Signal-Domain Fully Coherent Accurate Measurement and Tracking of High-Speed Target

Abstract

The high speed and maneuverability of the spacecraft make the traditional wideband tracking algorithms fail to achieve echo coherent recovery under low SNR, resulting in reduced tracking accuracy. This paper proposes a fully coherent accurate measurement and tracking method based on the multi-channel hypothesis to realize the fully coherent recovery of dechirp echo and Doppler phase disambiguation. The algorithm performs initialization estimation and designs the multi-channel hypothesis velocity ambiguity interval. Then, it traverses the interval to perform the fully coherent accurate measurement and tracking to obtain the motion state update, employed to echo coherent recovery. Finally, the N/M criterion is introduced to evaluate the envelope alignment of the recovered echoes and filter out the unambiguous velocity. Experiments demonstrate its remarkable performance in low SNR conditions.