改进的基于MSR二维谱的OMEGA-K双基SAR成像算法

Modified OMEGA-K imaging algorithm for bistatic SAR based on MSR 2D spectrum

提出了一种改进的基于级数反演(MSR)二维谱的双基合成孔径雷达(SAR)OMEGAK成像算法。在双基SAR OMEGA-K算法的基础上,通过在距离频域方位时域内的斜距历程高阶项对消处理,使回波信号二维谱和基于低阶泰勒展开的MSR二维谱相匹配,进而采用OMEGA-K成像算法实现聚焦成像。仿真实验中,在斜距历程同为二阶展开的情况下,改进的OMEGA-K算法的聚焦效果要优于常规OMEGA-K算法,而与三阶泰勒展开时的常规OMEGA-K算法聚焦效果非常接近,表明该算法在斜距历程低阶泰勒展开的情况下可以取得较好的聚焦效果,能够降低算法的复杂度。

A modified OMEGA-K imaging algorithm is proposed to reduce the computational complexity of the Method of Series Reversion （MSR） 2D point target spectrum for the bistatic Synthetic Aperture Radar （SAR）. By performing the cancellation of the high order term of range history in range-frequency azimuth-time domain, 2D point target spectrum can be matched with low order Taylor expansion of echo signal, so that the focused imaging can be achieved by the OMEGA-K algorithm. The simulation results indicate that the modified OMEGA-K for range history approximated by second order Taylor expansion can achieve better focused performance than that of conventional algorithm for range history approximated by second order Taylor expansion, and approach the performance of the conventional algorithm for range history approximated by three order expansion. This demonstrates that the proposed algorithm has a good focusing performance by low order Taylor expansion, thus lowers the computational complexity.