Polynomial Phase Adjustment by Contrast Enhancement Algorithm for SAR

摘要

Phase Adjustment by Contrast Enhancement (PACE) is an autofocus algorithm that is capable of performancernunattainable by conventional techniques. It is a nonparametric method that requires no constraints on the type ofrnphase error to be measured. The algorithm does not require special data culling techniques or the presence ofrnisolated scatterers. However, the drawback of the PACE algorithm is that the number of estimated variables isrnvery large, this leads to a long computational time. This paper presented a polynomial PACE algorithm, itrnconstrain the phase error as a polynomial expression with respect to the azimuth frequency. It can correct highrnorder phase error and the number of variables can be reduced since the variables are the coefficients of thernpolynomial expression. The polynomial PACE algorithm can significantly reduce the computational time whilernthe accuracy is sufficient. This paper derived the details of the polynomial PACE and the results of experimentsrnusing real SAR data are presented to show the validity of the proposed algorithm.