Controlled-source frequency electromagnetic method with multiple reference channels

Land-based Controlled-Source Electromagnetic (CSEM) methods are extensively utilized in hydrology, engineering geology, and resource exploration. This study focuses on the significant challenge of denoising electromagnetic data, especially under strong interference or complex geological conditions. Traditional scalar CSAMT, which measures orthogonal horizontal components of electric and magnetic fields in the far field, faces limitations due to weak magnetic signals and the need for precise orientation of magnetic sensors. This research introduces a novel CSEM method integrating multiple reference channels, including Noise Reference Channels (NRC) and Scalar Reference Channels (SRC), to overcome these obstacles. The NRC is designed to record “pure” noise at the same site, reducing noise interference in normal survey channel data. The SRC, distributed discretely over the survey area, records both electric and magnetic fields, enhancing interpretation accuracy for Ex detection in far-field scenarios. This method shows promise in robust anti-interference capabilities and accurate detection in complex environments.