基于Gaver-Stehfest算法的矩形发射回线激发的瞬变电磁场  

Rectangular loop transient electromagnetic field expressed by Gaver-Stehfest algorithm

作　　者：李建慧[1] 朱自强[1] 刘树才[2] 刘鑫明[2] 曾思红[1] 罗文歆[1] 

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]中国矿业大学资源与地球科学学院,江苏徐州221116

出　　处：《石油地球物理勘探》2011年第3期489-492,500+332,共4页Oil Geophysical Prospecting

基　　金：国家重点基础研究发展计划(973)项目(2007CB209400)资助

摘　　要：文中将矩形发射回线看作由无数磁偶源组成,并利用由垂直磁偶源激发的电场对磁矩按回线面积积分,推导出了矩形回线激发的频率域电场表达式,采用G-S(Gaver-Stehfest)算法求得时间域电场表达式,根据法拉第电磁感应定律,利用电场强度阶跃响应最终求得磁感应强度脉冲响应。将不同系数的G-S算法计算的感应电动势与张成范等计算的感应电动势相比较可知:采用14个系数时的G-S算法计算的感应电动势精度最高,最大相对误差为-3.8%,且表现出计算感应电动势的精度早期较高、晚期较低的特点。In this paper,we consider rectangular transmitting loop as numerous vertical magnetic dipoles.The electric field in frequency domain excited by a rectangular loop can be deduced using loop area integral for magnetic moment.Using G-S(Gaver-Stehfest) algorithm,the electric field in time domain is obtained.Based on Faraday law of electromagnetic induction,impulse responses of magnetic induction are deduced from electric field strength step responses.We compare the induction EMF values calculated by G-S algorithm using different numbers of coefficients with the induction EMF values calculated by Zhang Chengfan.The results show that the precision of the induction EMF values calculated by G-S algorithm is highest when 14 coefficients selected,that the maximum of relative error is-3.8%;and that the precision of the induction EMF values at early times higher than at late times.

关 键 词：G-S算法 矩形回线 瞬变电磁场 

分 类 号：P631[天文地球—地质矿产勘探]