Dual-frequency transmission radio wave-based exploration method and its application

Coal seams can act as the guided wave layers of high-frequency electromagnetic waves, and radio wave perspective technology can be used to detect geological structures within coal seams of a working face. Presently, radio wave perspective methods usually use a single frequency, leading to some problems such as improper frequency selection and limited detection accuracy in the exploration of mining faces. In response, this study developed a dual-frequency transmission radio wave-based exploration method. Based on theoretical analysis, as well as the field strength of dual-frequency perspective and attenuation coefficient, this study derived the calculation formula for the absorption factor γ of coals based on the measurement data of dual-frequency radio waves. Furthermore, using the finite element numerical simulation method, this study simulated and analyzed the conditions of coal seams bearing no anomalous geological structures and those containing faults. The experimental results show that the dual-frequency absorption factor was more sensitive to the geological anomalies of coal seams, verifying the effectiveness of the dual-frequency transmission radio wave-based exploration method. The comparison between the field experimental data and the mining drilling results also verified that the dual-frequency absorption factor γ exhibited better responses to geological anomalies than the single-frequency attenuation coefficient. The above experimental results show that the dual-frequency transmission radio wave-based method can improve the detection effects of geological anomalies within coal seam mining faces, providing a new method and idea for radio wave-based finescale exploration and the ascertainment of mine geology.