三维弹性波场的线性化逆散射问题

On Scattering Inversion of a Three-Dimensional Elastic Wave Equation

在弱散射假设下，建立了三维弹性波多参数反演的理论方法。采用两束相互垂直的宽带平面波照射目标体，在包围目标体的封闭测量面上获取散射玻场，通过计算“平面波散射振幅”并选择适当的偏振方向将未知参数在富立叶变换域内解耦．所得结果类似于Ｘ射线ＣＴ成像，具有“滤波反投影”的形式。

With weak scattering assumed,a theoretical approach to the scattering inversion of elas-tic wave in the solid with Born approximation is proposed.Two orthogonal illuminants ofwide-band plane waves,i.e., the P, SV , and SH waves,are used to illuminate an objec-tive, and the scattering data on the closed surface of measuremnt encircling the objectivehave been collected as a function of time, By calculating the plane-wave scattering ampli-tudes from the data and by choosing proper polarization of the incident S-waves, the un-known mass density and elastic parameters in wave-number space can be decoupled in Fouri-er transform domain, The inversion results obtained are in a form of filtered back-projectionbut with a weighting factor.