Li Z.-H.,Test and Assessment Center |
Jiao W.-H.,Test and Assessment Center |
Jiao W.-H.,Beijing Institute of Technology |
Huang X.-R.,Test and Assessment Center |
And 2 more authors.
Yuhang Xuebao/Journal of Astronautics | Year: 2013
Based on the experiments of GNSS signal-in-space availability varying with θHBW and Aknee, some results can be concluded: Aknee for GPS, GLONASS, Galileo and BeiDou is 3800km, 1100km, 3800km and 1000km respectively, and the corresponding average number of SVs is 25, 16, 22 and 14/22(MEO constellation/Integrated constellation for Asia-Pacific region) respectively. Then the satellite visibilities for three typical user orbits are analyzed. Showing that signal availabilities of BeiDou and GLONASS are slightly worse than GPS and Galileo in MEO and HEO user orbits, and in LEO user orbit, BeiDou had the best performance that the average number of SVs is about 20, and the distribution of availability time is even. Lastly GNSS spatial effective continued time segment is analyzed, with the increment of user altitude the number of segments increases and the total effective time decreases. The space domain that GPS, GLONASS, Galileo and BeiDou could supply effective service (100% continued time segments) is from the earth surface to the altitude of 6100km, 1600km, 6100km and 1700km respectively.