非平稳环境下主动声呐检测器研究

Research on active sonar detecter in non-stationary environment

针对在水下存在多途、混响及噪声边缘等非平稳背景条件下主动声呐检测器的检测性能,给出了一种变异指数的恒虚警率(Variability Index Constant False Alarm Rate,VI-CFAR)检测器。VI-CFAR结合了单元平均恒虚警率、最大选择恒虚警率和最小选择恒虚警率的检测算法,它在均匀平稳环境和非平稳环境下都具有较强的自适应性。理论分析和仿真结果表明,该检测器在均匀平稳背景下的检测性能与单元平均恒虚警率检测器相似,在多途、混响等干扰背景条件下具有较强的抗干扰能力,在噪声边缘背景下有较好的虚警概率控制能力且运算量小,是一种稳健的检测器。

The sonar background environment is not stationary at all times but is often filled with nonstationarity like multi-path and reverberation edges. The VI-CFAR is a combination of the cell-averaging CFAR（CA-CFAR）, smallest-of CFAR（SO-CFAR） and the greatest-of CFAR（GO-CFAR）, and it has high performance both in stationary environment and in non-stationary environment. Theoretical analysis and simulation results show that the performance of the proposed detector is typically identical with VI CFAR under the homogeneous and stationary background and well capable of anti-multi-path under the background of multi-path, has better capability of CFAR control under the background of clutter edge and less computation, being a sort of robust detector.