基于最小泛函的CSAMT视电阻率计算方法

Based on the minimum functional calculation method of the CSAMT apparent resistivity

可控源电磁时间域数据的视电阻率计算,因其原理简单,计算处理速度快,可以较快反映地下介质电阻率分布情况,而在实际生产中得到广泛应用。传统的视电阻率算法采用求解均匀半空间电磁场响应函数的根,没有从整体上考虑野外数据中存在的噪声对视电阻率地影响。利用最优化理论,考虑野外数据整体的拟合情况,采用求解特定目标泛函的变分问题,提出了一种可控源电磁勘探时间域数据视电阻率求解方法,在实际应用中得到了优于传统方法的计算结果。

The calculation of the apparent resistivity in time domain of controlled source electromagnetic method is widely used in geophysical exploration for its low time costing, which could quickly acquire the distribution of the ground resistivity. The conventional apparent resistivity calculating algorithm uses the root of the response function of the uniform half -space e-lectromagnetic field without considering the effect of the noise in the raw data on the apparent resistivity as a whole. In this pa-per ,we proposed a method to calculate the apparent resistivity in time domain for controlled -source electromagnetic method by using the optimization theory to solve the variational problem of specific target functional. The fitting accuracy of field data is considered as a whole in one section. The method has been used in field operation, and acquired more acceptable result than those of the conventional calculation.