Local correlation and orbit determination for DOR signals in Chang’E-3

Abstract

The X-band Delta-Differential One-way Range is first formally used in Chang’E-3 spacecraft, and will be continually used for other Chinese future deep space navigation. We have carried out researches on each DOR tone using local correlation method which is quite different from the conventional VLBI correlator. The CE-3 signal interferometry processing is completed with this method. High precision Delta-DOR group delay and radio source correction are obtained for orbit determination. The phase noise of local correlation is significantly smaller than that of the VLBI conventional correlator. The ephemeris from local correlation is about 20 m different from the precise ephemeris of CE-3 project, and the corresponding equivalent residual delay is about 0.4 ns. Experiment result shows that local correlation is more suitable for weak signal processing, and it can be used for the future Chinese lunar and other deep space exploration projects.