Flight Path Estimation of Stripmap SAR Based on Phase WeightedEstimation PGA Algorithm

The phase gradient autofocus (PGA) algorithm was been proved to be an efficient autofocus method. The PGA assume a narrow beam in range,so the algorithm can't be applied to some SAR system. Phase Weighted Estimation PGA(PWE PGA)is suggested which takes into consideration the range dependent phase error,so the PGA can be used in more fields. This paper studies the PWE-PGA algorithm and presents a method for estimating the flight path by using it,analyzes the factors which effect on estimation precision.