基于Chirp-Z变换的分布式SAR地面运动目标检测方法

A New GMTI Method Based on Chirp-Z Transform for Distributed Satellites Interferometric SAR

该文基于主辅星编队模式下的分布式卫星SAR系统,对Range-Doppler域地面运动目标检测方法进行了改进,提出回波信号经方位向相位补偿后,应用Chirp-Z变换能够将地面同一方位单元回波的频谱在不同通道内精确配准,而后通过干涉处理和频谱相位补偿来提取运动目标信息,并给出了频谱相位补偿对系统参数的约束条件以及频谱配准对目标速度的约束条件。最后仿真表明该方法在约束条件下是有效的。

Distributed satellites interferometric SAR is capable of detecting ground moving targets via along-track baseline. In this paper, the signal model and phase compensation for this INSAR system is analyzed firstly. A new method based on Chirp-Z transform for GMTI in range-Doppler domain is proposed. The received data of different channels can be co-registered precisely along azimuth direction after being transformed into Doppler domain via CZT, and moving target can be detected through interferometry procedure combined with spectrum phase compensation. In the end, the constraints of multistatic SAR configuration by spectrum phase compensation and target motion by spectrum co-registration are discussed. The final simulation demonstrates that this algorithm can detect moving target efficiently,