摘要
从二维地电模型的麦克斯韦方程出发,给出了大地电磁场的一种精确的简单积分方程式,并据此设计了一种二维反演方法——积分迭代法、先验地确定一初始模型,用有限元法作正演,形成线性方程组,然后求解地电断面的电性参数或其相对于初始模型的修改量。由于对地电断面的整体剖分、单点反演,因而解决了微机内存问题以及一次反演太多参数时容易出现非唯一性及不稳定性问题。利用复阻抗的反演精度比单独用视电阻率数据有所提高,采用较为稳定的代数重构算法解线性方程组。
According to the Maxwell's equation for a two-dimensional geoelectrical model. an exact but simple integral, equation for magnetotelluric field can be derived. Based on the integral equation, a two-dimensional inversion scheme adapting integral iterative techniques is proposed. At first, an initial geoelectrical model is give, and then, linear equations are formed by the finite element method to obtain the electrical parameters or their values of innovation of the geoelectrical section. Attributed to the overall griding of the whole section and inverting by site, this method overcomes the difficulty of the monuniqueness and unstability of the solution and reduces the computer storage requirement. The precision for inversion using the complex impedance data is better than that using apparent resistivity data only. In addition, a stable algebraic reconstruction technique is employed to solve this linear equations. The principle, equations and implementation of this method are discussed in detail.
出处
《江汉石油学院学报》
CSCD
北大核心
1993年第2期27-32,共6页
Journal of Jianghan Petroleum Institute
关键词
电法勘探
大地电磁场
反演
electrical sounding
magneto-telluric fields
maxwell equation
[inverse]
