Doppler parameters estimation for bistatic forward-looking SAR via ACFT

For high-precision synthetic aperture radar (SAR) processing, the estimation of Doppler centroid and Doppler frequency rate is essential for well-focused image. In this paper, we present a new method for estimation of Doppler parameters in bistatic forward-looking S AR (BFSAR). After range cell migration (RCM) of BFSAR is corrected by using the cross-correlation technique in inverse S AR, analog chirp-Fourier transform (ACFT) is applied to estimate the Doppler frequency rate. Afterwards, the unambiguous Doppler centroid is obtained by combining ACFT with resolving Doppler ambiguity. Experimental results show that the estimation errors of Doppler centroid and Doppler frequency rate are less than 0.2% and 0.15%, respectively.