On the Doppler Centroid Estimation of SAR System Using Coherence Information

The Doppler centroid estimation, one of key steps in synthetic aperture radar (SAR) processing, suffers from the asymmetry of Doppler frequency spectrum and the signal-to-noise ratio (SNR). In this paper, the coherence of the two adjacent samples in azimuth is utilized to reject the poor estimations. Accordingly, an improved Doppler centroid estimation method is proposed. The experimental results with the RadarSAT-1 data validate the effectiveness of the proposed method.