基于对角加载的STAP性能改善

空时自适应处理(STAP)作为动目标检测的关键技术，但是非均匀环境将会造成协方差矩阵的估计误差，进而严重影响STAP性能。对角加载主要用于改善空间滤波器对于有用信号空域特征失配和空域协方差矩阵失配的稳健性。该文考虑将对角加载应用于STAP协方差矩阵失配(统计失配)时的性能改善，即在实际的协方差矩阵和其估计值之间存在误差时，通过对角加载改善STAP的稳健性。文中给出了加载电平的选择方法，并进行了详细的性能分析，即合理的对角加载可以提高检测概率和输出信噪比。仿真分析验证了理论分析的正确性。

Improving the STAP Performance via Diagonal Loading

Space-Time Adaptive Processing (STAP) is a key technology for moving target detection, but nonhomogeneity will cause the covariance matrix estimation error, which substantially results in the STAP performance degradation. Diagonal loading is used as a means to improve the robustness of the spatial filter against mismatches in both the desired spatial signature and the spatial correlation matrix. In this paper, we consider the diagonal loading is applied to the case of covariance matrix mismatch (statistical mismatch) for STAP, i.e. when there is a mismatch between the actual covariance matrix of interest and the presumed one. The selecting method of the loading level is given, and the particular performance analysis indicates that the rational diagonal loading can improve the detection probability and the output signal-to-noise ratio. Numerical simulations attest the validity of the analysis.