大粗糙度起伏下一维海面声散射建模与分析

针对起伏海面高频声散射计算问题，提出了一种改进的基尔霍夫(Kirchhoff)近似方法。该方法考虑了海面的阴影区和亮区之间的多次散射声场，可对小入射角下大粗糙度起伏海面的散射声场进行计算。以一维余弦和高斯谱海面散射声场的有限元计算结果为标准解验证了所提方法的准确性和适用性。利用该方法计算了一维余弦海面的散射强度，分析了不同入射声波频率和角度下海面散射强度的分布情况，并解释了Bragg散射的产生机理，同时讨论了不同海面均方根高度和相关长度情况下高斯谱海面散射强度的变化规律。

Modeling and analysis of acoustic scattering from one-dimensional large roughness sea surface

For fast calculation of high-frequency sound scattering from undulating sea surface, an improved Kirchhoff approximation method is proposed. The method considers the multiple-scattering sound field between the shadow area and the bright area of the sea surface, and can calculate the scattering sound field of the rough sea surface at small incident angles. The accuracy and applicability of the proposed method are verified by taking the finite element calculation results of sound scattering from one-dimensional cosine and Gaussian sea surfaces as standard solutions. This method is used to calculate the scattering intensity from one-dimensional cosine sea surface, analyze the distribution of sea surface scattering intensity at different frequencies and angles of incident acoustic wave, and explain the generation mechanism of Bragg scattering. At the same time, the variation law of the scattering intensity from Gaussian spectral sea surface is discussed under the conditions of different root mean square heights and correlation lengths of sea surface.