Research and application of response characteristics of mine transient electromagnetic perspective detection technology

Aiming at the difficulty in detecting concealed geological isomers using conventional geophysical method in ultra-wide coal working face, the electromagnetic response mechanism of mine transient electromagnetic (TEM) perspective detection with opposite side emission and reception is revealed in this study. The electromagnetic field diffusion characteristics, data influence mechanism and detection capability of transient electromagnetic perspective detection technology are studied in detail by means of theoretical research, numerical simulation and analysis of measured data. The results show that the transient electromagnetic field diffusion of the full-space elongated emission loop is different from that of the half-space electromagnetic field diffusion due to the boundary between ground and air. In the full-space state, the extreme value of the induced electromotive force (EMF) is located in the center of the emission coil for a long time, which cannot be interpreted directly by using the ground ‘smoke ring