skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: PRECISION POINTING OF IBEX-Lo OBSERVATIONS

Abstract

Post-launch boresight of the IBEX-Lo instrument on board the Interstellar Boundary Explorer (IBEX) is determined based on IBEX-Lo Star Sensor observations. Accurate information on the boresight of the neutral gas camera is essential for precise determination of interstellar gas flow parameters. Utilizing spin-phase information from the spacecraft attitude control system (ACS), positions of stars observed by the Star Sensor during two years of IBEX measurements were analyzed and compared with positions obtained from a star catalog. No statistically significant differences were observed beyond those expected from the pre-launch uncertainty in the Star Sensor mounting. Based on the star observations and their positions in the spacecraft reference system, pointing of the IBEX satellite spin axis was determined and compared with the pointing obtained from the ACS. Again, no statistically significant deviations were observed. We conclude that no systematic correction for boresight geometry is needed in the analysis of IBEX-Lo observations to determine neutral interstellar gas flow properties. A stack-up of uncertainties in attitude knowledge shows that the instantaneous IBEX-Lo pointing is determined to within {approx}0.{sup 0}1 in both spin angle and elevation using either the Star Sensor or the ACS. Further, the Star Sensor can be used to independently determine themore » spacecraft spin axis. Thus, Star Sensor data can be used reliably to correct the spin phase when the Star Tracker (used by the ACS) is disabled by bright objects in its field of view. The Star Sensor can also determine the spin axis during most orbits and thus provides redundancy for the Star Tracker.« less

Authors:
;  [1]; ; ; ; ; ;  [2];  [3];  [4]
  1. Space Research Centre of the Polish Academy of Sciences, 18A Bartycka, 00-716 Warsaw (Poland)
  2. Space Science Center and Department of Physics, University of New Hampshire, Morse Hall, 8 College Road, Durham, NH 03824 (United States)
  3. Haystack Observatory, Massachusetts Institute of Technology, Route 40, Westford, MA 01886 (United States)
  4. Lockheed Martin, Space Physics Lab, 3251 Hanover Street, Palo Alto, CA 94304 (United States)
Publication Date:
OSTI Identifier:
22048044
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal, Supplement Series
Additional Journal Information:
Journal Volume: 198; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0067-0049
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; ASTROPHYSICS; ATOMS; CAMERAS; CATALOGS; CONTROL; CORRECTIONS; COSMIC GASES; GAS FLOW; HELIOSPHERE; INTERSTELLAR SPACE; ORBITS; ORIENTATION; SATELLITES; SENSORS; SPACE VEHICLES; SPIN; SUN

Citation Formats

Hlond, M, Bzowski, M, Moebius, E, Kucharek, H, Heirtzler, D, Schwadron, N A, Neill, M E. O', Clark, G, Crew, G B, Fuselier, S, and McComas, D. J., E-mail: mhlond@cbk.waw.pl, E-mail: eberhard.moebius@unh.edu, E-mail: gbc@haystack.mit.edu, E-mail: stephen.a.fuselier@linco.com, E-mail: DMcComas@swri.edu, E-mail: DMcComas@swri.edu. PRECISION POINTING OF IBEX-Lo OBSERVATIONS. United States: N. p., 2012. Web. doi:10.1088/0067-0049/198/2/9.
Hlond, M, Bzowski, M, Moebius, E, Kucharek, H, Heirtzler, D, Schwadron, N A, Neill, M E. O', Clark, G, Crew, G B, Fuselier, S, & McComas, D. J., E-mail: mhlond@cbk.waw.pl, E-mail: eberhard.moebius@unh.edu, E-mail: gbc@haystack.mit.edu, E-mail: stephen.a.fuselier@linco.com, E-mail: DMcComas@swri.edu, E-mail: DMcComas@swri.edu. PRECISION POINTING OF IBEX-Lo OBSERVATIONS. United States. https://doi.org/10.1088/0067-0049/198/2/9
Hlond, M, Bzowski, M, Moebius, E, Kucharek, H, Heirtzler, D, Schwadron, N A, Neill, M E. O', Clark, G, Crew, G B, Fuselier, S, and McComas, D. J., E-mail: mhlond@cbk.waw.pl, E-mail: eberhard.moebius@unh.edu, E-mail: gbc@haystack.mit.edu, E-mail: stephen.a.fuselier@linco.com, E-mail: DMcComas@swri.edu, E-mail: DMcComas@swri.edu. 2012. "PRECISION POINTING OF IBEX-Lo OBSERVATIONS". United States. https://doi.org/10.1088/0067-0049/198/2/9.
@article{osti_22048044,
title = {PRECISION POINTING OF IBEX-Lo OBSERVATIONS},
author = {Hlond, M and Bzowski, M and Moebius, E and Kucharek, H and Heirtzler, D and Schwadron, N A and Neill, M E. O' and Clark, G and Crew, G B and Fuselier, S and McComas, D. J., E-mail: mhlond@cbk.waw.pl, E-mail: eberhard.moebius@unh.edu, E-mail: gbc@haystack.mit.edu, E-mail: stephen.a.fuselier@linco.com, E-mail: DMcComas@swri.edu, E-mail: DMcComas@swri.edu},
abstractNote = {Post-launch boresight of the IBEX-Lo instrument on board the Interstellar Boundary Explorer (IBEX) is determined based on IBEX-Lo Star Sensor observations. Accurate information on the boresight of the neutral gas camera is essential for precise determination of interstellar gas flow parameters. Utilizing spin-phase information from the spacecraft attitude control system (ACS), positions of stars observed by the Star Sensor during two years of IBEX measurements were analyzed and compared with positions obtained from a star catalog. No statistically significant differences were observed beyond those expected from the pre-launch uncertainty in the Star Sensor mounting. Based on the star observations and their positions in the spacecraft reference system, pointing of the IBEX satellite spin axis was determined and compared with the pointing obtained from the ACS. Again, no statistically significant deviations were observed. We conclude that no systematic correction for boresight geometry is needed in the analysis of IBEX-Lo observations to determine neutral interstellar gas flow properties. A stack-up of uncertainties in attitude knowledge shows that the instantaneous IBEX-Lo pointing is determined to within {approx}0.{sup 0}1 in both spin angle and elevation using either the Star Sensor or the ACS. Further, the Star Sensor can be used to independently determine the spacecraft spin axis. Thus, Star Sensor data can be used reliably to correct the spin phase when the Star Tracker (used by the ACS) is disabled by bright objects in its field of view. The Star Sensor can also determine the spin axis during most orbits and thus provides redundancy for the Star Tracker.},
doi = {10.1088/0067-0049/198/2/9},
url = {https://www.osti.gov/biblio/22048044}, journal = {Astrophysical Journal, Supplement Series},
issn = {0067-0049},
number = 2,
volume = 198,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2012},
month = {Wed Feb 01 00:00:00 EST 2012}
}