Combined wave emission system based on dual resonance method for airborne transient electromagnetic detection

Abstract

To improve the detection efficiency of airborne transient electromagnetic method (ATEM) and reduce the times of flight experiment, a dual resonance-based combined wave emission circuit is proposed in this paper, which realizes the combined emission of half-sine wave and triangular wave through the selection of different resonant branches. Based on the operating principle of the proposed emission circuit, the model of second-order RLC equivalent circuit is established. Then, the generation process of the combined wave is analyzed, and the segmentation control method is proposed. Finally, the feasibility and effectiveness of the proposed combined wave emission system are verified by simulation model building and prototype testing, and the results show that the emission current is of good quality and high stability. Compared with the traditional emission of single wave current, the combined wave current has the advantages of large magnetic moment of half-sine wave and rich high frequency components of triangular narrow pulse, which can effectively expand the detection range and improve the measurement efficiency of ATEM.

Borehole transient electromagnetic response calculation and experimental study in coal mine tunnels

“…Traditional transient electromagnetic method (TEM) is commonly used in ground exploration and in tunnels, employing large-scale transceiver devices for extensive deep exploration [7][8][9][10]. Ground half-space borehole TEM (BTEM) research began in the mid-1980s.…”

Forward simulation of unfavorable geological bodies and analysis of waveform characteristics based on time domain finite difference method

“…The electromagnetic category mainly includes ground penetrating radar prediction (GPR) [14][15] and transient electromagnetic method prediction (TEM) [16][17] . In addition to the aforementioned techniques, resistivity method [18] , induced polarization method [19] , magnetic resonance sounding method [20] , infrared water exploration [21] , rock mass temperature method [22] , etc. have also been applied to the detection of unfavorable water-bearing geological bodies in front of the working face.…”