基于LCMV算法的星载SAR距离模糊抑制方法

Approach of range ambiguity suppression for spaceborne SAR based on LCMV algorithm

距离模糊抑制是星载合成孔径雷达(SAR)系统顶层设计中的关键问题之一.增加天线高度可以抑制距离模糊,但卫星平台往往对天线尺寸有所限制.指出了距离模糊抑制对于提高可视观测带宽度、产生高质量雷达图像的重要性,介绍了距离模糊的数学模型,提出了分布距离模糊度的概念,分析了平均距离模糊度与分布距离模糊度的区别,给出了应用线性约束最小方差(LCMV)算法抑制星载SAR距离模糊的方法.仿真结果证明,该方法在天线高度不变的情况下,不仅能够提高平均距离模糊度,也可以改善分布距离模糊度.

The range ambiguity suppression is a key problem in the design of the spaceborne synthetic aperture radar（SAR） system. Increasing the antenna height can solve this problem. But usually the satellite platform can not load the large antenna, which restricts the size of the antenna. The importance of suppressing the range ambiguity for observing the wide swath and producing the high quality radar image was pointed out. The mathematical model of the range ambiguity was described and a new concept was presented, i. e. , the distributed range ambiguity signal ratio（DRASR）. The difference between the average range ambiguity signal ratio（ARASR） and the DRASR was analyzed. An approach of the range ambiguity suppression for the spaceborne SAR based on the linearly constrained minimum variance（LCMV） algorithm was proposed. Simulation results prove that this approach not only increases ARASR, but also improves DRASR under the condition that the antenna height is not needed to be changed.