一种基于和差波束的机载 SAR 定位方法

摘要

机载 SAR 绝对定位技术可以直接对地面目标进行定位，无需地面参考点，对于军事及民事应用具有重要的实用价值。该文提出一种新的机载 SAR 对地定位方法，主要研究在无地面参考点的情况下，利用和差波束 SAR图像直接对地面目标定位，获取地面目标3维坐标信息。论文分析了载机速度、高度及测角误差对定位精度的影响，并与传统基于距离多普勒模型的定位方法进行了比较，最后通过仿真实验验证了该定位方法的有效性。%As an important technique in both civil and military affairs, airborne SAR absolute positioning can absolutely locate the ground targets without the support of ground reference point. In this paper, a new absolute positioning approach based on the sum-different SAR is presented to determine the locations of ground targets without any reference points. In this approach, three-dimensional coordinate information of ground targets is obtained by monopulse processing between difference and sum channels. Moreover, the influence of parameters mismatch on the accuracy of geolocation is analyzed. The new presented method is compared with SAR geolocation techniques based on the R-D model. Simulation results are provided to show effectiveness of the approach.