三维电阻率概率成像法研究

3-D RESISTIVITY IMAGING METHOD BY PROBABILITY TOMOGRAPHY

电阻率概率成像法是利用地表电场的测量值与电场扫描函数进行归一化的相似程度作为概率的成像方法。根据概率论的基本理论,引入幂函数并推导了电阻率异常发生概率函数。通过数值模型实验对此方法进行了验证,对多个孤立异常体和凹陷模型进行了概率成像。通过对浙江某地实测资料概率成像结果与常规最小二乘法反演结果进行比较表明,三维电阻率概率成像法能较好地分辨地下地电结构。

Probability tomography, as a new potential approach of geophysical interpretation, is based on the relation between the measured surface electric field and the scanning function. A new data interpretation method of 3-D resistivity imaging is presented. A power function is introduced to deduce the occurrence probability function of resistivity anomaly. The new procedure is proved by the experience of numerical simulation and the probability tomography for many independent anomalous bodies has been done. The comparison between the result from probability imaging and from conventional least square inversion of the observed data at some places in Zhejiang province showes that this imaging method can distinguish effectively the geoelectric structure.