电性源地空电磁法场源效应模拟分析

Simulation Analysis on Source Effect of Electrical Source Ground-to-air Electromagnetic Field

针对地空电磁受到场源效应影响时会与探测目标体产生的电磁响应叠加在一起,影响地质工作者对目标体的识别,为此从频率域磁场垂直分量(Hz)出发,模拟分析了地空电磁电性线源产生的磁场响应对均匀半空间内不同位置分布的高、低阻异常体产生的影响。研究表明:在均匀半空间内,当y<0时,Hz实部为负值,Hz虚部为正值,当y>0时正好相反。距离场源近的异常体引起的Hz幅值较大,关于y=0 m对称分布的异常体,引起的Hz响应也关于y=0 m对称。同一位置的高、低阻异常体引起的Hz实部曲线形态相反,高阻体的Hz虚部幅值大于半空间的,而低阻体的Hz虚部幅值小于半空间的。

When ground-to-air electromagnetism affected by source effect, the electromagnetic response of ground-to-air electromagnetism and detecting target body will be overlaid together, it will affects the identification of target body by geologists, therefore,the simulation analysis on electromagnetic response generated by ground-to-air electromagnetic electrical line source was carried out for its influence on high, low-resistance anomalies distributed in different position of uniform half space, based on the vertical components of the magnetic field in the frequency domain. Research shows: in uniform half space, when y<0, Hz real-part is negative, Hz imaginary part is positive value, when y >0, it is the other way around. Hz amplitude was big generated by anomalies close to field source, the symmetrically distributed anomalies about y=0m, the caused Hz response is also about y=0m symmetry. Hz real part curve in reverse form caused by high, low-resistance anomalies at the same position, when Hz imaginary part of high resistance body is larger than half space,Hz imaginary part of low resistance body is smaller than half space.