水下目标宽带回波特性的快速计算方法

基于传统板块元方法,运用切比雪夫多项式插值实现了水下目标宽带回波特性的快速计算.从散射声场的特性出发,将幅相分离的思想引入散射声场的分析.目标表面单个板块散射声场可分解为随频率变化的快速起伏和缓变函数的乘积,提取缓变函数切比雪夫节点处的板块散射声场,再利用切比雪夫逼近理论插值得到宽频带内各频率点处的精密计算.结合分离出的随频率快速起伏项,获取每个板块的宽带散射声场,通过各板块元散射声场叠加得到目标宽带回波特性.该方法避免了传统板块元算法逐频率点计算所带来的大量板块的重复计算,可以快速、精确计算水下目标宽带回波特性,计算效率大为提高.

A Fast Computation Method for Broadband Echo Characteristics of Underwater Target

A fast computation method for broadband echo characteristics was proposed based on the planar element method and by using Chebyshev polynomial interpolation. Introducing the amplitude and phase separation method, the scattering sound field of each planar element was decomposed into fast and slow fluctuating functions varied with frequency. For the function varied slowly with frequency, the Chebyshev approximation theory was used to obtain the precise calculation of each frequency point in broadband, when the scattered sound of Chebyshev nodes was given by the planar element method. The broadband echo characteristic of the target was calculated by the combination of the result of Chebyshev polynomial interpolation and fast fluctuating function. The method can avoid high cost of time in scattering field calculation, because it is not necessary to compute point by point in the frequent domain. Compared with the traditional planar element method, this method can compute the broadband echo characteristics of underwater target quickly and accurately.