非瑞利海洋混响抑制技术研究

随着主动声呐距离及角度分辨率的提高,海洋混响包络概率密度函数不再是瑞利分布,而是函数分布后端较瑞利分布具有严重拖尾性的非瑞利分布。但非瑞利分布模型的概率密度函数复杂,参数估计困难。通过对非瑞利分布混响进行恒虚警率检测处理,将严重拖尾部分数据值衰减为背景均值,从而将非瑞利分布混响信号转化为近似瑞利分布。由于去掉了对背景功率估计影响较重的干扰,并基于瑞利分布模型进行目标检测,本文目标检测方法具有较好的鲁棒性和计算简单等优点。文中对一组高分辨率声呐数据进行了恒虚警率检测,结果验证了方法的有效性。

Studies on techniques of non-Rayleigh oceanic reverberation suppression

With the range-bearing resolution of sonar image becoming higher and higher, the probability density function of the oceanic reverberation envelope is no longer Rayleigh distribution, but a non-Rayleigh probability density function with heavier tails. The non-Rayleigh probability density function is complicated, and it is difficult to estimate the function parameters accurately. With CFAR (Constant False Alarm Rate) processing of the reverberation envelope data, which attenuates the heavier tails data values to the background value, the data are transformed from non-Rayleigh distribution to being approximately Rayleigh distribution. Since it gets rid of the interferences which affect the estimation of background power, the detection can estimate the oceanic background power level more accurately and its capability is better and robust. With processing of high resolution sonar data, it is shown that the method is efficient.