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Title: Measurements of ionospheric effects on wideband signals at VHF

Abstract

Radars operating at very high frequency (VHF) have enhanced foliage and ground penetration compared to radars operated at higher frequencies. For example, VHF systems operated from airplanes have been used as synthetic aperture radars (SAR); a satellite-borne VHF SAR would have considerable utility. In order to operate with high resolution it would have to use both a large relative bandwidth and a large aperture. A satellite-borne radar would likely have to operate at altitudes above the maximum density of the ionosphere; the presence of the ionosphere in the propagation path of the radar will cause a deterioration of the performance because of dispersion over the bandwidth. The author presents measurements of the effects of the ionosphere on radar signals propagated from a source on the surface of the Earth and received by instruments on the FORTE satellite at altitudes of 800 km. The author employs signals with a 90 MHz bandwidth centered at 240 MHz with a continuous digital recording period of 0.6 s.

Authors:
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Assistant Secretary for Human Resources and Administration, Washington, DC (United States)
OSTI Identifier:
334342
Report Number(s):
LA-UR-98-3584; CONF-990406-
ON: DE99002249; TRN: AHC29914%%146
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Conference: 1999 IEEE radar conference, Boston, MA (United States), 20-22 Apr 1999; Other Information: PBD: 17 Aug 1998
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; RADAR; SATELLITES; IONOSPHERE; PERFORMANCE; FREQUENCY SELECTION; DISTURBANCES; MHZ RANGE; EXPERIMENTAL DATA

Citation Formats

Fitzgerald, T J. Measurements of ionospheric effects on wideband signals at VHF. United States: N. p., 1998. Web. doi:10.2172/334342.
Fitzgerald, T J. Measurements of ionospheric effects on wideband signals at VHF. United States. https://doi.org/10.2172/334342
Fitzgerald, T J. 1998. "Measurements of ionospheric effects on wideband signals at VHF". United States. https://doi.org/10.2172/334342. https://www.osti.gov/servlets/purl/334342.
@article{osti_334342,
title = {Measurements of ionospheric effects on wideband signals at VHF},
author = {Fitzgerald, T J},
abstractNote = {Radars operating at very high frequency (VHF) have enhanced foliage and ground penetration compared to radars operated at higher frequencies. For example, VHF systems operated from airplanes have been used as synthetic aperture radars (SAR); a satellite-borne VHF SAR would have considerable utility. In order to operate with high resolution it would have to use both a large relative bandwidth and a large aperture. A satellite-borne radar would likely have to operate at altitudes above the maximum density of the ionosphere; the presence of the ionosphere in the propagation path of the radar will cause a deterioration of the performance because of dispersion over the bandwidth. The author presents measurements of the effects of the ionosphere on radar signals propagated from a source on the surface of the Earth and received by instruments on the FORTE satellite at altitudes of 800 km. The author employs signals with a 90 MHz bandwidth centered at 240 MHz with a continuous digital recording period of 0.6 s.},
doi = {10.2172/334342},
url = {https://www.osti.gov/biblio/334342}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {8}
}