频率域可控源电磁法多源数据联合反演

在传统的地面频率域可控源电磁法(FCSEM)勘探中,通常针对单一发射源装置下的观测数据进行反演计算。因此,探索地面频率域可控源电磁法的多源联合反演方法很有必要。首先,利用一维自适应正则化反演(ARIA)算法实现了多源数据的联合反演; 然后,基于三层模型分析了不同源组合和不同数量源组合对联合反演效果的影响; 最后,评估了该联合反演方法应用于复杂模型的效果。结果表明:相较于单源反演,多源联合反演可以明显提高反演结果的精度,使获得的地电参数更加接近真实值; 随着参与反演源数量的增加,反演效果会得到进一步的改善; 在不同源组合方式中,除了赤道向源组合对高阻目标体不敏感外,其他形式的源组合都可以实现对高、低阻目标体的灵敏反映。上述研究可为建立合理的多源频率域可控源电磁法观测技术和实际数据处理提供指导。

Jointly Inversion of Multi-source Data of Frequency-domain Controlled Source Electromagnetic Method

In the traditional land frequency-domain controlled source electromagnetic method(FCSEM), an observing point generally only corresponds to a single transmitting source. Thus, it is necessary to explore the multi-source joint inversion method of land FCSEM. Firstly, the joint inversion of multi-source data was realized by using one-dimensional ARIA. Then, based on the three-layer model, the effects of different source combinations and source numbers on the joint inversion were analyzed. Finally, the results of this joint inversion on complex models were evaluated. The results show that compared with the single source inversion, joint inversion of multi-source data improves the accuracy of inversion results, making the obtained geoelectric parameters are closer to the real value especially when the models are more complicated; with the increase of the number of sources involved in the inversion, the results will be further improved. Except the combined broadside sources are not sensitive to the resistive target, the other forms of combined sources are all sensitive to the conductive and resistive bodies. The above research is willing to provide a guide for establishing a reasonable observation technology of multi-source FCSEM and processing pratical data.