Iterative Parameter Estimation for Precision SAR Processing Using Chirp Scaling

In this paper, we consider an iterative algorithm of parameter estimation suitable to precision SAR processing using chirp scaling. The parameters include Doppler centroid and effective radar speed. They are solved by minimizing the total cost of both image contrast and energy balance to the image azimuth spectrum. The algorithm is based on the steepest descent principle. To achieve stable convergence, the estimates are iterated in a turbo manner. We demonstrate its performance by computer simulations with the Chirp Scaling algorithm. It is verified that Doppler centroid and effective radar speed may converge to the optimum in a limited number of iterations.