Feasibility Analysis on the Application of GPS Relative Positioning in LEO Constellations

摘要

Although mane documents usualle used the same term when talking about the relative positioning of satellite formations and that of satellite constellations, they are actually different considering the ratio of the relative range between the satellites to the orbital radius. A certain number of researches have been done on the relative positioning of formation-fleing satellites using GPS measurements, while little has been done on that of satellite constellations. However, with the booming of LEO (Low Earth Orbit) communications constellations, relative navigation of satellite constellations should be given more attention because relative position information is necessary in constellation deployment and maintenance.This paper discussed the feasibility of using GPS relativernpositioning to determine the relative positions of LEOrnconstellations(altitude within 500~1500km).In detail itrnwas to analyze the number of the mutual GPS satellitesrnvisible to two LEO constellation satellites at the samernepoch(in this paper the minimum number above whichrnGPS relative positioning can be used was set to 5).rnSoftwares developed by the institute were used to producernthe RINEX observation data,which was then processedrnwith MATLAB programs to get the number of therncommon visible GPS satellites.Results indicate that usingrnGPS to obtain the relative position information of LEOrnconstellations is feasible,but it is subjected to thernelevation angles of the receivers and the satellite numberrnof the constellation.Orbit inclination and orbit altitudernalso have some influence.