Estimating the Doppler frequency rate for spaceborne SAR data with a new approach

The paper presents a new method to estimate the spaceborne SAR Doppler frequency rate. A polynomial model is set up to demonstrate the azimuth signal of the spaceborne SAR and converts frequency rate estimation to frequency estimation through difference processing. With the analysis of estimation accuracy and computational complexity, the method is proved to be able to reduce the burden of computation while the estimation accuracy is guaranteed. Finally, several simulations and processing of RADARSAT raw data are presented, which proves the validity of the proposed method.