半埋目标低频声波散射反演的一种新算法

A New Algorithm for Identifying the Shape of Objects Embedded Between Two Half-spaces

半埋目标低频声波散射在数学上归纳为求解带有混合边界的不可穿透的散射体外声场问题,是一个公认的理论难题。本文首次将区域导数法引入边界条件为混合边界不可穿透的散射体的外声场问题中,数值结果证明算法是可行的、正确的,为解决半埋目标低频声波散射物形状识别提供了一种新方法,这在工程实际及军事上均有重要的应用价值。

Acoustic wave detection is one of the important means to explore the unknown objects underwater. The problem of reconstruction of the shape of objects embedded between two half-spaces belongs to the blended boundary conditions. In this paper, the domain derivative of the far-field pattern blended boundary condition is introduced, a new algorithm to recover the boundary shape is constructed and some numerical examples are given. The algorithm is feasible and efficient for a reasonable reconstruction of a shape of flaws or cracks from the far-field measurements, even though less data of directions of incidence and observations for fewer wave numbers are used.