Autofocussing SAR and SAS images using a conjugate gradient search algorithm

We demonstrate a simple conjugate gradient optimizing algorithm that can restore motion-blurred spotlight SAR or SAS images. The key to an effective restoration is an appropriate cost function based on image sharpness criterion combined with the probability of the estimated path trajectory. The image can be optimized efficiently using the derivative of the cost function. Examples of blurred and restored simulated images are shown.