Doppler parameter estimation algorithms for SAR processing with the chirp scaling approach

Presents several correlation based methods for estimation of the Doppler parameters from SAR raw data in connection with the chirp scaling algorithm. For the estimation of the Doppler rate, a modified approach of the shift and correlate (SAC) algorithm is proposed. In this case, the auto-correlation function of each data set and the standard deviation of the velocity calculations are used in order to monitor the validity of the estimations. For resolving the PRF ambiguity, a new approach is proposed, which is based on the estimation of the range-frequency centroid as a function of the azimuth frequency. Several results of the Doppler parameters estimation are presented for airborne and spaceborne SAR data