Accurate Doppler Model Analysis of Geosynchronous SAR

In order to reduce the difficulty of imaging in geosynchronous synthetic aperture radar (GEO SAR), it is necessary to maintain the zero-Doppler centroid throughout the whole satellite orbit, which can be realized by adjusting the radar line of sight (RLS) in real-time. Considering the ultra-long synthetic aperture time of GEO SAR, the variation of RLS within the synthetic aperture cannot be ignored. Focusing on this problem, an accurate Doppler model of GEO SAR is proposed to accurately calculate the Doppler parameters. Finally, the effectiveness and necessity of the proposed model are verified by simulation experiments.