SAR距离-多普勒成像算法中的距离徙动及校正

Range migration and correction in SAR range-doppler imaging algorithm

在SAR距离-多普勒成像算法中,距离徙动会使距离向和方位向发生耦合,成像质量下降.典型的距离徙动校正插值算法有:最近邻插值、牛顿插值、辛格插值等.但以上算法的光滑性和收敛性不好,而三次样条函数具有连续的二阶导数,且可采用分段函数的形式,具有很好的光滑性和收敛性.作者用三次样条函数插值进行距离徙动校正,进行了点目标SAR仿真成像,得到了满意的仿真结果.

In SAR Range-Doppler Imaging algorithm, range migration results in the coupling between range and azimuth, and affects on imaging quality. Typical interpolation algorithms such as nearest neighbor interpolation, Newton interpolation, and sinc interpolation have been proposed for range migration correction. However, the smoothness and convergence of these methods are not satisfactory. Because cubic spline function can be a piecewise, and its second order derivative is continuous, it is smooth and convergent. In this paper, therefore, a new interpolation method using cubic spline function is presented for range migration correction. Using the method we presented, SPuR imaging simulation of point target has been done and the experiment results are satisfactory.