弹载斜视SAR成像的改进波数域算法

A Modified Wave-number Domain Algorithm for Missile-borne Squinted SAR Data Processing

导弹非匀速直线运动且速度快的特点,使得弹载SAR回波信号的多普勒参数随斜距的变化较大,因此在波数域进行相位补偿的波数域算法很难实现弹载SAR测绘带内的高精度成像处理。该文在经典波数域算法及相关文献的基础上对波数域成像算法进行改进,将2维波数域中的方位压缩处理变换至时域或空域进行,从而可完成成像过程中多普勒参数适应距离的变化,降低原有算法使用同一参数带来的相位误差,因此改进算法能适用于宽测绘带的弹载SAR精确成像。仿真实验验证了改进算法的有效性。

The Doppler parameters of missile-borne SAR received signal vary much with slant range due to missiles＇ high speed and non-ideal movements. Thus applying the classical wave-number domain algorithm can hardly achieve high precision for missile-borne SAR imaging processing. This paper proposes a modified wave-number domain algorithm based on the classical one to meet the demand of high resolution and wide swath for missile-borne SAR imaging. Azimuth compression is implemented in the range time domain or range space domain instead of two dimensional wave-number domain in which it is carried out for the classical algorithm. And Doppler parameters can not correspond to the variation of slant range in the two dimensional wave-number domain. Consequently the modified approach can eliminate the phase error brought by using the same Doppler parameters for the classical algorithm. Simulation result illustrates the validity of the approach.