壳体声接收基阵噪声数值计算方法在优化检测性能中的应用

A numerical method for acoustic hull array noise field calculation that optimizes detection performance

壳体声接收基阵的被动宽带检测性能是基阵优化设计的一个重要准则,然而优化过程需要波束形成器输出端噪声的先验信息.针对壳体声接收基阵承受近场离散噪声源干扰的问题,提出了一种数值计算基阵噪声响应的新方法,即利用边界元理论和SYSNOISE软件对噪声场进行数值计算,并将得到的波束形成器输出端噪声信息应用到提高基阵被动宽带检测性能的优化设计中.利用这种方法,一方面使得波束形成器输出端的噪声计算不再局限于基阵结构简单规则的情况,另一方面克服实际测量噪声场耗费大、不易推广等困难,使得壳体声接收基阵的宽带检测性能在其物理建造前就可以进行优化设计,获得良好的性能预报.以11元共形阵为例,对基阵各个阵元的噪声响应进行数值计算,并在此基础上对该共形阵进行基于提高被动宽带检测性能的优化设计.仿真结果表明,优化出的加权系数有效地提高了波束形成器输出的信噪比,使壳体声接收基阵获得良好的被动宽带检测性能.

A priori knowledge of noise information in the output end of beam former is necessary when optimizing the passive broadband detection performance of an acoustic hull array.When several noise sources are present and/or an analytical expression of the noise transfer function is not available,the sensor noise needs to be measured before optimization.This is very demanding when an array with a large number of sensors is considered.To avoid the tedious work of noise measurement,a new numerical method was developed.In this method,several noise sources in the near field were assigned and then the noise response of the sensor array was calculated via the boundary element method with the commercial software package SYSNOISE.By using this method,the detection performance of a sensor array can be predicted before it is physically built,and hence it could be tested under practical condition.A conformal array with 11 elements was considered.Computer simulations validated the effectiveness of this method.