点源二维电场正演的一组新的波数  

A set of new wave number for point source and 2-D electric field problems

作　　者：宋滔[1] 王绪本[2] 

机构地区：[1]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵阳550002 [2]成都理工大学地球物理学院,成都610059

出　　处：《地球物理学进展》2014年第1期166-171,共6页Progress in Geophysics

基　　金：973项目"华南大面积低温成矿作用"中"大型-超大型低温矿床成矿规律与找矿预测"课题(编号:2014CB440905);矿床地球化学国家重点实验室"十二五"项目群(编号:SKLODG-ZY125-01)联合资助

摘　　要：首先使用最优化方法计算在点源二维傅氏反变换问题中使用的波数,得到了两组波数,分别包含7个和9个.在极距范围为0.1 m到1000 m时,这两组波数傅氏反变换的误差在0.1%以内.然后使用有限单元法,结合文章中给出的波数,分别模拟了均匀大地,K型和H型地电结构的测深曲线,结果与解析解对比,相对误差在3%以内,而使用前人学者提出的波数在极距大于200 m时出现与解析解分离的情况.最后使用不同波数计算两个二维模型,与三维有限元模拟结果对比,验证了该组波数的正确性.同时发现,使用7个波数与9个波数计算精度相似,建议使用7个波教进行模拟.First, discuss the problem of the selection of wave number in fourier inverse transformation for the point source and two dimensional electric field using optimization method, and calculate 7 and 9 wave numbers under the condition of polar distance ranging from 0. 1 to 1000 m. And the error of this wave number is less than 0. 1% in fourier inverse transformation. Then use the finite element method analog uniform earth, K-type and H-type geoelectric section. Comparing the analytical solution with the one by using the wave number given in the article, the relative error is less than 3%, and with the one by using the wave number given by scholars before, the relative error is 30% at most. The results suggest that the latter solution began to deviate from the standard one（the analytical solution） when the polar distance above 200 rrL Finally, using 3D FEM modeling 2D models as references result, the curves and profile maps indicate that the new wave number have a better accuracy. In the meanwhile, the accuracy of the result of 7 wave numbers and the result of 9 wave numbers are almost the same, so while modeling, the 7 wave numbers is recommended.

关 键 词：波数 电场 最优化方法 有限元 大极距 

分 类 号：P318[天文地球—固体地球物理学] P319[天文地球—地球物理学]