线性相关距离扩展目标检测性能分析

Detection Performance Analysis for Linear Correlation Range-Spread Targets

随着雷达距离分辨率的不断提高,目标回波信号由占据一个距离单元的点目标会分裂为占据多个相邻距离单元的距离扩展目标,目标在不同距离单元之间的相关性是不应该被忽略的。本文研究了目标的空间相关性对距离扩展目标的自适应匹配滤波(AMF)检测器检测性能的影响。研究结果表明,如果背景的协方差矩阵结构R_c和目标的模式矩阵H可以写成对角阵的形式,那么对距离扩展目标的检测可以看作是在目标所占据的各个距离单元内分别独立完成,最后进行累加;距离扩展目标所占的单元数目L对信噪比有着重要的影响,对L的不准确估计会使输出信噪比降低;距离扩展目标占据的距离单元完全相关情况下,距离扩展目标的检测就退化为点目标检测。

The high range resolution can resolve the target into a number of scattering centers. And under high-range resolution radar mode, the target can be spatially distributed across some contiguous range cells to form a range-spread target. The range-spread target＇s correlation of different range ceils should not be ignorable. The effect of the spatial correlation of range-spread targets on the adaptive matched filter （AMF） detector is studied. The resolutions show that, if both the covariance matrix structure of clutter Re and the mode matrix of range-spread target H are the diagonal matrix, the tasks of range-spread target detection can be implemented at each cell under test respectively and independently. And the final decision statistics is the summation of statistics in every cell which is occupied by the range-spread target. It is shown that, the number of range ceils L, which are occupied by the range-spread target, has significant effect on the signal-to-clutter ratio. That is to say, inaccurate estimate for L can lead to the signal-to-clutter ratio loss. It is shown that, the spatial correlation of range-spread target among cells under test can make the range-spread target degenerate into the point target.