一种基于子孔径自聚焦的高频运动误差估计和补偿方法

A Method of Based on Sub-aperture Autofocus to Estimate the High-frequency Motion-error and Compensation

采用现有的运动补偿方法,通过多次迭代,理论上可以将SAR成像中运动误差的低频分量补偿掉,但对高频分量是无法进行估计和补偿的,最终会造成当SAR平台运动不稳定时,无法进行高分辨成像。该文针对这一问题,提出了在进行常规运动补偿后对方位数据进行子孔径高频误差分量估计和补偿的方法。这种方法不仅能获得比传统运动补偿方法更好的成像效果,而且运算量也有所减小。仿真和实测数据的处理结果证实了该文方法可以对高频运动误差进行有效性的补偿。

With the traditional motion compensation methods, the low-frequency motion-error can be completely compensated during SAR imaging process in the theory. But the high-frequency motion-error can’t be estimated and compensated. So when the platform of SAR system is not stable, the high-resolution imagery is hardly obtained. In the paper, a new compensation method is proposed to solve this problem—compensating the high-frequency motion-error based on sub-aperture autofocus after traditional motion compensation. With this new method, not only the imaging results are greatly improved, also the operation quantity is greatly cut down. The experiment results using both simulated data and measured data validate the effectiveness of the method for the compensation of high-frequency motion-error.