On Orbit Lifetime of GTO Debris;

The theoretical analysis and simulation result indicate that the satellite orbit and attitude changes have a great influence upon the space-borne SAR imaging.

And a comparison with GPS system of Galileo system is studied in the following aspects: the satellite orbit deployment,the frequency and signal design,the pseudo-satellite technology and signal service.

The experiment result with real measurement shows that the new method can be used in real time autonomous satellite orbit determination with high accuracy.

According to the limitation of the satellite orbits and spectrum resources,this paper puts forward some methods for making effective use of the satellite orbits and spectrum resources.