论文部分内容阅读
采用非线性最小二乘法结合蒙特卡罗法,实现宽带高频电磁场椭圆极化率数据的精确反演,确定地下层状介质的真实电阻率和介电常数.反演结果表明,对于均匀半空间和二层介质模型,最小二乘法能够很好地实现反演,而对于三层或更多层的介质,首先利用蒙特卡罗法确定拟合初始模型,再进行最小二乘反演,能够避免收敛到局部极小值,提高了反演的稳定性.为了加速正演响应函数的计算和迭代的速度,采用高密度采样的线性滤波算法,大大加快了该精确反演方法的速度.针对如覆盖区地质填图和土壤调查等大面积确定地质体性质的应用,本文还给出了一种近似反演方法(相位矢量图法),能够快速获取视电阻率和视介电常数,不仅可以为应用提供有用的基础信息,而且可作为精确反演方法的初始模型.
The nonlinear least square method combined with Monte Carlo method is used to realize the accurate inversion of elliptic polarizability data of broadband high frequency electromagnetic field and determine the real resistivity and dielectric constant of underground layered media.The inversion results show that for the uniform half-space And two-layer model, the least-squares method can well perform inversion. For three-layer or multi-layer media, the Monte Carlo method is first used to determine the initial model and then the least squares inversion can be avoided Converge to the local minimum and improve the stability of the inversion.In order to speed up the calculation and iteration of the forward response function, the linear filtering algorithm of high-density sampling is adopted to speed up the exact inversion method greatly. Covering the area of geological mapping and soil survey and other large areas to determine the nature of geological applications, this paper also gives an approximate inversion method (phase vector diagram method), can quickly obtain apparent resistivity and apparent dielectric constant, not only can Provide useful basic information for the application, and can be used as the initial model of accurate inversion method.