospheres is a field that has). At the time of that book, only one of these satellites, Io, was thought to possess an atmosphere, although

Johnson, Robert E.

46

4, 39794004, 2007 Snow satellite images

  Physics Websites

Summary: HESSD 4, 3979­4004, 2007 Snow satellite images for calibration of snow dynamic C. Corbari et al System Sciences Snow satellite images for calibration of snow dynamic in a continuous distributed. Corbari (chiara.corbari@mail.polimi.it) 3979 #12;HESSD 4, 3979­4004, 2007 Snow satellite images

Paris-Sud XI, Université de

47

A Satellite LO system B. G. Clark

  Physics Websites

Summary: A Satellite LO system B. G. Clark March 2002 One of the surprises in developing the VLBA holography system was that the satellite beacons being used for the purpose are actually very good oscillators from L a2 by the motion of the satellite during a transit time). The di#11;erence between these signals

Groppi, Christopher

48

The Aerospace Corporation 2009 Communication Satellite Systems

  Computer Technologies and Information Sciences Websites

Summary: © The Aerospace Corporation 2009 Communication Satellite Systems Trends and Network Aspects Paul://www.aero.org/ Lee Center, Caltech 13 April 2009 #12;22 Communication Satellites · Brief History by Decade · Trends: ­ Communication Satellites, fifth edition, by D. Martin, P. Anderson, L. Bartamian, Aerospace / AIAA Press, 2006

Low, Steven H.

49

SCTP over Satellite Networks Shaojian Fu

  Computer Technologies and Information Sciences Websites

Summary: of SCTP for data communications over satellite links. We describe SCTP features that allow SCTP to betSCTP over Satellite Networks Shaojian Fu Mohammed Atiquzzaman School of Computer Science University of Oklahoma, Norman, OK 73019-6151. William Ivancic Satellite Networks & Architectures Branch NASA Glenn

Atiquzzaman, Mohammed

50

NASA Launches Next-Generation Communications Satellite

  Physics Websites

Summary: NASA Launches Next-Generation Communications Satellite Pg 3 Triumph Over Tragedy: Columbia's Last in Florida. "TDRS-K bolsters our network of satellites that provides essential communications to support Goddard View The Weekly ­ 2 NASA Launches Next-Generation Communications Satellite ­ 3 Dinosaur Footprints

Christian, Eric

51

Electromagnetic Formation Flight of Satellite Arrays

  Engineering Websites

Summary: Electromagnetic Formation Flight of Satellite Arrays Daniel W. Kwon and David W. Miller February 2005 SSL # 2-05 #12;#12;Electromagnetic Formation Flight of Satellite Arrays By DANIEL W. KWON S;#12;Electromagnetic Formation Flight of Satellite Arrays by DANIEL W. KWON Submitted to the Department of Aeronautics


52

Dynamics and Control of Electromagnetic Satellite Formations

  Engineering Websites

Summary: Dynamics and Control of Electromagnetic Satellite Formations Umair Ahsun, David W. Miller June 2007 SSL # 12-07 #12;2 #12;Dynamics and Control of Electromagnetic Satellite Formations by Umair Ahsun B page] #12;3 Dynamics and Control of Electromagnetic Satellite Formations by Umair Ahsun Abstract


53

7, 60376075, 2007 Balloon and satellite

  Physics Websites

Summary: ACPD 7, 6037­6075, 2007 Balloon and satellite H2O measurements in the tropical UTLS N. Montoux et a Creative Commons License. Atmospheric Chemistry and Physics Discussions Evaluation of balloon and satellite Balloon and satellite H2O measurements in the tropical UTLS N. Montoux et al. Title Page Abstract

Paris-Sud XI, Université de

54

1, 337378, 2001 Modeling of satellite

  Computer Technologies and Information Sciences Websites

Summary: ACPD 1, 337­378, 2001 Modeling of satellite derived tropospheric ozone W. Peters et al. Title Page-transport modeling of the satellite observed distribution of tropical tropospheric ozone W. Peters1, M. Krol1, F Modeling of satellite derived tropospheric ozone W. Peters et al. Title Page Abstract Introduction

Boyer, Edmond

55

Reliable Multicast Transport by Satellite: a Hybrid Satellite/Terrestrial Solution with Erasure Codes

  Computer Technologies and Information Sciences Websites

Summary: multipoint communication service. In the context of reliable multicast communications, a new hybrid satellite/terrestrial approach is proposed. It aims at reducing the overall communication cost using satellite broadcasting onlyReliable Multicast Transport by Satellite: a Hybrid Satellite/Terrestrial Solution with Erasure

Mailhes, Corinne

56

Satellite Transport Protocol (STP): An SSCOPbased Transport Protocol for Datagram Satellite Networks

  Computer Technologies and Information Sciences Websites

Summary: challenges of data communications over satellite networks is the efficient transport of data over connections1 Satellite Transport Protocol (STP): An SSCOP­based Transport Protocol for Datagram Satellite in a datagram­based satellite data network. This protocol operates with high throughput and efficiency over

California at Berkeley, University of

57

Sweeping and shaking dwarf satellites

  Astrophysics (arXiv)

Summary: We present the first high-resolution N-Body/SPH simulations that follow the evolution of low surface brightness disk satellites in a primary halo containing both dark matter and a hot gas component. Tidal shocks turn the stellar disk into a spheroid with low $v/\\sigma$ and remove most of the outer dark and baryonic mass. In addition, by weakening the potential well of the dwarf, tides enhance the effect of ram pressure, and the gas is stripped down to radius three times smaller than the stellar component A very low gas/stars ratio results after several Gyr, similarly to what seen in dwarf spheroidal satellites of the Milky Way and M31.

Lucio Mayer; James Wadsley
2003-09-02

58

River extraction from satellite image

  CiteSeer

Summary: Satellite image processing plays a cr ucial role for the research developments in many fields of study including Astronomy, Remote Sensing, GIS, Agriculture Monitoring and Disaster Management. The remote sensing images are utilized in many of the researches with the aim of predicting natural disasters so that essential precautions can be taken to protect the environment. Besides the other, the water resource analysis plays a vital role in these researches. Traditionally, lots of methods are utilized for the analysis and determine some resources like water which are becoming extinct in nature. In this work, the methods like edge detection, thresholding, image erosion and other color and feature extraction algorithms are presented to extract water content (river). The algorithms used here includes, K means clustering algorithm, Hill Climbing Algorithm, Color histogram and image thresholding. Here, the condition of river like normal, drought or flood is also predicted by visual inspection of the processed satellite image.

Ms. Venu Shah; Ms. Archana Choudhary; Prof Kavita Tewari

59

Star Formation in Satellite Galaxies

  CERN Preprints

Summary: The study of satellite galaxies can provide information on the merging and aggregation processes which, according to the hierarchical clustering models, form the larger spiral galaxies we observe. With the aim of testing hierarchical models of galaxy formation, we have conducted an observational program which comprises H$\\alpha$ imaging for both the parent and the satellite galaxies, taken from the compilation by Zaritsky et al. (1997) that contains 115 galaxies orbiting 69 primary isolated spiral galaxies. We have observed a subsample of 37 spiral and irregular galaxies taken from the compilation mentioned above. The aim of this study is to determine star formation properties of the sample galaxies. In this work we present the preliminary results of this program that we have carried out with the 1.8-m Vatican Telescope (VATT).

Funes, S J; Prada, F; Azzaro, M; Ribeiro, M B; SJ, Jose G. Funes; Gutierrez, Carlos M.; Prada, Francisco; Azzaro, Marco; Ribeiro, Marcelo B.
2003-01-01

60

Picard satellite for solar astrometry

  CERN Preprints

Summary: The Picard solar satellite has been launched on June 15, 2010. This mission is dedicated to the measurement of the solar diameter with an expected accuracy of milliarcseconds of arc. The radiometer onboard is to measure the total solar irradiance. The final goal is the evaluation of the W, the logarithmic ratio of radius and luminosity. This parameter will help the climatologists to recover past values of the solar luminosity when the radius is available from ancient eclipses data.

Sigismondi, Costantino
2011-01-01

61

Information Delivery Through Broadcasting in Satellite Communication Networks

  Engineering Websites

Summary: Information Delivery Through Broadcasting in Satellite Communication Networks Leandros Tassiulas­range multicasting capability of satellites and the asymmetry of satellite communications (high bandwidth downlink. We consider a data broadcasting model that is encountered in most asymmetric satellite communication

Tassiulas, Leandros

62

Discs of Satellites: the new dwarf spheroidals

  CERN Preprints

Summary: The spatial distributions of the most recently discovered ultra faint dwarf satellites around the Milky Way and the Andromeda galaxy are compared to the previously reported discs-of-satellites (DoS) of their host galaxies. In our investigation we pay special attention to the selection bias introduced due to the limited sky coverage of SDSS. We find that the new Milky Way satellite galaxies follow closely the DoS defined by the more luminous dwarfs, thereby further emphasizing the statistical significance of this feature in the Galactic halo. We also notice a deficit of satellite galaxies with Galactocentric distances larger than 100 kpc that are away from the disc-of-satellites of the Milky Way. In the case of Andromeda, we obtain similar results, naturally complementing our previous finding and strengthening the notion that the discs-of-satellites are optical manifestations of a phase-space correlation of satellite galaxies.

Metz, Manuel; Jerjen, Helmut
2009-01-01

63

SMALL SATELLITES – A TOOL FOR EARTH OBSERVATION?

  CiteSeer

Summary: Small satellites with a mass between 10 to 500 kg have become a competitor to large satellites with a mass of over 1000 kg. This development has come about through the technological advances in micro-electronics. Small satellites are obviously less costly for launch. However, limitations for uses of small satellites exist through special requirements imposed in particular for remote sensing missions such as orbital and attitude control, sensor design and data readout. About 500 small satellites have been launched sofar, but only a small percentage of these for earth observation. Nevertheless sensing with 8 m ground pixels has been achieved. The International Academy of Aeronautics and its biannual symposia on small satellites in Berlin promote the future uses of small satellites as a cost-saving measure.

Gottfried Konecny

64

The Satellite-substructure Connection

  Astrophysics (arXiv)

Summary: We describe our recent attempts to model substructure in dark matter halos down to very small masses, using a semi-analytic model of halo formation. The results suggest that numerical simulations of halo formation may still be missing substructure in the central regions of halos due to purely numerical effects. If confirmed, this central 'overmerging' problem will have important consequences for the interpretation of lensing measurements of substructure. We also show that the spatial distribution of subhalos relative to the satellite companions of the Milky Way rules out at least one simple model of how dwarf galaxies form in low-mass halos.

James E. Taylor; Arif Babul; Joseph Silk
2003-11-28

65

Satellite-based quantum clock synchronization

  CERN Preprints

Summary: We propose a practical satellite-based quantum clock synchronization scheme with dispersion cancellation and by taking into account effects of gravitational frequency shift of the Earth. Two frequency entangled pulses are employed to synchronize two clocks, one at a ground station and the other at a satellite. The time discrepancy of the two clocks is introduced into the pulses by moving mirrors and is extracted by measuring the coincidence rate of the pulses in the interferometer. We find that the pulses are distorted due to effects of the gravitational frequency shift when they propagate between the Earth and the satellite. It is shown that the coincidence rate as well as precision of the time discrepancy are remarkably affected by gravitational frequency shift effects both for the low earth orbits satellite and geostationary earth orbits satellite cases. We also find that the precision of the clock synchronization are sensitive to the source parameters and the altitude of the satellite. Our proposal can be...

Wang, Jieci; Jing, Jiliang; Fan, Heng
2015-01-01

66

Ravens satellite mission concept study

  CERN Preprints

Summary: The concept for Ravens satellite mission was proposed in response to a CSA AO for potential Canadian mission contributions to the International Living With a Star (ILWS) program. Ravens was conceived of to fill an important gap in the ILWS program: global imaging. Ravens will build on the heritage of world-class global imaging carried out in Canada. It would do much more than provide global observations to complete the system level capabilities of ILWS. Ravens would be comprised of two satellites on elliptical polar orbits, relatively phased on those orbits to provide the first-ever continuous (ie., 24 hours per day 7 days per week) global imaging of the northern hemisphere auroral and polar cap regions. This would provide the first-ever unbroken sequences of global images of the auroral response during long duration geomagnetic processes like storms and steady magnetospheric convection events. Ravens could track the spatio-temporal evolution of the global electron and proton auroral distribution, and would o...

Donovan, Eric F
2011-01-01

67

Dynamics of the Galaxy's Satellites

  Astrophysics (arXiv)

Summary: The Milky Way's satellites provide unique information about the density of the Galactic halo at large radii. The inclusion of even a few rather inaccurate proper motions resolves an ambiguity in older mass estimates in favour of higher values. Many of the satellites are concentrated into streams. The dynamics of the Magellanic Stream provided an early indication that the halo reaches out to beyond 100 kpc. Tidal forces between the Clouds are currently disturbing the Clouds' internal dynamics. One would expect this damage to worsen rapidly as the tidal field of the MW excites the eccentricity of the Clouds' mutual orbit. This process, which has yet to be completely modelled, is important for understanding the degree of self-lensing in searches for gravitational lensing events. The Sagittarius Dwarf galaxy very likely contributes significantly to the Galactic warp. The direction of the warp's line of nodes is incorrectly predicted by the simplest models of the Dwarf's orbit. More sophisticated models, in which a complex distribution of stripped dark matter is predicted, may be more successful.

James Binney
2000-06-28

68

Satellite Ecology: The Dearth of Environment Dependence

  Astrophysics (arXiv)

Summary: Using the Sloan Digital Sky Survey (SDSS) galaxy group catalogue of Yang et al. (2007), we study the average colour and average concentration of satellite galaxies as function of (i) their stellar mass, (ii) their group mass, and (iii) their group-centric radius. We find that the colours and concentrations of satellite galaxies are (almost) completely determined by their stellar mass. In particular, at fixed stellar mass, the average colours and concentrations of satellite galaxies are independent of either halo mass or halo-centric radius. We find clear evidence for mass segregation of satellite galaxies in haloes of all masses, and argue that this explains why satellites at smaller halo-centric radii are somewhat redder and somewhat more concentrated. In addition, the weak colour and concentration dependence of satellite galaxies on halo mass is simply a reflection of the fact that more massive haloes host, on average, more massive satellites. Combining these results with the fact that satellite galaxies are, on average, redder and somewhat more concentrated than central galaxies of the same stellar mass, the following picture emerges: galaxies become redder and somewhat more concentrated once they fall into a bigger halo (i.e., once they become a satellite galaxy). This is a clear manifestation of environment dependence. However, there is no indication that the magnitude of the transformation (or its timescale) depends on environment; a galaxy undergoes a transition when it becomes a satellite, but it does not matter whether it becomes a satellite of a small (Milky Way sized) halo, or of a massive cluster. We discuss the implication of this `dearth' of environment dependence for the physical processes responsible for transforming satellite galaxies.

Frank C. van den Bosch; Anna Pasquali; Xiaohu Yang; H. J. Mo; Simone Weinmann; Daniel H. McIntosh; Daniel Aquino
2008-05-01

69

A Search for Satellite around Ceres

  CERN Preprints

Summary: We conducted a satellite search around the dwarf planet 1 Ceres using Hubble Space Telescope and ground-based Palomar data. No candidate objects were found orbiting Ceres in its entire stability region down to ~500km from the surface of Ceres. Assuming a satellite would have the same albedo as Ceres, which has a visual geometric albedo of 0.07-0.10, our detection limit is sensitive to satellites larger than 1-2 km in diameter.

Bieryla, A; Young, E F; McFadden, L A; Russell, C T; Stern, S A; Sykes, M V; Gladman, B
2011-01-01

70

SaVi: satellite constellation visualization

  CERN Preprints

Summary: SaVi, a program for visualizing satellite orbits, movement, and coverage, is maintained at the University of Surrey. This tool has been used for research in academic papers, and by industry companies designing and intending to deploy satellite constellations. It has also proven useful for demonstrating aspects of satellite constellations and their geometry, coverage and movement for educational and teaching purposes. SaVi is introduced and described briefly here.

Wood, Lloyd
2012-01-01

71

Satellites of the largest Kuiper belt objects

  Astrophysics (arXiv)

Summary: We have searched the four brightest objects in the Kuiper belt for the presence of satellites using the newly commissioned Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen around three of the four objects: Pluto (whose satellite Charon is well-known), 2003 EL61, and 2003 UB313. The object 2005 FY9, the brightest Kuiper belt object after Pluto, does not have a satellite detectable within 0.4 arcseconds with a brightness of more than 0.5% of the primary. The presence of satellites to 3 of the 4 brightest Kuiper belt objects is inconsistent with the fraction of satellites in the Kuiper belt at large at the 99.1% confidence level, suggesting a different formation mechanism for these largest KBO satellites. The satellites of 2003 EL61 and 2003 UB313, with fractional brightnesses of 5% and 2% of their primaries, respectively, are significantly fainter relative to their primaries than other known Kuiper belt object satellites, again pointing to possible differences in their origin.

M. E. Brown; M. A. van Dam; A. H. Bouchez; D. Le Mignant; R. D. Campbell; J. C. Y. Chin; A. Conrad; S. K. Hartman; E. M. Johansson; R. E. Lafon; D. L. Rabinowitz; P. J. Stomski, Jr.; D. M. Summers; C. A. Trujillo; P. L. Wizinowich
2005-10-03

72

Origin of Europa and the Galilean Satellites

  CERN Preprints

Summary: Europa is believed to have formed near the very end of Jupiter's own accretion, within a circumplanetary disk of gas and solid particles. We review the formation of the Galilean satellites in the context of current constraints and understanding of giant planet formation, focusing on recent models of satellite growth within a circumjovian accretion disk produced during the final stages of gas inflow to Jupiter. In such a disk, the Galilean satellites would have accreted slowly, in more than 10^5 yr, and in a low pressure, low gas density environment. Gravitational interactions between the satellites and the gas disk lead to inward orbital migration and loss of satellites to Jupiter. Such effects tend to select for a maximum satellite mass and a common total satellite system mass compared to the planet's mass. One implication is that multiple satellite systems may have formed and been lost during the final stages of Jupiter's growth, with the Galilean satellites being the last generation that survived as gas in...

Canup, Robin M
2008-01-01

73

Modeling and Control of SPIDER Satellite Components.

  Open Access Theses and Dissertations

Summary: ??Space satellite technology is heading in the direction of ultra-large, lightweight structures deployable on orbit. Minimal structural mass translates into minimal launch costs, while increased… (more)

Ruggiero, Eric John
2005-01-01

74

Black rain: The burial of the Galilean satellites in irregular satellite debris William F. Bottke a,

  Physics Websites

Summary: Black rain: The burial of the Galilean satellites in irregular satellite debris William F. Bottke a Lunar Science Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302, USA b Institute of Astronomy

Bottke, William F.

75

Characterizing switching problems in low earth orbit satellite constellations with satellite failures

  Texas A&M University - TxSpace

Summary: CHARACTERIZING SWITCHING PROBLEMS IN LOW EARTH ORBIT SATELLITE CONSTELLATIONS WITH SATELLITE FAILURES A Thesis by BRANDON SCOTT WADSWORTH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1999 Major Subject: Computer Science CHARACTERIZING SWITCHING PROBLEMS IN LOW EARTH ORBIT SATELLITE CONSTELLATIONS WITH SATELLITE FAILURES A Thesis By BRANDON SCOTT WADSWORTH Submitted to Texas...

Wadsworth, Brandon Scott
2012-06-07

76

PERFORMANCE EVALUATION OF LEO SATELLITE CONSTELLATIONS WITH INTER-SATELLITE LINKS

  Computer Technologies and Information Sciences Websites

Summary: 1 PERFORMANCE EVALUATION OF LEO SATELLITE CONSTELLATIONS WITH INTER-SATELLITE LINKS UNDER SELF orbit (LEO) satellite constellations, used for the interconnection of high-speed networks, is presented worldwide for supporting real-time communications. Low Earth Orbit (LEO) constellations, specially those

Papapetrou, Evaggelos

77

Extracting River Discharge from Satellite Altimetry

  Geosciences Websites

Summary: propose an algorithm to extract river discharge by comput- ing a reliable level-discharge relationship. The prerequisite for computing a high-quality level-discharge is a reliable level from satellite altimetry waveforms. With the height information from satellite information improved, we obtain a reliable level

Stuttgart, Universität

78

Want to Install A Satellite Dish ?

  Environmental Sciences and Ecology Websites

Summary: utility lines would be interfered with by satellite dish post installation. 6. Entry into the unit in case of nearby utility lines or other factors. 3--Point of entry for satellite dish cable Housing! We want you to enjoy your home as much as possible; we only ask that you follow the guide- lines

Maxwell, Bruce D.

79

Opportunities and Challenges of Nano Satellites

  Plasma Physics and Fusion Websites

Summary: #12;2 AXELSPACE - Who are we? Space venture company specialized in nano-satellites. Developer of nano. of Tech. #12;5 University Space Engineering Consortium (UNISEC) Founded in 2002, obtained legal status for space development/utilization Technology development for nano-satellites and hybrid rockets http


80

Signal Deformations On Nominally Healthy GPS Satellites

  Engineering Websites

Summary: Signal Deformations On Nominally Healthy GPS Satellites Alexander M. Mitelman, R. Eric Phelts University in 1997 and 2001. His research involves multipath mitiga- tion techniques and satellite signal at Stanford, where he has supported GPS Local Area Augmentation System (LAAS) and Wide Area Augmentation

Stanford University

81

Using Satellite Data to Forecast . Bleaching Events

  Geosciences Websites

Summary: 1 Using Satellite Data to Forecast . Bleaching Events . By Tyler Christensen . NOAA Coral Reef Watch Satellite Imagery Worksheet The main condition that is linked to coral bleaching is unusually high for the warmest month. One degree above that is the threshold temperature for coral bleaching, shown as the solid


82

MICHAELMATSON NOAA National Earth Satellite Service

  Environmental Sciences and Ecology Websites

Summary: for con- verting the satellite-measured thermal energy emitted by the Earth and its atmosphere Sources Using a Thermal IR Sensor Steel mills, and gas flares from oil fields, were identified by using-GENERATION,polar orbiting, TIROS-N series of environmental satellites provides two thermal infrared (IR) channels for twice

Dozier, Jeff

83

Introduction satellite based scatterometers provide high

  Geosciences Websites

Summary: on the Quikscat satellite. The EUMETsAT Advanced scatterometer AsCAT on Met- Op-A was launched on 19 October 2006Winds scatterometers. Together, the AsCAT, ERs-2 and seaWinds scattero- meters provide good coverage over the oceans. The KNMI contribution to the EUMETsAT satellite Application Facilities (sAFs), the AsCAT calibration

Haak, Hein

84

Satellite Navigation Integrity Assurance: Lessons Learned

  Engineering Websites

Summary: Satellite Navigation Integrity Assurance: Lessons Learned from Hurricane Katrina ION GNSS 2008 by the FAA Satellite Navigation Program Office #12;17 September 2008 Lessons Learned from Hurricane Katrina 2 Outline · The Destruction of Much of Greater New Orleans in late August 2005 (Hurricane Katrina) · Flaws

Stanford University

85

Satellite Eye for Galathea 3 -Slutrapport

  Multidisciplinary Databases and Resources Websites

Summary: Satellite Eye for Galathea 3 - Slutrapport Charlotte Bay Hasager, Peter Brøgger Sørensen, Jacob L Abstract (in English) (max. 2000 char.): The Satellite Eye for Galathea 3 project started on the 10th March August 2006. The expedition lasted in total 256 days (8 months), and the Satelitte Eye project continued


86

4, 68236836, 2004 A global satellite view

  Physics Websites

Summary: ACPD 4, 6823­6836, 2004 A global satellite view of aerosol cloud interactions C. Luo Title Page and Physics Discussions A global satellite view of aerosol cloud interactions C. Luo Institute for Computational Earth System Science, University of California, Santa Barbara, California 6832 Ellison Hall

Paris-Sud XI, Université de

87

Capture of Irregular Satellites at Jupiter

  CERN Preprints

Summary: The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early Solar System instability when encounters between the outer planets occurred (Nesvorny, Vokrouhlicky & Morbidelli 2007, AJ 133; hereafter NVM07). NVM07 already showed that the irregular satellites of Saturn, Uranus and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary d...

Nesvorny, D; Deienno, R
2014-01-01

88

How do the planetary satellites rotate?

  CERN Preprints

Summary: On the basis of tidal despinning timescale arguments, Peale showed in 1977 that the majority of irregular satellites (with unknown rotation states) are expected to reside close to their initial (fast) rotation states. Here we investigate the problem of typical rotation states among satellites from a viewpoint of dynamical stability. We explore location of the known planetary satellites on the ``$\\omega_0$--$e$'' stability diagram, where $\\omega_0$ is an inertial parameter of a satellite and $e$ is its orbital eccentricity. We show that most of the satellites with unknown rotation states cannot rotate synchronously, because no stable synchronous 1:1 spin-orbit state exists for them. They rotate either much faster than synchronously (those tidally unevolved) or, what is much less probable, chaotically (tidally evolved objects or captured slow rotators).

Melnikov, Alexander V
2009-01-01

89

Turbo-Coded APSK Modulations Design for Satellite Broadband Communications

  Computer Technologies and Information Sciences Websites

Summary: Turbo-Coded APSK Modulations Design for Satellite Broadband Communications Riccardo De Gaudenzi with application to satellite broad- band communications. APSK represents an attractive modulation format systems. 1 Introduction Satellite communication systems strength lies in their ability to efficiently

Guillén i Fàbregas, Albert

90

Gas Shepherding by an Infalling Satellite

  Astrophysics (arXiv)

Summary: I calculate the action of a satellite, infalling through dynamical friction, on a coplanar gaseous disk of finite radial extent. The disk tides, raised by the infalling satellite, couple the satellite and disk. Dynamical friction acting on the satellite then shrinks the radius of the coupled satellite-disk system. Thus, the gas is ``shepherded'' to smaller radii. In addition, gas shepherding produces a large surface density enhancement at the disk edge. If the disk edge then becomes gravitationally unstable and fragments, it may give rise to enhanced star formation. On the other hand, if the satellite is sufficiently massive and dense, the gas may be transported from $\\sim 100$ pc to inside of a 10 to 10s of parsecs before completely fragmenting into stars. I argue that gas shepherding may drive the fueling of active galaxies and central starbursts and I compare this scenario to competing scenarios. I argue that sufficiently large and dense super star clusters (acting as the shepherding satellites) can shepherd a gas disk down to ten to tens of parsecs. Inside of ten to tens of parsecs, another mechanism may operate, i.e., cloud-cloud collisions or a marginally (gravitationally) stable disk, that drives the gas $\\lesssim 1$ pc, where it can be viscously accreted, feeding a central engine.

P. Chang
2008-01-14

91

Satellites around massive galaxies since z~2

  CERN Preprints

Summary: Accretion of minor satellites has been postulated as the most likely mechanism to explain the significant size evolution of the massive galaxies over cosmic time. Using a sample of 629 massive (Mstar~10^11 Msun) galaxies from the near-infrared Palomar/DEEP-2 survey, we explore which fraction of these objects has satellites with 0.01 Msat < Mcentral < 1 (1:100) up to z=1 and which fraction has satellites with 0.1 Msat < Mcentral < 1 (1:10) up to z=2 within a projected radial distance of 100 kpc. We find that the fraction of massive galaxies with satellites, after the background correction, remains basically constant and close to ~30% for satellites with a mass ratio down to 1:100 up to z=1, and ~15% for satellites with a 1:10 mass ratio up to z=2. The family of spheroid-like massive galaxies presents a 2-3 times larger fraction of objects with satellites than the group of disk-like massive galaxies. A crude estimation of the number of 1:3 mergers a massive spheroid-like galaxy experiences since z~2...

Mármol-Queraltó, E; Pérez-González, P G; Varela, J; Barro, G
2012-01-01

92

Probing Dark Matter Haloes with Satellite Kinematics

  Astrophysics (arXiv)

Summary: Using detailed mock galaxy redshift surveys we investigate to what extent the kinematics of large samples of satellites galaxies extracted from flux-limited surveys can be used to constrain halo masses. Previous host-satellite selection criteria yield relatively large fractions of interlopers and with a velocity distribution that, contrary to what has typically been assumed, differs strongly from uniform. A new adaptive selection criterion is proposed which yields much larger host-satellite samples and with strongly reduced interloper fractions. We show that satellite weighting, which occurs naturally when stacking many host-satellite pairs, introduces a bias towards higher velocity dispersions compared to the true, host-averaged mean. A further bias, in the same direction, is introduced when using flux-limited, rather than volume-limited surveys. We apply our adaptive selection criterion to the 2dFGRS and obtain a sample of 12613 satellite galaxies and 8004 host galaxies. The satellite kinematics are in excellent agreement with predictions based on the conditional luminosity function (CLF), providing independent, dynamical confirmation of the average mass-to-light ratios predicted by the CLF formalism.

Frank C. van den Bosch; Peder Norberg; H. J. Mo; Xiaohu Yang
2004-04-01

93

Star Formation in Satellite Galaxies

  CERN Preprints

Summary: We present narrow-band observations of the H$\\alpha$ emission in a sample of 31 satellite orbiting isolated giant spiral galaxies. The sample studied spans the range $-19

Gutíerrez, C M; Funes, J G; Ribeiro, M B
2006-01-01

94

Dark Satellites and Cosmic Reionization

  Astrophysics (arXiv)

Summary: A possible explanation of the present discrepancy between the abundance of galactic subhaloes predicted by N-Body simulations with those observed in the Local Group is presented. We study the impact of an early reionization on the baryonic component of the Universe using SPH simulations on group and galactic scales. We use a simplified model for reionization described as an instantaneous increment of the IGM temperature (with 1e5 8). We find that a key role is played by compton cooling (interaction between hot electrons and the CMB photons); at high redshift (z_r>10) this cooling is very efficient and it is able to counteract any heating of the gas within few Myrs. This means that a late reionization is needed (z_r<9) to sufficiently reduce the number of luminous dwarf satellites around our Galaxy. For a reionization redshift z_r=8 and a reionization temperature of T_{IGM}~1e5 K we are able to reproduce the observed number of Local Group dwarf galaxies in our simulations.

Andrea V. Maccio'; Ben Moore; Joachim Stadel; Doug Potter
2006-09-06

95

The Transiting Exoplanet Survey Satellite

  CERN Preprints

Summary: The Transiting Exoplanet Survey Satellite (TESS) will search for planets transiting bright and nearby stars. TESS has been selected by NASA for launch in 2017 as an Astrophysics Explorer mission. The spacecraft will be placed into a highly elliptical 13.7-day orbit around the Earth. During its two-year mission, TESS will employ four wide-field optical CCD cameras to monitor at least 200,000 main-sequence dwarf stars with I<13 for temporary drops in brightness caused by planetary transits. Each star will be observed for an interval ranging from one month to one year, depending mainly on the star's ecliptic latitude. The longest observing intervals will be for stars near the ecliptic poles, which are the optimal locations for follow-up observations with the James Webb Space Telescope. Brightness measurements of preselected target stars will be recorded every 2 min, and full frame images will be recorded every 30 min. TESS stars will be 10-100 times brighter than those surveyed by the pioneering Kepler missio...

Ricker, George R; Vanderspek, Roland; Latham, David W; Bakos, Gaspar A; Bean, Jacob L; Berta-Thompson, Zachory K; Brown, Timothy M; Buchhave, Lars; Butler, Nathaniel R; Butler, R Paul; Chaplin, William J; Charbonneau, David; Christensen-Dalsgaard, Jorgen; Clampin, Mark; Deming, Drake; Doty, John; De Lee, Nathan; Dressing, Courtney; Dunham, E W; Endl, Michael; Fressin, Francois; Ge, Jian; Henning, Thomas; Holman, Matthew J; Howard, Andrew W; Ida, Shigeru; Jenkins, Jon; Jernigan, Garrett; Johnson, John Asher; Kaltenegger, Lisa; Kawai, Nobuyuki; Kjeldsen, Hans; Laughlin, Gregory; Levine, Alan M; Lin, Douglas; Lissauer, Jack J; MacQueen, Phillip; Marcy, Geoffrey; McCullough, P R; Morton, Timothy D; Narita, Norio; Paegert, Martin; Palle, Enric; Pepe, Francesco; Pepper, Joshua; Quirrenbach, Andreas; Rinehart, S A; Sasselov, Dimitar; Sato, Bun'ei; Seager, Sara; Sozzetti, Alessandro; Stassun, Keivan G; Sullivan, Peter; Szentgyorgyi, Andrew; Torres, Guillermo; Udry, Stephane; Villasenor, Joel
2014-01-01

96

Nighttime lights - DMSP Satellite Data

  CiteSeer

Summary: This paper describes an assessment of the DMSP/OLS nighttime satellite imagery as evidence of human presence and activity over the Brazilian Amazonia region. The study explores the potential of the sensor on a regional scale, and verifies the correlation between DMSP nighttime light foci and population and between nighttime light foci and electrical power consumption. Using a mosaic of DMSP/OLS nighttime light imagery from September 1999, 248 towns from a total of 749 municpios in Amazonia were detected. It was found that the nighttime light foci were related to human activity, including urban settlements, mining, industries, and civil construction. Restricting the analysis to the state of Par and excluding Census data and DMSP nighttime light foci. Similarly, electrical power consumption for 1999 was linearly correlated with DMSP nightlights foci (R = 0.79). It may, thus, be concluded that DMSP/OLS imagery can be used as an indicator of human presence in the Amazonia region in the analysis of spatial-temporal patterns in Amazonia because they are closely related to urban population and electrical power consumption. Remote sensing imagery is useful, considering the continental dimension of Amazonia, the absence of demographic information between the official population census (taken at a 10 year interval), and the dynamics and complexity of human activity in the region. DMSP nighttime light foci can be a valuable data source for studies, modelling, and planning activities where the human dimension must be consider throughout Amazonia.

As An Indicator; Silvana Amaral; Gilberto Câmara; Antônio Miguel; Vieira Monteiro; Christopher D. Elvidge; S. Amaral A; G. Câmara A; A. M. V. Monteiro A; C. D. Elvidge B; J. A. Quintanilha C

97

Star Formation Histories of the Galactic Satellites

  Astrophysics (arXiv)

Summary: Late accretion models for formation of the Galactic halo require that many Galactic satellite galaxies have been cannibalised into the halo field. Comparison of the metallicity and age distribution function of stars in the surviving satellites with the apparently exclusively old stars in the field halo can constrain the importance of any such process. We have developed a new objective technique to determine star formation histories in dSph galaxies. We apply this technique to the surviving Galactic satellites, deducing an approximately uniform distribution of ages for the constituents, quite unlike the halo field stars. Thus, late accretion did not play a substantial part in Galactic halo formation.

Gerard Gilmore; Xavier Hernandez; David Valls-Gabaud
1999-10-22

98

Satellite galaxies in cosmological dark matter halos

  CERN Preprints

Summary: We present preliminary results from a series of high-resolution N-body simulations that focus on 8 dark matter halos each of order a million particles within the virial radius. We follow the time evolution of hundreds of individually tracked satellite galaxies and relate their physical properties to the differing halo environmental conditions. Our main science driver is to understand how satellite galaxies lose their mass and react to tidal stripping. Unlike previous work our results are performed in a fully self-consistent cosmological context. The preliminary results demonstrate that while environment may vary considerably with respects to formation time and richness of substructure, the satellites evolve similarly.

Gill, S P D; Gibson, B K; Gill, Stuart P.D.; Knebe, Alexander; Gibson, Brad K.
2003-01-01

99

Satellite galaxies in cosmological dark matter halos

  Astrophysics (arXiv)

Summary: We present preliminary results from a series of high-resolution N-body simulations that focus on 8 dark matter halos each of order a million particles within the virial radius. We follow the time evolution of hundreds of individually tracked satellite galaxies and relate their physical properties to the differing halo environmental conditions. Our main science driver is to understand how satellite galaxies lose their mass and react to tidal stripping. Unlike previous work our results are performed in a fully self-consistent cosmological context. The preliminary results demonstrate that while environment may vary considerably with respects to formation time and richness of substructure, the satellites evolve similarly.

Stuart P. D. Gill; Alexander Knebe; Brad K. Gibson
2003-11-28

100

Disruption of satellites in cosmological haloes

  Astrophysics (arXiv)

Summary: We investigate how the survival of dark matter satellites inside virialized halos depends on tidal stripping and dynamical friction. We use an analytic approach and then compare the results with N-Body simulations. Both the satellites and the primary halos are similar to cosmological haloes and have NFW density profiles. Satellites can either merge with the primary halo or continue to move on barely perturbed orbits, eventually being disrupted, depending on the relative strength of friction and tidal forces. We propose that their actual fate depends simply on their mass ratio relative to the primary halo.

Giuliano Taffoni; Lucio Mayer; Monica Colpi; Fabio Governato
2001-09-03

101

Star Formation in Satellite Galaxies

  Astrophysics (arXiv)

Summary: We present narrow-band observations of the H$\\alpha$ emission in a sample of 31 satellite orbiting isolated giant spiral galaxies. The sample studied spans the range $-19

C. M. Gutierrez; M. S. Alonso; J. G. Funes; M. B. Ribeiro
2006-04-14

102

Satellite-based quantum clock synchronization

  Quantum Physics (arXiv)

Summary: We propose a practical scheme of satellite-based quantum clock synchronization with atmospheric dispersion cancellation and by taking into account spacetime background of the Earth. Two frequency entangled pulses are employed to synchronize two clocks, one at a ground station and the other at a satellite. The time discrepancy of the two clocks is introduced into the pulses by moving mirrors and is extracted by measuring the coincidence rate of the pulses in the interferometer. We find that the pulses are distorted due to effects of gravity when they propagate between the Earth and the satellite, resulting in coincidence rate are remarkably affected. We also find that the precision of the clock synchronization are sensitive to the source parameters and the altitude of the satellite. Our proposal can be realized with current technology.

Jieci Wang; Zehua Tian; Jiliang Jing; Heng Fan
2015-01-26

103

Dynamics and control of electromagnetic satellite formations

  MIT - DSpace

Summary: Satellite formation flying is an enabling technology for many space missions, especially for space-based telescopes. Usually there is a tight formation-keeping requirement that may need constant expenditure of fuel or at ...

Ahsun, Umair, 1972-
2007-01-01

104

The Formation of Pluto's Low Mass Satellites

  CERN Preprints

Summary: Motivated by the New Horizons mission, we consider how Pluto's small satellites -- currently P5, Nix, P4, and Hydra -- grow in debris from the giant impact that forms the Pluto-Charon binary or in solid material captured from the protoplanetary debris disk. If the satellites have masses close to their minimum masses, our analysis suggests that capture of material into a circumplanetary or circumbinary debris disk is a viable mechanism for satellite formation. If the satellites are more massive, they probably form in debris from the giant impact. After the impact, Pluto and Charon accrete some of the debris and eject the rest from the binary orbit. During the ejection, high velocity collisions among debris particles produce a collisional cascade, leading to the ejection of some debris from the system and enabling the remaining debris particles to find stable orbits around the binary. Our numerical simulations of viscous diffusion, coagulation, and migration show that collisional evolution within a ring or disk...

Kenyon, Scott J
2013-01-01

105

NOAA NESDIS CENTER for SATELLITE APPLICATIONS and

  Geosciences Websites

Summary: 1 NOAA NESDIS CENTER for SATELLITE APPLICATIONS and RESEARCH ALGORITHM THEORETICAL BASIS DOCUMENT.......................................................................................................9 1.1 Purpose of This Document ..................................................................................9 1.2 Who Should Use This Document


106

Atmospheric delay modeling for satellite laser altimetry

  MIT - DSpace

Summary: NASA's Ice, Cloud, and Land Elevation Satellite (ICESat) is a laser altimetry mission with the primary purpose of measuring the mass balance of the ice sheets of Greenland and Antarctica. It will provide 5 years of topography ...

Quinn, Katherine J. (Katherine Jane), 1971-
2002-01-01

107

Emerging trends in the satellite industry

  MIT - DSpace

Summary: Risk aversion in the satellite industry has fostered long development cycles and low rates of innovation in the past. Emerging trends in propulsion technology development and spacecraft architecture design could lead to ...

Salazar, Vagn Knudsen
2012-01-01

108

Synthetic Aperture Radar Interferometry with 3 satellites

  MIT - DSpace

Summary: Our study investigates interferometric SAR (InSAR) post-processing height retrieval techniques. We explore the possible improvements by adding a third satellite to the two already in orbit, and examine some potential uses ...

Wong, Wallace D. (Wallace Dazheng)
2005-01-01

109

Resource management for advanced transmission antenna satellites

  MIT - DSpace

Summary: In satellite communications, narrow spotbeams can provide high power and data rates to the desired location while reducing spatial interference. Advanced transmission antenna technology is critical to generate and switch ...

Chan, Vincent W. S.

110

The Anisotropic Distribution of Satellite Galaxies

  Astrophysics (arXiv)

Summary: We identify satellites of isolated galaxies in SDSS and examine their angular distribution. Using mock catalogues generated from cosmological N-body simulations, we demonstrate that the selection criteria used to select isolated galaxies and their satellites must be very strict in order to correctly identify systems in which the primary galaxy dominates its environment. The criteria used in many previous studies instead select predominantly group members. We refine a set of selection criteria for which the group contamination is estimated to be less than 7% and present a catalogue of the resulting sample. The angular distribution of satellites about their host is biased towards the major axes for spheroidal galaxies and probably also for red disc galaxies, but is isotropic for blue disc galaxies, i.e. it is the colour of the host that determines the distribution of its satellites rather than its morphology. The similar anisotropy measured in this study as in studies that were dominated by groups implies that group-specific processes are not responsible for the angular distribution. Satellites that are most likely to have been recently accreted show a tendancy to lie along the same axis as the surrounding large scale structure. The orientations of isolated early and intermediate-type galaxies also align with the surrounding large scale structures. We discuss the origin of the anisotropic satellite distribution and consider the implications of our results, critically assessing the respective roles played by the orientation of the visible galaxy within its dark matter halo; anisotropic accretion of satellites from the larger scale environment; and the biased nature of satellites as tracers of the underlying dark matter subhalo population. (Abridged)

Jeremy Bailin; Chris Power; Peder Norberg; Dennis Zaritsky; Brad K. Gibson
2007-06-10

111

Satellite Systems around Galaxies in Hydrodynamic Simulations

  CERN Preprints

Summary: We investigate the properties of satellite galaxies formed in N-body/SPH simulations of galaxy formation in the $\\Lambda$CDM cosmology. The simulations include the main physical effects thought to be important in galaxy formation and, in several cases, produce realistic spiral discs. In total, a sample of 9 galaxies of luminosity comparable to the Milky Way was obtained. At magnitudes brighter than the resolution limit, $M_V=-12$, the luminosity function of the satellite galaxies in the simulations is in excellent agreement with data for the Local Group. The radial number density profile of the model satellites, as well as their gas fractions also match observations very well. In agreement with previous N-body studies, we find that the satellites tend to be distributed in highly flattened configurations whose major axis is aligned with the major axis of the (generally triaxial) dark halo. In 2 out of 3 systems with sufficiently large satellite populations, the satellite system is nearly perpendicular to the p...

Libeskind, N I; Frenk, C S; Okamoto, T; Jenkins, A; Libeskind, Noam I; Cole, Shaun; Frenk, Carlos S; Okamoto, Takashi; Jenkins, Adrian
2006-01-01

112

Ion Micro-Propulsion and Cost Modeling for Satellite Clusters

  Engineering Websites

Summary: Ion Micro-Propulsion and Cost Modeling for Satellite Clusters b y Gregory Yashko B.S. Aerospace;3 Ion Micro-Propulsion and Cost Modeling for Satellite Clusters b y Gregory Yashko Submitted modeling of distributed satellite systems, determination of propulsion system requirements for satellite


113

CIRES/NGDC Research Associate Satellite Sensor Systems Engineer

  Multidisciplinary Databases and Resources Websites

Summary: CIRES/NGDC Research Associate Satellite Sensor Systems Engineer The Cooperative Institute, Boulder, CO. This position is for a Satellite Sensor Systems Engineer within the NGDC Solar. The Satellite Sensor Systems Engineer is STP's primary scientific and technical interface to NOAA satellite

Colorado at Boulder, University of

114

Satellite Eye for Galathea 3 Annual Report 2007

  Multidisciplinary Databases and Resources Websites

Summary: -real-time on Google Earth along with near-real-time ship observations. Based on the satellite images, the ship of the 40 weekly images and a series of satellite image animations that shows our living Earth from space through Earth observation satellites. The satellite images were displayed in near-real-time in Google


115

MLSR: A Novel Routing Algorithm for Multilayered Satellite IP Networks

  CiteSeer

Summary: Several IP-based routing algorithms have been developed for low-Earth orbit (LEO) satellite networks in recent years. The performance of the satellite IP networks can be improved drastically if multiple satellite constellations are used in the architecture. In this work, a multilayered satellite IP network is introduced that consists of LEO, medium-Earth orbit (MEO), and geostationary Earth orbit (GEO) satellites. A new multilayered satellite routing algorithm (MLSR) is developed that calculates routing tables efficiently using the collected delay measurements. The performance of the multilayered satellite network and MLSR is evaluated through simulations and analysis.

Ian F. Akyildiz; Eylem Ekici; Michael D. Bender
2002-01-01

116

The satellite distribution of M31

  Astrophysics (arXiv)

Summary: (Abridged) The spatial distribution of the Galactic satellite system plays an important role in Galactic dynamics and cosmology, where its successful reproduction is a key test of simulations of galaxy halo formation. Here, we examine its representative nature by conducting an analysis of the 3-dimensional spatial distribution of the M31 subgroup of galaxies. We begin by a discussion of distance estimates and incompleteness concerns, before revisiting the question of membership of the M31 subgroup. Comparison of the distribution of M31 and Galactic satellites relative to the galactic disks suggests that the Galactic system is probably modestly incomplete at low latitudes by ~20%. We find that the radial distribution of satellites around M31 is more extended than the Galactic subgroup; 50% of the Galactic satellites are found within ~100kpc of the Galaxy, compared to ~200kpc for M31. We search for ``ghostly streams'' of satellites around M31, in the same way others have done for the Galaxy, and find several. The lack of M31-centric kinematic data, however, means we are unable to probe whether these streams represent real physical associations. Finally, we find that the M31 satellites are asymmetrically distributed with respect to our line-of-sight to this object, so that the majority of its satellites are on its near side with respect to our line-of-sight. We quantify this result and find it to be significant at the ~3 sigma level. Until such time as a satisfactory explanation for this finding is presented, our results warn against treating the M31 subgroup as complete, unbiased and relaxed.

Alan McConnachie; Mike Irwin
2005-10-21

117

6Name ________________________________ Satellite technology is everywhere! Right now, there are over 1587 working satellites orbiting

  Environmental Sciences and Ecology Websites

Summary: , there are over 1587 working satellites orbiting Earth. They represent over $160 billion in assets to the world years as new services are created, and better technology is developed. Satellites in the lowest orbits, called Low Earth Orbit (LEO) orbit between 300 to 1000 kilometers above the ground. Because Earth


118

Macho Parallaxes From A Single Satellite

  Astrophysics (arXiv)

Summary: Massive Compact Objects (Machos) are currently being discovered at substantially higher rates than would be expected from standard models of known stellar populations. To determine whether they are due to non-standard distri- butions of known populations or to a heretofore unknown (`dark') population, one must acquire more information about the individual events. Space-based parallaxes are potentially the best tool for extracting additional information. To leading order, parallax measurements by a single satellite result in a four- fold degeneracy: two possible values of $\\tilde v$ and two possible signs for the component of motion perpendicular to the projected satellite-Earth vector. It had been believed that a second satellite would be required to break this degeneracy. I show that the velocity difference between the satellite and the Earth allows one to partially or totally break the degeneracy using a single satellite. For most Macho events it is possible to measure $\\tilde v$ and $\\tilde r_e$. For some it is also possible to measure $\\Phi$. The proposed Space Infrared Telescope could measure $\\sim 100$ parallaxes per year by applying $\\sim 400\\,$hr of telescope time.

Andrew Gould
1994-08-10

119

Notes on the Missing Satellites Problem

  CERN Preprints

Summary: The Missing Satellites Problem (MSP) broadly refers to the overabundance of predicted Cold Dark Matter (CDM) subhalos compared to satellite galaxies known to exist in the Local Group. The most popular interpretation of the MSP is that the smallest dark matter halos in the universe are extremely inefficient at forming stars. The question from that standpoint is to identify the feedback source that makes small halos dark and to identify any obvious mass scale where the truncation in the efficiency of galaxy formation occurs. Among the most exciting developments in near-field cosmology in recent years is the discovery of a new population satellite galaxies orbiting the Milky Way and M31. Wide field, resolved star surveys have more than doubled the dwarf satellite count in less than a decade, revealing a population of ultrafaint galaxies that are less luminous that some star clusters. For the first time, there are empirical reasons to believe that there really are missing satellite galaxies in the Local Group, lu...

Bullock, James S
2010-01-01

120

The satellite distribution of M31

  CERN Preprints

Summary: (Abridged) The spatial distribution of the Galactic satellite system plays an important role in Galactic dynamics and cosmology, where its successful reproduction is a key test of simulations of galaxy halo formation. Here, we examine its representative nature by conducting an analysis of the 3-dimensional spatial distribution of the M31 subgroup of galaxies. We begin by a discussion of distance estimates and incompleteness concerns, before revisiting the question of membership of the M31 subgroup. Comparison of the distribution of M31 and Galactic satellites relative to the galactic disks suggests that the Galactic system is probably modestly incomplete at low latitudes by ~20%. We find that the radial distribution of satellites around M31 is more extended than the Galactic subgroup; 50% of the Galactic satellites are found within ~100kpc of the Galaxy, compared to ~200kpc for M31. We search for ``ghostly streams'' of satellites around M31, in the same way others have done for the Galaxy, and find several. T...

Irwin, A M C M
2006-01-01

121

Reionization and the abundance of galactic satellites

  Astrophysics (arXiv)

Summary: One of the main challenges facing standard hierarchical structure formation models is that the predicted abundance of galactic subhalos with circular velocities of 10-30 km/s is an order of magnitude higher than the number of satellites actually observed within the Local Group. Using a simple model for the formation and evolution of dark halos, based on the extended Press-Schechter formalism and tested against N-body results, we show that the theoretical predictions can be reconciled with observations if gas accretion in low-mass halos is suppressed after the epoch of reionization. In this picture, the observed dwarf satellites correspond to the small fraction of halos that accreted substantial amounts of gas before reionization. The photoionization mechanism naturally explains why the discrepancy between predicted halos and observed satellites sets in at about 30 km/s, and for reasonable choices of the reionization redshift (z_re = 5-12) the model can reproduce both the amplitude and shape of the observed velocity function of galactic satellites. If this explanation is correct, then typical bright galaxy halos contain many low-mass dark matter subhalos. These might be detectable through their gravitational lensing effects, through their influence on stellar disks, or as dwarf satellites with very high mass-to-light ratios. This model also predicts a diffuse stellar component produced by large numbers of tidally disrupted dwarfs, perhaps sufficient to account for most of the Milky Way's stellar halo.

James S. Bullock; Andrey V. Kravtsov; David H. Weinberg
2000-02-09

122

On Asymmetric Distributions of Satellite Galaxies

  CERN Preprints

Summary: We demonstrate that the asymmetric distribution of M31 satellites cannot be produced by tides from the Milky Way as such effects are too weak. However, loosely bound associations and groups of satellites can fall into larger haloes and give rise to asymmetries. We compute the survival times for such associations. We prove that the survival time is always shortest in Keplerian potentials, and can be ~ 3 times longer in logarithmic potentials. We provide an analytical formula for the dispersal time in terms of the size and velocity dispersion of the infalling structure. We show that, if an association of ~10 dwarfs fell into the M31 halo, its present aspect would be that of an asymmetric disk of satellites. We also discuss the case of cold substructure in the Andromeda II and Ursa Minor dwarfs.

Bowden, A; Belokurov, V
2014-01-01

123

Introducing Relativity in Global Navigation Satellite Systems

  General Relativity & Quantum Cosmology (arXiv)

Summary: Today, the Global Navigation Satellite Systems, used as global positioning systems, are the GPS and the GLONASS. They are based on a Newtonian model and hence they are only operative when several relativistic effects are taken into account. The most important relativistic effects (to order 1/c^2) are: the Einstein gravitational blue shift effect of the satellite clock frequency (Equivalence Principle of General Relativity) and the Doppler red shift of second order, due to the motion of the satellite (Special Relativity). On the other hand, in a few years the Galileo system will be built, copying the GPS system unless an alternative project is designed. In this work, it will be also shown that the SYPOR project, using fully relativistic concepts, is an alternative to a mere copy of the GPS system. According to this project, the Galileo system would be exact and there would be no need for relativistic corrections.

J. -F. Pascual-Sanchez
2005-07-28

124

Modeling the Milky-Way Satellite galaxies

  Astrophysics (arXiv)

Summary: We revisit the Milky Way satellite problem using a semi-analytical model of galaxy formation and compare the predicted luminosity function to recent result from the SDSS. With cosmic photoionization, the luminosity function can be brought into broad agreement with the data between $-15< M_{V} <-2$. This improvement over previous semi-analytical model results (e.g., Benson et al.2002) is from our adoption of improved models for galaxy merger history and galaxy merging time-scales. The very faint satellites ($M_{v} > -5$) formed in halos with virial temperature over $10^{4}K$ (mass around $10^{9} M_{\\odot}$ before accretion), but their baryon content are strongly suppressed by photoionization. We model the mass evolution of the subhalos, and compare the predicted mass-to-light ratio with the data. We find that the measured total mass inside the luminous radii of satellites are about 5% of their present total dark matter mass.

X. Kang
2008-06-19

125

The morphological evolution of galaxy satellites

  Astrophysics (arXiv)

Summary: We study the evolution of galaxy satellites with high resolution N-body simulations. Satellites are modeled as replicas of typical low and high surface brightness galaxies (LSBs and HSBs). Encounters on high eccentricity orbits (as typical in hierarchical models of galaxy formation) strip LSBs of most of their stars and tend to decrease their surface brightness. On the contrary, bar instability in HSBs leads to substantial loss of angular momentum of the stellar component and to an increase of central surface brightness. In both cases the remnant resembles a spheroidal galaxy with an exponential surface brightness profile. A simple modeling of color evolution and interactions driven star formation gives M/L ratios for the remnants that are roughly consistent with observations. These results suggest an evolutionary scenario for the dwarf galaxies in our Local Group, faint dSphs being the descendents of LSBs and brighter dSphs/dEs being the final state of HSB satellites.

Lucio Mayer; Fabio Governato; Monica Colpi; Ben Moore; Thomas R. Quinn; Carlton M. Baugh
1999-03-30

126

Simulating Sinking Satellites with SUPERBOX-10

  CERN Preprints

Summary: SUPERBOX-10 is the successor of SUPERBOX, a particle-mesh code where additional grids and sub-grids are applied to regions of high particle density. Previous limitations have been solved. For instance, the vertical resolution is improved considerably when flattened grids are used. Since the computationally most intensive part is the Fast Fourier Transform, we introduce a parallelised version using the library FFTW, resulting in a speed-up of a few. The new features are tested using a galaxy model consisting of an exponential disc, a bulge and a dark matter halo. We demonstrate that the use of flattened grids efficiently reduces numerical heating. We simulate the merging of disc-bulge-halo galaxies with small spherical satellites. As a result, satellites on orbits with both low eccentricity and inclination heat the disc most efficiently. Moreover, we find that most of the satellite's energy and angular momentum is transfered to the halo.

Bien, Reinhold; Just, Andreas
2012-01-01

127

Dwarf satellite galaxies in the modified dynamics

  CERN Preprints

Summary: In the modified dynamics (MOND) the inner workings of dwarf satellites can be greatly affected by their mother galaxy-over and beyond its tidal effects. Because of MOND's nonlinearity a system's internal dynamics can be altered by an external field in which it is immersed (even when this field, by itself, is constant in space). As a result, the size and velocity dispersion of the satellite vary as the external field varies along its orbit. A notable outcome of this is a substantial increase in the dwarf's vulnerability to eventual tidal disruption-rather higher than Newtonian dynamics (with a dark-matter halo) would lead us to expect for a satellite with given observed parameters.

Milgrom, M
2000-01-01

128

Satellite Systems around Galaxies in Hydrodynamic Simulations

  Astrophysics (arXiv)

Summary: We investigate the properties of satellite galaxies formed in N-body/SPH simulations of galaxy formation in the $\\Lambda$CDM cosmology. The simulations include the main physical effects thought to be important in galaxy formation and, in several cases, produce realistic spiral discs. In total, a sample of 9 galaxies of luminosity comparable to the Milky Way was obtained. At magnitudes brighter than the resolution limit, $M_V=-12$, the luminosity function of the satellite galaxies in the simulations is in excellent agreement with data for the Local Group. The radial number density profile of the model satellites, as well as their gas fractions also match observations very well. In agreement with previous N-body studies, we find that the satellites tend to be distributed in highly flattened configurations whose major axis is aligned with the major axis of the (generally triaxial) dark halo. In 2 out of 3 systems with sufficiently large satellite populations, the satellite system is nearly perpendicular to the plane of the galactic disc, a configuration analogous to that observed in the Milk Way. The discs themselves are perpendicular to the minor axis of their host halos in the inner parts, and the correlation between the orientation of the galaxy and the shape of the halo persists even out to the virial radius. However, in one case the disc's minor axis ends up, at the virial radius, perpendicular to the minor axis of the halo. The angular momenta of the galaxies and their host halo tend to be well aligned.

Noam I Libeskind; Shaun Cole; Carlos S Frenk; Takashi Okamoto; Adrian Jenkins
2006-07-11

129

A relativistic and autonomous navigation satellite system

  General Relativity & Quantum Cosmology (arXiv)

Summary: A relativistic positioning system has been proposed by Bartolom\\'e Coll in 2002. Since then, several group developed this topic with different approaches. I will present a work done in collaboration with Ljubljana University and the ESA Advanced Concepts Team. We developed a concept, Autonomous Basis of Coordinates, in order to take advantage of the full autonomy of a satellite constellation for navigation and positioning, by means of satellite inter-links. I will present the advantages of this new paradigm and a number of potential application for reference systems, geophysics and relativistic gravitation.

Pacôme Delva; Andrej Cadez; Uros Kostic; Sante Carloni
2011-06-17

130

Internal waves and vortices in satellite images

  CERN Preprints

Summary: Some recent papers proposed the use of the satellite images of Google Earth in teaching physics, in particular to see some behaviours of waves. Reflection, refraction, diffraction and interference are easy to be found in these satellite maps. Besides Google Earth, other sites exist, such as Earth Observatory or Earth Snapshot, suitable for illustrating the large-scale phenomena in atmosphere and oceans In this paper, we will see some examples for teaching surface and internal sea waves, and internal waves and the K\\'arm\\'an vortices in the atmosphere. Aim of this proposal is attracting the interest of students of engineering schools to the physics of waves.

Sparavigna, Amelia Carolina
2012-01-01

131

Performance Analysis of LEO Satellite Networks

  CiteSeer

Summary: We present an analytical model fl computing call blocking probabilities in a LEO satellite network that carries voice calls. Both satellite-fixed and earth-fixed constellations with inter-orbit links and hand-o#s are considered. The model is analyzed approximately by decomposing it into sub-systems. Each sub-system is solved in isolation exactly using a Markov process, and the individual results are combined together through an iterative method. Numerical results demonstrate that our method is accuratefc a wide rangeof tra#c patterns. 1

A. Halim Zaim; Harry G. Perros; George N. Rouskas
2002-01-01

132

On the orbit of the LARES satellite

  CERN Preprints

Summary: This paper is motivated by the recent possibility to find an inexpensive launching vehicle for the LARES satellite, however at an altitude much lower than originally planned for the LAGEOS III/LARES satellite. We present here a preliminary error analysis corresponding to a lower, quasi-polar, orbit, in particular we analyze the effect on the LARES node of the Earth's static gravitational field, and in particular of the Earth's even zonal harmonics, the effect of the time dependent Earth's gravitational field, and in particular of the K1 tide, and the effect of particle drag.

Ciufolini, I
2006-01-01

133

On the orbit of the LARES satellite

  General Relativity & Quantum Cosmology (arXiv)

Summary: This paper is motivated by the recent possibility to find an inexpensive launching vehicle for the LARES satellite, however at an altitude much lower than originally planned for the LAGEOS III/LARES satellite. We present here a preliminary error analysis corresponding to a lower, quasi-polar, orbit, in particular we analyze the effect on the LARES node of the Earth's static gravitational field, and in particular of the Earth's even zonal harmonics, the effect of the time dependent Earth's gravitational field, and in particular of the K1 tide, and the effect of particle drag.

Ignazio Ciufolini
2006-09-20

134

Isolated Galaxies and Isolated Satellite Systems

  CERN Preprints

Summary: We search for isolated galaxies using a volume-limited sample of galaxies with 0.02r_{vir,nei} and \\rho <\\bar{\\rho} well segregates the CIG galaxies. We confirm the morphology conformity between the host and their satellites, which suggests importance of hydrodynamic interaction among galaxies within their virial radii in galaxy evolution.

Ann, H B; Choi, Yun-Young
2009-01-01

135

INTRODUCTION Satellites contain onboard equipment for sens-

  Computer Technologies and Information Sciences Websites

Summary: are downloaded when a satellite comes in contact with a ground station and are stored on a computer for further, and the resulting disconnection and reconnection to ground stations give rise to mobility management and connection Engineering Task Force (IETF) designed Mobile IP (MIP) [6] and Mobile IP version 6 (MIPv6) [7] to manage host

Atiquzzaman, Mohammed

136

RADIO PLANNING IN MULTIBEAM GEOSTATIONARY SATELLITE NETWORKS

  Engineering Websites

Summary: Sophia-Antipolis Cedex, France § Alcatel Space Industries, Toulouse, France We consider the problem geographical areas. An actual as- signed unit of bandwidth may correspond to different amounts of throughput conditions. The geographical area covered by a geostationary satellite is divided into hexagonal areas called


137

The chemical composition of the Galileian satellites

  Astrophysics (arXiv)

Summary: Using the semiclassical theory of dense matter proposed by P.Savic and R.Kasanin,the mean molecular masses of the Galilean satellites of Jupiter are determined.The calculated values are fitted by plausible combinations of chemical elements,and the results are in good agreement with the observations by "Galileo".Possible cosmogonical explanations are briefly discussed.

V. Celebonovic
1998-07-20

138

MFR PAPER 1230 Finding Fish With Satellites

  Environmental Sciences and Ecology Websites

Summary: area is covered every 9 days. 2. Q. What is the purpose of the LANDSAT Menhaden and Thread Herring scanners in LANDSA T satellites to measure certain ocean features for locating fishing areas for menhaden and thread herring. Two study areas were selected for field operations during the 1975 menhaden fishing


139

DISASTER RECOVERY APPLICATIONS FOR SATELLITE COMMUNICATIONS SYSTEMS

  Engineering Websites

Summary: in our test network. We can confirm full compatibility between the ACTS system and terrestrial networkDISASTER RECOVERY APPLICATIONS FOR SATELLITE COMMUNICATIONS SYSTEMS Hans Kruse, Tony Mele, Sara Young, Chris Washburn J. Warren McClure School of Communication Systems Management Don Flournoy School

Kruse, Hans

140

COORDINATED CONTROL OF SATELLITES: THE ATTITUDE CASE

  Engineering Websites

Summary: -controller structure for attitude synchronization of a satellite formation is presented. The design applies methods robots [5]­ [7], and was also applied to spacecraft formations in [8]. In the virtual structure approach Cybernetics, Norwegian University of Science and Technology N-7491 Trondheim, Norway thomas

Gravdahl, Jan Tommy

141

Satellite Tagging and Cardiac Physiology Reveal Niche

  Geosciences Websites

Summary: Satellite Tagging and Cardiac Physiology Reveal Niche Expansion in Salmon Sharks Kevin C. Weng,1. Schallert,3 Kenneth J. Goldman,4 Barbara A. Block1 . Shark populations are declining globally, yet to track salmon sharks (Lamna ditropis) for up to 3.2 years. Here we show that salmon sharks have

Luther, Douglas S.

142

Networks and Small Worlds Satellite 4

  Mathematics Websites

Summary: Networks and Small Worlds Satellite 4 Nicholas Jackson Easter 2013 Nicholas Jackson Networks and Small Worlds #12;The Bridges of K¨onigsberg 1 Nicholas Jackson Networks and Small Worlds #12;The Bridges of K¨onigsberg 1 Nicholas Jackson Networks and Small Worlds #12;Leonhard Euler (1707­1783) 2 Born

Jackson, Nicholas

143

Propagation Effects Handbook for Satellite Systems Design

  Energy Storage, Conversion and Utilization Websites

Summary: for Satellite Systems Design continues the long process of a continuing NASA commitment to provide communications system design and performance. The National Aeronautics and Space Administration, NASA, which has, an update to two previous NASA handbooks; the fourth edition of a handbook which focused on propagation

Pulfrey, David L.

144

Asymmetric Warfare: M31 and its Satellites

  CERN Preprints

Summary: Photometric surveys of M31's halo vividly illustrate the wreckage caused by hierarchical galaxy formation. Several of M31's satellites are being disrupted by M31's tidal field, among them M33 and And I, while other tidal structures are the corpses of satellites already destroyed. The extent to which M31's satellites have left battle scars upon it is unknown; to answer this we need accurate orbits and masses of the perturbers. I focus here on M31's 150-kpc-long Giant Southern Stream (GSS) as an example of how these can be determined even in the absence of a visible progenitor. Comparing N-body models to photometric and spectroscopic data, I find this stream resulted from the disruption of a large satellite galaxy by a close passage about 750 Myr ago. The GSS is connected to several other debris structures in M31's halo. Bayesian sampling of the simulations estimates the progenitor's initial mass as log(Mstar/Msun) = 9.5 +- 0.2, showing it was one of the most massive Local Group galaxies until quite recently. T...

Fardal, Mark A
2009-01-01

145

Satellite Infrared Soundings From NOAA Spacecraft

  Environmental Sciences and Ecology Websites

Summary: Meteorology Methods of observation and computation Upper air data computation Instrument carriers Meteorological satellites Meteorological instruments Radiation instruments #12;CONTENTS Abstract and Atmospheric Administration Washington, D. C. I ABSTRACT. Data a r e c u r r e n t l y being received from


146

Modern Digital Satellite Television: How It Works

  Computer Technologies and Information Sciences Websites

Summary: #12;Outline 1 Satellite Television Standards 2 DVB-S2 Modulation 3 LDPC Coding 4 Constellation Shaping Television Standards 2 DVB-S2 Modulation 3 LDPC Coding 4 Constellation Shaping 5 Conclusion M.C. Valenti-S2 Modulation 3 LDPC Coding 4 Constellation Shaping 5 Conclusion M.C. Valenti ( Lane Department

Valenti, Matthew C.

147

SEMI EMPIRICAL SATELLITE MODELS Richard Perez1

  Renewable Energy Websites

Summary: University of New York, ASRC, Albany, NY, USA 2 GeoModel Solar, Bratislava, Slovakia Abstract This chapter discusses basic principles of solar irradiance modeling based on the use of input data from geostationary satellites and atmospheric models. Two operational approaches (SUNY/SolarAnywhere and SolarGIS) based

Perez, Richard R.

148

Total Solar Irradiance Satellite Composites and their

  Mathematics Websites

Summary: Chapter 12 Total Solar Irradiance Satellite Composites and their Phenomenological Effect on Climate. Phenomenological solar signature on climate 310 9. Conclusion 312 1. INTRODUCTION A contiguoustotal solar from each other, in particular about whether the TSI minimum during solar Cycles 22e23 (1995

Scafetta, Nicola

149

Communication Satellites: Frequency Band limitations Versus Implementations

  CiteSeer

Summary: The role of communications satellites in the national and global information infrastructure is diverse. Communications satellites utilize electromagnetic spectrum to transmit information. The material in this project is involved in studying the application of telecommunication devices for various frequency ranges, such as L-band, C-band, Kuband, Ka-band, etc. in implementing the emerging frequency band of Ka-band, a broadband with approximate width of 18 – 40 Giga hertz. This broadband is now becoming a big issue because the lower frequency bandwidth between 12-18 Giga hertz named Ku-band will be occupied by larger telecommunication service providers filling up the band while various factors such as rain attenuation, antenna wetting, depolarization due to rain and ice, cloud attenuation etc. still affect significantly high frequency propagation. As the traffic of the Ku-band and other lower band spectra are highly congested, regulatory organizations encounter problems in reallocating services to other frequencies. If reallocations of frequency are to be sought to certain bandwidth, it would result a loss of billions of dollars per year to previously mounted communications satellites which transport various signals. Hence, this paper shall explore the new technologies and concepts in implementing wireless devices that have potential in alleviating traffic congestion of communication satellites. I.

Kirubel Z. Seifu; Mentor Dr; Chiu Tai Law

150

Using Satellite Imagery to Detect Illegal Logging

  Renewable Energy Websites

Summary: ;Landsat Imagery IKONOS Image LANDSAT Image Road River Road Cloud 10km #12;Satellite Imagery: IKONOS vs · Cost (images, software, computers,training) · Challenging to learn/ access to training · Time-consuming · Computer cost & space · Cloudiness esp. in tropics · Field audits to support RS work Benefits · Objective


151

An Algorithm to Estimate Satellite Rainfall Rate

  Geosciences Websites

Summary: effect on the shape of the drop-size distribution. #12;Methodology · The proposed algorithm has two majorAn Algorithm to Estimate Satellite Rainfall Rate Joan Manuel Castro Sánchez Advisor: Dr. Nazario Ramirez 11th PRYSIG Meeting October 4, 2013 #12;Introduction · Hydro-Estimator (HE) has been

Gilbes, Fernando

152

The surprising inefficiency of dwarf satellite quenching

  CERN Preprints

Summary: We study dwarf satellite galaxy quenching using observations from the Geha et al. (2012) NSA/SDSS catalog together with LCDM cosmological simulations to facilitate selection and interpretation. We show that fewer than 30% of dwarfs (M* ~ 10^8.5-10^9.5 Msun) identified as satellites within massive host halos (Mhost ~ 10^12.5-10^14 Msun) are quenched, in spite of the expectation from simulations that half of them should have been accreted more than 6 Gyr ago. We conclude that whatever the action triggering environmental quenching of dwarf satellites, the process must be highly inefficient. We investigate a series of simple, one-parameter quenching models in order understand what is required to explain the low quenched fraction and conclude that either the quenching timescale is very long (> 9.5 Gyr, a "slow starvation" scenario) or that the environmental trigger is not well matched to accretion within the virial volume. We discuss these results in light of the fact that most of the low mass dwarf satellites in ...

Wheeler, Coral; Cooper, Michael C; Boylan-Kolchin, Mike; Bullock, James S
2014-01-01

153

HORSESHOE PERIODIC ORBITS FOR SATURN COORBITAL SATELLITES

  Mathematics Websites

Summary: HORSESHOE PERIODIC ORBITS FOR SATURN COORBITAL SATELLITES Jaume Llibre and Merc`e Oll'e Dept. Matem conclude that there exist stable horseshoe periodic orbits which fit with the motion of Saturn coorbital­ stricted problem. 1. Introduction In 1981 the successful Voyager flights to Saturn confirmed the existence

Politècnica de Catalunya, Universitat

154

6, 1008710152, 2006 Evaluation of satellite

  Computer Technologies and Information Sciences Websites

Summary: , SAGE II and III, Odin-OSIRIS and SMR, and ENVISAT-GOMOS, -SCIAMACHY and -MIPAS ozone profiles Interactive Discussion EGU Abstract The performances of satellite and sondes ozone measuring instruments (OSIRIS, SCIAMACHY). The ozone relative biases10 are generally limited, between ­4% and +4

Boyer, Edmond

155

Dynamics and real-time optimal control of satellite attitude and satellite formation systems

  Texas A&M University - TxSpace

Summary: . Three-axis magnetic attitude stabilization is achieved by using a pseudospectral control law via the receding horizon control for satellites in eccentric low Earth orbits. The solutions from the pseudospectral control law are in excellent agreement...

Yan, Hui
2006-10-30

156

Geosynchronous satellite maneuver detection and orbit recovery using ground based optical tracking .

  Open Access Theses and Dissertations

Summary: ??Geosynchronous satellite orbit maintenance is a very important issue. Satellites maneuver frequently requiring the ability to detect unknown maneuvers for target satellites and quickly recover… (more)

Aaron, Benjamin S. (Benjamin Samuel)
2006-01-01

157

Cooperative Institute for Meteorological Satellite Studies University of Wisconsin -Madison

  Geosciences Websites

Summary: Cooperative Institute for Meteorological Satellite Studies University of Wisconsin University of Wisconsin #12;Cooperative Institute for Meteorological Satellite Studies University of Wisconsin - Madison In 1979.... #12;Cooperative Institute for Meteorological

Collett Jr., Jeffrey L.

158

The Generalized Information Network Analysis Methodology for Distributed Satellite Systems

  Engineering Websites

Summary: The Generalized Information Network Analysis Methodology for Distributed Satellite Systems satellite applications involve the collection and dissemination of information and can thus be treated as modular information process- ing networks. This generalization allows the adoption of the mathematics


159

Studies on circularly polarized antennas for small satellites.

  Open Access Theses and Dissertations

Summary: ??Small satellites, especially nano- and pico-satellites, are attracting increasing attentions from educational institutions, business organizations and amateur groups. Nanyang Technological University is developing Singapore’s first… (more)

Luo, Jiayu
2013-01-01

160

STABILITY OF SATELLITES IN CLOSELY PACKED PLANETARY SYSTEMS

  MIT - DSpace

Summary: We perform numerical integrations of four-body (star, planet, planet, satellite) systems to investigate the stability of satellites in planetary systems with tightly packed inner planets (STIPs). We find that the majority ...

Payne, Matthew J.

161

Achieving broad access to satellite control research with zero robotics

  MIT - DSpace

Summary: Since operations began in 2006, the SPHERES facility, including three satellites aboard the International Space Station (ISS), has demonstrated many future satellite technologies in a true microgravity environment and ...

Katz, Jacob G
2013-01-01

162

THE EUROPEAN SATELLITE TELECOMMUNICATIONS REGULATORY FRAMEWORK FOR BROADBAND COMMUNICATIONS

  CiteSeer

Summary: Abstract 1 By its nature, the satellite sector is the most “pan-European ” of all communications infrastructures and services. Unlike any terrestrial network, satellite networks can provide coverage to all parts of Europe. This strength of satellite networks, nonetheless, creates a great regulatory challenge. Due to wide satellite coverage, operators depend on harmonized spectrum allocations. The services that the operators provide depend on authorizations and spectrum allocations in each country of the planned coverage area. Frequency use, network operations, service provision and the use of radio terminal can be considered as the main elements which have been the target of a number of regulatory measures (licensing conditions and procedures) meant to help the development of satellite telecommunications and facilitate market access to satellite providers. This paper gives an overview of satellite regulatory framework in the European Union looking more particularly into measures for satellite licensing and authorizations adopted by the Italian administration. 1.

Giovanni Santella; Roberto De Martino; Enrico Russo; Centro Direzionale; Isola B; Torre Francesco

163

INSURED project (INtegrated Satellite UMTS Real Environment Demonstrator)

  Engineering Websites

Summary: satellite system (IRIDIUM) and a GSM network. The trials carried out with the demonstrator are of paramount; the first pre-operational IRIDIUM satellites are available for experimentation. The INSURED project

Vouyioukas, Demosthenes

164

Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function

  Astrophysics (arXiv)

Summary: We correct the observed Milky Way satellite luminosity function for luminosity bias using published completeness limits for the Sloan Digital Sky Survey DR5. Assuming that the spatial distribution of Milky Way satellites tracks the subhalos found in the Via Lactea LCDM N-body simulation, we show that there should be between ~300 and ~600 satellites within 400 kpc of the Sun that are brighter than the faintest known dwarf galaxies, and that there may be as many as ~ 1000, depending on assumptions. By taking into account completeness limits, we show that the radial distribution of known Milky Way dwarfs is consistent with our assumption that the full satellite population tracks that of subhalos. These results alleviate the primary worries associated with the so-called missing satellites problem in CDM. We show that future, deep wide-field surveys such as SkyMapper, the Dark Energy Survey (DES), PanSTARRS, and the Large Synoptic Survey Telescope (LSST) will deliver a complete census of ultra-faint dwarf satellites out to the Milky Way virial radius, offer new limits on the free-streaming scale of dark matter, and provide unprecedented constraints on the low-luminosity threshold of galaxy formation.

Erik J. Tollerud; James S. Bullock; Louis E. Strigari; Beth Willman
2008-10-08

165

Handover management in Low Earth Orbit (LEO) satellite networks

  CiteSeer

Summary: Low Earth Orbit (LEO) satellite networks will play an important role in the evolving information infrastructure. Satellites in the low earth orbits provide communication with shorter end-to-end delays and efficient frequency usage. However, some problems need to be solved before LEO satellite systems can be successfully deployed. One of these problems is the handover management. The objective of this paper is to survey the basic concepts of LEO satellite networks and the handover research. 1.

Ian F. Akyildiz A; Hüseyin Uzunalio?glu B; Michael D. Bender C

166

A model for improving ocean wind forecasts using satellite

  Mathematics Websites

Summary: Using the dynamical model from previous talk we now want to assimilate the satellite measurements Using the dynamical model from previous talk we now want to assimilate the satellite measurements now want to assimilate the satellite measurements into this model. We will discuss the measurement

Malmberg, Anders

167

From the Atlanta Workshop -Use Satellite Data for Model Evaluation

  Environmental Sciences and Ecology Websites

Summary: From the Atlanta Workshop - Use Satellite Data for Model Evaluation At the Atlanta Physical Atmosphere Workshop it was concluded that the low hanging fruit was more use of satellite data for model @20GMT ~73% agreed Use of Satellite Data for Model Evaluation #12;#12;NWS Observations on 32km Grid

Jacob, Daniel J.

168

WDM Polymer Substrate Mode Photonic Interconnects for Satellite Communications

  Engineering Websites

Summary: photomc signals without any delay. On the other hand, due to the limitation of space and power supply power. Furthermore, since the carrier frequencies are very high, wavelength division multiplexing (WDM between satellite and ground stations, satellite- to-satellite, aircraft and ground stations, aircraft-to-aircraft

Chen, Ray

169

Measurement and Analysis of Traffic in a Hybrid Satellite-

  Computer Technologies and Information Sciences Websites

Summary: Measurement and Analysis of Traffic in a Hybrid Satellite- Terrestrial Network Qing (Kenny) Shao University #12;April 8, 2004 Measurement and Analysis of Traffic in a Hybrid Satellite-Terrestrial Network 2 References #12;April 8, 2004 Measurement and Analysis of Traffic in a Hybrid Satellite-Terrestrial Network 3

Trajkovic, Ljiljana

170

NO2 lidar profile measurements for satellite interpretation and validation

  Geosciences Websites

Summary: of validation measurements and methods). [3] One of the major sources of uncertainty in satellite NO2NO2 lidar profile measurements for satellite interpretation and validation H. Volten,1 E. J for the interpretation and validation of satellite data. During the DANDELIONS campaign in 2006 we obtained an extensive

Dirksen, Ruud

171

Ris-R-1298(EN) Validation of Satellite SAR Offshore

  Multidisciplinary Databases and Resources Websites

Summary: Risø-R-1298(EN) Validation of Satellite SAR Offshore Wind Speed Maps to In-Situ Data, Microscale- cision and accuracy of the satellite-derived ERS-2 SAR wind products in off- shore regions. The overall project goal is to develop a method for utilizing the satellite wind speed maps for offshore wind


172

Quasi-Zenith Satellite System Dr. Suelynn Choy

  Engineering Websites

Summary: over 24 hours RMIT University UNSW SNAP Lab Launch 2014 5 (JAXA, 2013) #12;Signal-In-Space User Range Satellite `Michibiki': ­Launched in September 2010 · Future QZSS Satellites: ­2 HEO and 1 GEO ­4 satellite' ©JAXA 2UNSW SNAP Lab Launch 2014RMIT University #12;QZSS Signals v Augmentation information

Sekercioglu, Y. Ahmet

173

Satellite Communications David Hart, dhart@cis.ohio-state.edu

  Computer Technologies and Information Sciences Websites

Summary: : The Satellite The satellite itself is also known as the space segment, and is composed of three separate units includes the receiving antenna to pick-up signals from the ground station, a broad band receiver, an input of a telecom satellite, the primary task is to receive signals from a ground station and send them down

Jain, Raj

174

GROUP SIZE ESTIMATION FOR HYBRID SATELLITE/TERRESTRIAL RELIABLE

  Computer Technologies and Information Sciences Websites

Summary: hop. Satellite communications seem too expensive at first sight. Neverthe- less, in the context updates. Satellite communications are prone to transmission errors (due to atmo- spheric perturbations the satellite communication) grows. Consequently, the pro- posed approach consists of transmitting data via

Mailhes, Corinne

175

SATELLITE ATM NETWORK ARCHITECTURAL CONSIDERATIONS AND TCP IP PERFORMANCE1

  Computer Technologies and Information Sciences Websites

Summary: technology and Ka-Band satellite communications systems will lead to a vast array of opportunities for new in satellite communications exhibit an increased emphasis on new services as opposed to point-to-point data ATM networking is due to the several advantages o ered by satellite communications technology 3, 8

Jain, Raj

176

SCALABLE AND ROBUST RELIABLE MULTICAST FOR SATELLITE NETWORKS Kyriakos Manousakis

  Engineering Websites

Summary: Center for Satellite and Hybrid Communication Networks University of Maryland, College Park College Park efficiently. One way of accomplishing that is by using multicast communication between the satellite1 SCALABLE AND ROBUST RELIABLE MULTICAST FOR SATELLITE NETWORKS Kyriakos Manousakis John S. Baras

Baras, John S.

177

On the perturbations on satellites probing General Relativity

  CERN Preprints

Summary: Non-gravitational Yarkovsky-Rubincam effect for LAGEOS and LAGEOS 2 satellites used to probe General Relativity has been revealed by means of the Kolmogorov analysis of their perturbations. We present the method and its efficiency at modeling of generated systems with properties expected at the satellite laser ranging measurements and then at satellite residual data analysis.

Sargsyan, S; Mirzoyan, S
2013-01-01

178

AVIATION UTILIZATION OF GEOSTATIONARY SATELLITES FOR THE AUGMENTATION TO

  Engineering Websites

Summary: AVIATION UTILIZATION OF GEOSTATIONARY SATELLITES FOR THE AUGMENTATION TO GPS: RANGING AND DATA LINK satellites. A master station that combines data from a continental network of reference GPS receivers will create these messages. The geostationary satellites serve both as wide-area differential GPS data links

Stanford University

179

Applications of Recent Wireless Standards in Satellite Networking

  CiteSeer

Summary: Recent developments and research in the aerospace industry have lead to an increased adoption of recent wireless standards in building satellite networks. These standards include ZigBee and Bluetooth for intra-satellite networking and Wi-Fi and WiMAX for inter-satellite networking.

unknown authors

180

Analysis of billing data from a hybrid satellite network

  Engineering Websites

Summary: Data transfer pair for dialup, DSL, or cable modem is: source (user) IP, destination IP DirecPC data and television services: DirecTV: satellite television service DirecPC: unidirectional satellite data service DirecWay: bi-directional satellite data service replacing DirecPC #12;November 29, 2005

Trajkovic, Ljiljana

181

ORIGINAL ARTICLE Satellite clock bias estimation for iGPS

  Geosciences Websites

Summary: performance by combining conventional GPS with a communications and ranging broadcast from the Iridium is key to performance. An approach is presented for estimating the bias of each Iridium satellite clock the communications capability of the satellite network from Iridium Satellite LLC, hereafter referred to as Iridium

Larson, Kristine

182

Efficient statistical classification of satellite measurements

  CERN Preprints

Summary: Supervised statistical classification is a vital tool for satellite image processing. It is useful not only when a discrete result, such as feature extraction or surface type, is required, but also for continuum retrievals by dividing the quantity of interest into discrete ranges. Because of the high resolution of modern satellite instruments and because of the requirement for real-time processing, any algorithm has to be fast to be useful. Here we describe an algorithm based on kernel estimation called Adaptive Gaussian Filtering that incorporates several innovations to produce superior efficiency as compared to three other popular methods: k-nearest-neighbour (KNN), Learning Vector Quantization (LVQ) and Support Vector Machines (SVM). This efficiency is gained with no compromises: accuracy is maintained, while estimates of the conditional probabilities are returned. These are useful not only to gauge the accuracy of an estimate in the absence of its true value, but also to re-calibrate a retrieved image and...

Mills, Peter
2012-01-01

183

Atmospheric structure determined from satellite data

  Texas A&M University - TxSpace

Summary: for the satellite sounding points, surface hourly data were obtained from ~&e Texas ASN University archives of National Weather Service teletype and facsimile data, and from the National Climatic Center. Surface values of temperature, dew-point temperature.... Rawinsonde data Rawinsonde data for this study were obtained in part from the Texas A&51 University meteorological archives of National Weather Service teletype and facsimile data, and ir. part from the National Climatic Center. Quantities used include...

Knight, Keith Shelburne
2012-06-07

184

Modelling and control of satellite formations

  Texas A&M University - TxSpace

Summary: the problems of initiatialization, maintenance and recon¯guration of satellite formations in Earth orbits. Achieving the objectives of maintenance and recon¯guration, with the least amount of fuel is the key to the success of the mission. Therefore, under... solutions that are of particular interest to formation °ying. However, these solutions may not be realistic. In this dissertation, bounded relative orbit solutions are obtained, for models, more sophisticated than that given by the HCW equations. The e...

Vaddi, Veera Venkata Sesha Sai
2004-09-30

185

The dynamics of tidal tails from massive satellites

  Astrophysics (arXiv)

Summary: (Abbreviated) We investigate the dynamical mechanisms responsible for producing tidal tails from dwarf satellites using N-body simulations. We identify two important dynamical co-conspirators: 1) the points where the attractive force of the host halo and satellite are balanced do not occur at equal distances from the satellite centre or at the same equipotential value for massive satellites, breaking the morphological symmetry of the leading and trailing tails; and 2) the escaped ejecta in the leading (trailing) tail continues to be decelerated (accelerated) by the satellite's gravity leading to large offsets of the ejecta orbits from the satellite orbit. The effect of the satellite's self gravity decreases only weakly with a decreasing ratio of satellite mass to host halo mass, demonstrating the importance of these effects over a wide range of subhalo masses. Not only will the morphology of the leading and trailing tails for massive satellites be different, but the observed radial velocities of the tails will be displaced from that of the satellite orbit; both the displacement and the peak radial velocity is proportional to satellite mass. If the tails are assumed to follow the progenitor satellite orbits, the tails from satellites with masses greater than 0.0001 of the host halo virial mass in a spherical halo will appear to indicate a flattened halo. Therefore, a constraint on the Milky Way halo shape using tidal streams requires mass-dependent modelling. Similarly, we compute the the distribution of tail orbits both in E_{r}-r^{-2} space and in E-L_{z} space, advocated for identifying satellite stream relics. The acceleration of ejecta by a massive satellite during escape spreads the velocity distribution and obscures the signature of a well-defined ``moving group'' in phase space.

Jun-Hwan Choi; Martin D. Weinberg; Neal Katz
2007-02-14

186

Measurement of Satellite Bunches at the LHC

  CERN Preprints

Summary: The RF gymnastics involved in the delivery of proton and lead ion bunches to the LHC can result in satellite bunches of varying intensity occupying the nominally empty RF buckets. Quantification of these satellites is crucial for bunch-by-bunch luminosity normalization as well as for machine protection. We present an overview of the longitudinal density monitor (LDM) which is the principal instrument for the measurement of satellite bunches in the LHC. The LDM uses single photon counting of synchrotron light. The very high energies reached in the LHC, combined with a dedicated undulator for diagnostics, allow synchrotron light measurements to be made with both protons and heavy ions. The arrival times of photons are collected over a few million turns, with the resulting histogram corrected for the effects of the detector’s deadtime and afterpulsing in order to reconstruct the longitudinal profile of the entire LHC ring. The LDM has achieved a dynamic range in excess of 105 and a time resolution of 90 ps. Ex...

Jeff, A; Boccardi, A; Bozyigit, S; Bravin, E; Lefevre, T; Rabiller, A; Roncarolo, F; Welsch, C P; Fisher, A S
2012-01-01

187

Photometric Survey of the Irregular Satellites

  CERN Preprints

Summary: We present BVRI colors of 13 Jovian and 8 Saturnian irregular satellites obtained with the 2.56m Nordic Optical Telescope on La Palma, the 6.5m Magellan Baade Telescope on La Campanas, and the 6m MMT on Mt. Hopkins. The observations were performed between December 2001 to March 2002. Nearly all of the known irregular satellites can be divided into two distinct classes based on their colors. One, the grey color class, has the similar colors to the C-type asteroid, and the other, the light red color class, has colors similar to P/D-type asteroids. We also find at least one object, the Jovian irregular J XXIII Kalyke, that has colors similar to the red colored Centaurs/TNOs, although its classification is unsecure. We also find that there is a correlation between the physical properties and dynamical properties of the irregular satellites. Most of the dynamical clusters have homogeneous colors, which points to single homogeneous progenitors being cratered or fragmented as the source of each individual cluster. T...

Grav, T; Gladman, B; Aksnes, K; Grav, Tommy; Holman, Matthew J.; Gladman, Brett; Aksnes, Kaare
2003-01-01

188

The reionization of galactic satellite populations

  CERN Preprints

Summary: We use high resolution simulations of the formation of the local group post-processed by a radiative transfer code for UV photons, to investigate the reionization of the satellite populations of an isolated Milky Way-M31 galaxy pair in a variety of scenarios. We use an improved version of ATON which includes a simple recipe for radiative feedback. In our baseline models, reionization is initiated by low mass, radiatively regulated haloes at high redshift, until more massive haloes appear, which then dominate and complete the reionization process. We investigate the relation between reionization history and present-day positions of the satellite population. We find that the average reionization redshift (zr) of satellites is higher near galaxy centers (MW and M31). This is due to the inside-out reionization patterns imprinted by massive haloes within the progenitor during the EoR, which end up forming the center of the galaxy. Thanks to incomplete dynamical mixing during galaxy assembly, these early patterns s...

Ocvirk, P; Aubert, D; Knebe, A; Libeskind, N; Chardin, J; Gottlöber, S; Yepes, G; Hoffman, Y
2014-01-01

189

Formal Specification and Quantitative Analysis of a Constellation of Navigation Satellites

  Computer Technologies and Information Sciences Websites

Summary: Formal Specification and Quantitative Analysis of a Constellation of Navigation Satellites a single satellite and a navigation satellite constellation and logical specification of their reliability in satellite constellations Correspondence to: Yu Lu, School of Computing Science, University of Glasgow

Miller, Alice

190

AIAA 2001-4030 CONSTRAINED TRAJECTORY GENERATION FOR MICRO-SATELLITE

  Energy Storage, Conversion and Utilization Websites

Summary: on each satellite and induces secular motion between the micro-satellites in the formation. Sedwick et al-satellite formation in a polar, circular orbit. The appropriate choice of initial conditions for a micro-satellite can


191

Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function

  CERN Preprints

Summary: We correct the observed Milky Way satellite luminosity function for luminosity bias using published completeness limits for the Sloan Digital Sky Survey DR5. Assuming that the spatial distribution of Milky Way satellites tracks the subhalos found in the Via Lactea LambdaCDM N-body simulation, we show that there should be between ~300 and ~600 satellites within 400 kpc of the Sun that are brighter than the faintest known dwarf galaxies, and that there may be as many as ~1000, depending on assumptions. By taking into account completeness limits, we show that the radial distribution of known Milky Way dwarfs is consistent with our assumption that the full satellite population tracks that of subhalos. These results alleviate the primary worries associated with the so-called "Missing Satellites Problem" in CDM. We show that future, deep wide-field surveys like SkyMapper, the Dark Energy Survey (DES), PanSTARRS, and the Large Synoptic Survey Telescope (LSST) will deliver a complete census of ultra-faint dwarf satel...

Tollerud, Erik J; Strigari, Louis E; Willman, Beth
2008-01-01

192

The Principle of Navigation Constellation Composed of SIGSO Communication Satellites

  CERN Preprints

Summary: The Chinese Area Positioning System (CAPS), a navigation system based on GEO communication satellites, was developed in 2002 by astronomers at Chinese Academy of Sciences. Extensive positioning experiments of CAPS have been performed since 2005. On the basis of CAPS, this paper studies the principle of navigation constellation composed of Slightly Inclined Geostationary Orbit (SIGSO) communication satellites. SIGSO satellites are derived from end-of-life Geostationary Orbit (GEO) satellites under inclined orbit operation. Considering the abundant frequency resources of SIGSO satellites, multi-frequency observations could be conducted to enhance the precision of pseudorange measurements and ameliorate the positioning performence. The constellation composed of two GEO satellites and four SIGSO satellites with inclination of 5 degrees can provide the most territory of China with 24-hour maximum PDOP less than 42. With synthetic utilization of the truncated precise (TP) code and physical augmentation factor in fo...

Ji, Hai-Fu; Ai, Guo-Xiang; Shi, Hu-Li
2012-01-01

193

Planetesimals and Satellitesimals: Formation of the Satellite Systems

  CERN Preprints

Summary: The origin of the regular satellites ties directly to planetary formation in that the satellites form in gas and dust disks around the giant planets and may be viewed as mini-solar systems, involving a number of closely related underlying physical processes. The regular satellites of Jupiter and Saturn share a number of remarkable similarities that taken together make a compelling case for a deep-seated order and structure governing their origin. Furthermore, the similarities in the mass ratio of the largest satellites to their primaries, the specific angular momenta, and the bulk compositions of the two satellite systems are significant and in need of explanation. Yet, the differences are also striking. We advance a common framework for the origin of the regular satellites of Jupiter and Saturn and discuss the accretion of satellites in gaseous, circumplanetary disks. Following giant planet formation, planetesimals in the planet's feeding zone undergo a brief period of intense collisional grinding. Mass deli...

Mosqueira, Ignacio; Turrini, Diego
2009-01-01

194

Footprint handover rerouting protocol for low Earth orbit satellite networks

  CiteSeer

Summary: Low Earth Orbit (LEO) satellite networks will be an integral part of the next generation telecommunications infrastructures. In a LEO satellite network, satellites and their individual coverage areas move relative to a fixed observer on Earth. To ensure that ongoing calls are not disrupted as a result of satellite movement, calls should be transferred or handed over to new satellites. Since two satellites are involved in a satellite handover, connection route should be modified to include the new satellite into the connection route. The route change can be achieved by augmenting the existing route with the new satellite or by completely rerouting the connection. Route augmentation is simple to implement, however the resulting route is not optimal. Complete rerouting achieves optimal routes at the expense of signaling overhead. In this paper, we introduce a handover rerouting protocol that maintains the optimality of the initial route without performing a routing algorithm after intersatellite handovers. The FHRP makes use of the footprints of the satellites in the initial route as the reference for rerouting. More specifically, after an optimum route has been determined during the call establishment process, the FHRP ensures that the new route due to handover is also optimum. The FHRP demands easy processing, signaling, and storage costs. The performance results show that the FHRP performs similar to a network without any handovers in terms of call blocking probability. 1.

Hüseyin Uzunalio?glu A; Ian F. Akyildiz B; Yelena Yesha C; Wei Yen D

195

From Tidal Dwarf Galaxies to Satellite Galaxies

  Astrophysics (arXiv)

Summary: Cosmological models have granted dwarf galaxies a key role: their properties constrain the distribution of dark matter and the physical evolution of their hosts. There is increasing evidence that objects with masses of dwarf galaxies form in the tidal tails of colliding galaxies and speculations that they could become satellite-like galaxies around their progenitors and thus be cosmologically important. Yet, whether these "Tidal Dwarf Galaxies" (TDGs) candidates are really long-lived and not only present in young interacting systems is still an open question to which numerical simulations may give answers. We present a set of 96 simulations of colliding galaxies with various mass ratios and encounter geometries, and statistically study the evolution of their TDG candidates. Among the 593 substructures initially identified in tidal tails, about 75% fall back onto their progenitor or are disrupted in a few 10^8 years. The remaining 25% become long-lived bound objects that typically survive more than 2Gyr with masses above 10^8 M_sun. These long-lived, satellite-like objects, are found to form in the outer most regions of the tidal tails. We infer several basic properties that dwarf galaxies should meet to have a tidal origin and apply these criteria to the Local Group dwarfs. We also find that the presence of TDGs would foster the anisotropy observed in the distribution of satellite galaxies around their host. Identifying the conditions required for interacting systems to form long-lived tidal dwarfs, we roughly estimate their contribution to the overall population of dwarfs. We conclude that a small but significant fraction of them - typically a few percent, and possibly more in dense environments or around early-type galaxies - could be of tidal origin.

F. Bournaud; P. -A. Duc
2006-05-15

196

The Anisotropic Distribution of Galactic Satellites

  Astrophysics (arXiv)

Summary: We present a study of the spatial distribution of subhalos in galactic dark matter halos using dissipationless cosmological simulations of the concordance LCDM model. We find that subhalos are distributed anisotropically and are preferentially located along the major axes of the triaxial mass distributions of their hosts. The Kolmogorov-Smirnov probability for drawing our simulated subhalo sample from an isotropic distribution is P_KS \\simeq 1.5 \\times 10^{-4}. An isotropic distribution of subhalos is thus not the correct null hypothesis for testing the CDM paradigm. The nearly planar distribution of observed Milky Way (MW) satellites is marginally consistent (probability \\simeq 0.02) with being drawn randomly from the subhalo distribution in our simulations. Furthermore, if we select the subhalos likely to be luminous, we find a distribution that is consistent with the observed MW satellites. In fact, we show that subsamples of the subhalo population with a centrally-concentrated radial distribution, similar to that of the MW dwarfs, typically exhibit a comparable degree of planarity. We explore the origin of the observed subhalo anisotropy and conclude that it is likely due to (1) preferential accretion of subhalos along filaments, often closely aligned with the major axis of the host halo, and (2) evolution of satellite orbits within the prolate, triaxial potentials typical of CDM halos. Agreement between predictions and observations requires the major axis of the outer dark matter halo of the Milky Way to be nearly perpendicular to the disk. We discuss possible observational tests of such disk-halo alignment with current large galaxy surveys.

Andrew R. Zentner; Andrey V. Kravtsov; Oleg Y. Gnedin; Anatoly A. Klypin
2005-02-24

197

Turbo Equalization of the Nonlinear Satellite Channel

  CiteSeer

Summary: A typical satellite communications channel can be modelled by the concatenation of the transmit filter, nonlinear amplifier and the receive filter. This nonlinear channel can be viewed as an ISI channel with memory, whose length is determined by the impulse responses of the filters. This paper presents a 16QAM turbo equalization scheme which can mitigate this nonlinear ISI. A soft interference canceller, IC, is followed by an SCCC turbo decoder. A posteriori probabilities are passed from the SCCC decoder to the IC for each iteration. The IC has linear complexity with channel memory length.

Craig Burnet Adrian; S. Adrian Barbulescu; William G. Cowley

198

Andromeda and its satellites - a kinematic perspective

  CERN Preprints

Summary: Using spectroscopic data taken with Keck II DEIMOS by the Z-PAndAS team in the Andromeda-Triangulum region, I present a comparison of the disc and satellite systems of Andromeda with those of our own Galaxy. I discuss the observed discrepancies between the masses and scale radii of Andromeda dwarf spheroidal galaxies of a given luminosity with those of the Milky Way. I also also present an analysis of the newly discovered M31 thick disc, which is measured to be hotter, more extended and thicker than that seen in the Milky Way.

Collins, Michelle L M; Chapman, Scott C
2012-01-01

199

Satellite streamfunction analysis for the California current

  Texas A&M University - TxSpace

Summary: . Orthogonal Curvilinear Case 37 37 41 V. SUMMARY AND CONCLUSIONS REFERENCES . APPENDIX A 49 VITA 59 LIST OF FIGURES Figure 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. Streamfunction domain for the Cartesian case...(~) Figure 21. Sea surface topography contours (kl, 13, +6, 19, cm) and satellite-derived surface flow vectors (em s ') for the orthogonal curvilinear case plotted in ((, rt) space. 41' 124 1?5 12S' , 0' S-v 0 0 0 0 0 00 . -~. 00 0 00 I 'I...

Arango, Hernan Guillermo
2012-06-07

200

8A Problem in Satellite Synchrony The THEMIS program has launched five satellites that will orbit earth at different distances to

  Geosciences Websites

Summary: 8A Problem in Satellite Synchrony The THEMIS program has launched five satellites that will orbit longitude. Problem 4 - The THEMIS mission uses five satellites with periods of about 19 hours, 24 hours, 24


201

Advanced hybrid satellite andAdvanced hybrid satellite and terrestrial system architecture forterrestrial system architecture for

  Engineering Websites

Summary: forterrestrial system architecture for emergency mobile communicationsemergency mobile communications Giuliana Iapichino 1st phase of Ph.D. research on ``Ad hoc mobility in satellite-based networks for security phases and requirements for disaster management Hybrid system architecture for emergency mobile

Gesbert, David

202

LARES succesfully launched in orbit: satellite and mission description

  CERN Preprints

Summary: On February 13th 2012, the LARES satellite of the Italian Space Agency (ASI) was launched into orbit with the qualification flight of the new VEGA launcher of the European Space Agency (ESA). The payload was released very accurately in the nominal orbit. The name LARES means LAser RElativity Satellite and summarises the objective of the mission and some characteristics of the satellite. It is, in fact, a mission designed to test Einstein's General Relativity Theory (specifically 'frame dragging' and Lense-Thirring effect). The satellite is passive and covered with optical retroreflectors that send back laser pulses to the emitting ground station. This allows accurate positioning of the satellite, which is important for measuring the very small deviations from Galilei-Newton's laws. In 2008, ASI selected the prime industrial contractor for the LARES system with a heavy involvement of the universities in all phases of the programme, from the design to the construction and testing of the satellite and separation...

Paolozzi, Antonio
2013-01-01

203

A Region Void of Irregular Satellites Around Jupiter

  CERN Preprints

Summary: An interesting feature of the giant planets of our solar system is the existence of regions around these objects where no irregular satellites are observed. Surveys have shown that, around Jupiter, such a region extends from the outermost regular satellite Callisto, to the vicinity of Themisto, the innermost irregular satellite. To understand the reason for the existence of such a satellite-void region, we have studied the dynamical evolution of Jovian irregulars by numerically integrating the orbits of several hundred test particles, distributed in a region between 30 and 80 Jupiter-radii, for different values of their semimajor axes, orbital eccentricities, and inclinations. As expected, our simulations indicate that objects in or close to the influence zones of the Galilean satellites become unstable because of interactions with Ganymede and Callisto. However, these perturbations cannot account for the lack of irregular satellites in the entire region between Callisto and Themisto. It is suggested that at ...

Haghighipour, N
2008-01-01

204

The Spatial Distribution of Galactic Satellites in the LCDM Cosmology

  CERN Preprints

Summary: We investigate the spatial distribution of galactic satellites in high resolution simulations of structure formation in the LCDM model: the Aquarius dark matter simulations of individual halos and the Millennium II simulation of a large cosmological volume. To relate the simulations to observations of the Milky Way we use two alternative models to populate dark halos with "visible" galaxies: a semi-analytic model of galaxy formation and an abundance matching technique. We find that the radial density profile of massive satellites roughly follows that of the dark matter halo (unlike the distribution of dark matter subhalos). Furthermore, our two galaxy formation models give results consistent with the observed profile of the 11 classical satellites of the Milky Way. Our simulations predict that larger, fainter samples of satellites should still retain this profile at least up to samples of 100 satellites. The angular distribution of the classical satellites of the Milky Way is known to be highly anisotropic. D...

Wang, Jie; Cooper, Andrew P
2012-01-01

205

Fast object detection for use onboard satellites

  Astrophysics (arXiv)

Summary: We propose an object detection algorithm which is efficient and fast enough to be used in (almost) real time with the limited computer capacities onboard satellites. For stars below the saturation limit of the CCD detectors it is based on a four neighbourhood local maximum criterion in order to find the centre of a stellar image. For saturated stars it is based on the assumption that the image is increasing monotonically towards the centre in the unsaturated part of the image. The algorithm also calculates approximate stellar magnitudes and efficiently rejects most of the cosmics which would otherwise lead to a large number of false detections. The quality of the algorithm was evaluated with the help of a large set of simulated data for the DIVA satellite mission; different assumptions were made for the noise level, and the presence of cosmics or for a variable sky background. We could show that our algorithm fulfills the requirements for DIVA; only in the case of simulated images which included the bright galaxy M31 some fainter stars could not be detected in the galaxy's vicinity. Since stellar images contain large areas without any stars, we propose an additional block-skipping algorithm which can be coded on special-purpose hardware.

Martin Bange; Stefan Jordan; Michael Biermann; Thomas Kaempke; R alf-Dieter Scholz
2003-01-30

206

Sundman Stability of Natural Planet Satellites

  CERN Preprints

Summary: The stability of the motion of the planet satellites is considered in the model of the general three-body problem (Sun-planet-satellite). "Sundman surfaces" are constructed, by means of which the concept "Sundman stability" is formulated. The comparison of the Sundman stability with the results of Golubev's c2h method and with the Hill's classical stability in the restricted three-body problem is performed. The constructed Sundman stability regions in the plane of the parameters "energy - moment of momentum" coincide with the analogous regions obtained by Golubev's method, with the value (c2h)cr. The construction of the Sundman surfaces in the three-dimensional space of the specially selected coordinates xyR is carried out by means of the exact Sundman inequality in the general three-body problem. The determination of the singular points of surfaces, the regions of the possible motion and Sundman stability analysis are implemented. It is shown that the singular points of the Sundman surfaces in the coordinate...

Lukyanov, L G
2012-01-01

207

MARINE MAMMAL CENSUS USING SPACE SATELLITE IMAGERY

  CiteSeer

Summary: A new era of commercial high-resolution imagery from space began late in 1999 resulting in resolution that is now sufficient to resolve marine mammals. This encouraged investigating the use of satellite imagery for marine-mammal population census and related studies. The question was raised: Can marine mammals be reliably detected above sensor noise and ocean clutter? To answer this question, a signal model was developed and simulated 14-meter targets were injected into IKONOS satellite imagery. A variation of a well-known, two-color method was used to subtract the ocean clutter. After clutter mitigation, it was possible to detect the simulated animals to depths of approximately 20 meters depending on the animal’s size, spectral reflectivity, and the optical properties of the ocean. The first images of marine mammals from space are presented. These examples, however, were targets of opportunity without ground truth. The preliminary assessment on the detectability of marine mammals rests largely on models and simulations. I.

Ron Abileah
2001-01-01

208

Satellite dynamics on the Laplace surface

  Astrophysics (arXiv)

Summary: The orbital dynamics of most planetary satellites is governed by the quadrupole moment from the equatorial bulge of the host planet and the tidal field from the Sun. On the Laplace surface, the long-term orbital evolution driven by the combined effects of these forces is zero, so that orbits have a fixed orientation and shape. The "classical" Laplace surface is defined for circular orbits, and coincides with the planet's equator at small planetocentric distances and with its orbital plane at large distances. A dissipative circumplanetary disk should settle to this surface, and hence satellites formed from such a disk are likely to orbit in or near the classical Laplace surface. This paper studies the properties of Laplace surfaces. Our principal results are: (i) if the planetary obliquity exceeds 68.875 deg there is a range of semimajor axes in which the classical Laplace surface is unstable; (ii) at some obliquities and planetocentric distances there is a distinct Laplace surface consisting of nested eccentric orbits, which bifurcates from the classical Laplace surface at the point where instability sets in; (iii) there is also a "polar" Laplace surface perpendicular to the line of nodes of the planetary equator on the planetary orbit; (iv) for circular orbits, the polar Laplace surface is stable at small planetocentric distances and unstable at large distances; (v) at the onset of instability this polar Laplace surface bifurcates into two polar Laplace surfaces composed of nested eccentric orbits.

Scott Tremaine; Jihad Touma; Fathi Namouni
2008-09-01

209

Satellite dynamics on the Laplace surface

  CERN Preprints

Summary: The orbital dynamics of most planetary satellites is governed by the quadrupole moment from the equatorial bulge of the host planet and the tidal field from the Sun. On the Laplace surface, the long-term orbital evolution driven by the combined effects of these forces is zero, so that orbits have a fixed orientation and shape. The "classical" Laplace surface is defined for circular orbits, and coincides with the planet's equator at small planetocentric distances and with its orbital plane at large distances. A dissipative circumplanetary disk should settle to this surface, and hence satellites formed from such a disk are likely to orbit in or near the classical Laplace surface. This paper studies the properties of Laplace surfaces. Our principal results are: (i) if the planetary obliquity exceeds 68.875 deg there is a range of semimajor axes in which the classical Laplace surface is unstable; (ii) at some obliquities and planetocentric distances there is a distinct Laplace surface consisting of nested eccentr...

Tremaine, Scott; Namouni, Fathi
2008-01-01

210

The subhalo - satellite connection and the fate of disrupted satellite galaxies

  Astrophysics (arXiv)

Summary: In the standard paradigm, satellite galaxies are believed to be associated with the population of dark matter subhalos. In this paper, we use the conditional stellar mass functions of {\\it satellite galaxies} obtained from a large galaxy group catalogue together with models of the subhalo mass functions to explore the fraction and fate of stripped stars from satellites in galaxy groups and clusters of different masses. The majority of the stripped stars in massive halos are predicted to end up as intra-cluster stars, and the predicted amounts of the intra-cluster component as a function of the velocity dispersion of galaxy system match well the observational results obtained by Gonzalez et al. (2007). The fraction of the mass in the stripped stars to that remain bound in the central and satellite galaxies is the highest ($\\sim 40%$ of the total stellar mass) in halos with masses $M_h\\sim 10^{14}\\msunh$. If all these stars end up in the intra-cluster component (Max), or maximum of them are accreted into the central galaxy (Min), then we can predict that a maximum $\\sim 19%$ and a minimum $\\sim 5%$ of the total stars in the whole universe are in terms of the diffused intra-cluster component. In the former case, in massive halos with $M_h \\sim 10^{15} \\msunh$, the stellar mass of the intra-cluster component is roughly 6 times as large as that of the central galaxy. This factor decreases to $\\sim 2$, 1 and 0.1 in halos with $M_h \\sim 10^{14}$, $10^{13}$, and $10^{12} \\msunh$, respectively. The total amount of stars stripped from satellite galaxies is insufficient to build up the central galaxies in halos with masses $\\la 10^{12.5}\\msunh$, and so the quenching of star formation must occur in halos with higher masses. Abridged.

Xiaohu Yang; H. J. Mo; Frank C. van den Bosch
2008-11-14

211

Re-Routing Algorithms in a Meshed Satellite Constellation

  CiteSeer

Summary: In this paper we present a simple model for satellite constellations with polar orbits and inter-satellite links. This model is used to propose and study two algorithms for routing and re-routing communications, which aim at improving the quality of service for long communications. In order to study these algorithms, we have developed a satellite constellation simulator. Some of its results are presented.

A. Ferreira; J. Galtier; J.-N. Petit; H. Rivano
2001-01-01

212

Development of Modular Thermal Control Architecture for Modular Satellites.

  Open Access Theses and Dissertations

Summary: ??Research has been completed to determine the most effective thermal control architecture for modular satellites. This research investigated principles of modularity, modular spacecraft examples, thermal… (more)

Young, Quinn Eric
2008-01-01

213

Performance analysis of cooperative diversity in land mobile satellite systems.

  Open Access Theses and Dissertations

Summary: ??Land Mobile Satellite Systems (LMSS) generally differ from other terrestrial wireless systems. The LMSS exhibit unique characteristics with regard to the physical layer, interference scenarios,… (more)

Awoyemi, Babatunde Seun.
2013-01-01

214

Satellite specific multiple access control algorithms for packet data.

  Open Access Theses and Dissertations

Summary: ??This thesis investigates the ability of dynamic algorithms to adequately share limited satellite channel resources between explicit user demands for bandwidth, anticipated bandwidth demands from… (more)

Hale, Ben Bruce.
2007-01-01

215

Designing Satellite Communication Networks by Zero-One Quadratic Programming

  MIT - DSpace

Summary: In satellite communications networks, distinctive facilities called homing stations perform special transmission functions. Local demand nodes clustered around each homing station communicate with each other via a local ...

Helme, Marcia P.

216

Notes to Saturn satellites Ijiraq and Kiviuq mutual close encounters

  CERN Preprints

Summary: The problem of origin of outer irregular satellites of large planets is considered. The capture way of their origin most probable, however there is not detail theory. There are a number of irregular satellites, discovered in recent time. It gives an ability to investigate the statistics of orbital interaction and try to reconstruct real collision history of these objects We restrict this consideration by pair of orbits with close elements: Kiviuq and Ijiraq and determine period of close encounters between this satellites. It may be considered as a first step on road to the construction of theory of origin of the abundant class of irregular satellites.

Rosaev, A E
2006-01-01

217

Notes to Saturn satellites Ijiraq and Kiviuq mutual close encounters

  Astrophysics (arXiv)

Summary: The problem of origin of outer irregular satellites of large planets is considered. The capture way of their origin most probable, however there is not detail theory. There are a number of irregular satellites, discovered in recent time. It gives an ability to investigate the statistics of orbital interaction and try to reconstruct real collision history of these objects We restrict this consideration by pair of orbits with close elements: Kiviuq and Ijiraq and determine period of close encounters between this satellites. It may be considered as a first step on road to the construction of theory of origin of the abundant class of irregular satellites.

A. E. Rosaev
2006-02-01

218

Downburst Prediction Applications of Meteorological Geostationary Satellites

  CERN Preprints

Summary: A suite of products has been developed and evaluated to assess hazards presented by convective storm downbursts derived from the current generation of Geostationary Operational Environmental Satellite (GOES) (13-15). The existing suite of GOES downburst prediction products employs the GOES sounder to calculate risk based on conceptual models of favorable environmental profiles for convective downburst generation. A diagnostic nowcasting product, the Microburst Windspeed Potential Index (MWPI), is designed to infer attributes of a favorable downburst environment: 1) the presence of large convective available potential energy (CAPE), and 2) the presence of a surface-based or elevated mixed layer with a steep temperature lapse rate and vertical relative humidity gradient. These conditions foster intense convective downdrafts upon the interaction of sub-saturated air in the elevated or sub-cloud mixed layer with the storm precipitation core. This paper provides an updated assessment of the MWPI algorithm, present...

Pryor, Kenneth L
2014-01-01

219

Symmetric Satellite Swarms and Choreographic Crystals

  CERN Preprints

Summary: In this paper, we introduce a natural dynamical analogue of crystalline order, which we call choreographic order. In an ordinary (static) crystal, a high degree of symmetry may be achieved through a careful arrangement of the fundamental repeated elements. In the dynamical analogue, a high degree of symmetry may be achieved by having the fundamental elements perform a carefully choreographed dance. For starters, we show how to construct and classify all symmetric satellite constellations. Then we explain how to generalize these ideas to construct and classify choreographic crystals more broadly. We introduce a quantity, called the "choreography" of a given configuration. We discuss the possibility that some (naturally occurring or artificial) many-body or condensed-matter systems may exhibit choreographic order, and suggest natural experimental signatures that could be used to identify and characterize such systems.

Boyle, Latham; Smith, Kendrick
2014-01-01

220

Symmetric Satellite Swarms and Choreographic Crystals

  Mathematical Physics (arXiv)

Summary: In this paper, we introduce a natural dynamical analogue of crystalline order, which we call choreographic order. In an ordinary (static) crystal, a high degree of symmetry may be achieved through a careful arrangement of the fundamental repeated elements. In the dynamical analogue, a high degree of symmetry may be achieved by having the fundamental elements perform a carefully choreographed dance. For starters, we show how to construct and classify all symmetric satellite constellations. Then we explain how to generalize these ideas to construct and classify choreographic crystals more broadly. We introduce a quantity, called the "choreography" of a given configuration. We discuss the possibility that some (naturally occurring or artificial) many-body or condensed-matter systems may exhibit choreographic order, and suggest natural experimental signatures that could be used to identify and characterize such systems.

Latham Boyle; Jun Yong Khoo; Kendrick Smith
2014-07-22

221

Submerged turbulence detection with optical satellites

  CERN Preprints

Summary: During fall periods in 2002, 2003 and 2004 three major oceanographic expeditions were carried out in Mamala Bay, Hawaii. These were part of the RASP Remote Anthropogenic Sensing Program. Ikonos and Quickbird optical satellite images of sea surface glint revealed ~100 m spectral anomalies in km^2 averaging patches in regions leading from the Honolulu Sand Island Municipal Outfall diffuser to distances up to 20 km. To determine the mechanisms behind this phenomenon, the RASP expeditions monitored the waters adjacent to the outfall with an array of hydrographic, optical and turbulence microstructure sensors in anomaly and ambient background regions. Drogue tracks and mean turbulence parameters for 2x10^4 microstructure patches were analyzed to understand complex turbulence, fossil turbulence and zombie turbulence near-vertical internal wave transport processes. The dominant mechanism appears to be generic to stratified natural fluids including planet and star atmospheres and is termed beamed zombie turbulence ma...

Gibson, Carl H; Bondur, Valery G; Leung, Pak T; Prandke, H; Vithanage, D
2007-01-01

222

Properties of cluster satellites in hydrodynamical simulations

  Astrophysics (arXiv)

Summary: We analyze the dynamical and thermal evolution of dark matter and ICM in hydrodynamical Tree-SPH simulations of galaxy clusters. Starting from a sample of 17 high-resolution objects, with virial mass ranging from 3 10^{14} to 1.7 10^{15} M_sun, we follow the build-up of the systems in dark matter and hot gas through the repeated merging of satellites along their merging history trees. We measure the self-bound mass fraction of subhaloes as a function of time after the merging, estimate the satellite mean orbital properties as a function of the mass ratio with the main cluster at merging time, and study the evolution of their internal velocity dispersion, gas temperature and entropy as the substructure is disrupted by various dynamical processes, reaching eventually thermo-dynamic equilibrium in the gravitational potential of the main cluster. We model some relevant properties of subhalo orbits, as the time of the first pericentric and apocentric passages, and the typical distances and velocities at the corresponding times. This survival study can be used to interpret the dynamics of observed merging clusters; as an example we apply our results to the system 1E0657-56. We show that, in the light of our results, the most likely interpretation of the data for this cluster points to the merger of a small group with mass M\\approx 1 10^{13} M_sun with a massive cluster with M\\approx 1.3 10^{15} M_sun.

Giuseppe Tormen; Lauro Moscardini; Naoki Yoshida
2004-03-04

223

NATIONAL POLAR-ORBITTING OPERATIONAL ENVIRONMENTAL SATELLITE SYSTEM (NPOESS)

  Geosciences Websites

Summary: NATIONAL POLAR-ORBITTING OPERATIONAL ENVIRONMENTAL SATELLITE SYSTEM (NPOESS) INTEGRATED PROGRAM/Validation Plan for the NPOESS Preparatory Project VIIRS Land Environmental Data Products DATE: 22 May 2009 No. I) National Polar-orbiting Operational Environmental Satellite System (NPOESS) Integrated Program Office (IPO


224

Title: IKONOS Satellite Image of North York, Ontario Data Creator /

  Computer Technologies and Information Sciences Websites

Summary: Title: IKONOS Satellite Image of North York, Ontario Data Creator / Copyright Owner: Geo: -79.3930 degrees #12;Index Map: N/A Keywords (Place): Toronto, Ontario; North York, Ontario; York University, Ontario Keywords (Subject): Satellite Imagery, Aerial Images Restrictions: Data is licensed


225

Analysis of sampling behavior of candidate SWOT satellite orbits

  Geosciences Websites

Summary: Analysis of sampling behavior of candidate SWOT satellite orbits Sh. Roohi, N. Sneeuw Institute- ficiency. A careful repeat orbit design plays important role in sampling the earth from the space by SWOT satellite. Choice an optimized repeat orbit is a key element for successful establishment of this mission

Stuttgart, Universität

226

Monitoring drying up of Urmia lake satellite altimetry

  Geosciences Websites

Summary: Monitoring drying up of Urmia lake with satellite altimetry Sh. Roohi (shirzad Validation Analysis and conclusion Monitoring drying up of Urmia lake with satellite altimetry 1 #12;Introduction Urmia lake Geography Chemistry Ecology Main inflow rivers Monitoring drying up of Urmia lake

Stuttgart, Universität

227

TOWARDS USING SATELLITE ALTIMETRY FOR THE OBSERVATION OF COASTAL DYNAMICS.

  Environmental Sciences and Ecology Websites

Summary: TOWARDS USING SATELLITE ALTIMETRY FOR THE OBSERVATION OF COASTAL DYNAMICS. Florence Birol (1 be observed with satellite altimetry. Therefore, we have used a new data processing approach developed Over the last decade, altimetry has been shown to be a powerful tool to obtain informations about


228

Can oceanic submesoscale processes be observed with satellite altimetry?

  Geosciences Websites

Summary: Can oceanic submesoscale processes be observed with satellite altimetry? Cédric P. Chavanne1 with satellite altimetry. Our results highlight two major problems that must be overcome before being able to resolve submesoscale processes with altimetry: (i) signal contamination from highfrequency motions


229

Digital Video Broadcasting By Satellite Matthew C. Valenti

  Computer Technologies and Information Sciences Websites

Summary: Providers Digital Satellite Television in the United States DirecTV Spinoff of Hughes Network Systems. Began Network Systems. DirecTV. M.C. Valenti ( Lane Department of Computer Science and Electrical Engineering West Virginia UniverLDPC Codes Apr. 2, 2012 2 / 41 #12;Outline 1 Satellite Television Standards 2 DVB

Valenti, Matthew C.

230

Atmospheric Density Reconstruction Using Satellite Orbit Tomography1

  Engineering Websites

Summary: = summed kernel, km2 /s3 i = satellite index K = set of times in a given cell k = discrete time index I = X a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes #12;2 m = mass, kg N = number of cells in grid n = cell index P = number of satellite points in a cell

Wohlberg, Brendt

231

EUMETSAT Meteorological Satellite conference, Cordoba, 21/9/2010 observation

  Geosciences Websites

Summary: EUMETSAT Meteorological Satellite conference, Cordoba, 21/9/2010 ADM-Aeolus wind observation from Meteorological Satellite conference, Cordoba, 21/9/2010 Need for space winds · Wind determines small and sparse 3D meteorological observations are present; reduce errors over the ocean · Transport

Stoffelen, Ad

232

Observing ocean heat content using satellite gravity and altimetry

  Geosciences Websites

Summary: . Geophys. Res., 108(C2), 3031, doi:10.1029/2002JC001619, 2003. 1. Introduction [2] The exchange of heatObserving ocean heat content using satellite gravity and altimetry Steven R. Jayne1,2 and John M with satellite measurements of the Earth's time-varying gravity to give improved estimates of the ocean's heat

Jayne, Steven

233

On the scarcity of Magellanic Cloud-like satellites

  CERN Preprints

Summary: We have used H alpha narrow-band imaging to search for star-forming satellite galaxies around 143 luminous spiral galaxies, with the goal of quantifying the frequency of occurrence of satellites resembling the Magellanic Clouds, around galaxies comparable to the Milky Way. For two-thirds of the central galaxies, no star-forming satellites are found, down to luminosities and star-formation rates well below those of the Magellanic Clouds. A total of 62 satellites is found, associated with 47 of the central galaxies searched. The R-band magnitude difference between central galaxies and their satellites has a median value of 4.6 mag, and a maximum of 10.2 mag. The mean projected separation of the satellites from their central galaxies is 81 kpc, or 98 kpc for systems beyond 30 Mpc. Thus star-forming satellites are quite rare, and the Milky Way is unusual both for the luminosity and the proximity of its two brightest satellites. We also find that the Clouds themselves are unusual in that they appear to form a boun...

James, Phil A
2010-01-01

234

SPICE Testbed: A DTN Testbed for Satellite and Space Communications

  Engineering Websites

Summary: SPICE Testbed: A DTN Testbed for Satellite and Space Communications Ioannis Komnios, Ioannis SPICE testbed, a state-of-the-art Delay Tolerant Networking testbed for satellite and space of underlying and overlying protocols. SPICE testbed is equipped with specialised hardware components

Tsaoussidis, Vassilis

235

VERY HIGH RESOLUTION SATELLITE IMAGES FOR PARAMETERIZATION OF

  Computer Technologies and Information Sciences Websites

Summary: VERY HIGH RESOLUTION SATELLITE IMAGES FOR PARAMETERIZATION OF TREE-SCALE FOREST PROCESS-BASED MODEL (VHSR) satellite images provide interesting information for parameterizing tree-scale forest process-based models, and in particular their light absorption submodels, which is at the basis of photosynthesis

Boyer, Edmond

236

Multidisciplinary Design Optimization Methodology for Distributed Satellite Systems

  CiteSeer

Summary: A multiobjective, multidisciplinary design optimization methodology for mathematically modeling the distributed satellite system (DSS) conceptual design problem as an optimization problem has been developed to advance the state-of-the-art in complex distributed satellite network design. An increasing number of space missions are utilizing DSS architectures

Cyrus D. Jilla; D. Jilla
2004-01-01

237

Management and Service Discovery in Satellite and Avionic Networks

  Computer Technologies and Information Sciences Websites

Summary: delays to satellites and limited data transit over band- width constrained links. Low latencyManagement and Service Discovery in Satellite and Avionic Networks Todd Sproull and John W:john.l.meier@boeing.com Abstract--Command and control services manage network- attached assets deployed in distributed systems

Lockwood, John W.

238

Resonant Thickening of Disks by Small Satellite Galaxies

  Astrophysics (arXiv)

Summary: We study the vertical heating and thickening of galaxy disks due to accretion of small satellites. Our simulations are restricted to axial symmetry, which largely eliminates numerical evolution of the target galaxy but requires the trajectory of the satellite to be along the symmetry axis of the target. We find that direct heating of disk stars by the satellite is not important because the satellite's gravitational perturbation has little power at frequencies resonant with the vertical stellar orbits. The satellite does little damage to the disk until its decaying orbit resonantly excites large-scale disk bending waves. Bending waves can damp through dynamical friction from the halo or internal wave-particle resonances; we find that wave-particle resonances dominate the damping. The principal vertical heating mechanism is therefore dissipation of bending waves at resonances with stellar orbits in the disk. Energy can thus be deposited some distance from the point of impact of the satellite. The net heating from a tightly bound satellite can be substantial, but satellites that are tidally disrupted before they are able to excite bending waves do not thicken the disk.

J. A. Sellwood; Robert W. Nelson; Scott Tremaine
1998-05-12

239

MAPPING FERRUGINOUS HAWK (BUTEO REGALIS) HABITAT USING SATELLITE DATA

  Biology and Medicine Websites

Summary: MAPPING FERRUGINOUS HAWK (BUTEO REGALIS) HABITAT USING SATELLITE DATA BY NATALYA V. ANTONOVA _________________________ #12;MAPPING FERRUGINOUS HAWK HABITAT USING SATELLITE DATA A Thesis Presented to The Faculty of Western quality and abundance. One species of special concern is the ferruginous hawk (Buteo regalis), which

Wallin, David O.

240

Modelling Uncertainty in Satellite Derived Land Edward Cripps

  Mathematics Websites

Summary: Modelling Uncertainty in Satellite Derived Land Cover Maps Edward Cripps Anthony O'Hagan Tristan Quaife Clive Anderson March 24, 2009 Abstract Maps of land cover, derived from satellite observation, the true land cover category at a given site may differ from the category assigned in the map

O'Hagan, Tony

241

MULTIVARIATE REGRESSION OF SATELLITE-LINKED DIVE RECORDER

  Biology and Medicine Websites

Summary: MULTIVARIATE REGRESSION OF SATELLITE-LINKED DIVE RECORDER DATA: SIMULTANEOUS ANALYSIS OF ALL BINS M of diving behavior data collected from satellite-linked dive recorders (SDRs) can be challenging because: (1 of dives can be correlated among depth bins. Previous analyses often have ignored one or more

Laidre, Kristin L.

242

Effects of Rain Attenuation on Satellite Video Transmission

  Computer Technologies and Information Sciences Websites

Summary: -band is therefore suscep- tible to attenuation. We present the setup of a high-speed link via the WINDS satellite in tropical countries such as Singapore. The operation of high- speed satellite transmission in the Ka using an ultra small aperture terminals (USAT). Video streaming is performed over the high-speed link so

Winkler, Stefan

243

Adaptive Multimedia Communication over Satellite Routed IP Michael Welzl

  Computer Technologies and Information Sciences Websites

Summary: congestion", in which the sender can not fill the satellite channel in a timely fashion due to slow, but the end user's outgoing traffic is still sent over a slow terrestrial link (or a satellite uplink, slow-start as well as congestion avoidance will take very long due to the long RTT. Some proposed

Welzl, Michael

244

On the central configurations of the coorbital satellite problem

  Mathematics Websites

Summary: On the central configurations of the coorbital satellite problem Josep M. Cors 1 Jaume Llibre 2 Merc`e Oll'e 3 Abstract In this communication we study the central configurations of the coorbital satellite problem --also called 1 +n body problem--, that is, we study the central configurations of a large

Politècnica de Catalunya, Universitat

245

Adaptive Beamforming in Mobile, Massively Multiuser Satellite Communications: A System

  Engineering Websites

Summary: Adaptive Beamforming in Mobile, Massively Multiuser Satellite Communications: A System Perspective Xiao Lei, Laura Cottatellucci, Samah A. M. Ghanem Mobile Communications Department, Eurecom, France Email: {xiao.lei; laura.cottatellucci; samah.ghanem}@eurecom.fr Abstract--We consider a Mobile Satellite

Gesbert, David

246

A NOVEL DIMENSIONING METHOD FOR HIGH THROUGHPUT SATELLITE DESIGN

  Physics Websites

Summary: A NOVEL DIMENSIONING METHOD FOR HIGH THROUGHPUT SATELLITE DESIGN Dimitri Serrano-Velarde Eutelsat@eutelsat.com Georges Rodriguez-Guisantes TELECOM ParisTech, Communications and Electronics, 46, rue Barrault, 75634 describes a novel methodology for the dimensioning of a Ka-Band high throughput satellite for broadband

Paris-Sud XI, Université de

247

Bandwidth Allocation for IP Traffic Over Satellite Links

  Computer Technologies and Information Sciences Websites

Summary: provisioning is discussed. Index terms: satellite communications, ground terminals, TCP/IP, QoS, qualityBandwidth Allocation for IP Traffic Over Satellite Links Claude Bélisle, Peter Andreadis, Steve Bernier, François Lévesque, and Michel Barbeau Communications Research Centre Canada 3701 Carling Avenue

Barbeau, Michel

248

Novel cluster maintenance protocol for efficient satellite integration in MANETs

  Physics Websites

Summary: /Institut T´el´ecom, Rennes, France Mobile ad hoc networks (MANETs) are a promising technology for emergency of communications due to partitioning compromises the rescue and recovery operations. Satellites may help, called clusterheads provid- ing access to the satellite communication, while optimizing the network load

Paris-Sud XI, Université de

249

Asteroid 2014 OL339: yet another Earth quasi-satellite

  CERN Preprints

Summary: Our planet has one permanently bound satellite -the Moon-, a likely large number of mini-moons or transient irregular natural satellites, and three temporary natural retrograde satellites or quasi-satellites. These quasi-moons -(164207) 2004 GU9, (277810) 2006 FV35 and 2013 LX28- are unbound companions to the Earth. The orbital evolution of quasi-satellites may transform them into temporarily bound satellites of our planet. Here, we study the dynamical evolution of the recently discovered Aten asteroid 2014 OL339 to show that it is currently following a quasi-satellite orbit with respect to the Earth. This episode started at least about 775 yr ago and it will end 165 yr from now. The orbit of this object is quite chaotic and together with 164207 are the most unstable of the known Earth quasi-satellites. This group of minor bodies is, dynamically speaking, very heterogeneous but three of them exhibit Kozai-like dynamics: the argument of perihelion of 164207 oscillates around -90 degrees, the one of 277810 libr...

Marcos, C de la Fuente
2014-01-01

250

IP ROUTING ISSUES IN SATELLITE CONSTELLATION NETWORKS A. CLERGET,2

  Engineering Websites

Summary: 1 IP ROUTING ISSUES IN SATELLITE CONSTELLATION NETWORKS L. WOOD,*1 A. CLERGET,2 I. ANDRIKOPOULOS,1 broadband satellite constellation networks, currently under development, will be required to transport IP traffic. A case can be made for implementing IP routing directly within the constellation network

Wood, Lloyd

251

Peer-to-Peer Refueling for Circular Satellite Constellations

  Engineering Websites

Summary: Peer-to-Peer Refueling for Circular Satellite Constellations Haijun Shen and Panagiotis Tsiotras constellation. It is assumed that there is no fuel delivered to the constellation from an external source. Instead, all satellites in the constellation are assumed to be capable of refueling each other (peer

Tsiotras, Panagiotis

252

First satellite observations of lower tropospheric ammonia and methanol

  Geosciences Websites

Summary: First satellite observations of lower tropospheric ammonia and methanol Reinhard Beer,1 Mark W) and methanol (CH3OH), well above the normal background levels. This is the first time that these molecules have. Citation: Beer, R., et al. (2008), First satellite observations of lower tropospheric ammonia and methanol


253

Satellite Measurements of Trace Gases or Air Pollutants

  Geosciences Websites

Summary: ://www.wisedude.com/science_engineering/satellites.htm · The Eccentric orbit holds a satellite that measures the Earth's magnetic and electric fields. This orbit #12;ACTIVE VS. PASSIVE REMOTE SENSING Passive Remote Sensing: Natural sources of radiation, CALIPSO Intensity of return vs. 4me lag measures ver4cal profile Pros: · High

Dickerson, Russell R.

254

ON THINNING METHODS FOR DATA ASSIMILATION OF SATELLITE OBSERVATIONS

  Computer Technologies and Information Sciences Websites

Summary: 2B.3 ON THINNING METHODS FOR DATA ASSIMILATION OF SATELLITE OBSERVATIONS T. Ochotta1 C. Gebhardt2 V ABSTRACT Thinning of observational data sets is an essen- tial task in assimilation of satellite data error analysis (EEA). EEA is an adaptive thinning method that iteratively removes observations from

Reiterer, Harald

255

Satellite Services Rate Schedule Effective March 26, 2014

  Computer Technologies and Information Sciences Websites

Summary: and classes take place every day through our facilities at Zehmer Hall. For questions or information about UVa Satellite Services email satellite@virginia.edu or call 434-982-5268. Services UVa/State Regular* UVa UVa holidays. Holidays will be billed at the overtime rates. ·Universityand

Acton, Scott

256

Jupiter's Outer Satellites and Trojans David C. Jewitt

  Physics Websites

Summary: 12 Jupiter's Outer Satellites and Trojans David C. Jewitt Institute for Astronomy, University Institute 12.1 INTRODUCTION Jupiter's irregular satellites possess large, eccentric and highly inclined and the Trojans (the latter co-orbiting the Sun leading and trailing Jupiter by 60 ). However, there is reason

Jewitt, David C.

257

Jupiter's Outer Satellites and Trojans David C. Jewitt

  Physics Websites

Summary: 12 Jupiter's Outer Satellites and Trojans David C. Jewitt Institute for Astronomy, University Institute 12.1 INTRODUCTION Jupiter's irregular satellites possess large, eccentric and highly inclined and the Trojans (the latter co-orbiting the Sun leading and trailing Jupiter by 60 deg). However, there is reason

Jewitt, David C.

258

Link Strategy for the Mobile Satellite System Iridium

  CiteSeer

Summary: This paper developes crosslink routing strategies for the Mobile Satellite System Iridium [1,3,6,8]. Motorola's Iridium satellite constellation, based on the orbit design of Adams and Rider [2] is to provide mobile satellite service for hand-held personal telephones. The Iridium system will have 66 satellites in 6 orbital planes at an altitude of h = 780 km and a minimum elevation angle of q = 8.2 degrees for an optimal satellite distribution around the globe. It will be a system with direct connections between satellites (Intersatellite Links ISLs). These connections can be established with Intra-Orbit ISLs and with Inter-Orbit ISLs. The problem of routing messages through the satellite network is complicated by the time-varying satellite system geometry. The relative motion between the synchronized orbital planes is relatively small. However, orbital planes 1 and 6 are counterrotating and have large relative motion. Different Inter-Orbit ISL routing strategies are needed for these tw...

Harald Keller; Horst Salzwedel
1996-01-01

259

Because of its excellence in satellite-based research,

  Geosciences Websites

Summary: Studying the Ocean from Space Because of its excellence in satellite-based research, the College of Oceanic and Atmospheric Sciences (COAS) at Oregon State University was selected to develop a center of excellence in satellite remote-sensing research and modeling of the ocean. The Cooperative Institute

Kurapov, Alexander

260

On-Demand Routing in LEO Satellite Systems Stylianos Karapantazis

  Computer Technologies and Information Sciences Websites

Summary: -satellite links (ISLs). Further, most of them take advantage of the deterministic dynamics of this network propagation and queuing delays in each ISL. Nonetheless, albeit update intervals of about 30 secs (adopted that employ ISLs. The protocol introduces the well-known concept of on-demand routing to satellite networks

Papapetrou, Evaggelos

261

ighly capable small satellites are commonplace today, but this was-

  Physics Websites

Summary: (SMC) and the National Reconnaissance Office (NRO) asked The Aerospace Corporation for information 2000/2001 capabilities and costs of such systems. In re- sponse,Aerospace commissioned a study to small-satellite pro- grams. To meet this need, Aerospace even- tually developed the Small Satellite Cost

Rhoads, James

262

Parallelization of the Naval Space Surveillance Satellite Motion Model

  Mathematics Websites

Summary: Parallelization of the Naval Space Surveillance Satellite Motion Model Warren E. Phipps Jr. Beny Author to whom correspondence should be addressed. #12;Abstract The Naval Space Surveillance Center-node hypercube. Introduction The Naval Space SurveillanceCenter (NAVSPASUR) uses an analytic satellite

Danielson, Don

263

Research Article The Effect of Lunarlike Satellites on the Orbital

  Geosciences Websites

Summary: Research Article The Effect of Lunarlike Satellites on the Orbital Infrared Light Curves of Earth the influence of lunarlike satellites on the infrared orbital light curves of Earth-analog extrasolar planets orbit. We used an energy balance model to calculate disk-averaged infrared (bolometric) fluxes from

Moskovitz, Nicholas

264

Physical aspects to consider in radiometric calibration of satellite images

  CERN Preprints

Summary: It does a revision about the physical principles involved in digital processing of satellite images, more specifically in radiometric calibration of them. It shows a conceptual description of the interaction between radiation and atmosphere and radiation and soil in order to help the reader understand in more detail which means the information contained in satellite images.

Delgado-Correal, Camilo
2012-01-01

265

Validation of satellite ozone profile retrievals using Beijing ozonesonde data

  Geosciences Websites

Summary: Validation of satellite ozone profile retrievals using Beijing ozonesonde data Jianchun Bian,1 year time period (September 2002 to July 2005) are used to evaluate the performance of ozone profile) on the NASA Aura satellite. Since the Global Positioning System ozone sensors (GPSO3) used in Beijing

Pan, Laura

266

Tropospheric Ozone Satellite Retrievals in the Pacific Northwest

  Physics Websites

Summary: Tropospheric Ozone Satellite Retrievals in the Pacific Northwest Jacqueline Costello1, Farren: Tropospheric ozone is difficult to retrieve from satellites because of the abundance of ozone in the stratosphere. Tropospheric ozone has become a significant environmental issue and can be exacerbated by UT

Collins, Gary S.

267

NASA ACTS SATELLITE: A DISASTER RECOVERY TEST Dr. Hans Kruse

  Engineering Websites

Summary: NASA ACTS SATELLITE: A DISASTER RECOVERY TEST Dr. Hans Kruse School of Communications Systems In September 1993, NASA launched its long- awaited Advanced Communication Technology (ACTS) satellite. ACTS links. The ACTS Disaster Recovery Project was designed to test the Bank's ability to by

Kruse, Hans

268

(Preprint) AAS 13-279 ATMOSPHERIC DENSITY RECONSTRUCTION USING SATELLITE

  Engineering Websites

Summary: (Preprint) AAS 13-279 ATMOSPHERIC DENSITY RECONSTRUCTION USING SATELLITE ORBIT TOMOGRAPHY Michael A. Shoemaker , Brendt Wohlberg , and Josef Koller , Improved thermospheric neutral density models are required to better predict LEO satellite orbits. This research describes a new method to estimate the density us- ing

Wohlberg, Brendt

269

TriAnd and its Siblings: Satellites of Satellites in the Milky Way Halo

  CERN Preprints

Summary: We explore the Triangulum-Andromeda (TriAnd) overdensity in the SPLASH (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo) and SEGUE (the Sloan Extension for Galactic Understanding and Exploration) spectroscopic surveys. Milky Way main sequence turn-off stars in the SPLASH survey reveal that the TriAnd overdensity and the recently discovered PAndAS stream (Martin et al. 2014) share a common distance (D ~ 20 kpc), position on the sky, and line-of-sight velocity (V_GSR ~ 50 km/s). Similarly, A-type, giant, and main sequence turn-off stars selected from the SEGUE survey in the vicinity of the Segue 2 dwarf show that TriAnd is prevalent in these fields, with a velocity and distance similar to the Segue 2 satellite. The coincidence of the PAndAS stream and Segue 2 satellite in positional and velocity space to TriAnd suggests that these substructures are all associated, and may be a fossil record of group-infall onto the Milky Way halo. In this scenario, the Segue 2 satellite and PAndAS stream are...

Deason, A J; Hamren, K M; Koposov, S E; Gilbert, K M; Beaton, R L; Dorman, C E; Guhathakurta, P; Majewski, S R; Cunningham, E C
2014-01-01

270

Dark influences: imprints of dark satellites on dwarf galaxies

  CERN Preprints

Summary: In the context of the current $\\Lambda$CDM cosmological model small dark matter haloes are abundant and satellites of dwarf galaxies are expected to be predominantly dark. Since low mass galaxies have smaller baryon fractions interactions with these satellites may leave particularly dramatic imprints. We uncover the influence of the most massive of these dark satellites on disky dwarf galaxies and the possible dynamical and morphological transformations that result from these interactions. We use a suite of carefully set-up, controlled simulations of isolated dwarf galaxies. The primary dwarf galaxies have solely a stellar disk in the dark matter halo and the secundaries are completely devoid of baryons. We vary the disk mass, halo concentration, initial disk thickness and inclination of the satellite orbit. The disky dwarf galaxies are heated and disrupted due to the minor merger event, more extremely for higher satellite over disk mass ratios, and the morphology and kinematics are significantly altered. Mor...

Starkenburg, Tjitske K
2014-01-01

271

Asymptotic behavior of an elastic satellite with internal friction

  Mathematical Physics (arXiv)

Summary: We study the dynamics of an elastic body whose shape and position evolve due to the gravitational forces exerted by a pointlike planet. The main result is that, if all the deformations of the satellite dissipate some energy, then under a suitable nondegeneracy condition there are only three possible outcomes for the dynamics: (i) the orbit of the satellite is unbounded, (ii) the satellite falls on the planet, (iii) the satellite is captured in synchronous resonance i.e. its orbit is asymptotic to a motion in which the barycenter moves on a circular orbit, and the satellite moves rigidly, always showing the same face to the planet. The result is obtained by making use of LaSalle's invariance principle and by a careful kinematic analysis showing that energy stops dissipating only on synchronous orbits. We also use in quite an extensive way the fact that conservative elastodynamics is a Hamiltonian system invariant under the action of the rotation group.

Emanuele Haus; Dario Bambusi
2012-12-04

272

The rotation states predominant among the planetary satellites

  CERN Preprints

Summary: On the basis of tidal despinning timescale arguments, Peale showed in 1977 that the majority of irregular satellites (with unknown rotation states) are expected to reside close to their initial (fast) rotation states. Here we investigate the problem of the current typical rotation states among all known satellites from a viewpoint of dynamical stability. We explore location of the known planetary satellites on the ($\\omega_0$, $e$) stability diagram, where $\\omega_0$ is an inertial parameter of a satellite and $e$ is its orbital eccentricity. We show that most of the satellites with unknown rotation states cannot rotate synchronously, because no stable synchronous 1:1 spin-orbit state exists for them. They rotate either much faster than synchronously (those tidally unevolved) or, what is much less probable, chaotically (tidally evolved objects or captured slow rotators).

Melnikov, A V
2013-01-01

273

Satellite Test and Operation Procedures Cost Reduction Through Standardization

  CiteSeer

Summary: Abstract—Rhea has been involved in the development, maintenance and execution of satellite test and operations procedures, both in manufacturing plants and operation environments ever since its founding in 1992. This paper 12 will describe how Rhea and ADGA are supporting ongoing standardization efforts within the European Cooperation for Space Standardization (ECSS) and the Object Management Group (OMG) to enable the reduction in the costs associated with satellite procedures. The OMG and ECSS organizations have identified the problems that arise when transferring procedural data between organizations, be that satellite manufacturer to operator, instrument manufacturer to prime contractor, or satellite operators transferring control of satellites. This paper will briefly discuss the problems inherent in

Stuart James Cater

274

Satellite Image Automatic MapperTM -SIAMTM -Patent pending - Andrea Baraldi University of Maryland Satellite Image Automatic MapperTM

  Geosciences Websites

Summary: Satellite Image Automatic MapperTM - SIAMTM - Patent pending - © Andrea Baraldi University MapperTM - SIAMTM - Patent pending - © Andrea Baraldi University of Maryland - Email: andrea.baraldi@hermes.geog.umd.edu #12;Satellite Image Automatic MapperTM - SIAMTM - Patent pending - © Andrea Baraldi University

Kuligowski, Bob

275

1Hinode Satellite Power The Hinode satellite weighs approximately 700 kg (dry) and carries 170 kg of gas for

  Environmental Sciences and Ecology Websites

Summary: for up to two years. The satellite has two solar panels (blue) that produce all of the spacecraft's power by the solar panels when facing the sun? Can the satellite supply enough power to operate the experiments which.03 watts of power for each square centimeter of area, what is the total power produced by the solar panels


276

Geosynchronous satellite maneuver detection and orbit recovery using ground based optical tracking

  MIT - DSpace

Summary: Geosynchronous satellite orbit maintenance is a very important issue. Satellites maneuver frequently requiring the ability to detect unknown maneuvers for target satellites and quickly recover an accurate orbit. This study ...

Aaron, Benjamin S. (Benjamin Samuel)
2006-01-01

277

ForPeerReview Multi-sensor Satellite Remote Sensing of Dust Aerosols over

  Environmental Sciences and Ecology Websites

Summary: ForPeerReview Multi-sensor Satellite Remote Sensing of Dust Aerosols over North Africa during Keywords: GERBILS, Satellite remote Sensing, Aerosols Quarterly Journal of the Royal Meteorological Society #12;ForPeerReview Satellite Remote Sensing during GERBILS

Christopher, Sundar A.

278

Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese Geostationary Meteorological Satellites

  Geosciences Websites

Summary: Geostationary Meteorological Satellites JINJUN TONG Environmental Science and Engineering Program, University Calibration and Validation for Environmental Satellites, China Meteorological Administration, National Satellite Meteorology Center, Beijing, China STEPHEN J. DE´ RY Environmental Science and Engineering Program

Dery, Stephen

279

FPGA Implementation of a Satellite Attitude Control using Variable Structure Control

  Computer Technologies and Information Sciences Websites

Summary: FPGA Implementation of a Satellite Attitude Control using Variable Structure Control Mokhtar Dept. of Electrical Engineering Effat University Jeddah Saudi Arabia Abstract-- Satellite control implementation of a Variable Structure Controller (VSC) for a satellite. Our implementation uses fixed point

Aboelaze, Mokhtar

280

THE GLOBAL IMPACT OF SATELLITE-DERIVED POLAR WINDS ON MODEL FORECASTS

  Environmental Sciences and Ecology Websites

Summary: THE GLOBAL IMPACT OF SATELLITE-DERIVED POLAR WINDS ON MODEL FORECASTS by David A. Santek........................................................................................................... 1 2. Satellite-derived winds algorithm........................................................................... 6 2.1 Geostationary satellite winds algorithm

Wisconsin at Madison, University of

281

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING Int. J. Satell. Commun. Network. 2006; 24:261281

  Computer Technologies and Information Sciences Websites

Summary: INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING Int. J. Satell. Commun. Network: 10.1002/sat.841 Turbo-coded APSK modulations design for satellite broadband communications Riccardo phase shift keying (APSK) modulation with application to satellite broadband communications. APSK


282

Improved Explicit Congestion Notification for Satellite Networks Arjan Durresi*a

  Computer Technologies and Information Sciences Websites

Summary: of the greatest challenges before telecommunications industry in the 21st century. Satellite communicationImproved Explicit Congestion Notification for Satellite Networks Arjan Durresi*a , Mukundan University b Nayna Networks, Inc. ABSTRACT Due to the fundamental satellite system characteristics

Jain, Raj

283

Enhancing the Economics of Satellite Constellations via Staged Deployment and Orbital

  Engineering Websites

Summary: Enhancing the Economics of Satellite Constellations via Staged Deployment and Orbital Students #12;2 #12;Enhancing the Economics of Satellite Constellations via Staged Deployment and Orbital and Astronautics Abstract The "traditional" way of designing constellations of communications satellites


284

INTERNATIONAL SATELLITE CLOUD CLIMATOLOGY PROJECT (ISCCP) DESCRIPTION OF MONTHLY MEAN CLOUD DATA (STAGE C2)

  Geosciences Websites

Summary: APPENDIX C INTERNATIONAL SATELLITE CLOUD CLIMATOLOGY PROJECT (ISCCP) DESCRIPTION OF MONTHLY MEAN The International Satellite Cloud Climatology Project (ISCCP) collects satellite measurements of spectral radiances data with the same spatial resolution and including mean diurnal variations. The analysis procedures


285

Satellite galaxies around present-day massive ellipticals

  CERN Preprints

Summary: Using the spectroscopic and photometric catalogues of the Sloan Digital Sky Survey (SDSS DR7), we have explored the satellite distribution around $\\sim$1000 massive (M$_\\star$$\\gtrsim$2$\\times$10$^{11}$M$_\\odot$) visually classified elliptical galaxies down to a satellite mass ratio of 1:400 (i.e. 5$\\times$$10^{8}$$\\lesssim$M$_{sat}$$\\lesssim$2$\\times$10$^{11}$M$_\\odot$). Our host galaxies were selected to be representative of a mass complete sample. The satellites of these galaxies were searched within a projected radial distance of 100 kpc to their hosts. We have found that only 17-23% of the massive ellipticals has at least a satellite down to a mass ratio 1:10. This number increases to 40-52% if we explore satellites down to 1:100 and is $>$55-70% if we go further down to 1:400. The average projected radial distance of the satellites to their hosts is $\\sim$59 kpc (which can be decreased down to 49-51 kpc if we account for incompleteness effects). The number of satellites per galaxy host only increases ve...

Ruiz, Pablo; Mármol-Queraltó, Esther
2013-01-01

286

SSC99-III-3 University Nanosatellite Distributed Satellite Capabilities to

  CiteSeer

Summary: ABSTRACT. A new way to perform space missions utilizes the concept of clusters of satellites that cooperate to perform the function of a larger, single satellite. Each smaller satellite communicates with the others and shares the processing, communications, and payload or mission functions. The required functionality is thus spread across the satellites in the cluster, the aggregate forming a "virtual satellite". The Air Force Research Laboratory (AFRL) initiated the TechSat 21 program to explore the basic technologies required to enable such distributed satellite systems. For this purpose, Space Based Radar (SBR) was selected as a reference mission to help identify technology requirements and to allow an easy comparison to a conventional approach. A summary of the basic mission and the performance requirements is provided. The satellite cluster approach to space missions requires science and technology advances in several key areas. Each of these challenges is described in some detail, with specific stressing requirements driven by the SBR reference mission. These TechSat 21 research and technology areas are being studied in a coordinated effort between several directorates within AFRL and the Air

Dr. Howard Schlossberg; Afosr Mr; Joe Mitola; Darpa Dr; Dave Weidow; Gsfc Dr; Richard Blomquist

287

LARES succesfully launched in orbit: satellite and mission description

  General Relativity & Quantum Cosmology (arXiv)

Summary: On February 13th 2012, the LARES satellite of the Italian Space Agency (ASI) was launched into orbit with the qualification flight of the new VEGA launcher of the European Space Agency (ESA). The payload was released very accurately in the nominal orbit. The name LARES means LAser RElativity Satellite and summarises the objective of the mission and some characteristics of the satellite. It is, in fact, a mission designed to test Einstein's General Relativity Theory (specifically 'frame dragging' and Lense-Thirring effect). The satellite is passive and covered with optical retroreflectors that send back laser pulses to the emitting ground station. This allows accurate positioning of the satellite, which is important for measuring the very small deviations from Galilei-Newton's laws. In 2008, ASI selected the prime industrial contractor for the LARES system with a heavy involvement of the universities in all phases of the programme, from the design to the construction and testing of the satellite and separation system. The data exploitation phase started immediately after the launch under a new contract between ASI and those universities. Tracking of the satellite is provided by the International Laser Ranging Service. Due to its particular design, LARES is the orbiting object with the highest known mean density in the solar system. In this paper, it is shown that this peculiarity makes it the best proof particle ever manufactured. Design aspects, mission objectives and preliminary data analysis will be also presented.

Antonio Paolozzi; Ignazio Ciufolini
2013-05-29

288

The population of natural Earth satellites

  CERN Preprints

Summary: We have for the first time calculated the population characteristics of the Earth's irregular natural satellites (NES) that are temporarily captured from the near-Earth-object (NEO) population. The steady-state NES size-frequency and residence-time distributions were determined under the dynamical influence of all the massive bodies in the solar system (but mainly the Sun, Earth, and Moon) for NEOs of negligible mass. To this end, we compute the NES capture probability from the NEO population as a function of the latter's heliocentric orbital elements and combine those results with the current best estimates for the NEO size-frequency and orbital distribution. At any given time there should be at least one NES of 1-meter diameter orbiting the Earth. The average temporarily-captured orbiter (TCO; an object that makes at least one revolution around the Earth in a co-rotating coordinate system) completes $(2.88\\pm0.82)\\rev$ around the Earth during a capture event that lasts $(286\\pm18)\\days$. We find a small pre...

Granvik, Mikael; Jedicke, Robert
2011-01-01

289

Generalized Morse Potential: Symmetry and Satellite Potentials

  HEP - Theory (arXiv)

Summary: We study in detail the bound state spectrum of the generalized Morse potential~(GMP), which was proposed by Deng and Fan as a potential function for diatomic molecules. By connecting the corresponding Schr\\"odinger equation with the Laplace equation on the hyperboloid and the Schr\\"odinger equation for the P\\"oschl-Teller potential, we explain the exact solvability of the problem by an $so(2,2)$ symmetry algebra, and obtain an explicit realization of the latter as $su(1,1) \\oplus su(1,1)$. We prove that some of the $so(2,2)$ generators connect among themselves wave functions belonging to different GMP's (called satellite potentials). The conserved quantity is some combination of the potential parameters instead of the level energy, as for potential algebras. Hence, $so(2,2)$ belongs to a new class of symmetry algebras. We also stress the usefulness of our algebraic results for simplifying the calculation of Frank-Condon factors for electromagnetic transitions between rovibrational levels based on different electronic states.

A. Del Sol Mesa; C. Quesne; Yu. F. Smirnov
1997-08-06

290

Dark matter subhalos and dwarf satellites

  CERN Preprints

Summary: The Via Lactea simulation of the dark matter halo of the Milky Way predicts the existence of many thousands of bound subhalos distributed approximately with equal mass per decade of mass. Here we show that: a) a similar steeply rising subhalo mass function is also present at redshift 0.5 in an elliptical-sized halo simulated with comparable resolution in a different cosmology. Compared to Via Lactea, this run produces nearly a factor of two more subhalos with large circular velocities; b) the fraction of Via Lactea mass brought in by subhalos that have a surviving bound remnant today with present-day peak circular velocity Vmax>2 km/s (>10 km/s) is 45% (30%); c) because of tidal mass loss, the number of subhalos surviving today that reached a peak circular velocity of >10 km/s throughout their lifetime exceeds half a thousand, five times larger than their present-day abundance and more than twenty times larger than the number of known satellites of the Milky Way; e) unless the circular velocity profiles of Ga...

Madau, Piero; Kuhlen, Michael
2008-01-01

291

Submerged turbulence detection with optical satellites

  Astrophysics (arXiv)

Summary: During fall periods in 2002, 2003 and 2004 three major oceanographic expeditions were carried out in Mamala Bay, Hawaii. These were part of the RASP Remote Anthropogenic Sensing Program. Ikonos and Quickbird optical satellite images of sea surface glint revealed ~100 m spectral anomalies in km^2 averaging patches in regions leading from the Honolulu Sand Island Municipal Outfall diffuser to distances up to 20 km. To determine the mechanisms behind this phenomenon, the RASP expeditions monitored the waters adjacent to the outfall with an array of hydrographic, optical and turbulence microstructure sensors in anomaly and ambient background regions. Drogue tracks and mean turbulence parameters for 2x10^4 microstructure patches were analyzed to understand complex turbulence, fossil turbulence and zombie turbulence near-vertical internal wave transport processes. The dominant mechanism appears to be generic to stratified natural fluids including planet and star atmospheres and is termed beamed zombie turbulence maser action (BZTMA). Most of the bottom turbulent kinetic energy is converted to ~100 m fossil turbulence waves. These activate secondary (zombie) turbulence in outfall fossil turbulence patches that transmit heat, mass, chemical species, momentum and information vertically to the sea surface for detection in an efficient maser action. The transport is beamed in intermittent mixing chimneys.

Carl H. Gibson; R. Norris Keeler; Valery G. Bondur; Pak T. Leung; H. Prandke; D. Vithanage
2007-09-05

292

Tidal gravitational effects in a satellite

  General Relativity & Quantum Cosmology (arXiv)

Summary: Atomic wave interferometers are tied to a telescope pointing towards a faraway star in a nearly free falling satellite. Such a device is sensitive to the acceleration and the rotation relatively to the local inertial frame and to the tidal gravitational effects too. We calculate the rotation of the telescope due to the aberration and the deflection of the light in the gravitational field of a central mass (the Earth and Jupiter). Within the framework of a general parametrized description of the problem, we discuss the contributions which must be taken into account in order to observe the Lense-Thirring effect. Using a geometrical model, we consider some perturbations to the idealized device and we calculate the corresponding effect on the periodic components of the signal. Some improvements in the knowledge of the gravitational field are still necessary as well as an increase of the experimental capabilities; however our conclusions support a reasonable optimism for the future. Finally we put forward the necessity of a more complete, realistic and powerful model in order to obtain a definitive conclusion on the feasibility of the experiment as far as the observation of the Lense-Thirring effect is involved.

Philippe Tourrenc; Marie-Christine Angonin-Willaime; Xavier Ovido
2004-07-23

293

The Role of Mobile and Remote Sensing Satellites in Disaster Management

  CiteSeer

Summary: Abstract: Disaster management aim is human casualty decreasing in natural events such as earth quack, flood, thunderstorms and …. As well as in air crashes, accidents and…. In this paper we use mobile satellite services (MSS) and remote sensing satellites to provide this purpose. Mobile satellites contains 3 type of satellites; LEO, MEO and GEO. Remote sensing satellites are two categories: optical and microwave. In first section the introduction is presented, section two and three are about mobile satellites and remote sensing satellites, section four analyzes data and finally conclusion will be presented. Key words: disaster management, mobile satellite, remote sensing. I.

Mehdi Mari; Amir Kabir

294

Satellite Motion in a Manev Potential with Drag

  CERN Preprints

Summary: In this paper, we consider a satellite orbiting in a Manev gravitational potential under the influence of an atmospheric drag force that varies with the square of velocity. Using an exponential atmosphere that varies with the orbital altitude of the satellite, we examine a circular orbit scenario. In particular, we derive expressions for the change in satellite radial distance as a function of the drag force parameters and obtain numerical results. The Manev potential is an alternative to the Newtonian potential that has a wide variety of applications, in astronomy, astrophysics, space dynamics, classical physics, mechanics, and even atomic physics.

Kirk, Samantha; Gkigkitzis, Ioannis
2012-01-01

295

OPTIMIZING COMMUNICATIONS SATELLITE DEPLOYMENT: DEVELOPMENT OF A DECISION AID

  CiteSeer

Summary: This paper discusses the problem of optimizing the utilization of communication satellite capacity. The modern fixed satellite service provider seeks improved methods to optimize the amount of service demand that is accommodated by capacity available on its satellite network. A mixed-integer programming (MIP) model is proposed for the solution of the problem, as part of a decision support tool. Such a tool integrates three system components, which are: a mathematical optimization model, an optimization algorithm, and a graphical user interface. This paper will discuss the design process associated with each component of the system and will conclude with preliminary results obtained from sample optimization runs.

Ian Ayers; Andrew Breton; Mark Farrington; Justin Landrum; Rachel Lee
2004-01-01

296

Satellite probing General Relativity and its extensions and Kolmogorov analysis

  General Relativity & Quantum Cosmology (arXiv)

Summary: We apply the Kolmogorov statistic to analyse the residual data of two LAGEOS satellites on General Relativistic Lense-Thirring effect, and show that it reveals a tiny difference in the properties of the satellites, possibly related to Yarkovsky-Rubincam effect. The recently launched LAser RElativity Satellite (LARES) can provide constraints to the extensions of General Relativity such as the Chern-Simons (CS) gravity with metric coupled to a scalar field through the Pontryagin density, so an explicit dependence on the frame dragging measurements vs the CS parameter is given.

V. G. Gurzadyan; I. Ciufolini; S. Sargsyan; G. Yegorian; S. Mirzoyan; A. Paolozzi
2013-06-24

297

The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem

  Astrophysics (arXiv)

Summary: We present Keck/DEIMOS spectroscopy of stars in 8 of the newly discovered ultra-faint dwarf galaxies around the Milky Way. We measure the velocity dispersions of Canes Venatici I and II, Ursa Major I and II, Coma Berenices, Hercules, Leo IV and Leo T from the velocities of 18 - 214 stars in each galaxy and find dispersions ranging from 3.3 to 7.6 km/s. The 6 galaxies with absolute magnitudes M_V < -4 are highly dark matter-dominated, with mass-to-light ratios approaching 1000. The measured velocity dispersions are inversely correlated with their luminosities, indicating that a minimum mass for luminous galactic systems may not yet have been reached. We also measure the metallicities of the observed stars and find that the 6 brightest of the ultra-faint dwarfs extend the luminosity-metallicity relationship followed by brighter dwarfs by 2 orders of magnitude in luminosity; several of these objects have mean metallicities as low as [Fe/H] = -2.3 and therefore represent some of the most metal-poor known stellar systems. We detect metallicity spreads of up to 0.5 dex in several objects, suggesting multiple star formation epochs. Having established the masses of the ultra-faint dwarfs, we re-examine the missing satellite problem. After correcting for the sky coverage of the SDSS, we find that the ultra-faint dwarfs substantially alleviate the discrepancy between the predicted and observed numbers of satellites around the Milky Way, but there are still a factor of ~4 too few dwarf galaxies over a significant range of masses. We show that if galaxy formation in low-mass dark matter halos is strongly suppressed after reionization, the simulated circular velocity function of CDM subhalos can be brought into approximate agreement with the observed circular velocity function of Milky Way satellite galaxies. [slightly abridged

Joshua D. Simon; Marla Geha
2007-07-26

298

Heating of Galactic Disks by Infalling Satellites

  Astrophysics (arXiv)

Summary: We develop an analytic model to calculate the rate at which galaxy disks are heated by dark matter substructures orbiting in their halos. The model takes into account the internal structure, mass function and accretion rate of satellites expected in the LambdaCDM cosmology, as well as the growth of the disk by accretion and mergers, but it ignores resonant heating of the disk and the dynamical effects of spiral arms and bars. We calibrate this model against N-body simulations and demonstrate that it is able to reproduce the N-body heating rates to within a factor of 3 in the majority of cases. Our model gives the distribution of disk scale-heights for galaxies of different luminosities. For L* spiral galaxies, it predicts a median disk thickness of only 5% of the radial scale-length if substructure is the only source of heating. The median disk thickness increases to nearly 20% of the radial scale-length when heating due to gravitational scattering of stars by molecular clouds is also included. The latter value is close to the thickness estimated observationally for the disk of the Milky Way galaxy. The distribution of disk thickness predicted by the model is also consistent with a recent observational determination for sub-L* galaxies by Bizyaev & Mitronova. Thus, the observed thickness of the stellar disks of spiral galaxies seems to be entirely compatible with the abundance of substructure in dark matter halos predicted by the standard Lambda-dominated cold dark matter model of structure formation. In an Omega_0=1 universe, our best model of galaxy formation produces similar scale-heights, a consequence of the fact that similar amounts of substructure are accreted by halos during the lifetime of the disk in Omega_0=1 and Omega_0=0.3, Lambda_0=0.7 cold dark matter cosmologies.

A. J. Benson; C. G. Lacey; C. S. Frenk; C. G. Baugh; S. Cole
2003-07-15

299

Risk management of student-run small satellite programs

  MIT - DSpace

Summary: This paper proposes an approach for failure mode identification in university-affiliated, small satellite programs. These small programs have a unique set of risks due to many factors, including a typically inexperienced ...

Deems, Elizabeth (Elizabeth Carolina)
2007-01-01

300

Cyclone Global Navigation Satellite System (CYGNSS) Mission Overview

  Engineering Websites

Summary: Cyclone Global Navigation Satellite System (CYGNSS) Mission Overview Ta007961_CYGNSS between ocean surface properties, moist atmospheric thermodynamics,radiation,andconvectivedynamicsintheinnercoreofaTropicalCyclone thermodynamics,radiation,andconvectivedynamicsintheinnercoreofaTropicalCyclone(TC). CYGNSS coverage map overlaid

Kamat, Vineet R.

301

Formation of dSph Satellites without Dark Matter

  Astrophysics (arXiv)

Summary: Recently it was shown that low-mass galaxies containing no dark matter can naturally evolve to dSph-like satellites in a tidal field. Such dSph-like satellites fake total domination by dark matter. If this is correct then it must be possible to assemble appropriate precursors of dSph satellites. The genesis of dwarf galaxies in tidal tails appears to be a likely possibility. This is documented by theoretical work and observational surveys. However, it is not yet clear if the Milky Way could have sustained one or two mergers or fly-bys that were mild enough not to have destroyed the Galactic disc. The tidal arms could have been pulled from the incoming galaxy. Also, this scenario has to account for the correlation between brightness and metal abundance displayed by the Galactic dSph satellites, and lead to at least some debris on bound eccentric orbits.

Pavel Kroupa
1998-01-07

302

Dynamic resource allocation DAMA alternatives study for satellite communications systems

  MIT - DSpace

Summary: We consider the design of demand assigned multiple access (DAMA) algorithms that efficiently utilize limited RF uplink resources for packet switched military satellite communication networks. In previous work, we designed ...

Yao, Huan

303

General Framework for the Reconfiguration of Satellite Constellations.

  Open Access Theses and Dissertations

Summary: ??From remote sensing to navigation and communication, satellite constellations have become an indispensible component of our society’s infrastructure. Recent events, including China’s intercept of their… (more)

Ferringer, Matthew
2009-01-01

304

Title: Worldview 2 Satellite Image of York University Data Creator /

  Computer Technologies and Information Sciences Websites

Summary: ;Keywords (Place): Toronto, Ontario; North York, Ontario; York University, Ontario Keywords (Subject@yorku.ca) Citation: "Worldview 2 Satellite Image of York University, North York, Ontario, July 25, 2012". Longmont


305

An integrated evolutionary model approach to small satellite engineering

  MIT - DSpace

Summary: A deficiency exists in the use of detailed integrated modeling in the design, fabrication, and operations of small satellites (<180kg). This need led to the design of the Integrated Evolutionary Model (IEM) approach to ...

Robinson, Joseph B. (Joseph Brian)
2010-01-01

306

On the use of Satellite Television in High Energy Physics

  HEP - Experiment (arXiv)

Summary: This paper assesses the feasibility of exploiting commercial satellite television technologies to broadcast video signals and data from major High Energy Physics facilities to collaborating institutes throughout the world.

Lucas Taylor; David O. Williams
1998-10-24

307

A small satellite preliminary thermal control and heat shield analysis

  MIT - DSpace

Summary: As part of a student owned small satellite project, a preliminary thermal control and heat shield analysis was developed to verify acceptable performance requirements for the system. For the thermal control section, the ...

Melani Barreiro, Diego A
2008-01-01

308

Multi-stakeholder Interactive Simulation for Federated Satellite Systems

  MIT - DSpace

Summary: Federated satellite systems (FSS) are a new class of space-based systems which emphasize a distributed architecture. New information exchanging functions among FSS members enable data transportation, storage, and processing ...

Grogan, Paul Thomas

309

Overconsumption, outflows and the quenching of satellite galaxies

  CERN Preprints

Summary: The baryon cycle of galaxies is a dynamic process involving the intake, consumption and ejection of vast quantities of gas. In contrast, the conventional picture of satellite galaxies has them methodically turning a large gas reservoir into stars until this reservoir is forcibly removed due to external ram pressure. This picture needs revision. Our modern understanding of the baryon cycle suggests that in some regimes the simple interruption of the fresh gas supply may quench satellite galaxies long before stripping events occur, a process we call overconsumption. We compile measurements from the literature of observed satellite quenching times at a range of redshifts to determine if satellites are principally quenched through orbit-based gas stripping events -- either direct stripping of the disk (ram pressure stripping) or the extended gas halo (strangulation) -- or from internally-driven star formation outflows via overconsumption. The observed timescales show significant deviation from the evolution expec...

McGee, Sean L; Balogh, Michael L
2014-01-01

310

Search for Dark Matter Satellites using the FERMI-LAT

  CERN Preprints

Summary: Numerical simulations based on the Lambda-CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the $b \\bar b$ channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the $b \\bar b$ channel.

Ackermann, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brandt, T J; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Burnett, T H; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; Charles, E; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; de Palma, F; Dermer, C D; Digel, S W; Silva, E do Couto e; Drell, P S; Drlica-Wagner, A; Essig, R; Falletti, L; Favuzzi, C; Fegan, S J; Focke, W B; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Guiriec, S; Gustafsson, M; Hadasch, D; Hayashida, M; Hou, X; Hughes, R E; Johnson, R P; Johnson, A S; Kamae, T; Katagiri, H; Kataoka, J; Knodlseder, J; Kuss, M; Lande, J; Latronico, L; Lee, S -H; Lionetto, A M; Garde, M Llena; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Naumann-Godo, M; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Orlando, E; Ormes, J F; Ozaki, M; Paneque, D; Pelassa, V; Pierbattista, M; Piron, F; Pivato, G; Porter, T A; Raino, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Ritz, S; Sadrozinski, H F -W; Sehgal, N; Sgro, C; Siskind, E J; Spinelli, P; Strigari, L; Suson, D J; Tajima, H; Takahashi, H; Tanaka, T; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Wang, P; Winer, B L; Wood, K S; Yang, Z; Zalewski, S; Zimmer, S
2012-01-01

311

The Elemental Abundance Distributions of Milky Way Satellite Galaxies

  CERN Preprints

Summary: The chemical compositions of the stars in Milky Way (MW) satellite galaxies reveals the history of gas flows and star formation (SF) intensity. This talk presented a Keck/DEIMOS spectroscopic survey of the Fe, Mg, Si, Ca, and Ti abundances of nearly 3000 red giants in eight MW dwarf satellites. The metallicity and alpha-to-iron ratio distributions obey the following trends: (1) The more luminous galaxies are more metal-rich, indicating that they retained gas more efficiently than the less luminous galaxies. (2) The shapes of the metallicity distributions of the more luminous galaxies require gas infall during their SF lifetimes. (3) At [Fe/H] < -1.5, [alpha/Fe] falls monotonically with increasing [Fe/H] in all MW satellites. One interpretation of these trends is that the SF timescale in any MW satellite is long enough that Type Ia supernovae exploded for nearly the entire SF lifetime.

Kirby, Evan N
2010-01-01

312

Satellites in the Local Group and Other Nearby Groups

  CERN Preprints

Summary: In recent years the census of known satellites in our own Local Group and in nearby galaxy groups has increased substantially due to sensitive wide-area surveys. In the Local Group these surveys have more than doubled its known galaxy content and extended the galaxy luminosity function to very faint total magnitudes. Deep ground-based imaging and spectroscopic observations as well as high-resolution imaging with the Hubble Space Telescope have revolutionized our understanding of the chemical evolution and star formation histories of the satellites. We often find long-lasting star formation episodes with low star formation efficiencies. There is evidence for localized, stochastic enrichment, and recent searches are now beginning to uncover even extremely metal-deficient stars. In many satellites evidence for two or more distinct stellar subpopulations is found. Differing fractions of old populations have been detected in all satellites studied in sufficient detail so far. Kinematic measurements support a pictu...

Grebel, Eva K
2011-01-01

313

Search for Dark Matter Satellites using the FERMI-LAT

  HEP - Experiment (arXiv)

Summary: Numerical simulations based on the Lambda-CDM model of cosmology predict a large number of as yet unobserved Galactic dark matter satellites. We report the results of a Large Area Telescope (LAT) search for these satellites via the gamma-ray emission expected from the annihilation of weakly interacting massive particle (WIMP) dark matter. Some dark matter satellites are expected to have hard gamma-ray spectra, finite angular extents, and a lack of counterparts at other wavelengths. We sought to identify LAT sources with these characteristics, focusing on gamma-ray spectra consistent with WIMP annihilation through the $b \\bar b$ channel. We found no viable dark matter satellite candidates using one year of data, and we present a framework for interpreting this result in the context of numerical simulations to constrain the velocity-averaged annihilation cross section for a conventional 100 GeV WIMP annihilating through the $b \\bar b$ channel.

The Fermi LAT Collaboration; M. Ackermann; A. Albert; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; K. Bechtol; R. Bellazzini; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; E. Bottacini; T. J. Brandt; J. Bregeon; M. Brigida; P. Bruel; R. Buehler; T. H. Burnett; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; E. Charles; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; J. Conrad; S. Cutini; F. de Palma; C. D. Dermer; S. W. Digel; E. do Couto e Silva; P. S. Drell; A. Drlica-Wagner; R. Essig; L. Falletti; C. Favuzzi; S. J. Fegan; W. B. Focke; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; S. Germani; N. Giglietto; F. Giordano; M. Giroletti; T. Glanzman; G. Godfrey; I. A. Grenier; S. Guiriec; M. Gustafsson; D. Hadasch; M. Hayashida; X. Hou; R. E. Hughes; R. P. Johnson; A. S. Johnson; T. Kamae; H. Katagiri; J. Kataoka; J. Knodlseder; M. Kuss; J. Lande; L. Latronico; S. -H. Lee; A. M. Lionetto; M. Llena Garde; F. Longo; F. Loparco; M. N. Lovellette; P. Lubrano; M. N. Mazziotta; J. E. McEnery; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; M. Naumann-Godo; J. P. Norris; E. Nuss; T. Ohsugi; A. Okumura; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; V. Pelassa; M. Pierbattista; F. Piron; G. Pivato; T. A. Porter; S. Raino; R. Rando; M. Razzano; A. Reimer; O. Reimer; S. Ritz; H. F. -W. Sadrozinski; N. Sehgal; C. Sgro; E. J. Siskind; P. Spinelli; L. Strigari; D. J. Suson; H. Tajima; H. Takahashi; T. Tanaka; J. G. Thayer; J. B. Thayer; L. Tibaldo; M. Tinivella; D. F. Torres; E. Troja; Y. Uchiyama; T. L. Usher; J. Vandenbroucke; V. Vasileiou; G. Vianello; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; Z. Yang; S. Zalewski; S. Zimmer
2012-01-12

314

MICROPROPULSION SYSTEM SELECTION FOR PRECISION FORMATION FLYING SATELLITES

  Engineering Websites

Summary: of Technology ABSTRACT Several upcoming scientific interferometry missions (ST-3, LISA, TPF, MAXIM and SPECS Challenges in Space Technology: Distributed Satellite Systems Contract #: F29601-97-K-0010. In addition


315

ARE SOME CLOUDS OBSCURED IN SATELLITE VIEW?* MIRELA VOICULESCU1

  Geosciences Websites

Summary: problems as low clouds masking by higher clouds in the satellite view. This problem has been addressed also with the magnetosphere [8] or UV heating [9]. These mechanisms can dominate at different altitudes, leading to opposite

Usoskin, Ilya G.

316

Codage par superposition pour les communications par satellite.

  Open Access Theses and Dissertations

Summary: ??Les systèmes de communication par satellite d’aujourd’hui reposent principalement sur le multiplexage temporel pour optimiser leurs performances. Chaque utilisateur utilise le canal pendant une fraction… (more)

Méric, Hugo
2012-01-01

317

Satellite Meeting of "Kochi School on Random Schrodinger Operators"

  Mathematics Websites

Summary: Satellite Meeting of "Kochi School on Random Schr¨odinger Operators" 2009, Nov. 29 ­ 30 Kuroshio communications between foreign and Japanese graduate students. Schedule: Nov. 29 (Su.), 16:00 ­ 18:00 : Talks

Nakamura, Shu

318

Achieving bounded delay on a time-varying satellite uplink

  MIT - DSpace

Summary: In this paper, we investigate the packet transmission delay in a time varying satellite uplink. Specifically, we are interested in bounding the packet transmission delay within the terminal router for uplink traffic in a ...

Wysocarski, Jeffrey S.

319

A Constrained Attitude Control Module for Small Satellites

  Engineering Websites

Summary: The University of Texas at Austin Small Satellite Conference Logan, Utah August 14, 2012 #12;Motivation Common&C Module being assembled Right: Front and back of the flight cold- gas thruster module #12;6 Traditional

Lightsey, Glenn

320

Reconstructing the assembly of the Milky Way dwarf satellite population

  CERN Preprints

Summary: We use a particle tagging technique to dynamically populate the N-body Via Lactea II high-resolution simulation with stars. The method is calibrated using the observed luminosity function of Milky Way satellites and the concentration of their stellar populations, and self-consistently follows the accretion and disruption of progenitor dwarfs and the build-up of the stellar halo in a cosmological "live host". Simple prescriptions for assigning stellar populations to collisionless particles are able to reproduce many properties of the observed Milky Way halo and its surviving dwarf satellites, like velocity dispersions, sizes, brightness profiles, metallicities, and spatial distribution. Our model predicts the existence of approximately 1,850 "extremely faint" satellites (with mass-to-light ratios >5,000) lying beyond the Sloan Digital Sky Survey detection threshold. Of these, about 20 are "first galaxies", i.e. satellites that formed a stellar mass above 10 Msun before redshift 9. The ten most luminous satelli...

Rashkov, Valery; Kuhlen, Michael; Diemand, Jurg
2011-01-01

321

Satellite constellation design for mid-course ballistic missile intercept

  MIT - DSpace

Summary: This thesis will establish a conceptual approach to the design of constellations for satellite-based mid-course missile defense. The ballistic missile intercept problem leads to a new paradigm of coverage where interceptor ...

Sauter, Luke Michael, 1979-
2004-01-01

322

Formation of dSph Satellites without Dark Matter

  CERN Preprints

Summary: Recently it was shown that low-mass galaxies containing no dark matter can naturally evolve to dSph-like satellites in a tidal field. Such dSph-like satellites fake total domination by dark matter. If this is correct then it must be possible to assemble appropriate precursors of dSph satellites. The genesis of dwarf galaxies in tidal tails appears to be a likely possibility. This is documented by theoretical work and observational surveys. However, it is not yet clear if the Milky Way could have sustained one or two mergers or fly-bys that were mild enough not to have destroyed the Galactic disc. The tidal arms could have been pulled from the incoming galaxy. Also, this scenario has to account for the correlation between brightness and metal abundance displayed by the Galactic dSph satellites, and lead to at least some debris on bound eccentric orbits.

Kroupa, P
1998-01-01

323

Micro-Navigation Satellite Network Design and Analysis

  Engineering Websites

Summary: -Ha Lee received the B.S. degree in electronic engineering from Inha University, Incheon, Korea, in 2000 of Satellite Communications Systems. He joined academia in 2000 at the University of North Dakota

Won, Chang-Hee

324

Satellite Remote Sensing of Mid-level Clouds

  Texas A&M University - TxSpace

Summary: This dissertation aims to study the mid-level clouds using satellite observations. It consists of two major parts: characteristics (including cloud top/base heights, cloud top pressure and temperature, and cloud thickness) and thermodynamic phase...

Jin, Hongchun 1980-
2012-11-07

325

Astrium Satellites UK Lunar Polar Lander meeting, RAS

  Geosciences Websites

Summary: Astrium Satellites UK Lunar Polar Lander meeting, RAS Matthew Stuttard Science & Robotic Divisions of Astrium Stevenage: Spacecraft Systems and Prime Planetary surface robotics Structures - MARVEL MoonLITE Science: Lunar Beagle Science: LVRAP Planetary Surface Robotics Sampling 19

Anand, Mahesh

326

A Connection Handover Protocol For LEO Satellite ATM Networks

  CiteSeer

Summary: Low Earth Orbit (LEO) satellite networks require a reliable handover re-routing protocol that is critical for connections with multihop intersatellite links (ISLs). In this paper, we introduce a footprint handover re-route protocol (FHRP) that maintains the optimality of the initial route without performing a routing algorithm after satellite handovers. Furthermore, the FHRP handles the inter-orbit handover problem. The FHRP makes use of the footprints of the satellites in the initial route as the reference for re-routing. More specifically, after an optimum route has been determined during the call establishment process, the FHRP ensures that the new route due to handover is also optimum. The FHRP is applicable to any type of connectionoriented networks. The adaptation of the FHRP to the widely accepted ATM technology, which will be employed in future satellite networks, is also addressed in this paper. The FHRP demands easy processing, signaling, and storage costs. The performance re...

Huseyin Uzunalioglu; Wei Yen; Ian F. Akyildiz
1997-01-01

327

The use of satellite-based technology in developing countries

  MIT - DSpace

Summary: Satellite technology in the areas of remote sensing, communication, and navigation can provide valuable information in a number of areas from business to disaster management to agriculture. There is great potential for ...

Wood, Danielle Renee
2007-01-01

328

Micro-electromagnetic formation flight of satellite systems

  MIT - DSpace

Summary: Electromagnetic formation flight (EMFF) investigates the concept of using electromagnets to provide the forces to maintain a satellite's relative position in a formation. Thus far, high temperature superconducting (HTS) ...

Sakaguchi, Aya, S.M. Massachusetts Institute of Technology
2007-01-01

329

The Fundamental Line of the Local Group Satellites

  Astrophysics (arXiv)

Summary: We present a new correlation between the mass-to-light (M/L) ratio and the mean metallicity for the satellites of the Local Group. This relation together with their central surface brightness define a Fundamental Line where metal poor and low surface brightness dwarfs are dark matter dominated while metal rich high surface brightness systems will have a low M/L ratio. This Fundamental Line is independent of distance to the central galaxy (M31 and the Milky Way) and morphological type among other global parameters as their star formation history. The new M/L-metallicity relation indicates that dwarf spheroidal galaxies are dark matter confined. It can be interpreted if satellites experienced a continuous loss of metals with a final episode of gas ejection at the end of the star formation epoch. Only Globular Clusters are found to lie outside the Fundamental Line of dwarf satellites. Unlike satellite galaxies they are not dark matter confined.

Francisco Prada; Andreas Burkert
2001-08-17

330

Satellite and Radar Meteorology Dr. Oleksandr Karabanov (Aleks)

  Environmental Sciences and Ecology Websites

Summary: Distributed targets, Doppler effect Tuesday, September 11, 2012 7 V and D aliasing, velocity patterns Thursday. Satellite Meteorology (Kidder & Vonder Haar) Advanced/additional: Richard J. Doviak, Dusan S. Zrnic. Doppler

Black, Robert X.

331

A Lagrangian Heuristic for Satellite Range Scheduling with ...

  Optimization Online

Summary: Satellite systems support a large number of services, such as surveillance, geodesy and navigation, remote sensing and monitoring, telecommunications and data relay. ... development of an optimization-based decision support tool for service ...


2006-05-24

332

Dwarf-spheroidal satellites: are they of tidal origin?

  Astrophysics (arXiv)

Summary: The Milky Way and Andromeda must have formed through an initial epoch of sub-structure merging. As a result of fundamental physical conservation laws tidal-dwarf galaxies (TDGs) have likely been produced. Here we show that such TDGs appear, after a Hubble-time of dynamical evolution in the host dark-matter halo, as objects that resemble known dSph satellite galaxies. We discuss the possibility that some of the Milky Way's satellites may be of tidal origin.

M. Metz; P. Kroupa
2007-01-10

333

Determination of wind from Nimbus-6 satellite sounding data

  Texas A&M University - TxSpace

Summary: DETERMINATION OF WIND FROM NIMBUS-6 SATELLITE SOUNDING DATA A Thesis by WILLIAM EVERETT CARLE Submitted to the Graduate College of Texas A&M University in partial fulfil!. ment of the requirement for the deg. . ec of MASTER OF SCIENCE... December 1979 Major Subject: Meteorology DETEIQ&INATION OE WIND PROS1 NINEDS-6 SATELLITE SOUNDING DATA A Thesis WILLIA11 EVERETT CARLE Aporoved as to style and content by: (Chairman of Commi tee) Nember) (Head of Department) December 1979...

Carle, William Everett
1979-01-01

334

An analysis of the properties of VAS satellite soundings

  Texas A&M University - TxSpace

Summary: AN ANALYSIS OF THE PROPERTIES OF VAS SATELLITE SOUNDINGS A Thesis by ROBERT CHARLES RHODES Submitted to the Graduate College of Texas AIIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1984... Major Subject: Meteorology AN ANALYSIS OF THE PROPERTIES OF VAS SATELLITE SOUNDINGS A Thesis by ROIIERT CHARLES RHODES Approved as to style and content by: James R. Scog (Chairman of Committee) Dusan Djuric (Member) Douglas A. Hensley (Member...

Rhodes, Robert Charles
2012-06-07

335

Testing modified gravity with motion of satellites around galaxies

  CERN Preprints

Summary: A modified gravity (MOG) theory that has been successfully fitted to galaxy rotational velocity data, cluster data and the Bullet Cluster 1E0657-56 is fitted to the motion of satellite galaxies around host galaxies at distances 50-400 kpc providing a new sensitive test to the MOG. We show that observational data from the Sloan Digital Sky Survey strongly favor the MOG, while Milgrom's MOND fails on these scales by predicting nearly constant rms velocities of satellites.

Moffat, J W
2007-01-01

336

Satellite-viewed cloud signatures associated with extratropical cyclogenesis

  Texas A&M University - TxSpace

Summary: SATELLITE-VIEWED CLOUD SIGNATURES ASSOCIATED WITH EXTRATROPICAL CYCLOGENESIS A Thesis by ROBERT LUCIEN LAPIERRE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1973 Major Subject: Meteorology SATELLITE-VIENED CLOUD SIGNATURES ASSOCIATED WITH EXTRATROPICAL CYCLOGENESIS A Thesis by ROBERT LUCIEN LAPIERRE Appi"o ed as to st~le and content by: n llcgrceo~& (C ai rman of Conmi t te~ YemberI Hay...

Lapierre, Robert Lucien
1973-01-01

337

Tactical and Strategic Models for Satellite Customer Assignment

  CiteSeer

Summary: In this paper we develop tactical and strategic models for assignments of customers to satellite channels. We solve this problem using mixed integer-linear programming, and study the managerial impacts of our models. As a managerial tool, the optimal placement of customer channels to minimize transponder re-balancing was found to have a real and observable profit potential in excess of $54 million for the GE Spacenet series geosynchronous orbit satellites. Further managerial findings and computational results are presented.

Carlton Scott Orlando; Carlton H. Scott; Erik Rolland

338

Entanglement over global distances via quantum repeaters with satellite links

  Quantum Physics (arXiv)

Summary: We study entanglement creation over global distances based on a quantum repeater architecture that uses low-earth orbit satellites equipped with entangled photon sources, as well as ground stations equipped with quantum non-demolition detectors and quantum memories. We show that this approach allows entanglement creation at viable rates over distances that are inaccessible via direct transmission through optical fibers or even from very distant satellites.

K. Boone; J. -P. Bourgoin; E. Meyer-Scott; K. Heshami; T. Jennewein; C. Simon
2014-10-20

339

Spiral and Bar Instabilities Provoked by Dark Matter Satellites

  Astrophysics (arXiv)

Summary: We explore the secular dynamical evolution of an N-body model of M31 in the presence of a population of 100 dark matter satellites over 10 Gyr. The satellite population has structural and kinematic characteristics modelled to follow the predictions of Lambda-CDM cosmological simulations. Vertical disk heating is a small effect despite many interactions with the satellite population with only a 20% increase in vertical velocity dispersion sigma_z and the disk scale height z_d at the equivalent solar radius R = 2.5R_d . However, the stellar disk is noticeably flared after 10 Gyr with z_d nearly doubling at the disk edge. Azimuthal disk heating is much larger with sigma_R and sigma_z both increasing by 1.7x. However, in a control experiment without satellites dispersion increases by 1.5x suggesting that most of the effect is due to heating through scattering off of spiral structure excited by swing-amplified noise. Surprisingly, direct impacts of satellites on the disk can excite spiral structure with a significant amplitude and in some cases impacts close to the disk center also induce the bar instability. The large number of dark matter satellite impacts expected over a galaxy's lifetime may be a significant source of external perturbations for driving disk secular evolution.

John Dubinski; Jean-Rene Gauthier; Larry Widrow; Sarah Nickerson
2008-02-27

340

The Colours of Satellite Galaxies in Groups and Clusters

  Astrophysics (arXiv)

Summary: Current models of galaxy formation predict satellite galaxies in groups and clusters that are redder than observed. We investigate the effect on the colours of satellite galaxies produced by the ram pressure stripping of their hot gaseous atmospheres as the satellites orbit within their parent halo. We incorporate a model of the stripping process based on detailed hydrodynamic simulations within the Durham semi-analytic model of galaxy formation. The simulations show that the environment in groups and clusters is less aggressive than previously assumed. The main uncertainty in the model is the treatment of gas expelled by supernovae. With reasonable assumptions for the stripping of this material, we find that satellite galaxies are able to retain a significant fraction of their hot gas for several Gigayears, thereby replenishing their reservoirs of cold, star forming gas and remaining blue for a relatively long period of time. A bimodal distribution of galaxy colours, similar to that observed in SDSS data, is established and the colours of the satellite galaxies are in good agreement with the data. In addition, our model naturally accounts for the observed dependence of satellite colours on environment, from small groups to high mass clusters.

Andreea S. Font; Richard G. Bower; Ian G. McCarthy; Andrew J. Benson; Carlos S. Frenk; John C. Helly; Cedric G. Lacey; Carlton M. Baugh; Shaun Cole
2008-09-23

341

The Discovery of Two New Satellites of Pluto

  Astrophysics (arXiv)

Summary: Pluto's first known moon, Charon, was discovered in 1978 (Christy 1978) and has a diameter about half that of Pluto (Buie 1992,Young 1994, Sicardy 2005), which makes it larger relative to its primary than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful (Stern 1991, Stern 1994, Stern 2003), but they were not sensitive to objects <=150 km in diameter and there are no fundamental reasons why Pluto should not have more satellites (Stern 1994). Here we report the discovery of two additional moons around Pluto, provisionally designated S/2005 P1 (hereafter P1) and S/2005 P2 (hereafter P2), which makes Pluto the first Kuiper belt object (KBO) known to have multiple satellites. These new satellites are much smaller than Charon (diameter~1200 km), with P1 ranging in diameter from 60-165 km depending on the surface reflectivity, and P2 about 20% smaller than P1. Although definitive orbits cannot be derived, both new satellites appear to be moving in circular orbits in the same orbital plane as Charon, with orbital periods of ~38 days (P1) and ~25 days (P2). The implications of the discovery of P1 and P2 for the origin and evolution of the Pluto system, and for the satellite formation process in the Kuiper belt, are discussed in a companion paper (Stern 2006).

H. A. Weaver; S. A. Stern; M. J. Mutchler; A. J. Steffl; M. W. Buie; W. J. Merline; J. R. Spencer; E. F. Young; L. A. Young
2006-01-02

342

Satellite Infall and the Growth of Bulges of Spiral Galaxies

  CERN Preprints

Summary: For bulges of spiral galaxies, the concentration, or Sersic index, increases with bulge luminosity and bulge-to-disk ratio B/D (Andredakis, Peletier, & Balcells 1995, MNRAS, 275, 874). Does this trend trace the growth of bulges via satellite accretion? And, is satellite infall consistent with this trend? Aguerri, Balcells, & Peletier (2001, A&A, 367, 428) investigated this question with N-body simulations of the accretion of dense, spheroidal satellites. Here, we expand on that work by running N-body simulations of the accretion of satellites that have realistic densities. Satellites are modelled as disk-bulge structures with their own dark-matter halo. A realistic density scaling with the primary galaxy is ensured by using the Tully-Fisher relation. Our merger models show that most satellites disrupt before reaching the center. However, a bulge-disk decomposition of the surface density profile after the accretion shows an increase of both the B/D and the Sersic index n of the bulge. The increase ...

Eliche-Moral, M C; López-Aguerri, J A; Gonzalez-Garcia, A C
2005-01-01

343

A Dichotomy in Satellite Quenching Around L* Galaxies

  CERN Preprints

Summary: We examine the star formation properties of bright (~0.1 L*) satellites around isolated ~L* hosts in the local Universe using spectroscopically confirmed systems in the Sloan Digital Sky Survey DR7. Our selection method is carefully designed with the aid of N-body simulations to avoid groups and clusters. We find that satellites are significantly more likely to be quenched than a stellar mass-matched sample of isolated galaxies. Remarkably, this quenching occurs only for satellites of hosts that are themselves quenched: while star formation is unaffected in the satellites of star-forming hosts, satellites around quiescent hosts are more than twice as likely to be quenched than stellar-mass matched field samples. One implication of this is that whatever shuts down star formation in isolated, passive L* galaxies also plays at least an indirect role in quenching star formation in their bright satellites. The previously-reported tendency for "galactic conformity" in color/morphology may be a by-product of this ho...

Phillips, John I; Boylan-Kolchin, Michael; Bullock, James S; Cooper, Michael C; Tollerud, Erik J
2013-01-01

344

TCP session analysis and modeling of hybrid satellite-terrestrial Internet

  Computer Technologies and Information Sciences Websites

Summary: TCP session analysis and modeling of hybrid satellite-terrestrial Internet traffic Savio Lau saviol University #12;April 25, 2006 BCNET Advanced Networks Conference: Hybrid satellite-terrestrial Internet Advanced Networks Conference: Hybrid satellite-terrestrial Internet traffic 3 Characteristics of satellite

Trajkovic, Ljiljana

345

Toward a Satellite Algorithm Test Bed Report of a Workshop Organized by National Oceanic and Atmospheric

  Environmental Sciences and Ecology Websites

Summary: 1 Toward a Satellite Algorithm Test Bed Report of a Workshop Organized by National Oceanic Institute for Meteorological Satellite Studies (CIMSS), Cooperative Institute for Oceanographic Satellite and Technology Center (CREST) at the National Satellite Operations Facility, Suitland, MD, February 26-27, 2008

Kuligowski, Bob

346

OPTIMAL DESPIN OF A TUMBLING SATELLITE WITH AN ARBITRARY THRUSTER CONFIGURATION, INERTIA MATRIX,

  Engineering Websites

Summary: satellite and fired remotely. If the tumbling satellite has a docking ring (such as on the Hubble Space, failed docking attempts, colli- sion with space debris, etc. In general, it cannot be assumed Telescope), a chaser satellite may rigidly dock with the tumbling satellite and then apply forces or torques


347

Finding the trigger to Iapetus' odd global albedo pattern: Dynamics of dust from Saturn's irregular satellites

  Physics Websites

Summary: Elsevier Inc. All rights reserved. 1. Introduction Over three dozen dark irregular satellites have been the dark outer irregular satellites to the generally brighter inner regu- lar satellites (see Fig. 1 satellites Daniel Tamayo a, , Joseph A. Burns b , Douglas P. Hamilton c , Matthew M. Hedman a a Department

Hamilton, Douglas P.

348

Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services Arjan Durresi1

  Computer Technologies and Information Sciences Websites

Summary: intersatellite links, advanced link access methods and multicast technologies. Many new satellite communication. However, satellite systems have several inherent constraints. The resources of the satellite communication1 Achieving QoS for TCP traffic in Satellite Networks with Differentiated Services Arjan Durresi1

Durresi, Arjan

349

Applicability and Performance of NEMO in Satellite Abu Zafar M. Shahriar

  Computer Technologies and Information Sciences Websites

Summary: for satellite communications [4]. Application of MIP to satellite networks has been proposed by Israel et al. [5Applicability and Performance of NEMO in Satellite Networks Abu Zafar M. Shahriar Mohammed}@ou.edu William Ivancic Satellite Networks and Architectures Branch NASA Glenn Research Center, Cleveland, OH

Atiquzzaman, Mohammed

350

SaVi satellite constellation visualization CCSR Research Symposium 2011 Lloyd Wood, Research Fellow

  Engineering Websites

Summary: SaVi satellite constellation visualization CCSR Research Symposium 2011 ­ Lloyd Wood, Research and coverage that results from multiple satellites orbiting to form a particular satellite constellation useful simulations of satellites and constellations for research and teaching purposes. System Model: Sa

Wood, Lloyd

351

Minimizing the Cost of Availability of Coverage from a Constellation of Satellites: Evaluation of Optimization Methods

  Energy Storage, Conversion and Utilization Websites

Summary: Minimizing the Cost of Availability of Coverage from a Constellation of Satellites: Evaluation such as constellation configuration, satellite design, and acquisition have generally been optimized separately. A model. #12;1 1.0 Introduction In recent years satellite constellations (a group of satellites working

Dessouky, Maged

352

Performance Analysis of LEO Satellite Networks A. Halim Zaim, Harry G. Perros, and George N. Rouskas

  Computer Technologies and Information Sciences Websites

Summary: network that carries voice calls. Both satellite-fixed and earth-fixed constellations with inter in trajectories relative to the earth. Such a set of satellites is referred to as a constellation of satellites. Depending on the antenna technology used, satellite constellations can provide one of two types of coverage


353

Using Outage History to Exclude High-Risk Satellites from GBAS Corrections

  Engineering Websites

Summary: integrity guarantees to users typically assume that all GNSS satellites have the same failure probability. The assumed failure probability is conservative such that variations among satellites in a given GNSS satellites to violate the overall satellite failure probability assumption, although this has not yet been

Stanford University

354

Planning for Agile Earth Observation Satellites Johannes Aldinger and Johannes Lohr

  Computer Technologies and Information Sciences Websites

Summary: Planning for Agile Earth Observation Satellites Johannes Aldinger and Johannes L¨ohr Albert}@informatik.uni-freiburg.de Abstract Agile Earth observation satellites are satellites orbiting Earth with the purpose to gather information of the Earth's surface by slewing the satellite toward regions of interest. Constraints arise

Nebel, Bernhard

355

INNOVATIVE SATELLITE IMAGE MAP OF R.ALKHABRTA AREA, SAUDI ARABIA USING HIGH RESOLUTION IMAGE

  CiteSeer

Summary: Satellite remote sensing can provide a variety of useful data for various type of research. Satellite image map is one of the products that aim to promote remote sensing. In this study, a high resolution satellite image was used to create a high resolution satellite image map over AlKhabra, Saudi Arabia. The objective of this project is to produce a satellite image map by using remote sensing technique to map the distribution of land use, land desrert characteristics, and related transportation variables through space and over time. A good quality satellite data have been selected to produce a satellite image map. Processing procedure includes geometric correction, contrast stretching, filtering and area cutting. The final product of satellite image map will be maps at scales of 1:91,831.00. This study indicated that the useful of high resolution satellite image to produce a high resolution satellite map. 1.

Sultan Alsultan; H. S. Lim; M. Z. Matjafri; K. Abdullah; N. Mohd Saleh

356

Disentangling satellite galaxy populations using orbit tracking in simulations

  CERN Preprints

Summary: Physical processes regulating star formation in satellite galaxies represent an area of ongoing research, but the projected nature of observed coordinates makes separating different populations of satellites (with different processes at work) difficult. The orbital history of a satellite galaxy leads to its present-day phase space coordinates; we can also work backwards and use these coordinates to statistically infer information about the orbital history. We use merger trees from the MultiDark Run 1 N-body simulation to compile a catalog of the orbits of satellite haloes in cluster environments. We parameterize the orbital history by the time since crossing within 2.5 rvir of the cluster centre and use our catalog to estimate the probability density over a range of this parameter given a set of present-day projected (i.e. observable) phase space coordinates. We show that different populations of satellite haloes, e.g. infalling, backsplash and virialized, occupy distinct regions of phase space, and semi-dist...

Oman, Kyle A; Behroozi, Peter S
2013-01-01

357

Orbital decay of satellites crossing an accretion disc

  Astrophysics (arXiv)

Summary: Motion of stellar-mass satellites is studied around a massive compact body which is surrounded by a gaseous slab of a stationary accretion disc. The satellites suffer an orbital decay due to hydrodynamical interaction with the disc medium (transitions across the disc, gap opening in the disc, density waves) and gravitational radiation. Arbitrary orbital eccentricities and inclinations are considered, and it is observed how the competing effects depend on the parameters of the model, namely, the mass and compactness of the orbiters, the osculating elements of their trajectories, and surface density of the disc. These effects have a visible impact on the satellites long-term motion, and they can produce observational consequences with respect to galactic central clusters. It is shown that the satellite-disc collisions do not impose serious restrictions on the results of gravitational wave experiments if the disc medium is diluted and the orbiter is compact but they are important in the case of environments with relatively high density. We thus concentrate on application to accretion flows in which the density is not negligible. We discuss the expected quasi-stationary structure of the cluster that is established on sub-parsec scales within the sphere of gravitational influence of the central object. Relevant to this region, we give the power-law slopes defining the radial profile of modified clusters and we show that their values are determined by satellite interaction with the accretion flow rather than their initial distribution.

V. Karas; L. Subr
2001-07-13

358

Spectroscopic confirmation of hydrogen alpha-selected satellite galaxies

  CERN Preprints

Summary: We present a spectroscopic test confirming the potential of narrow-band optical imaging as a method for detecting star-forming satellites around nearby galaxies. To date the efficiency of such methods, and particularly the fraction of false detections resulting from its use, has not been tested. In this paper we use optical spectroscopy to verify the nature of objects that are apparently emission-line satellites, taken from imaging presented elsewhere. Observations of 12 probable satellites around 11 host galaxies are presented and used to compare the recession velocities of the host and satellite. This test confirms, in all cases, that there is genuine line emission, that the detected line is hydrogen alpha, and that the satellites have similar recession velocities to their hosts with a maximum difference of ~ 250 km/s, consistent with their being gravitationally bound companions. We conclude that the spectroscopy has confirmed that narrow-band imaging through H alpha filters is a reliable method for detecti...

Ivory, Clare F
2010-01-01

359

On the Stability of the Satellites of Asteroid 87 Sylvia

  CERN Preprints

Summary: he triple asteroidal system (87) Sylvia is composed of a 280-km primary and two small moonlets named Romulus and Remus (Marchis et al 2005). Sylvia is located in the main asteroid belt. The satellites are in nearly equatorial circular orbits around the primary. In the present work we study the stability of the satellites Romulus and Remus, in order to identify the effects and the contribution of each perturber. The results from the 3-body problem, Sylvia-Romulus-Remus, show no significant variation of their orbital elements. However, the inclinations of the satellites present a long period evolution, when the Sun is included in the system. Such amplitude is amplified when Jupiter is included. An analysis of these results show that Romulus and Remus are librating in a secular resonance and their longitude of the nodes are locked to each other. The satellites get caught in an evection resonance with Jupiter. However, the orbital evolutions of the satellites became completely stable when the oblateness of Sylvia...

Winter, O C; Neto, E Vieira; Martins, R Vieira; Winter, S M Giuliatti; Gomes, R S; Marchis, F; Descamps, P
2009-01-01

360

Tidal disruption of satellites and formation of narrow rings

  CERN Preprints

Summary: In this paper we investigate the formation of narrow planetary rings such as those found around Uranus and Saturn through the tidal disruption of a weak, gravitationally bound satellite that migrates within its Roche limit. Using $N$-body simulations, we study the behaviour of rubble piles placed on circular orbits at different distances from a central planet. We consider both homogeneous satellites and differentiated bodies containing a denser core. We show that the Roche limit for a rubble pile is closer to the planet than for a fluid body of the same mean density. The Roche limit for a differentiated body is also closer to the planet than for a homogeneous satellite of the same mean density. Within its Roche limit, a homogeneous satellite totally disrupts and forms a narrow ring. The initial stages of the disruption are similar to the evolution of a viscous fluid ellipsoid, which can be computed semi-analytically. On the other hand, when a differentiated satellite is just within the Roche limit only the ma...

Leinhardt, Zoe M; Latter, Henrik N; Kokubo, Eiichiro
2012-01-01

361

The Rise and Fall of Satellites in Galaxy Clusters

  Astrophysics (arXiv)

Summary: We use N-body simulations to study the infall of dark matter haloes onto rich clusters of galaxies. After identification of all cluster progenitors in the simulations, we select those haloes which accrete directly onto the main cluster progenitor. We construct the mass function of these merging satellites, and calculate the main orbital parameters for the accreted lumps. The average circularity of the orbits is epsilon = 0.5, while either radial or almost circular orbits are equally avoided. More massive satellites move along slightly more eccentric orbits, with lower specific angular momentum and a smaller pericentre. We find that the infall of satellites onto the main cluster progenitor has a very anisotropic distribution. This anisotropy is to a large extent responsible for the shape and orientation of the final cluster and of its velocity ellipsoid. At the end of the simulations, the major axis of the cluster is aligned both with that of its velocity ellipsoid, and with the major axis of the ellipsoid defined by the satellite infall pattern, to 30 degrees on average. We also find that, in lower mass clusters, a higher fraction of the final virial mass is provided by small, dense satellites. These sink to the centre of the parent cluster and so enhance its central density. This mechanism is found to be partially responsible for the correlation between halo masses and characteristic overdensities, recently highlighted by Navarro, Frenk & White (1996).

Giuseppe Tormen
1998-02-23

362

The colors of satellite galaxies in the Illustris Simulation

  CERN Preprints

Summary: Observationally, the fraction of blue satellite galaxies decreases steeply with host halo mass, and their radial distribution around central galaxies is significantly shallower in massive (M_* >10e11M_sun) than in Milky Way like systems. Theoretical models, based primarily on semi-analytical techniques, have had a long-standing problem with reproducing these trends, instead predicting too few blue satellites in general but also estimating a radial distribution that is too shallow, regardless of primary mass. In this Letter, we use the Illustris cosmological simulation to study the properties of satellite galaxies around isolated primaries. For the first time, we find good agreement between theory and observations. We identify the main source of this success relative to earlier work to be a consequence of the large gas contents of satellites at infall, a factor ~5-10 times larger than in semi-analytical models. Because of their relatively large gas reservoirs, satellites can continue to form stars long after i...

Sales, Laura V; Genel, Shy; Torrey, Paul; Nelson, Dylan; Rodriguez-Gomez, Vicente; Wang, Wenting; Pillepich, Annalisa; Sijacki, Debora; Springel, Volker; Hernquist, Lars
2014-01-01

363

The Effect of Satellite Galaxies on Gravitational Lensing Flux Ratios

  CERN Preprints

Summary: Gravitational lenses with anomalous flux ratios are often cited as possible evidence for dark matter satellites predicted by simulations of hierarchical merging in cold dark matter cosmogonies. We show that the fraction of quads with anomalous flux ratios depends primarily on the total mass and spatial extent of the satellites, and the characteristic lengthscale R of their distribution. If R is 100 kpc, then for a moderately elliptical galaxy with a line-of-sight velocity dispersion of 250 km/s, a mass of 3 x 10^9 solar masses in highly-concentrated (Plummer model) satellites is needed for 20% of quadruplets to show anomalous flux ratios, rising to 1.25 x 10^10 solar masses for 50%. Several times these masses are required if the satellites have more extended Hernquist profiles. Compared to a typical elliptical, the flux ratios of quads formed by typical edge-on disc galaxies with maximum discs are significantly less susceptible to changes through substructure -- three times the mass in satellite galaxies is n...

Shin, E M
2008-01-01

364

Satellite Galaxies and Fossil Groups in the Millennium Simulation

  Astrophysics (arXiv)

Summary: We use a semianalytic galaxy catalogue constructed from the Millennium Simulation to study the satellites of isolated galaxies in the LCDM cosmogony. This sample (~80,000$ bright primaries, surrounded by ~178,000 satellites) allows the characterization, with minimal statistical uncertainty, of the dynamical properties of satellite/primary galaxy systems in a LCDM universe. We find that, overall, the satellite population traces the dark matter rather well: its spatial distribution and kinematics may be approximated by an NFW profile with a mildly anisotropic velocity distribution. Their spatial distribution is also mildly anisotropic, with a well-defined ``anti-Holmberg'' effect that reflects the misalignment between the major axis and angular momentum of the host halo. The isolation criteria for our primaries picks not only galaxies in sparse environments, but also a number of primaries at the centre of ''fossil'' groups. We find that the abundance and luminosity function of these unusual systems are in reasonable agreement with the few available observational constraints. We recover the expected L_{host} \\sigma_{sat}^3 relation for LCDM models for truly-isolated primaries. Less strict primary selection, however, leads to substantial modification of the scaling relation. Our analysis also highlights a number of difficulties afflicting studies that rely on blind stacking of satellite systems to constrain the mean halo mass of the primary galaxies.

L. V. Sales; J. F. Navarro; D. G. Lambas; S. D. M. White; D. J. Croton
2007-09-27

365

The Luminosity Function of the Milky Way Satellites

  Astrophysics (arXiv)

Summary: We quantify the detectability of stellar Milky Way satellites in the Sloan Digital Sky Survey (SDSS) Data Release 5. We show that the effective search volumes for the recently discovered SDSS--satellites depend strongly on their luminosity, with their maximum distance, $D_{max}$, substantially smaller than the Milky Way halo's virial radius. Calculating the maximum accessible volume, $V_{max}$, for all faint detected satellites, allows the calculation of the luminosity function for Milky Way satellite galaxies, accounting quantitatively for their detectability. We find that the number density of satellite galaxies continues to rise towards low luminosities, but may flatten at $M_V \\sim -5$; within the uncertainties, the luminosity function can be described by a single power law $dN/dM_{V}= 10 \\times 10^{0.1 (M_V+5)}$, spanning luminosities from $M_V=-2$ all the way to the luminosity of the Large Magellanic Cloud. Comparing these results to several semi-analytic galaxy formation models, we find that their predictions differ significantly from the data: either the shape of the luminosity function, or the surface brightness distributions of the models, do not match.

S. Koposov; V. Belokurov; N. W. Evans; P. C. Hewett; M. J. Irwin; G. Gilmore; D. B. Zucker; H. -W. Rix; M. Fellhauer; E. F. Bell; E. V. Glushkova
2007-06-19

366

A census of orbital properties of the M31 satellites

  CERN Preprints

Summary: We present an analysis of the dynamics of the M31 satellite system. Proper motion data exist for only two of the M31 satellites. We account for this incompleteness in velocity data by a statistical analysis using a combination of the timing argument and phase-space distribution functions. The bulk of the M31 satellites are well fit by these models and we offer a table of orbital properties, including period, eccentricity and semi-major axis. This enables us to search for evidence of group infall based on orbital similarity rather than propinquity on the sky. Our results favour an association between Cass II and NGC 185, as the orbital parameters are in close agreement, but not for NGC 185 and NGC 147, which have often been associated in the past. Other possible satellite groupings include the pair And I and And XVII; the pair And IX and And X; and the triple And V, And XXV and NGC 147. And XXII has been claimed as a satellite of M33; we find that they are not moving independently along the same orbit, but can...

Watkins, Laura L; van de Ven, Glenn
2012-01-01

367

Experimental Single-Photon Transmission from Satellite to Earth

  Quantum Physics (arXiv)

Summary: Free-space quantum communication with satellites opens a promising avenue for global secure quantum network and large-scale test of quantum foundations. Recently, numerous experimental efforts have been carried out towards this ambitious goal. However, one essential step - transmitting single photons from the satellite to the ground with high signal-to-noise ratio (SNR) at realistic environments - remains experimental challenging. Here, we report a direct experimental demonstration of the satellite-ground transmission of a quasi-single-photon source. In the experiment, single photons (~0.85 photon per pulse) are generated by reflecting weak laser pulses back to earth with a cube-corner retro-reflector on the satellite Champ, collected by a 600-mm diameter telescope at the ground station, and finally detected by single-photon counting modules (SPCMs) after 400-km free-space link transmission. With the help of high accuracy time synchronization, narrow receiver field-of-view (FOV) and high-repetition-rate pulses (76 MHz), a SNR of better than 16:1 is obtained, which is sufficient for a secure quantum key distribution. Our experimental results represent an important step towards satellite-ground quantum communication.

Juan Yin; Yuan Cao; Shu-Bin Liu; Ge-Sheng Pan; Jin-Hong Wang; Tao Yang; Zhong-Ping Zhang; Fu-Min Yang; Yu-Ao Chen; Cheng-Zhi Peng; Jian-Wei Pan
2013-06-04

368

Channel Estimation And Multiuser Detection In Asynchronous Satellite Communications

  CERN Preprints

Summary: In this paper, we propose a new method of channel estimation for asynchronous additive white Gaussian noise channels in satellite communications. This method is based on signals correlation and multiuser interference cancellation which adopts a successive structure. Propagation delays and signals amplitudes are jointly estimated in order to be used for data detection at the receiver. As, a multiuser detector, a single stage successive interference cancellation (SIC) architecture is analyzed and integrated to the channel estimation technique and the whole system is evaluated. The satellite access method adopted is the direct sequence code division multiple access (DS CDMA) one. To evaluate the channel estimation and the detection technique, we have simulated a satellite uplink with an asynchronous multiuser access.

Chaouech, Helmi; 10.5121/ijwmn.2010.2411
2010-01-01

369

Mouse satellite DNA, centromere structure, and sister chromatid pairing

  CiteSeer

Summary: Abstract. The experiments described were directed toward understanding relationships between mouse satellite DNA, sister chromatid pairing, and centromere function. Electron microscopy of a large mouse L929 marker chromosome shows that each of its multiple constrictions is coincident with a site of sister chromatid contact and the presence of mouse satellite DNA. However, only one of these sites, the central one, possesses kinetochores. This observation suggests either that satellite DNA alone is not sufficient for kinetochore formation or that when one kinetochore forms, other potential sites are suppressed. In the second set of experiments, we show that highly extended chromosomes from Hoechst 33258-treated cells (Hilwig, I., and A. Gropp, 1973, Exp. Cell Res.,

Lorraine M. Lica; Ya Narayanswami; Barbara A. Hamkalo; To B. A. Hamkalo
1986-01-01

370

IMAGE FUSION OF LANDSAT AND KOREAN SATELLITE KOMPSAT

  CiteSeer

Summary: Korea is providing images with the resolution of 6.6m level as launching multi-purpose satellite, Arirang satellite, in Dec. 1999. This study analyzed advantages and disadvantages of image fusion methods as applying fusion techniques to panchromatic images of high resolution of Arirang satellite and multi-spectral images of LANDSAT as test images. Analysis showed that the wavelet image fusion technique is good for a variety of test fields. 1. BACKGROUND AND GOALS This study aims to create components for fusion techniques for spatial information of high resolution images and spectral information of multi-spectral images. General purpose of image fusion is to produce images that can be more easily analyzed as enhancing spatial resolutions of low resolution images with spectral data. This study carried out creation of components as applying the method to fuse spectral resolution of multi-spectral images from multiple wavelength ranges with inferior spatial resolution and spatial resolution of

S. H Han A; J. M Kang B

371

Orbital Perturbations of the Galilean Satellites During Planetary Encounters

  CERN Preprints

Summary: The Nice model of the dynamical instability and migration of the giant planets can explain many properties of the present Solar System, and can be used to constrain its early architecture. In the jumping-Jupiter version of the Nice model, required from the terrestrial planet constraint and dynamical structure of the asteroid belt, Jupiter has encounters with an ice giant. Here we study the survival of the Galilean satellites in the jumping-Jupiter model. This is an important concern because the ice-giant encounters, if deep enough, could dynamically perturb the orbits of the Galilean satellites, and lead to implausible results. We performed numerical integrations where we tracked the effect of planetary encounters on the Galilean moons. We considered three instability cases from Nesvorny & Morbidelli (2012) that differed in the number and distribution of encounters. We found that in one case, where the number of close encounters was relatively small, the Galilean satellite orbits were not significantly af...

Deienno, R; Vokrouhlicky, D; Yokoyama, T
2014-01-01

372

Dust en-route to Jupiter and the Galilean satellites

  CERN Preprints

Summary: Spacecraft investigations during the last ten years have vastly improved our knowledge about dust in the Jovian system. All Galilean satellites, and probably all smaller satellites as well, are sources of dust in the Jovian system. In-situ measurements with the dust detectors on board the Ulysses and Galileo spacecraft have for the first time demonstrated the electromagnetic interaction of charged dust grains with the interplanetary magnetic field and with a planetary magnetosphere. Jupiter's magnetosphere acts as a giant mass-velocity spectrometer for charged 10-nanometer dust grains. These dust grains are released from Jupiter's moon Io with typical rate of 1 kg s^1. The dust streams probe the plasma conditions in the Io plasma torus and can be used as a potential monitor of Io's volcanic plume activity. The other Galilean satellites are surrounded by tenuous impact-generated clouds of mostly sub-micrometer ejecta grains. Galileo measurements have demonstrated that impact-ejecta derived from hypervelocity i...

Krüger, H; Krueger, Harald; Gruen, Eberhard
2002-01-01

373

Modelling the dynamical friction timescale of sinking satellite

  CERN Preprints

Summary: When a satellite galaxy falls into a massive dark matter halo, it suffers the dynamical friction force which drag it into the halo center and finally it merger with the central galaxy. The time interval between entry and merger is called as the dynamical friction timescale (T_df). Many studies have been dedicated to derive T_df using analytical models or N-body simulations. These studies have obtained qualitative agreements on how T_df depends on the orbit parameters, and mass ratio between satellite and host halo. However, there are still disagreements on the accurate form of T_df . In this paper, we present a semi-analytical model to predict T_df and we focus on interpreting the discrepancies among different studies. We find that the treatment of mass loss from satellite by tidal stripping dominates the behavior of T_df . We also identify other model parameters which affect the predicted T_df.

Gan, Jianling; Hou, Jinliang; Chang, Ruixiang
2010-01-01

374

Secure Satellite Communication Systems Design with Individual Secrecy Rate Constraints

  CERN Preprints

Summary: In this paper, we study multibeam satellite secure communication through physical (PHY) layer security techniques, i.e., joint power control and beamforming. By first assuming that the Channel State Information (CSI) is available and the beamforming weights are fixed, a novel secure satellite system design is investigated to minimize the transmit power with individual secrecy rate constraints. An iterative algorithm is proposed to obtain an optimized power allocation strategy. Moreover, sub-optimal beamforming weights are obtained by completely eliminating the co-channel interference and nulling the eavesdroppers' signal simultaneously. In order to obtain jointly optimized power allocation and beamforming strategy in some practical cases, e.g., with certain estimation errors of the CSI, we further evaluate the impact of the eavesdropper's CSI on the secure multibeam satellite system design. The convergence of the iterative algorithm is proven under justifiable assumptions. The performance is evaluated by taki...

Lei, Jiang; Vázquez-Castro, M A; Hjørungnes, Are
2011-01-01

375

A Curious New Milky Way Satellite in Ursa Major

  CERN Preprints

Summary: In this Letter, we study a localized stellar overdensity in the constellation of Ursa Major, first identified in the Sloan Digital Sky Survey (SDSS) data and subsequently followed up with Subaru imaging. Its color-magnitude diagram shows a well-defined sub-giant branch, main sequence and turn-off, from which we estimate a distance of about 30 kpc and a projected size of about 250 pc. Based on its extent and its stellar population, we argue that this is a previously unknown satellite galaxy of the Milky Way, hereby named after its constellation as Ursa Major II (UMa II). Using SDSS data, we find an absolute magnitude of M_V = -3.8, which would make it the faintest known satellite galaxy. UMa II's isophotes are irregular and distorted with evidence for multiple concentrations; this suggests that the satellite may be in the process of disruption.

Zucker, D B; Evans, N W; Irwin, M J; Kleyna, J T; Wilkinson, M I; Fellhauer, M; Bramich, D M; Gilmore, G; Newberg, H J; Yanny, B; Smith, J A; Hewett, P C; Bell, E F; Rix, H W; Gnedin, O Y; Vidrih, S; Wyse, R F G; Willman, B; Grebel, E K; Schneider, D P; Beers, T C; Kniazev, A Yu; Barentine, J C; Brewington, H; Brinkmann, J; Harvanek, M; Kleinman, S J; Krzesínski, J; Long, D; Nitta, A; Snedden, S A
2006-01-01

376

A Curious New Milky Way Satellite in Ursa Major

  Astrophysics (arXiv)

Summary: In this Letter, we study a localized stellar overdensity in the constellation of Ursa Major, first identified in Sloan Digital Sky Survey (SDSS) data and subsequently followed up with Subaru imaging. Its color-magnitude diagram (CMD) shows a well-defined sub-giant branch, main sequence and turn-off, from which we estimate a distance of ~30 kpc and a projected size of ~250 x 125 pc. The CMD suggests a composite population with some range in metallicity and/or age. Based on its extent and stellar population, we argue that this is a previously unknown satellite galaxy of the Milky Way, hereby named Ursa Major II (UMa II) after its constellation. Using SDSS data, we find an absolute magnitude of M_V \\~ -3.8, which would make it the faintest known satellite galaxy. UMa II's isophotes are irregular and distorted with evidence for multiple concentrations; this suggests that the satellite is in the process of disruption.

D. B. Zucker; V. Belokurov; N. W. Evans; J. T. Kleyna; M. J. Irwin; M. I. Wilkinson; M. Fellhauer; D. M. Bramich; G. Gilmore; H. J. Newberg; B. Yanny; J. A. Smith; P. C. Hewett; E. F. Bell; H. -W. Rix; O. Y. Gnedin; S. Vidrih; R. F. G. Wyse; B. Willman; E. K. Grebel; D. P. Schneider; T. C. Beers; A. Y. Kniazev; J. C. Barentine; H. Brewington; J. Brinkmann; M. Harvanek; S. J. Kleinman; J. Krzesinski; D. Long; A. Nitta; S. A. Snedden
2006-07-04

377

The IntraCoastal Satellite Communicator System (ICSCS)

  CiteSeer

Summary: This paper describes an application of the ORBCOMM satellite system for helping pleasure-boat sailors to navigate. The IntraCoastal Satellite Communication System (ICSCS) is an improvement on the well established ChartPlotter made by Geonav 11E Navionix for bidirectional coastal communication. By using a terminal of the ORBCOMM system, ICSCS allows the sailors to access and retrieve information which has been coded ad-hoc on web sites. The paper briefly describes the software architecture of the system and presents the additional user facilities. The IntraCoastal Satellite Communicator System has been available on the market since beginning of year 2000, and has already been installed on many pleasure boats in Italy.

Nedo Celandroni Erina; Nedo Cel; Erina Ferro; Francesco Potortì; Giacomo Saviozzi; Marco Boldrini

378

Operational Satellite Monitoring Systems for Marine Oil and Gas Industry

  CiteSeer

Summary: Abstract- Shipping activities, oil production and transport in the sea, oil handled in harbors, construction of oil and gas pipelines have a number of negative impacts on the marine environment and coastal zone. We elaborated several operational satellite monitoring systems for oil and gas companies in Russia and performed complex satellite monitoring of the ecological state of coastal waters, which included oil pollution, suspended matter, and algae bloom, in a fully operational regime. Our experience includes: (1) monitoring of the Lukoil D-6 oil rig in the southeastern Baltic Sea in 2004-2005; (2) monitoring of the underwater gas pipeline “Dzhubga-Lazarevskoe-Sochi ” construction in the eastern Black Sea (2010); (3) monitoring of the “Nord Stream ” underwater gas pipeline construction in the Baltic Sea (2010); (4) elaboration of the structure and principles of the complex satellite monitoring system organization for all coastal seas of Russia (2009-2010).

A. G. Kostianoy A; D. M. Solovyov B

379

Sinking Satellites and the Heating of Galaxy Discs

  Astrophysics (arXiv)

Summary: We have carried out a set of self-consistent N-body simulations to study the interaction between disc galaxies and merging satellites with the aim of determining the disc kinematical changes induced by such events. We explore a region of the parameter space embracing satellites with different masses and internal structure and orbits of various eccentricities. We find that the analyt ic estimates of T\\'oth and Ostriker (1992) are high; overestimating the disc heating and thickening resulting from the accretion process by a factor of about 2-3. We find that the heating and thickening of the disc differ for satellites on prograde and retrograde orbits. The former tend to heat the stellar disc while the latter primarily produce a coherent tilt. Thus, disc galaxies may accrete quite massive satellites without destroying the disc, particularly, if the orbits are retrograde. We also find that a massive bulge may play a role in reducing these effects. We have quantified the importance of the responsiveness of the halo by replacing it by a rigid potentia l in several simulations. In these cases, the increase of the vertical scale length is larger by a factor of $1.5-2$, indicating that a self-consistent treatment is essential to get realistic results. A frequent by-product of the accretion process is the formation of weak stellar warps and asymmetric discs. Finally, we have checked how well Chandrasekhar's dynamical friction formula reproduces the sinking rates in several of our experiments. We find that it works well provided a suitable value is chosen for the Coulomb logarithm and the satellite mass is taken to be the mass still bound to the satellite at each moment.

H. Velazquez; Simon D. M. White
1998-09-30

380

Modeling the Jovian subnebula: II - Composition of regular satellites ices

  Astrophysics (arXiv)

Summary: We use the evolutionary turbulent model of Jupiter's subnebula described by Alibert et al. (2005a) to constrain the composition of ices incorporated in its regular icy satellites. We consider CO2, CO, CH4, N2, NH3, H2S, Ar, Kr, and Xe as the major volatile species existing in the gas-phase of the solar nebula. All these volatile species, except CO2 which crystallized as a pure condensate, are assumed to be trapped by H2O to form hydrates or clathrate hydrates in the solar nebula. Once condensed, these ices were incorporated into the growing planetesimals produced in the feeding zone of proto-Jupiter. Some of these solids then flowed from the solar nebula to the subnebula, and may have been accreted by the forming Jovian regular satellites. We show that ices embedded in solids entering at early epochs into the Jovian subdisk were all vaporized. This leads us to consider two different scenarios of regular icy satellites formation in order to estimate the composition of the ices they contain. In the first scenario, icy satellites were accreted from planetesimals that have been produced in Jupiter's feeding zone without further vaporization, whereas, in the second scenario, icy satellites were accreted from planetesimals produced in the Jovian subnebula. In this latter case, we study the evolution of carbon and nitrogen gas-phase chemistries in the Jovian subnebula and we show that the conversions of N2 to NH3, of CO to CO2, and of CO to CH4 were all inhibited in the major part of the subdisk. Finally, we assess the mass abundances of the major volatile species with respect to H2O in the interiors of the Jovian regular icy satellites. Our results are then compatible with the detection of CO2 on the surfaces of Callisto and Ganymede and with the presence of NH3 envisaged in subsurface oceans within Ganymede and Callisto.

Olivier Mousis; Yann Alibert
2005-10-28

381

Viability of ISI-Based TETRA over Satellite

  CiteSeer

Summary: Abstract: Satellite communications, by its very nature of providing wide-area coverage, can play an important role in interconnecting TETRA networks. A satellite link may be used to support any of the interfaces in TETRA network. However, the selection of particular interface applies to specific scenarios and provides different advantages and disadvantages. The viability of a satellite link for the interconnection of two TETRA networks using the Inter-System Interface (ISI) is studied with respect to desired functionality and QoS. ISI-based TETRA over satellite can be used in emergency situations when no terrestrial infrastructure exists between the two networks, as well as in normal operations as an alternative to ground based interconnection infrastructure. The response time of different services in a given network architecture is of primary concern because large propagation delay is the main source of service degradation. A modified version of critical path analysis, as it applies to protocols, is used to estimate total propagation delays for a set of ISI services. The appealing property of the critical path length is that it gives an accurate estimate of total propagation delay for a given service and thus represents a quantitative measure of QoS degradation as experienced by the end user. The results presented show larger degradations of QoS for the group call scenarios. The most disturbed are acknowledged group call setup and group call maintenance. A Performance Enhancing Proxy (PEP) is proposed to improve the performance of the TETRA services over the ISI if satellite links are involved. Key-Words: TETRA, satellites, Inter-System Interface, propagation delay, critical path, QoS 1

Roman Novak; Roman Novak

382

AB Levitrons and their Applications to Earth's Motionless Satellites

  Physics (arXiv)

Summary: Author offers the new and distinctly revolutionary method of levitation in artificial magnetic field. It is shown that a very big space station and small satellites may be suspended over the Earth's surface and used as motionless radio-TV translators, telecommunication boosters, absolute geographic position locators, personal and mass entertainment and as planet-observation platforms. Presented here is the theory of big AB artificial magnetic field and levitation in it is generally developed. Computation of three macro-projects: space station at altitude 100 km, TV-communication antenna at height 500 m, and multi-path magnetic highway. Key words: levitation, AB Levitrons, motionless space satellite.

Alexander Bolonkin
2007-08-18

383

Silicon avalanche photodiode operation and lifetime analysis for small satellites

  Quantum Physics (arXiv)

Summary: Silicon avalanche photodiodes (APDs) are sensitive to operating temperature fluctuations and are also susceptible to radiation flux expected in satellite-based quantum experiments. We introduce a low power voltage adjusting mechanism to overcome the effects of in-orbit temperature fluctuations. We also present data on the performance of Si APDs after irradiation (gamma-ray and proton beam). Combined with an analysis of expected orbital irradiation, we propose that a Si APD in a 400 km equatorial orbit may operate beyond the lifetime of the satellite.

Yue Chuan Tan; Rakhitha Chandrasekara; Cliff Cheng; Alexander Ling
2013-06-28

384

Measuring Time of Flight Using Satellite-Based Clocks

  Physics (arXiv)

Summary: Considering the OPERA neutrino-velocity measurement from the point of view of a GPS satellite we find that the detector at Gran Sasso has a velocity component in the order of $10^{-5}c$ towards the neutrino emission location at CERN. On GPS-receivers this translates into first-order Doppler terms, therefore a correction is required for, among other things, this ephemeris-and-location-dependent relativistic effect. To ensure correct time-of-flight measurements using satellite-based clocks we propose to extend their calibration procedures with an explicit check on these relativistic corrections.

Ronald A. J. van Elburg
2011-10-12

385

Satellite design parameters for detecting coherence in the microwave sky

  Astrophysics (arXiv)

Summary: Recently it has been realized that observations of fluctuations in the cosmic microwave background (CMB) can reveal very interesting information about the degree of coherence exhibited by the perturbations at early times. This fact should allow sufficiently detailed observations to clearly differentiate among several competing models of structure formation. We study the mission parameters required for a satellite to address the issue of coherence. Our results emphasize the importance of a small beamwidth, and support the cases for the PSI, FIRE and COBRAS/SAMBA satellite proposals (in increasing order of resolving power). Design parameters for a fourth proposal, MAP, have not been made available.

Andreas Albrecht; Benjamin D. Wandelt
1996-02-08

386

AB Levitrons and their Applications to Earth's Motionless Satellites

  CERN Preprints

Summary: Author offers the new and distinctly revolutionary method of levitation in artificial magnetic field. It is shown that a very big space station and small satellites may be suspended over the Earth's surface and used as motionless radio-TV translators, telecommunication boosters, absolute geographic position locators, personal and mass entertainment and as planet-observation platforms. Presented here is the theory of big AB artificial magnetic field and levitation in it is generally developed. Computation of three macro-projects: space station at altitude 100 km, TV-communication antenna at height 500 m, and multi-path magnetic highway. Key words: levitation, AB Levitrons, motionless space satellite.

Bolonkin, Alexander
2007-01-01

387

Recent Improvements in Testing General Relativity with Satellite Laser Ranging

  General Relativity & Quantum Cosmology (arXiv)

Summary: In this work some aspects of the detection of certain general relativistic effects in the weak gravitational field of the Earth via laser-ranged data to some existing or proposed geodetic satellites are examined. The focus is on the Lense-Thirring drag of the orbit of a test body, the gravitomagnetic clock effect and the gravitoelectric perigee shift. The impact of some sources of systematic errors is investigated. An experiment whose goal is the measurement of the PPN parameters beta and gamma in the terrestrial field with LAGEOS satellites at a level of 10^(-3)is presented. A modified version of the proposed LARES mission is examined.

Lorenzo Iorio
2002-05-22

388

A mathematical simulation of earth satellite explosion debris orbital elements

  Texas A&M University - TxSpace

Summary: the aspherical nature of the earth, the effects of atmospheric drag, gravitational attractions of other bodies (sun, moon, etc. ), and solar radiation pressure. In near earth satellite orbit calculations it is usually sufficient to consider only these; while... are theoretically considered in the same manner as those caused by the earth (HacKillian, 19)0). Because of the distances involved, for earth satellites, it is usually sufficient to consider only the effects of the sun snd the moon as point masses. General near...

Mabrey, Wayne Edward
2012-06-07

389

Silicon avalanche photodiode operation and lifetime analysis for small satellites

  CERN Preprints

Summary: Silicon avalanche photodiodes (APDs) are sensitive to operating temperature fluctuations and are also susceptible to radiation flux expected in satellite-based quantum experiments. We introduce a low power voltage adjusting mechanism to overcome the effects of in-orbit temperature fluctuations. We also present data on the performance of Si APDs after irradiation (gamma-ray and proton beam). Combined with an analysis of expected orbital irradiation, we propose that a Si APD in a 400 km equatorial orbit may operate beyond the lifetime of the satellite.

Tan, Yue Chuan; Cheng, Cliff; Ling, Alexander
2013-01-01

390

Testing General Relativity with Satellite Laser Ranging: Recent Developments

  General Relativity & Quantum Cosmology (arXiv)

Summary: In this paper the most recent developments in testing General Relativity in the gravitational field of the Earth with the technique of Satellite Laser Ranging are presented. In particular, we concentrate our attention on some gravitoelectric and gravitomagnetic post--Newtonian orbital effects on the motion of a test body in the external field of a central mass.

Lorenzo Iorio
2002-10-19

391

Genesis of tropical cyclone Nargis revealed by multiple satellite observations

  Geosciences Websites

Summary: Genesis of tropical cyclone Nargis revealed by multiple satellite observations Kazuyoshi Kikuchi,1 March 2009. [1] Tropical cyclone (TC) Nargis recently battered Myanmar on May 2 2008 is one of the most Ocean. Citation: Kikuchi, K., B. Wang, and H. Fudeyasu (2009), Genesis of tropical cyclone Nargis

Wang, Bin

392

Satellite Data Assimilation for Naval Undersea Capability Improvement

  Geosciences Websites

Summary: Undersea Warfare Center, Newport, RI 02841 Abstract-- Impact of the satellite data assimilation SVP information that might not be current. The Generalized Digital Environmental Model (GDEM bathythermographs (XBT) casts may give accurate and timely information, however, it is not likely to have large

Chu, Peter C.

393

The properties of satellite galaxies in simulations of galaxy formation

  CERN Preprints

Summary: We investigate the properties of satellite galaxies in cosmological N-body/SPH simulations of galaxy formation in Milky Way-sized haloes. Because of their shallow potential wells, satellite galaxies are very sensitive to heating processes which affect their gas content. Their properties can therefore be used to constrain the nature of feedback processes that regulate galaxy formation. In our simulations, we assume that all the energy produced by supernovae is used as kinetic energy to drive galactic winds. Several of our simulations produce bright, disc-dominated galaxies. We find that wind models in which the wind speed, v_w, is proportional to local velocity dispersion of dark matter, sigma, (and thus the wind mass-loading, eta_w \\propto sigma^{-2}) have episodic star formation histories, reproduce the observed satellite luminosity function quite well (down to M_v=-7) and match the luminosity-metallicity relation observed in the Local Group satellites. By contrast, models that assume a constant wind speed o...

Okamoto, Takashi; Jenkins, Adrian; Theuns, Tom
2009-01-01

394

INTERDISCIPLINARY SCIENCE AND APPLICATIONS USING SATELLITE RADAR ALTIMETRY

  Engineering Websites

Summary: ://ibis.grdl.noaa.gov/SAT/Bathy.intro.html Credit: David Sandwell, Walter Smith #12;20 Outline Principle Instrumentation · Sea-Level Rise latitude coverage Earth Satellite Altimeters Altimeter measures geocentric sea level and ice sheet · Conclusion Sea-Level Trend: tide gauges (1900­2009), altimetry (1985­2010) Estimated Global Sea Level Trend


395

Long-Distance Quantum Communication with Entangled Photons using Satellites

  CERN Preprints

Summary: The use of satellites to distribute entangled photon pairs (and single photons) provides a unique solution for long-distance quantum communication networks. This overcomes the principle limitations of Earth-bound technology, i.e. the narrow range of some 100 km provided by optical fiber and terrestrial free-space links.

Aspelmeyer, M; Pfennigbauer, M; Leeb, W; Zeilinger, Anton; Aspelmeyer, Markus; Jennewein, Thomas; Pfennigbauer, Martin; Leeb, Walter; Zeilinger, Anton
2003-01-01

396

A Satellite Survey Cloud Cover and Water Vapor

  Physics Websites

Summary: A Satellite Survey of Cloud Cover and Water Vapor in Northern Chile A study conducted for: Cerro;EXECUTIVE SUMMARY Cloud cover and water vapor conditions in Northern Chile have been surveyed using fifty the trade wind inversion. Light pollution from Tocopilla, likely to increase in the years to come, also


397

Tuesday, March 24, 2009 POSTER SESSION I: ICY SATELLITES

  Physics Websites

Summary: . Hansen G. B. Investigation of Carbon Dioxide Distributions on Saturnian and Galilean Satellites Through and carbon dioxide ice grains have been experimentally acquired in the laboratory. The spectral influence of gaseous CO2 in an icy matrix is discussed. Palmer E. E. Brown R. H. Carbon Dioxide on the Surface

Rathbun, Julie A.

398

Cognitive Vision for Autonomous Satellite Rendezvous and Docking

  Computer Technologies and Information Sciences Websites

Summary: Cognitive Vision for Autonomous Satellite Rendezvous and Docking Faisal Z. Qureshi and Demetri MDRobotics Limited, Brampton, ON L6S 4J3, Canada Abstract We present a cognitively-controlled vision system module, which encodes a model of the environment, performs deliberation to 1) guide the vision system

Toronto, University of

399

A Satellite Survey of Cloud Cover and Water Vapour

  Physics Websites

Summary: A Satellite Survey of Cloud Cover and Water Vapour in Morocco and Southern Spain and a Verification on atmospheric cloud cover and water vapour, it has been recognized that a quantitative survey and water vapour at telescope sites but basically there are two categories: ground-based observations


400

Design, Implementation and Control of a Sparse Aperture Imaging Satellite

  Engineering Websites

Summary: was undertaken. The MIT Adaptive Reconnaissance Golay- 3 Optical Satellite (ARGOS) project exploits wide techniques are explored to mit-igate initial misalignment and to feed back real-time aberrations into the optical control loop. This paper presents the results and the lessons learned from the conceive, design


401

Global assessment of ocean carbon export by combining satellite observations

  Geosciences Websites

Summary: Global assessment of ocean carbon export by combining satellite observations and food-web models D, to drive a food-web model that estimates the production of sinking zooplankton feces and algal aggregates the surface ocean by sinking particles is an important, yet highly uncertain, component of the global carbon

Buesseler, Ken

402

Calculating Change Curves for Multitemporal Satellite Imagery: Mount St. Helens

  Environmental Sciences and Ecology Websites

Summary: Calculating Change Curves for Multitemporal Satellite Imagery: Mount St. Helens 1980­1995 Rick L is flexible and allows an analyst to extract specific of Mount St. Helens in southwest Washington has been a 550 sq km the Mount St. Helens, Washington, blast zone from 1984 homogeneous "moonscape" following

Lawrence, Rick L.

403

Sea Oil Field Satellite Monitoring: An Opera3onal View

  Geosciences Websites

Summary: :on Petroleum or crude oil is a naturally occurring, toxic, flammable liquid consisSea Oil Field Satellite Monitoring: An Opera3onal View Maurizio, Camp Springs, MD 20746 #12;Outline Introduc:on Sea oil fields Synthe:c Aperture

Kuligowski, Bob

404

Rotational spectroscopy of S2O: vibrational satellites, 33

  Physics Websites

Summary: Rotational spectroscopy of S2O: vibrational satellites, 33 S isotopomers, and the submillimeter-wave species; and (iii) a millimeter and submillimeter wave investigation of S2O in the ground vibrational transitions of 34SSO and S34SO. Vibrationally excited states (v1, v2, v3) up to (0, 8, 0), combination states

Thorwirth, Sven

405

A CRC Usefulness Assessment for Adaptation Layers in Satellite Systems

  Computer Technologies and Information Sciences Websites

Summary: A CRC Usefulness Assessment for Adaptation Layers in Satellite Systems Juan Cantillo , Jérôme layers under the lights of enhanced error control and framing techniques, focusing on the DVB-S and DVB mapping network layer packets -such as IP datagrams- into link-layer entities not initially intended

Mailhes, Corinne

406

Indexing of satellite images with different resolutions by wavelet features

  Physics Websites

Summary: and search their images. One particularity of satellite image databases, compared to e.g. natural images they originate from. In contrast, natural image databases are made of pictures with different resolutions are rapidly building up massive image databases. A particularity of these databases is that they are made

Paris-Sud XI, Université de

407

Dark satellites and the morphology of dwarf galaxies

  CERN Preprints

Summary: One of the strongest predictions of the LambdaCDM cosmological model is the presence of dark satellites orbiting all types of galaxies. We focus here on the dynamical effects of such satellites on disky dwarf galaxies, and demonstrate that these encounters can be dramatic. Although mergers with M_sat > M_d are not very common, because of the lower baryonic content they occur much more frequently on the dwarf scale than for L_*-galaxies. As an example, we present a numerical simulation of a 20% (virial) mass ratio merger between a dark satellite and a disky dwarf (akin to the Fornax dwarf galaxy in luminosity) that shows that the merger remnant has a spheroidal morphology. We conclude that perturbations by dark satellites provide a plausible path for the formation of dSph systems and also could trigger starbursts in gas rich dwarf galaxies. Therefore the transition from disky to the often amorphous, irregular, or spheroidal morphologies of dwarfs could be a natural consequence of the dynamical heating of hithe...

Helmi, Amina; Starkenburg, E; Starkenburg, T K; Vera-Ciro, C A; De Lucia, G; Li, Y -S
2012-01-01

408

Anisotropy in the Distribution of Satellite Galaxy Orbits

  Astrophysics (arXiv)

Summary: Nearby clusters such as Virgo and Coma possess galaxy distributions which tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical analysis of some 300 Abell clusters where the effect has been linked to the dynamical state of the cluster. Moreover, the orbits of satellite galaxies in galactic systems like our own Milky Way also demonstrate a high degree of anisotropy - the so-called Holmberg effect, the origin of which has been the subject of debate for more than 30 years. This study presents the analysis of cosmological simulations focusing on the orbits of satellite galaxies within dark matter halos. The apocentres of the orbits of these satellites are preferentially found within a cone of opening angle ~40 around the major axis of the host halo, in accordance with the observed anisotropy found in galaxy clusters. We do, however, note that a link to the dynamical age of the cluster is not well established as both our oldest dark matter halos do show a clear anisotropy signal. Further analysis connects this distribution to the infall pattern of satellites along the filaments: the orbits are determined rather by the environment of the host halo than some "dynamical selection" during their life within the host's virial radius.

Alexander Knebe; Stuart P. D. Gill; Brad K. Gibson; Geraint F. Lewis; Rodrigo A. Ibata; Michael A. Dopita
2003-11-10

409

Decentralized Telescope Management for Satellite Tracking Feyza Merve Hafizoglu

  Computer Technologies and Information Sciences Websites

Summary: level are the Hubble telescope, the International Space Station (ISS), and many of our communicationDecentralized Telescope Management for Satellite Tracking Feyza Merve Hafizoglu Tandy School States utilizes 29 sites that comprise the Space Surveillance Network (SSN). However, numerous countries

Mailler, Roger

410

Effect of Land Surface Heterogeneity on Satellite Near-

  Environmental Sciences and Ecology Websites

Summary: moisture will be the Soil Moisture and Ocean Salinity Mission (SMOS), due to be launched in September 2009Effect of Land Surface Heterogeneity on Satellite Near- Surface Soil Moisture Observations by Rocco 2009 Department of Civil and Environmental Engineering, The University of Melbourne, Australia #12

Walker, Jeff

411

AIAA 2004-3150 ARCHITECTING A COMMUNICATION SATELLITE PRODUCT LINE

  Engineering Websites

Summary: panels cellsbatteryN number of battery cells DCP high power amplifier input DC power PRF amplifier output RF power BOLcellP solar cell beginning of life power EOL power of cellP solar cell end of life power of commercial communication satellites. NOMENCLATURE SAA solar array area radiatorA thermal radiator area c

de Weck, Olivier L.

412

Annual AIAA/USU Conference on Small Satellites

  Computer Technologies and Information Sciences Websites

Summary: 9670 s.jain1@csuohio.edu, d.j.simon@csuohio.edu ABSTRACT: Small spacecraft that are powered by solar energy have limitations because of the size of their solar panels. With the limitations on the solar panel size, it is generally hard to comply with the demands from all the satellite subsystems, payloads

Simon, Dan

413

Optimal Energy Allocation and Admission Control for Communications Satellites

  Computer Technologies and Information Sciences Websites

Summary: with lower energy requirements requires a smaller energy source (solar panel, reactor, etc.) and a lighter continuous sunshine for its solar cells except for brief periods of eclipse, while demand for energy1 Optimal Energy Allocation and Admission Control for Communications Satellites Alvin Fu, Eytan

Modiano, Eytan

414

Estimating lightning current moment waveforms from satellite optical measurements

  Physics Websites

Summary: Estimating lightning current moment waveforms from satellite optical measurements Toru Adachi,1 and Duke magnetometer observed clear optical and radio signatures of 12 sprite- producing lightning events to remotely measure lightning current moment, which is critical for understanding the production of sprites

California at Berkeley, University of

415

Mismatch and Misalignment: Dark Haloes and Satellites of Disc Galaxies

  CERN Preprints

Summary: (Abridged) We study the phase-space distribution of satellite galaxies associated with late-type galaxies in the GIMIC suite of simulations. GIMIC consists of re-simulations of 5 cosmologically representative regions from the Millennium simulation, which have higher resolution and incorporate baryonic physics. Whilst the disc of the galaxy is well aligned with the inner regions (r ~ 0.1r_200) of the dark matter halo, both in shape and angular momentum, there can be substantial misalignments at larger radii (r ~ r_200). Misalignments of > 45 deg are seen in ~ 30% of our sample. We find that the satellite population aligns with the shape (and angular momentum) of the outer dark matter halo. However, the alignment with the galaxy is weak owing to the mismatch between the disc and dark matter halo. Roughly 20% of the satellite systems with ten bright galaxies within r_200 exhibit a polar spatial alignment with respect to the galaxy --- an orientation reminiscent of the classical satellites of the Milky Way. We fi...

Deason, A J; Font, A; Evans, N W; Frenk, C S; Belokurov, V; Libeskind, N I; Crain, R A; Theuns, T
2011-01-01

416

Molecular biology study of satellite panicum mosaic virus capsid protein

  Texas A&M University - TxSpace

Summary: Satellite panicum mosaic virus (SPMV) depends on its helper Panicum mosaic virus (PMV) for replication and movement in host plants. The positive-sense single-stranded genomic RNA of SPMV encodes a 17-kDa capsid protein (CP) to form 16-nm virions...

Qi, Dong
2009-05-15

417

Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

  Physics Websites

Summary: Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection Simona Ozden1 , Michel Gessain1 , Pierre-Emmanuel Ceccaldi1 * 1 Unite´ Epide´miologie et Physiopathologie des Virus Oncoge, Saint-Denis de la Re´union, France, 9 Unite´ Virus et Immunite´, Institut Pasteur, Paris, France

Paris-Sud XI, Université de

418

Tropospheric carbon monoxide: satellite observations and their applications 

  Edinburgh, University of - Research Archive

Summary: of greenhouse gases such as CH4 and O3. Consequently, CO has an atmospheric lifetime of 1-3 months, making it a good tracer for studying the long range transport of pollution. Satellite observations present a valuable tool to investigate tropospheric CO...

MacCallum, Stuart Neil
2008-01-01

419

Intrepreting Debris from Satellite Disruption In External Galaxies

  CERN Preprints

Summary: We examine the detectability and interpretation of debris trails caused by satellite disruption in external galaxies using semi-analytic approximations for the dependence of streamer length, width and surface brightness on satellite and primary galaxy characteristics. The semi-analytic method is tested successfully against N-body simulations and then applied to three representative astronomical applications. First, we show how streamer properties can be used to estimate mass-to-light ratios $\\Upsilon$ and streamer ages of totally disrupted satellites, and apply the method to the stellar arc in NGC 5907. Second, we discuss how the lack of observed tidal debris around a satellite can provide an upper limit on its mass-loss rate, and, as an example, derive the implied limits on mass-loss rates for M32 and NGC 205 around Andromeda. Finally, we point out that a statistical analysis of streamer properties might be applied to test and refine cosmological models of hierachical galaxy formation, and use the predicted ...

Johnston, K V; Bullock, J S; Johnston, Kathryn V.; Sackett, Penny D.; Bullock, James S.
2001-01-01

420

Galactic Encounters: The Dynamics of Mergers and Satellite Accretion

  Physics Websites

Summary: of the Andromeda galaxy (M31) is shown (taken from Ferguson et.al (2002)). Close to the southern minor axis a giant Ferguson et.al (2002). Substructure from recent satellite accretion can be seen at large radii. Note in par

Tittley, Eric

421

How Does Feedback Affect Milky Way Satellite Formation?

  CERN Preprints

Summary: We use sub-parsec resolution hydrodynamic resimulations of a Milky Way (MW) like galaxy at high redshift to investigate the formation of the MW satellite galaxies. More specifically, we assess the impact of supernova feedback on the dwarf progenitors of these satellite, and the efficiency of a simple instantaneous reionisation scenario in suppressing star formation at the low-mass end of this dwarf distribution. Identifying galaxies in our high redshift simulation and tracking them to z=0 using a dark matter halo merger tree, we compare our results to present-day observations and determine the epoch at which we deem satellite galaxy formation must be completed. We find that only the low-mass end of the population of luminous subhalos of the Milky-Way like galaxy is not complete before redshift 8, and that although supernovae feedback reduces the stellar mass of the low-mass subhalos (log(M/Msolar) < 9), the number of surviving satellites around the Milky-Way like galaxy at z = 0 is the same in the run with...

Geen, Sam; Devriendt, Julien
2011-01-01

422

Observing geomagnetic induction in magnetic satellite measurements and associated

  Fossil Fuels Websites

Summary: Observing geomagnetic induction in magnetic satellite measurements and associated implications@ucsd.edu; cconstable@ucsd.edu) [1] Currents induced in Earth by temporal variations in the external magnetic field have magnetic measurements: this is done by removing the magnetic contributions of the main (core) magnetic

Constable, Steve

423

Using Internet nodes and routers onboard satellites W. Ivancic,

  Engineering Websites

Summary: , California. Air Force Space Battlelab, Schriever Air Force Base, Colorado. ~ Universal Space Network, Inc was integrated into the UK-DMC remote-sensing satellite as a secondary experimental payload. This commercial product has been orbiting in space for over three years. We describe the integration of the router

Wood, Lloyd

424

International Global Navigation Satellite Systems Society IGNSS Symposium 2011

  Geosciences Websites

Summary: observed at seven reference stations distributed across the study area. The data was processed on an epoch-by-epoch basis in the double-differenced mode with mixed, kinematic and static stations. The correlation between) are currently operational Global Navigation Satellite Systems (GNSS) and play an important role as space

Schuh, Harald

425

2014 AADR Satellite Symposium in Clinical Research Charlotte, North Carolina

  Biology and Medicine Websites

Summary: . This symposium will provide an overview of clinical research methods for dental faculty/staff and government/industry. Registration is complimentary for employees of Task Force industry sponsors. * This satellite symposium tank" supported by industry and composed of academic, industry and government researchers (http

Klein, Ophir

426

Improving TCP Performance in TDMA-based Satellite Access Networks

  Engineering Websites

Summary: Improving TCP Performance in TDMA-based Satellite Access Networks Jing Zhu, Sumit Roy {zhuj, roy propose a new MAC protocol (CA-GRAP) using cumulative acknowledgment (CA) technique to further improve-GRAP is improved by in- troducing contention index. Our proposal does not require collision or error detection

Roy, Sumit

427

Heuristics for Robust Resource Allocation of Satellite Weather Data Processing

  Engineering Websites

Summary: .g., telemetry, tracking, and control), and revenue generating (e.g., data processing and data research broad categories: 1) high-priority tasks for positioning and 2) revenue generating data processingHeuristics for Robust Resource Allocation of Satellite Weather Data Processing on a Heterogeneous

Maciejewski, Anthony A.

428

DRAG COEFFICIENT ESTIMATION USING SATELLITE ATTITUDE AND ORBIT DATA

  Chemistry Websites

Summary: PENNSTATE _ DRAG COEFFICIENT ESTIMATION USING SATELLITE ATTITUDE AND ORBIT DATA 2Lt. Christopher L of drag using orbital data gathered from NASA's Swift spacecraft. In order to accomplish this task, an accurate cross-sectional area calculation algorithm is generated and an atmospheric model is utilized

Maroncelli, Mark

429

Contention Resolution and Channel Estimation in Satellite Random Access Channels

  Engineering Websites

Summary: Contention Resolution and Channel Estimation in Satellite Random Access Channels Lei Xiao EURECOM Mobile Communications Department BP193, F-06560 Sophia Antipolis, France Email: lei.xiao@eurecom.fr Laura Cottatellucci EURECOM Mobile Communications Department BP193, F-06560 Sophia Antipolis, France Email: laura

Gesbert, David

430

Parametric Least Squares Estimation for Nonlinear Satellite Channels

  Engineering Websites

Summary: Parametric Least Squares Estimation for Nonlinear Satellite Channels Lei Xiao EURECOM Mobile Communications Department BP193, F-06560 Sophia Antipolis, France Email: lei.xiao@eurecom.fr Laura Cottatellucci EURECOM Mobile Communications Department BP193, F-06560 Sophia Antipolis, France Email: laura

Gesbert, David

431

Growth of Galactic Bulges by Mergers; 1, Dense Satellites

  CERN Preprints

Summary: Andredakis, Peletier & Balcells (1995) fit Sersic's law $\\mu(r) \\sim r^{1/n}$ to the bulges of the Balcells & Peletier (1994) galaxy sample, and infer that $n$ drops with morphological type T from $n \\approx$ 4--6 for S0 to $n=1$ (exponential) for Sc's. We use collisionless N body simulations to test the assumption that initially the surface brightness profiles of all bulges were exponential, and that the steepening of the profiles toward the early-types is due to satellite accretion. The results are positive. After the accretion of a satellite, bulge-disk fits show that the bulge grows and that the bulge profile index $n$ increases proportional to the satellite mass. For a satellite as massive as the bulge, $n$ rises from 1 to 4. We present kinematic diagnostics on the remnants and disk thickening. The latter suggests that the bulge growth must have occurred before the last formation of a thin disk in the galaxy. The thick disks created by the merger are reminiscent of thick disks seen in early-type ...

López-Aguerri, J A; Balcells, M
2001-01-01

432

Growth of Galactic Bulges by Mergers: I. Dense Satellites

  Astrophysics (arXiv)

Summary: Andredakis, Peletier & Balcells (1995) fit Sersic's law $\\mu(r) \\sim r^{1/n}$ to the bulges of the Balcells & Peletier (1994) galaxy sample, and infer that $n$ drops with morphological type T from $n \\approx$ 4--6 for S0 to $n=1$ (exponential) for Sc's. We use collisionless N body simulations to test the assumption that initially the surface brightness profiles of all bulges were exponential, and that the steepening of the profiles toward the early-types is due to satellite accretion. The results are positive. After the accretion of a satellite, bulge-disk fits show that the bulge grows and that the bulge profile index $n$ increases proportional to the satellite mass. For a satellite as massive as the bulge, $n$ rises from 1 to 4. We present kinematic diagnostics on the remnants and disk thickening. The latter suggests that the bulge growth must have occurred before the last formation of a thin disk in the galaxy. The thick disks created by the merger are reminiscent of thick disks seen in early-type edge-on galaxies. The efficiency of the process suggests that present day bulges of late-type spirals showing exponential profiles cannot have grown significantly by collisionless mergers.

J. A. L. Aguerri; M. Balcells; R. F. Peletier
2000-12-07

433

15 Minutes about satellite aerosol products (from VIIRS)

  Environmental Sciences and Ecology Websites

Summary: in the atmosphere scatter and absorb radiation · Satellites measure at multiple wavelengths and angles.221 MISR N=903 r=0.107 #12;Conditions for success of Empirical AODtoPM conversion · Calibration case (AOD · Plume aloft will break correlation ­ Have same boundary layer height · This varies seasonally and can

Jacob, Daniel J.

434

The Generalized Information Network Analysis Methodology for Distributed Satellite Systems

  CiteSeer

Summary: A systematic analysis methodology for distributed satellite systems is developed that is generalizable and can be applied to any satellite mission in communications, sensing or nav-igation. The primary enabler is that almost all satellite applications involve the collection and dissemination of information and can thus be treated as modular information process-ing networks. This generalization allows the adoption of the mathematics for information network ow, leading to a logical classi cation scheme for satellite systems. The bene ts and issues that are characteristic of each system class are identi ed, in terms of their capa-bility, performance and cost. The quantitative analysis methodology speci es measurable, unambiguous metrics for the cost, capability, performance and adaptability. The Capabili-ties are characterized by four quality of service parameters that relate to the isolation, rate, integrity and availability of the information transferred between origin-destination pairs within a market. Performance is the probability of satisfying the user's requirements for these parameters. The Cost per Function metric is the average cost incurred to provide satisfactory service to a single user, and Adapatability metrics are sensitivity indicators. Validation of the methodology is provided by a comprehensive quantitative analysis of the

Graeme B. Shaw
1998-01-01

435

Satellite Accretion Onto Massive Galaxies With Central Black Holes

  CERN Preprints

Summary: Minor mergers of galaxies are expected to be common in a hierarchical cosmology such as $\\Lambda$CDM and have the potential to significantly affect galactic structure. In this paper we dissect the case-by-case outcome from a set of numerical simulations of a single satellite elliptical galaxy accreting onto a massive elliptical galaxy. We take care to explore cosmologically relevant orbital parameters and to set up realistic initial galaxy models that include all three relevant dynamical components: dark matter halos, stellar bulges, and central massive black holes. The effects of several different parameters are considered, including orbital energy and angular momentum, satellite density and inner density profile, satellite-to-host mass ratio, and presence of a black hole at the center of the host. Black holes play a crucial role in protecting the shallow stellar cores of the hosts, as satellites merging onto a host with a central black hole are more strongly disrupted than those merging onto hosts without b...

Boylan-Kolchin, M; Boylan-Kolchin, Michael; Ma, Chung-Pei
2006-01-01

436

Global Navigation Satellite Systems (GNSSs) for Monitoring Long Suspension Bridges

  Geosciences Websites

Summary: 16 1 A BRIEF INTRODUCTION TO THE GLOBAL POSITIONING SYSTEM 1.1 GPS constellation The full term consists of three segments: the space segment--a constellation of 24 (nominal) satel- lites distributed]. As discussed by [47, 50, 61], current GPS constel- lation causes an uneven distribution of satellites in view

Santerre, Rock

437

REMOTE SATELLITE POSITION & POSE ESTIMATION USING MONOCULAR VISION

  Mathematics Websites

Summary: .H. Steyn + Prof. B.M. Herbst # Key Words: 3D Tracking, Computer Vision, Kalman Filter, Structure from position and pose. Optical computer vision could represent an affordable and practical way to determineREMOTE SATELLITE POSITION & POSE ESTIMATION USING MONOCULAR VISION Daniël François Malan + Prof. W

Herbst, Ben

438

Adaptive Thermal Modeling Architecture for Small Satellite Applications

  Engineering Websites

Summary: : Colonel John Keesee, USAF Retired Title: Senior Lecturer Thesis Supervisor: David W. Miller TitleAdaptive Thermal Modeling Architecture for Small Satellite Applications 2Lt. John Anger Richmond, USAF Colonel John Keesee, USAF Retired May 2010 SSL # 4-10 #12;#12;Adaptive Thermal Modeling


439

An Integrated Evolutionary Model Approach to Small Satellite Engineering

  Engineering Websites

Summary: , Col (Ret.) John Keesee, David W. Miller May 2010 SSL #5-10 #12;#12;An Integrated Evolutionary Model Approach to Small Satellite Engineering 2LT Joseph B. Robinson, Col (Ret.) John Keesee, David W. Miller May: John Keesee Title: Senior Lecturer Thesis Supervisor: David W. Miller Title: Professor 3 #12;4 #12


440

RNS Implementation of High Performance Filters for Satellite Demultiplexing

  Computer Technologies and Information Sciences Websites

Summary: RNS Implementation of High Performance Filters for Satellite Demultiplexing G.C. Cardarilli, A. Del we present a Residue Number System (RNS) implementation of digital filters to be used for space applications. The RNS is particularly attractive because of the reduced power dissipation with respect

Nannarelli, Alberto

441

Network Mobility in Satellite Networks: Architecture and the Protocol

  Computer Technologies and Information Sciences Websites

Summary: 1 Network Mobility in Satellite Networks: Architecture and the Protocol Abu Zafar M. Shahriar 44135. wivancic@grc.nasa.gov Abstract--Mobility management is required to ensure the session continuity (NEMO) can efficiently manage the mobility of multiple IP-enabled devices that are connected as a mobile

Atiquzzaman, Mohammed

442

Sinking Satellites and the Heating of Galaxy Discs

  CERN Preprints

Summary: We have carried out a set of self-consistent N-body simulations to study the interaction between disc galaxies and merging satellites with the aim of determining the disc kinematical changes induced by such events. We explore a region of the parameter space embracing satellites with different masses and internal structure and orbits of various eccentricities. We find that the analyt ic estimates of Tóth and Ostriker (1992) are high; overestimating the disc heating and thickening resulting from the accretion process by a factor of about 2-3. We find that the heating and thickening of the disc differ for satellites on prograde and retrograde orbits. The former tend to heat the stellar disc while the latter primarily produce a coherent tilt. Thus, disc galaxies may accrete quite massive satellites without destroying the disc, particularly, if the orbits are retrograde. We also find that a massive bulge may play a role in reducing these effects. We have quantified the importance of the responsiveness of the halo...

Velazquez, H; White, Simon D. M.
1998-01-01

443

Satellite observation of dehydration in the Arctic Polar stratosphere

  Geosciences Websites

Summary: between 23 and 26 km. In some cases, the dehydrated air was downwind from mountain wave induced PolarSatellite observation of dehydration in the Arctic Polar stratosphere L. L. Pan,1 W. J. Randel,1 H 2002. [1] We report the first space-borne observation of dehydration in the Arctic polar stratosphere

Pan, Laura

444

EvaluatingSatelliteDerivedandMeasured IrradianceAccuracyforPVResource

  Renewable Energy Websites

Summary: at Albany ABSTRACT This article evaluates the ability of three operational satellite models (Solar on the power grids to which they are connected. SolarAnywhere Standard, Enhanced, and High Resolution produce cost. SolarAnywhere Enhanced and High Resolution have an annual error that is slightly higher than

Perez, Richard R.

445

Telescope Management for Satellite Tracking: A Decentralized Approach

  Computer Technologies and Information Sciences Websites

Summary: 100 million pieces of space junk exist in Low-Earth Orbit (LEO) with over 21,000 objects being larger) monitors the trajectories of large orbiting objects using 29 sites located around the world. Due and the fidelity of tracks. Many of LEO satellites are bright enough to be seen by the naked eye as they streak

Mailler, Roger

446

FORMATION FLYING SATELLITE CONTROL UTILIZING INPUT SHAPING Erika Biediger

  Engineering Websites

Summary: Singhose The precise control of spacecraft with flexible appendages, such as solar panels or antennas Architectures The precise control of spacecraft with flexible appendages, such as solar panels or antennas recognizable being solar panels and communications antennae. Many flexible satellites are positioned

Singhose, William

447

Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings

  Physics Websites

Summary: Cassini Imaging of Jupiter's Atmosphere, Satellites, and Rings Carolyn C. Porco,1 * Robert A. West Science Subsystem acquired about 26,000 images of the Jupiter system as the spacecraft encountered the giant planet en route to Saturn. We report findings on Jupiter's zonal winds, convective storms, low


448

Compliance of Hazardous Waste Satellite Accumulation Areas (SAAs)

  Plasma Physics and Fusion Websites

Summary: Compliance of Hazardous Waste Satellite Accumulation Areas (SAAs) All Hazardous waste generated and California state regulations. All waste that is ignitable, toxic corrosive and /or reactive is determined will keep a list of all SAA's in the division and must be notified before an accumulation area


449

Using 8-color Multispectral Satellite for Observation of Wave Motion

  Computer Technologies and Information Sciences Websites

Summary: relation for surface gravity waves was used to de- termine nearshore ocean depthUsing 8-color Multispectral Satellite for Observation of Wave Motion COASTAL BATHYMETRY For Further Postgraduate School RRSSCC Coastal bathymetry near Camp Pendleton, California was mea- sured using wave motion


450

Princeton University Assimilation of Satellite Remote Sensing Data

  Engineering Websites

Summary: Princeton University Assimilation of Satellite Remote Sensing Data into Land Surface Modeling (Land) Water Budget: QETP dt dSl --= )( #12;4 Princeton University Remote Sensing ­ Soil MoistureTb #12;5 Princeton University Remote Sensing ­ Evapotranspiration (ET) SEBS (Surface Energy Balance

Pan, Ming

451

Studying the Ocean CIOSSCooperative Institute for Oceanographic Satellite Studies

  Geosciences Websites

Summary: Studying the Ocean from Space CIOSSCooperative Institute for Oceanographic Satellite Studies #12 understanding of, and operational products related to, the upper ocean and air-sea interface by using data from incorporate those products and understanding into ocean and atmosphere circulation models. CIOSS education

Kurapov, Alexander

452

Stability of Satellites Around Close-in Extrasolar Giant Planets

  CERN Preprints

Summary: We investigate the long-term dynamical stability of hypothetical moons orbiting extrasolar giant planets. Stellar tides brake a planet's rotation and, together with tidal migration, act to remove satellites; this process limits the lifetimes of larger moons in extrasolar planetary systems. Because more massive satellites are removed more quickly than less massive ones, we are able to derive an upper mass limit for those satellites that might have survived to the present day. For example, we estimate that no primordial satellites with masses greater than 7 x 10^{-7} M_Earth$ (~ \\70km radius for rho=3 g cm^{-3}) could have survived around the transiting planet HD209458b for the age of the system. No meaningful mass limits can be placed on moons orbiting Jovian planets more than ~0.6 AU from their parent stars. Earth-like moons of Jovian planets could exist for 5 Gyr in systems where the stellar mass is greater than 0.15 M_Sun. Transits show the most promise for the discovery of extrasolar moons -- we discuss pr...

Barnes, J W; Barnes, Jason W.
2002-01-01

453

Core Flow Modelling using CHAMP Satellite Vector Data

  Geosciences Websites

Summary: #12;Overview · Motive / Background · Core Flow modelling ­ Method ­ Data · Ground Observatories · Satellite Measurements · Virtual Observatories ­ Results · Core Flows · Residuals · Future Work #12;Secular by the motion of liquid iron in the Earth's outer core ­ fluid flow is unpredictable over long periods of time


454

Segmentation of Occluded Sidewalks in Satellite Images Turgay Senlet1

  Computer Technologies and Information Sciences Websites

Summary: propose a framework to construct sidewalk and crosswalk maps from satellite images. This is a challenging roads, occluders and sidewalk structures. We present successful sidewalk segmentation results from available road maps have been extensively used for vehicle navigation and vehicle path-planning. In order

Elgammal, Ahmed

455

Frequency allocation problem in a SDMA satellite communication system

  Computer Technologies and Information Sciences Websites

Summary: Frequency allocation problem in a SDMA satellite communication system Laurent Houssina SDMA (Spatial Division Multiple Access) is a principle of radio resource sharing that relies on the division of the space dimension into separated communication channels. SDMA basically relies on adaptive

Boyer, Edmond

456

Use of Visible Geostationary Operational Meteorological Satellite Imagery in

  Environmental Management and Restoration Websites

Summary: is typically computed at specific locations based on weather station data. Estimates of incoming solar determinant of spatial variation in these values, particularly in areas with heterogeneous cloud cover. RET continuous methods of computing RET and PET. A robust insolation calibration framework coupled to a satellite


457

Using Belief Functions to Forecast Demand for Mobile Satellite Services

  Computer Technologies and Information Sciences Websites

Summary: Using Belief Functions to Forecast Demand for Mobile Satellite Services Peter McBurney and Simon.j.mcburney,s.d.parsonsg@elec.qmw.ac.uk Abstract. This paper outlines an application of belief functions to forecasting the demand for a new service in a new category, based on new technology. Forecasting demand for a new product or service

McBurney, Peter

458

The Luminosity Function of the Milky Way Satellites

  CERN Preprints

Summary: We quantify the algorithmic detectability of stellar Milky Way satellites in data release 5 (DR5) of the Sloan Digital Sky Survey (SDSS), and use this to estimate the luminosity function of faint satellite galaxies in our halo. We develop a satellite detection algorithm based on the convolution of the DR5 star catalog with a kernel of zero net flux that is the difference of a narrow positive Gaussian and a much wider negative Gaussian, which removes the background star-count level. This permits us to assess the significance of any (positive) detection in terms of deviations of this map. The efficiency of this algorithm is tested by computing the recovery rate of a large set of mock objects added to SDSS DR5 as a function of their luminosity, size and distance from the Sun. Most of the recent Milky Way satellite discoveries, made by SDSS, are shown to lie very close to the survey's detection limits. Calculating the maximum accessible volume $V_{max}$ for all faint detected objects makes it possible for the fir...

Koposov, S; Evans, N W; Hewett, P C; Irwin, M J; Gilmore, G; Zucker, D B; Rix, H -W; Fellhauer, M; Bell, E F; Glushkova, E V
2007-01-01

459

Satellite measurements of the clear-sky greenhouse effect from

  Geosciences Websites

Summary: LETTERS Satellite measurements of the clear-sky greenhouse effect from tropospheric ozone HELEN M of 0.48±0.14 W m-2 between 45 S and 45 N. This estimate of the clear-sky greenhouse effect from, USA Present Address: Atmospheric Chemistry Division, National Center for Atmospheric Research, PO Box

Waliser, Duane E.

460

Stephen Volz Assistant Administrator for Satellite & Information Services

  Environmental Sciences and Ecology Websites

Summary: for research and development of products and programs to archive and provide access to a variety of Earth observations via three national data centers. Dr. Volz is a leader in the international Earth observation community, serving as the NOAA Principal to the Committee on Earth Observation Satellites (CEOS


461

Long-Distance Quantum Communication with Entangled Photons using Satellites

  Quantum Physics (arXiv)

Summary: The use of satellites to distribute entangled photon pairs (and single photons) provides a unique solution for long-distance quantum communication networks. This overcomes the principle limitations of Earth-bound technology, i.e. the narrow range of some 100 km provided by optical fiber and terrestrial free-space links.

Markus Aspelmeyer; Thomas Jennewein; Martin Pfennigbauer; Walter Leeb; Anton Zeilinger
2003-05-19

462

Relativistic analysis of an earth-satellite time transfer

  General Relativity & Quantum Cosmology (arXiv)

Summary: Analytical treatment of time transfer problem for Earth-Satellite system is presented. The development was made in a complete relativistic framework. In accordance with modern clock precision and for low altitude orbits, we neglect the other bodies and consider only the 1/c^2 Earth potential developed up to the J_2 term in spherical harmonics.

Olivier Minazzoli; Bertrand Chauvineau
2007-09-28

463

Introduction to satellite constellations orbital types, uses and related facts

  Engineering Websites

Summary: .sf.net created with #12;All orbits are ellipses · Kepler's first law Earth mass M at focus of an ellipse #12;Most useful for communications ­ geostationary Earth orbit (GEO) · Altitude (35786km) chosen so that satellite moves at same angular velocity as Earth's rotation, so appears still. (period: 1 sidereal day

Wood, Lloyd

464

Improved Validation of Satellite SST for Climate Research

  Environmental Sciences and Ecology Websites

Summary: , and resolution) #12;Upper Ocean Thermal Structure SSTskin ~500µm conductive and diffusive heat transfer processes Warm Layer Thermal stratification can cause large differences between SST measured at 1 µm, 1 mm, and 1 characterization of upper ocean thermal structure ____________________ · Rigorous validation of satellite SSTs


465

Studies on Replication of Cucumber Mosaic Virus Satellite RNA

  University of California eScholarship Repository

Summary: origin and life cycle of viroids and human hepatitis delta virus.origin of the subviral agents in general. Figure 2-1 Helper virusvirus (CMV) replicase (Burgyan and Garcia- Arenal, 1998) may also support the idea of satellite RNA origin

Choi, Soon Ho
2011-01-01

466

Aerospace Power & Electronics Simulation Workshop 2004 Satellite Attitude Control

  Computer Technologies and Information Sciences Websites

Summary: & Electronics Simulation Workshop 2004 Disturbance torques · Aerodynamic · Gravity gradient · Magnetic · Solar Simulation Workshop 2004 Spacecraft control type · Passive control - Gravity gradient control - Spin controlAerospace Power & Electronics Simulation Workshop 2004 · Satellite Attitude Control System Design

Simon, Dan

467

ccsd00002305, Tidal gravitational e ects in a satellite.

  Mathematics Websites

Summary: rotation of a gyroscope relatively to a telescope pointing towards a far away star. It is a relativistic Paris CEDEX 05, France (Dated: July 23, 2004) Atomic wave interferometers are tied to a telescope pointing towards a faraway star in a nearly free falling satellite. Such a device is sensitive


468

Interpreting Debris from Satellite Disruption In External Galaxies

  Astrophysics (arXiv)

Summary: We examine the detectability and interpretation of debris trails caused by satellite disruption in external galaxies using semi-analytic approximations for the dependence of streamer length, width and surface brightness on satellite and primary galaxy characteristics. The semi-analytic method is tested successfully against N-body simulations and then applied to three representative astronomical applications. First, we show how streamer properties can be used to estimate mass-to-light ratios $\\Upsilon$ and streamer ages of totally disrupted satellites, and apply the method to the stellar arc in NGC 5907. Second, we discuss how the lack of observed tidal debris around a satellite can provide an upper limit on its mass-loss rate, and, as an example, derive the implied limits on mass-loss rates for M32 and NGC 205 around Andromeda. Finally, we point out that a statistical analysis of streamer properties might be applied to test and refine cosmological models of hierarchical galaxy formation, and use the predicted debris from a standard $\\Lambda$CDM realization to test the feasibility of such a study. Using the Local Group satellites and the few known examples of debris trails in the Galaxy and in external systems, we estimate that the best current techniques could characterize the brightest ($R < 29$ mag/ arcsec$^{2}$) portions of the youngest (3 dynamical periods) debris streamers. If systematics can be controlled, planned large-aperture telescopes such as CELT and OWL may allow fainter trails to be detected routinely and thus used for statistical studies such as those required for tests of galaxy formation.

Kathryn V. Johnston; Penny D. Sackett; James S. Bullock
2001-01-30

469

The Alignment between Satellites and Central Galaxies: Theory vs. Observations

  Astrophysics (arXiv)

Summary: Recent studies have shown that the distribution of satellite galaxies is preferentially aligned with the major axis of their central galaxy. The strength of this alignment has been found to depend strongly on the colours of the satellite and central galaxies, and only weakly on the mass of the halo in which the galaxies reside. In this paper we study whether these alignment signals, and their dependence on galaxy and halo properties, can be reproduced in a hierarchical structure formation model of a $\\Lambda$CDM concordance cosmology. To that extent we use a large $N$-body simulation which we populate with galaxies following a semi-analytical model for galaxy formation. We find that if the orientation of the central galaxy is perfectly aligned with that of its dark matter halo, then the predicted central-satellite alignment signal is much stronger than observed. If, however, the minor axis of a central galaxy is perfectly aligned with the angular momentum vector of its dark matter halo, we can accurately reproduce the observed alignment strength as function of halo mass and galaxy color. Although this suggests that the orientation of central galaxies is governed by the angular momentum of their dark matter haloes, we emphasize that any other scenario in which the minor axes of central galaxy and halo are misaligned by $\\sim 40^{\\circ}$ (on average) will match the data equally well. Finally, we show that dependence of the alignment strength on the color of the central galaxy is most likely an artefact due to interlopers in the group catalogue. The dependence on the color of the satellite galaxies, on the other hand, is real and owes to the fact that red satellites are associated with subhaloes that were more massive at their time of accretion.

X. Kang; Frank C. van den Bosch; Xiaohu Yang; Shude Mao; H. J. Mo; Cheng Li; Y. P. Jing
2007-04-24

470

Fig.1. A hybrid network of MANET-satellite-Internet. Adaptive Hierarchical Resource Management for Satellite Channel in Hybrid MANET-

  Engineering Websites

Summary: make the satellite link unique as a scarce resource. First, it is the only link that all data have provides the only link for the MANETs to communicate with the rest part of the world. It faces many in response to traffic and link status changes. The algorithm turns out to be in line with reinforcement

Baras, John S.

471

The use of Coral Physiology to combine Satellite SST and Insolation to trackSatellite SST and Insolation to track

  Geosciences Websites

Summary: Barrier Reef Great Cape Y k Great Barrier Reef Cairns York Townsville Rockhampton Keppel Is/temp product development team Funding: NOAANOAA - Coral Reef Conservation Program (CRCP) - Center for Satellite Applications and Research (STAR) 2x Australian Research Council Linkage Grants Future of Reefs in a Changing

Kuligowski, Bob

472

History of NOAA Satellite Programs--Updated June 2011 Page 1 History of the NOAA Satellite Program

  Environmental Sciences and Ecology Websites

Summary: an integral key to life-saving weather and climate forecasts for the United States. NOAA, the National Oceanic soundings, atmospheric temperature and moisture data in all weather situations. During those 46 years, NOAA climate. The article, History of the NOAA Satellite Program, traces the development of the U.S. weather


473

History of NOAA Satellite Programs--Updated October 2009 Page 1 History of the NOAA Satellite Program

  Environmental Sciences and Ecology Websites

Summary: to life-saving weather and climate forecasts for the United States. NOAA, the National Oceanic soundings, atmospheric temperature and moisture data in all weather situations. During those 46 years, NOAA climate. The article, History of the NOAA Satellite Program, traces the development of the U.S. weather


474

GNSS Satellite Orbit Validation Using Satellite Laser Ranging O. Montenbruck (1), P. Steigenberger (2), G. Kirchner (3)

  Materials Science Websites

Summary: satellites of the new constellations (i.e. Galileo, BeiDou, QZSS and IRNSS) are equipped with laser ranging constellations. As an independent and unambiguous tracking system, SLR helps to gain a better understanding will eventually triple the number of constellations available to the user. Among these, the Chinese BeiDou system

Heiz, Ulrich

475

The co-planarity of satellite galaxies delivered by randomly aligned cold mode accretion streams

  CERN Preprints

Summary: Recent observations have shown that the majority of the Andromeda galaxy's satellites are aligned in a thin plane. On the theoretical side it has been proposed that galaxies acquire their gas via cold streams. In addition, numerical simulations show that the same streams also deliver satellites. Assuming that cold streams are the major source of satellite systems around galaxies we calculate the probabilities to find a certain fraction of satellites within a thin plane around the central galaxy of the host halo. Using simple geometrical considerations and adopting a random orientation of the streams we demonstrate that the vast thin disk of satellites detected around Andromeda can naturally be explained within this framework. In fact, without any satellite scattering, three streams or less would lead to too many satellites in the thin plane, compared with the observations. Four to seven streams reproduce the observations very well. Thin disks of satellites might therefore provide important relic information a...

Goerdt, Tobias
2013-01-01

476

Submitted for Publication to SOLAR ENERGY PRODUCING SATELLITE-DERIVED IRRADIANCES IN COMPLEX ARID TERRAIN

  Renewable Energy Websites

Summary: channel1 of geostationary weather satellites (Perez et al., 2002). This model was a logical evolution of earlier work by Cano et al., (1986) and Zelenka et al., (1999). 1 Weather satellites typically have

Perez, Richard R.

477

Synchronization of system-of-systems interfaces in military satellite communications

  MIT - DSpace

Summary: Military systems continue to become more complex and nearly all are now part of one or more system of systems (SoS). Military satellite communications programs have expanded over the last decade from three distinct satellite ...

Davis, Mark J. (Mark Jeffrey)
2008-01-01

478

Adaptation de la couche transport des systèmes de communication hybrides satellite/terrestre.

  Open Access Theses and Dissertations

Summary: ??Nos travaux de thèse ont pour objectif l'adaptation de la couche transport des systèmes de communications hybrides satellite/terrestre. Les réseaux satellites DVB-S2/RCS représente une solution… (more)

Tou, Ihsane
2012-01-01

479

Reduced Sensitivity to Nitric Oxide Limits Satellite Cell Activity on Cultured Myofibers from Aged Mice.

  Open Access Theses and Dissertations

Summary: ??Although aging-induced deficits in satellite cell proliferation and muscle regeneration are well-characterized, our investigation provides novel evidence of an age-related deficit in satellite cell activation,… (more)

Betters, Jenna Leigh Jones
2007-01-01

480

Satellite relative motion propagation and control in the presence of J2 perturbations

  Texas A&M University - TxSpace

Summary: Formation flying is a new satellite mission concept that is concerned with clusters of satellites in neighboring orbits cooperating to perform a specific task. The tasks may be Earth observation or space-based interferometry where a cluster of small...

Sengupta, Prasenjit
2004-09-30

481

Computing Call Blocking Probabilities in LEO Satellite Networks: The Single Orbit Case

  CiteSeer

Summary: We study the problem of carrying voice calls over a LEO satellite network, and we present an analytical model for computing call blocking probabilities for a single orbit of a satellite constellation. We have devised a method to solve...

A. Halim Zaim; George N. Rouskas; Harry G. Perros
2001-01-01

482

Risk mitigation strategies for reliability improvement of university built satellite programs.

  Open Access Theses and Dissertations

Summary: ??University-built satellite programs are prone to failure because these projects are performed by inexperienced student-engineers during the early parts of the satellite-building “learning curve”. However,… (more)

Gencturk, Iklim
2010-01-01

483

Synchronization of earth stations to a switching satellite using non-coherent frequency shift keying.

  Open Access Theses and Dissertations

Summary: ?? In a space division multiple access/spacecraft switched-time division multiple access (SDMA/SS-TDMA) satellite system, precise synchronization between the satellite switching sequence and the earth stations… (more)

Fainecos, Yannis
1977-01-01

484

Resource allocation and scheduling for communication satellites with advanced transmission antennas

  MIT - DSpace

Summary: For multimedia and other data services over satellite networks, the efficient management of scarce satellite communication resources is critical for the economic competitiveness of the medium. To support a broad spectrum ...

Choi, Jihwan Patrick, 1975-
2006-01-01

485

Continental Shelf Research 24 (2004) 10011013 Assimilation of drifter and satellite data in a model of the

  Geosciences Websites

Summary: Continental Shelf Research 24 (2004) 1001­1013 Assimilation of drifter and satellite data. Assimilation that used a combination of drifter and satellite data reproduced the drifter trajectories. Keywords: Data assimilation; Drifter; Satellite; Gulf of Mexico; Circulation model 1. Introduction


486

Comparisons between Nimbus 6 satellite and rawinsonde soundings for several geographical areas

  Texas A&M University - TxSpace

Summary: of MASTER OF SCIENCE May 1979 Major Subject: Meteorology COMPARISONS BETWEEN NIMBUS 6 SATELLITE AND RAWINSONDE SOUNDINGS FOR SEVERAL GEOGRAPHICAL AREAS A Thesis by NINE-MIN CHOU Approved as to style and content by: (Chairman of Committee) (Member... (dots) for the area covered by the satellite data Satellite sounding locations (crosses) along Nimbus 6 orbit between 0735 and 0740 GNT on 3 September 1975, and rawinsonde stations (dots) for the area covered by the satellite data The four...

Chou, Nine-Min
1979-01-01

487

Dcouverte de motifs d'volution significatifs dans les sries temporelles d'images satellites

  Physics Websites

Summary: 'images satellites (ou Satellite Image Time Series ­ SITS) sont d'importantes sources d'informations sur l impose de répondre à plusieurs défis qui sont liés aux caractéristiques des SITS et à leurs contraintes'images satellites (ou Satellite Image Time Series ­ SITS) sont une source importante d'in- formation pour étudier l

Paris-Sud XI, Université de

488

New Constraints on Additional Satellites of the Pluto System

  Astrophysics (arXiv)

Summary: Observations of Pluto and its solar-tidal stability zone were made using the Advanced Camera for Surveys' (ACS) Wide Field Channel (WFC) on the Hubble Space Telescope on UT 2005 May 15 and UT 2005 May 18. Two small satellites of Pluto, provisionally designated S/2005 P 1 and S/2005 P 2, were discovered, as discussed by Weaver et al. (2006) and Stern et al. (2006a). Confirming observations of the newly discovered moons were obtained using the ACS in the High Resolution Channel (HRC) mode on 2006 Feb 15 (Mutchler et al. 2006). Both sets of observations provide strong constraints on the existence of any additional satellites in the Pluto system. Based on the May 2005 observations using the ACS/WFC, we place a 90%-confidence lower limit of m_V = 26.8 (m_V = 27.4 for a 50%-confidence lower limit) on the magnitude of undiscovered satellites greater than 5" (1.1x10^5 km) from Pluto. Using the 2005 Feb 15 ACS/HRC observations we place 90%-confidence lower limits on the apparent magnitude of any additional satellites of m_V = 26.4 between 3"-5" (6.9x10^4-1.1x10^5 km) from Pluto, m_V = 25.7 between 1"-3" (2.3x10^4-6.9x10^4 km) from Pluto, and m_V = 24. between 0.3"-1" (6.9x10^3-2.3x10^4 km) from Pluto. The 90%-confidence magnitude limits translate into upper limits on the diameters of undiscovered satellites of 29 km outside of 5" from Pluto, 36 km between 3"-5" from Pluto, 49 km between 1"-3" from Pluto, and 115 km between 0.3"-1" for a comet-like albedo of p_V = 0.04. If potential satellites are assumed to have a Charon-like albedo of p_V = 0.38, the diameter limits are 9 km, 12 km, 16 km, and 37 km, respectively.

A. J. Steffl; M. J. Mutchler; H. A. Weaver; S. A. Stern; D. D. Durda; D. Terrell; W. J. Merline; L. A. Young; E. F. Young; M. W. Buie; J. R. Spencer
2005-11-30

489

Dielectronic satellite spectra of heliumlike iron and nickel from the unified recombination method

  Physics Websites

Summary: , and profiles of satellite lines may be obtained accurately using the Breit-Pauli R-matrix method of dielectronic satellite lines of He-like Fe XXV and Ni XXVII are obtained in an ab initio manner. Detailed and capture of the incident electron. These resonances appear as "satellite" lines at energies somewhat lower

Nahar, Sultana Nurun

490

P5.60B DERIVATION OF DAYLIGHT AND SOLAR IRRADIANCE DATA FROM SATELLITE OBSERVATIONS

  Power Transmission, Distribution and Plants Websites

Summary: P5.60B DERIVATION OF DAYLIGHT AND SOLAR IRRADIANCE DATA FROM SATELLITE OBSERVATIONS A. Hammer, D of the downward surface shortwave irradiance from satellite observations has been subject to numerous project SATELLIGHT an attempt is made to use satellite methods to derive daylight and solar irradiance

Heinemann, Detlev

491

Vertical and spatial distribution of dust from aircraft and satellite measurements during the GERBILS field campaign

  Environmental Sciences and Ecology Websites

Summary: Africa through field experiments and advances in satellite remote sensing has increased our understanding of dust aerosol properties and their effects. Multi-spectral satellite remote sensing techni- ques's are higher (AOD > 1). New satellite sensors coupled with new algorithms are now providing valuable

Christopher, Sundar A.

492

Peer-to-Peer Error Recovery for Hybrid Satellite-Terrestrial Networks Eric Weigle

  Computer Technologies and Information Sciences Websites

Summary: Peer-to-Peer Error Recovery for Hybrid Satellite-Terrestrial Networks Eric Weigle , Matti Hiltunen of terrestrial networks of sufficient scope and band- width, satellite networks are the most common means that combines the advantages of satellite and terrestrial networks to provide cost-effective reliable file

Fisher, Kathleen

493

Quantifying the seasonal and interannual variability of North American isoprene emissions using satellite observations of the

  Geosciences Websites

Summary: satellite observations of the formaldehyde column Paul I. Palmer,1,2 Dorian S. Abbot,1 Tzung-May Fu,1 Daniel isoprene emissions using satellite observations of the formaldehyde (HCHO) columns is subject to errors satellite observations of the formaldehyde column, J. Geophys. Res., 111, D12315, doi:10.1029/2005JD006689

Abbot, Dorian Schuyler

494

Using CO2 spatial variability to quantify representation errors of satellite CO2 retrievals

  Environmental Sciences and Ecology Websites

Summary: of information that satellite retrievals contribute towards improving CO2 flux estimates will dependUsing CO2 spatial variability to quantify representation errors of satellite CO2 retrievals A. A scale between satellite retrievals and atmospheric transport models contribute to the uncertainty

Michalak, Anna M.

495

An extensive comparison of 0-1 linear programs for the daily satellite mission planning

  Physics Websites

Summary: An extensive comparison of 0-1 linear programs for the daily satellite mission planning Virginie-1 linear programs for solving the satellite mission planning problem. Several heuristics have already been,version1-27Nov2006 #12;An extensive comparison of 0-1 linear programs for the daily satellite mission

Paris-Sud XI, Université de

496

Capacity Evaluation of a SIMO Satellite System at L, S and Ku Bands

  Engineering Websites

Summary: Capacity Evaluation of a SIMO Satellite System at L, S and Ku Bands Argyris Kyriazos, Nektarios for satellite applications. The theoretical study is performed at three different frequency bands. Overall, very terminal which embeds antennas with multiple elements. There are few papers dealing with MIMO satellite

Vouyioukas, Demosthenes

497

MULTI-USER LEO-SATELLITE RECEIVER FOR ROBUST SPACE DETECTION OF AIS MESSAGES

  Computer Technologies and Information Sciences Websites

Summary: present a multi-user receiver equipped with an antenna array on LEO satellites, which explores the spatial random directions and at sparse time points, an antenna array on the satellite can explore the spatialMULTI-USER LEO-SATELLITE RECEIVER FOR ROBUST SPACE DETECTION OF AIS MESSAGES Mu Zhou, Alle-Jan van

Langendoen, Koen

498

Statistical Characterization of the Interference on the Return Link of a Broadband Satellite System

  Physics Websites

Summary: at satellite antenna level as a benchmark parameter, in order to find the most faithful statistical lawStatistical Characterization of the Interference on the Return Link of a Broadband Satellite System an interference study of the return link (user terminals to gateways) of a high throughput satellite (HTS

Paris-Sud XI, Université de

499

submitted to AJ, July 1999 NearInfrared Spectroscopy of Centaurs and Irregular Satellites

  Physics Websites

Summary: and irregular satellites of the giant planets. Centaurs are the presumed transition objects between transsubmitted to AJ, July 1999 Near­Infrared Spectroscopy of Centaurs and Irregular Satellites Michael and of 5 irregular satellites of giant planets. Many of these objects show 1.5 and 2.0 µm absorption bands

Brown, Michael E.

500

ANALYSIS OF CONCENTRATED ALOHA SATELLITE LINKS* Mart L. Molle and Leonard Kleinrock

  Computer Technologies and Information Sciences Websites

Summary: ANALYSIS OF CONCENTRATED ALOHA SATELLITE LINKS* Mart L. Molle and Leonard Kleinrock Computer A conventional ALOHA satellite link uses a transponder which blindly echoes all up-channel trafficou the down and slabilily effects are considered, varying tile number of up-cllauuels per down-chanuel and the satellite

Kleinrock, Leonard

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