基于双曲等效的双星滑动聚束SAR两步成像算法

Two-step imaging algorithm of bistatic sliding-spotlight SAR based on hyperbolic equivalent method

双星滑动聚束模式合成孔径雷达(SAR)既保持了双星SAR的灵活性、可靠性和稳定性,同时还可产生高分辨率的图像对,对于观测和测绘具有巨大的潜力。这种模式下需要兼顾双星成像与多普勒带宽显著增加的问题。分析双星滑动聚束SAR系统下目标的多普勒特性,结合双星成像算法与频谱分析法,提出一种基于双曲等效的双星滑动聚束SAR 2步成像算法。同时,针对双曲等效模型误差导致算法聚焦质量下降的问题,提出模型误差补偿方法,给出完整算法处理流程,最后用仿真实验验证所提出的算法。

Bistatic sliding-spotlight synthetic aperture radar(SAR)can not only maintains the flexibility,reliability and stability of the bistatic SAR,but also produce high-resolution image pairs with great potential for observation and mapping.This mode should consider both characteristics of bistatic imaging and a significant increase in Doppler bandwidth.In this paper,the Doppler characteristics of the target in bistatic sliding-spotlight SAR system are analyzed,then,a two-step imaging algorithm based on hyperbolic equivalent method is proposed by combining the bistatic imaging algorithm with the spectrum analysis method.At the same time,for the degradation of the focus quality caused by the error of hyperbolic equivalent model,the model error compensation method is proposed,and the complete algorithm processing flow is given.Finally,the proposed algorithm is verified by simulation experiments.