ISAR成象中包络对齐的幅度相关全局最优法

在ISAR成象运动补偿过程中,运用幅度相关法进行包络对齐时,以相邻的回波作为包络对齐的基准,无法避免由于误差积累带来的漂移误差以及由于严重的闪烁现象带来的突跳误差。这些误差可以大到几个距离单元的长度。本文提出全局最优法,考虑某次回波的偏移量时,不只依据邻近的一次回波,而以整个观测期的回波为依据,从而避免了常规幅度相关法的漂移误差和突跳误差,提高了包络对齐的精度,减小了包络对齐时包络位置的漂移和突跳现象,改善了ISAR成象质量。对实测数据的处理结果清楚地表明,与常规方法相比,本方法具有明显的优越性。

GLOBAL OPTIMUM METHOD FOR MOTION COMPENSATION IN ISAR IMAGERY

A method finding the global optimum value of misalignment is presented. It isused to increase the accuracy of range alignment. There exist the drift and jump errors when use the classical amplitude correlation method to align the envelope of the echoes. Sometimes, these errors are so great that they are as large as the width of several range bins. So the quality of image is badly affected. By using global optimum method, the range alignment is more accurate, the drift and jump phenomena of echo envelope are decreased and the quality of the image is improved. From the image result of real measured data, it can be seen that this method is much better than the classical method.