College of Geo-Exploration Science and Technology, Jilin University, Changchun 130026, China

There is usually source effect in the field work of controlled-source audio-frequency magnetotelluric method. Source effect is a thorny problem during field working, data processing and interpretation. Therefore, it is very important for the results of field prospecting to model source effect and summarize its influence rules. Based on the previous research, the authors use 3D finite difference method to simulate the electromagnetic field and set different anomaly situation to study the source effect in near-field measurement, then conclude the in-fluence rules of source effect. Simulations provide the reference for the actual field work and data processing to correct the influence of source effect, so the information of the underground will be more approaching to the real.

Supported by project of China Geological Survey (No.12120113098400).