天基稀疏阵杂波自由度分析

Estimation of the Clutter Rank of Space-Based Sparse Array

天基稀疏孔径实现地面运动目标指示具有很大吸引力,如何简单准确地估计空时自适应处理器的杂波自由度是一个重要的课题.针对天基稀疏孔径的两种常用类型———稀疏子阵列和非全向性阵元稀疏阵,基于空时等效理论,从等效的虚拟空间阵列角度分析了阵列的杂波自由度,得到了预测杂波自由度的简单方法,仿真结果验证了方法的有效性.最后从杂波自由度得到分布式小卫星雷达实现地面运动目标指示的基本设计约束条件.

Ground moving target indicator （GMTI） using space-based sparse array is attractive. How to estimate the clutter rank simply and accurately is an essential issue in space time adaptive processing （STAP） Space-based sparse arrays usually appear as subarrays or arrays with non-isotropic elements. The 2D space time signal can be viewed as 1D space signal received from an equivalent synthetic space array according to space time equivalence theory. Then simple and accurate clutter rank estimating formulas are derived from the synthetic space array according to these two classes of sparse array. The simulations verify the accuracy of the formulas. Basic design constraints of the distributed small satellite based GMTI radar are derived from the clutter rank.