水下甚低频目标的深度分类及布放预报

Depth sorting and distribution forecasting of underwater very low frequency targets

基于水下目标在甚低频段（10~100 Hz）其主要声学特征较为明显的现状,采用声压水平振速互谱的有功分量（PHVCA）进行了水面船和水下目标的区分.基于Pekeris波导模型,提出了被动垂直双矢量水听器的深度布放预报公式,用于指导双矢量水听器的实际布放.通过公式推导及仿真分析指出：当双矢量水听器布放深度之和等于有效深度时,PHVCA的正负号分布不再随着水平距离的变化而变化;在有效深度内,整个声场的PHVCA被分为三个不同符号的水平区域（负-正-负）,两临界面之和等于有效深度,若第一临界面小于有效深度与实际水深之差,则第二临界面大于实际水深,从而实现水下目标的深度分类.仿真验证了该算法及布放深度预报公式的有效性.

In very low frequency（VLF）sound field,active component of sound pressure horizontal velocity cross spectrum（PHVCA）was adopted to distinguish surface ships from underwater targets.The depth distribution forecasting formula of passive vertical double vector hydrophone was proposed based on the effective depth of Pekeris waveguide.Formula and simulation show that when the sum of depth of two hydrophones is effective depth,the sign distribution of PHVCA has no connection with the horizontal distance and the sign distribution of PHVCA is divided into three horizontal fields（negative-positive-negative）.The sum of the first and the second critical surface is equal to the effective depth,and if setting the first critical surface is less than the gap between effective depth and actual depth,then the second critical surface is greater than the actual depth,thus realizing the depth sorting of underwater targets.Simulation verified the effectiveness of this algorithm and distribution depth forecasting formula.