多通道宽带雷达不仅要求能够对大场景进行高分辨成像,而且要求具有动目标检测的能力。该文提出一种三通道TOPSAR模式下对地面动目标检测与定位(GMTI)的方法。首先建立三通道TOPSAR-GMTI系统几何模型,并对三通道回波数据进行全孔径成像,然后采用相位中心偏置天线(DPcA)和双门限单元平均恒虚警(CFAR)检测方法完成动目标的检测,最后推导出TOPSAR—GMTI模式下动目标干涉相位与速度的关系,完成对动目标的速度估计并在SAR图像中对其进行重新精确定位。仿真数据处理结果验证了该算法的有效性。
Multi-channel wideband radar requires not only the ability of high-resolution imaging for wide coverage, but also the ability of moving target detection. This paper proposes a method based on three-channel Terrain Observation by Progressive scan SAR (TOPSAR) mode for Ground Moving Target Indication (GMTI). First of all, the geometric model of the three-channel TOPSAR-GMTI system is established, and then full-aperture imaging method is used for processing the three-channel echo data. After that, the Displaced Phase Center Antenna (DPCA) and Constant False Alarm Rate (CFAR) methods are used to accomplish the detection of moving targets. Finally, the relationship between the interferometric phase and speed is deduced for seeking to estimate the speed of the target and remark its correct position in the SAR image. The results of simulation are provided to demonstrate the effectiveness of the proposed method.