针对直升机载旋转式合成孔径雷达(rotating synthetic aperture radar,ROSAR)方位向分辨率依赖于重构角度大小,大重构角时传统子孔径处理带来的孔径损失导致方位向分辨率降低的问题,使用高阶逼近模型建立了ROSAR的回波信号模型,结合级数反演的思想推导出了其精确的二维频谱表达式。在此基础上,提出一种适合高分辨ROSAR的成像算法,并对相应的参数选择和性能进行了分析。最后,仿真结果验证了分析结论的正确性和算法的有效性。
Considering the dependence of the azimuth resolution on the reconstruction angle and the azimuth resolution deterioration caused by aperture loss using the traditional sub-aperture procession in the case of a large reconstruction angle the for helicopter-borne rotating synthetic aperture radar(ROSAR),a novel echo model is established using a higher order range model for ROSAR,and the two-dimensional point target spectrum is derived by the series reversion.Based on that,a novel high resolution imaging algorithm is proposed for helicopter-borne ROASR,besides the parameters selection and analysis of performances is presented.Finally,the accuracy and validity of the proposed algorithm is demonstrated through simulation results.