通过时间-频率转换关系,TEM数据可以转换成平面波场测深数据,从而可以对TEM资料进行拟平面波场处理解释.在对瞬变电磁视电阻率数据向平面波场测深视电阻率数据转换时,发现由于瞬变电磁使用晚期计算公式及装置问题,使测深曲线早期数据发生畸变.文中建立了视电阻率曲线进入晚期所满足的关系式,从理论上给出不同情况下瞬变电磁测深视电阻率曲线进入晚期的临界点.以瞬变电磁、大地电磁、CSAMT为例,对大量的模型进行正演计算,对计算结果进行对比分析,建立不同地表电性结构、不同时间延迟情况下,瞬变电磁早期数据误差的校正量板.
According to the relationship between time and frequency, TEM sounding data can be transformed into plane-wave sounding data, for the purpose to process TEM data as MT . During the study of transformation from TEM diffusion field sounding data to plane-wave electromagnetic sounding data, it has been discovered that there exist distortions in early-time data because of using late-time calculating formula in all time delay and configuration. In this paper, the formula of late-time apperent resistivicy curve has been constructed. Theoretically, the late-time point of different configuration and geo-electric structure has been given. After a lot of calculation of models and theoretical analysis, according to different time-delay, survey configuration, geo-electric structure, a revised method of TEM early-time field data has been given.