与图像对比度准则相结合的PGA自聚焦算法

An Improved Phase-gradiemt Autofocus Algorithm Combined with the Image Contrast Criterion

根据图像对比度准则对标准的PGA算法[1 ] 作了改进 ,分析和实测数据试验表明 :改进后的PGA算法在计算量得以下降的同时 ,仍保持了PGA算法对高分辨率合成孔径雷达图像中未知相位误差的补偿能力 。

Based on the image contrast criterion, some modifications were made on the classical PGA technique in this paper,analysis and the results of processing real SAR image show that this improved PGA can reduce the computation burden dramatically, and maintain the same capability for correcting the unknown phase errors in defocused SAR image as the original PGA. Moreover, this improved PGA outperforms the original one in term on the independence on SAR scene contents.