地面移动源频率域电磁法及其探测效果

常规地面频域可控源电磁法采用单发射源，为获得较大探测深度需采用大收发距进行观测，这容易导致观测资料信噪比较低。为此，尝试在地面采用移动源，通过缩小收发距、采用不同偏移距的发射源进行观测，实现提高资料信噪比的目的，并通过综合利用几何测深与频率测深加大有效探测深度。结合典型一维层状模型，对地面移动源频率域电磁法与常规地面可控源电磁法的探测效果进行对比分析，结果表明移动源电磁法对常见的地电模型均有较好的探测效果，可弥补常规地面可控源电磁法对地下高阻层不敏感的缺点。对赣东北某矿区开展方法实验，数据处理结果验证了地面移动源电磁法对于解决实际问题的适用性。

Frequency-domain electromagnetic method with ground moving source and its detection effect

As the traditional ground frequency-domain controlled-source electromagnetic (CSEM) method uses a single transmitter,large source-receiver distances need to be adopted for observation to obtain large detection depths,which is highly likely to cause a low signal-to-noise ratio of the observed data. This paper attempts to use ground moving sources and achieve the purpose of improving the signal-to-noise ratio of the data by narrowing the source-receiver distance and employing transmitters with different offsets for observation. More-overthe effective detection depth is enhanced by comprehensively using geometric sounding and frequency sounding.The typical one-dimensional layered model is utilized to comparatively analyze the detection effects of the frequency-domain electromagnetic method with ground moving sources, i.e.,the ground frequency-domain MSEM method,and the traditional ground CSEM method.The results show that the MSEM method has a favorable detection effect on common geoelectric models and that it can make up for the disadvantage of the traditional ground CSEM method that it is not sensitive to underground high-resistance layers.Experiments on the proposed method are conducted in a mining area in northeast Jiangxi Province,and the data processing results verify the applicability of the ground MSEM method to solve practical problems.