瞬变电磁视电阻率对分预估计数值计算方法  

Numerical Calculation Method of Pre-bisection Estimation to Apparent Resistivity from Transient Electromagnetic Method

作　　者：谢林涛 伍平 唐跃林 付志红[2] 

机构地区：[1]重庆电网检修分公司,重庆400020 [2]重庆大学电气工程学院,重庆400030

出　　处：《工程地球物理学报》2010年第5期554-560,共7页Chinese Journal of Engineering Geophysics

基　　金：国家自然科学基金(编号:50577071)资助

摘　　要：提出了一种快速的计算全程视电阻率的方法-对分预估计法,避开了接收机用早、晚期渐近式计算视电阻率不精确的情况,更好地判断地下异常,指导探测工作。结合实际发射机关断延时小的特点,讨论了理想场源激励下的磁场、感应电压与电阻率的对应关系,构造求解瞬变常数u的函数。计算时,把瞬变过程分为早期、晚期两个阶段,确定最佳搜索区间,解决了牛顿法等初始值选取的问题。本文方法与其它数值计算方法做仿真对比,结果表明,对分预估计法稳定可靠并能快速的迭代到精确的视电阻率值。This paper proposes pre-bisection estimation method to guide detection work,for it can fast calculate the all-time apparent resistivity,and avoid inaccuracy caused by using early-time and late-time asymptotic formula.Considering the short turn-off time of transmitter,the paper also discusses the corresponding relation between apparent resistivity,voltage,and magnetic field,and constructs function to calculate the transient constant u.The transient process is divided into early and late stages.when calculating.During the calculating process,the optimal range of search is determined,which solves the problems of initial value selection of Newton＇s method.Comparied to other numerical methods,it is proved that the method of pre-bisection estimation is stable,reliable and can iterate fast to the precise value of the apparent resistivity.

关 键 词：瞬变电磁 视电阻率 对分预估计 迭代时间 

分 类 号：P631[天文地球—地质矿产勘探]