运动平台混响的时空耦合统计模型

The space-time coupling statistical model of reverberation from moving platforms

混响时空耦合特性是空时处理混响抑制方法中的关键问题之一。传统方法不是建立在统计模型基础上的,对实际海洋混响扩展、海洋混响环境影响及基阵非理想性导致的混响时空耦合分析缺乏有效性。论文在混响概率模型基础上,推导了运动平台的混响时空耦合关系,进一步给出了复杂水声混响环境及具体阵列指向特性下的混响时空耦合规律的统计模型。利用该模型,推导了理想窄波束基阵混响的时空耦合关系。理论解析结果和计算机仿真清晰地展示了理想阵列流形的混响时空分布规律,验证了本文理论推导结果的正确性。最后采用数值计算方法分析非理想基阵的混响空时耦合关系及空时分布规律,结果表明利用本文的混响空时耦合模型,能获得实际基阵的混响空时分布规律,可为空时处理混响抑制算法与系统设计提供一定的理论支撑。

The space-time coupling characteristic of reverberation is a key problem in reverberation suppression with space-time processing methods. Traditional methods are not based on the statistical characteristic of reverberation. Facing the problems as actual sea reverberation extension, sea reverberation environment influence and non-ideal arrays, they aren＇t suitable to analyze the space-time coupling characteristics of reverberation. Based on the statistical model of reverberation from moving platforms, the space-time coupling relationship is deduced, and then the space-time coupling statistical model is presented. It describes the space-time coupling law of reverberation, under the conditions as complex acoustic reverberation environments and an arbitrarily specified array. As for ideal arrays with narrow-beams, the mathematical expressions of space-time coupling relationship are given by using of the space-time coupling statistical model above. The space-time distribution laws of their reverberation are shown clearly by the analytical results and computer simulations, and then the validity of the statistical model is proven. The space-time distribution law of reverberation from a uniform linear array, which is a nonideal array, is also calculated. It is shown that the space-time distribution law of reverberation from any actual array can be acquired with the statistical model. Theoretical supports for the suppression algorithms of space-time reverberations and their systems design are presented.