| タイトル | Results from the GPS Flight Experiment on the High Earth Orbit AMSAT OSCAR-40 Spacecraft |
| 著者（英） | Carpenter, J. Russell; Davis, Edward P.; Moreau, Michael C.; Davis, George W.; Axelrad, Penina; Kelbel, David; Bauer, Frank |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2002-01-01 |
| 言語 | eng |
| 内容記述 | A GPS receiver flying on the High Earth Orbit (HEO) AMSAT-OSCAR 40 (AO-40) spacecraft has been returning GPS observations from high above the altitude of the GPS constellation. AO-40, an amateur radio satellite launched November 16, 2000, is currently in a low inclination, 1000 by 59000 lan altitude orbit. This low-cost experiment utilizes a mid 1990's era, 6-channel, CIA code receiver configured with high gain receiving antennas for tracking above the GPS constellation. The receiver has performed well, despite operating significantly outside of its original design environment. It has regularly returned GPS observations from points all around the orbit, with over ten weeks of GPS tracking data collected to date. Signal to noise levels as high as 48 B-Hz have been recorded near apogee, when the spacecraft was at an altitude of close to 60000 km. GPS side lobe signals have been tracked on several occasions, primarily from Block IIR GPS satellites. Although the receiver has not computed a solution in real-time, point solutions have been computed on the ground using simultaneous measurements from four satellites. This experiment has provided important experience dealing with the many challenges inherent to GPS tracking at high altitudes, and the measurements returned are providing valuable information about the characteristics of GPS signals available for future HE0 users. |
| NASA分類 | Space Communications, Spacecraft Communications, Command and Tracking |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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