Simulations of link opportunities between LEO Satellite and ground sites via modernized BDS

Abstract

BeiDou Navigation Satellite System (BDS) is one of the notably independent Global Navigation Satellite System (GNSS) devised in China. As of the year of 2018,BDS is still operational for regional navigation customers due to its incomplete engineering of global satellites constellation. BDS has a unique function of short message communication. Based on short message communication, low Earth orbiting spacecrafts (LEO S/C) could send imminent information to ground command center and scientific application center as promptly as possible. It is expected that the third phase of BDS will come into being by the end of the year 2020 or so. The third phase of BDS being finished, there will be 19 satellites which have functioning of short message communication; five out of 19 satellites are in geostationary orbits, whose footprints are located in geographic eastern longitude of 58.75deg ,80deg, 110.5deg, 140deg , 160deg; and the other 14 satellites are in middle Earth orbits. With such a modernized GNSS, LEO S/C will find an approach to forward imminent information to ground command center and scientific application center almost in real time, which will greatly improve the observation efficiency of LEO S/C. For LEO in three typical sun-synchronous orbits of 600km,800km,1000km, simulations are presented to demonstrate the advantages of LEO S/C under the co-elaboration with modernized BDS, respectively.