中心回线瞬变电磁响应计算的频-时域转换方法研究  

Research on frequency-time domain transform method in central-loop transient electromagnetic field response computation

作　　者：孙业发 李桐林[1] 范翠松[2] 陈闫[1] 

机构地区：[1]吉林大学,地球探测科学与技术学院,长春130026 [2]中国地质调查局天津地调中心,天津300170

出　　处：《地球物理学进展》2014年第3期1243-1247,共5页Progress in Geophysics

基　　金：中国地质调查局项目吉黑东部综合找矿方法研究([2013]01-060-004);国家重大科学仪器设备开发专项“大深度三维电磁探测技术工程化开发”(2011YQ05006009)联合资助

摘　　要：在中心回线瞬变电磁响应的正演模拟中,经频-时域转换后,垂直磁场随时间的变化率在晚期得到的结果通常精度不高.本文研究分析了三种频-时域转换方法(余弦变换的折线逼近法、正弦变换的数值滤波算法、余弦变换的数值滤波算法)的转换精度问题,得出了基于正弦变换的数值滤波的方法比其他两种方法在晚期计算中精度更高,之后对三种转换方法存在精度问题的原因进行了分析,有利于进一步提高频-时域转换的精度.In the forward modeling of central-loop transient electromagnetic,the vertical magnetic field with time change rate,which has been through frequency-time domain transform,usually has no high accuracy in the late-time＇s response.This paper analyzes the problem of transform accuracy of three methods of frequency-time domain transform（polygonal approximation method of cosine transform,digital filtering algorithm of sine transform,digital filtering algorithm of cosine transform）.It is concluded that the digital filtering method based on sine transform has higher computing precision than the other two methods.Then the reason that causes the error accuracy in three methods are analyzed,which will lead to further improvement on the transform accuracy in the frequency-time domain transform.

关 键 词：瞬变电磁 频-时域转换 正余弦变换 数值滤波 

分 类 号：P208[天文地球—地图制图学与地理信息工程]