Precise Intersatellite Ranging Technique Based on Fading Memory Gaussian Sum Filtering
Li Li-min①② Ma Lu①② Ren Qian-yi① Yu Jin-pei①②
①(Shanghai Engineering Center for Microsatellites, Shanghai 200050, China) ②(Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China)
Abstract:Precise ranging is the core technology of autonomous navigation. For code measurements yield noisy but unambiguous pseudorange estimates and the pseudorange obtained with carrier phase measurements are almost noiseless but are affected by integer ambiguity, a Fading Memory Gaussian Sum Filter (FMGSF) algorithm based on Bayesian recursive relations is proposed. Posteriori probability?density is approximated as a finite Gaussian mixture, the means and variances of Gaussian terms are updated according to the principle of Kalman filter. Fading memory factor is imported to avoid the issue of filter divergence due to mismodeling and resampling is performed to resolve the issue of increasing in computational complexity caused by carrier phase measurement uncertainty. Theoretical analysis and simulation results show that this algorithm can overcome the effect of cycle slips to a certain extent and achieve higher range accuracy.