Doppler Centroid estimation for Space-Surface BiSAR

Doppler Centroid estimation is a crucial problem in Synthetic Aperture Radar(SAR). In Bistatic SAR (BiSAR) phase synchronization error and Doppler phase have nearly the same form; Doppler centroid can not be estimated in traditional way. A Doppler centroid estimation method is proposed for Space-Surface BiSAR system through phase-cancellation of Dual-channel direct signal. Through phase cancellation, phase synchronization error can be counteracted while Doppler phase is reserved and Doppler centroid can be estimated from the reserved phase. This method needs little prior information and can suppress phase noise.