Allocation of satellites for GPS cold start in LEO orbit

Abstract

This paper presents an investigation on the allocation of satellites for GPS cold start for autonomous orbit determination of spacecraft in LEO orbit. The paper first described the general requirement for a space-based GPS receiver system for a microsatellite, in particular, the GPS receiver flown on TiungSAT-1, the first Malaysian microsatellite. This is followed by a discussion on the methods for tracking spacecraft in LEO orbit. Various cold-start autonomous orbit acquisition algorithms are developed and presented. Next, a simulator developed using MATLAB which simulate and evaluate the performance of the actual behavior of GPS and LEO satellites in orbit based on the developed algorithms is described. Later, results are presented and comparison of the various developed algorithms is discussed.