SYNTHETIC APERTURE IMAGING IN ADVANCED DETECTION OF ROADWAY USING MINE TRANSIENT ELECTROMAGNETIC METHOD

Abstract

During the data processing and interpretation of mine transient electromagnetic method (MTEM), in order to improve the identification of the geo-electrical interface between low resistivity abnormal body and surrounding rock in advanced detection, transient electromagnetic field was transformed to pseudo-seismic wave-field based on the function relationship between spreading electromagnetic field and seismic wave-field in whole-space. Meanwhile, the signal of pseudo-seismic after being transformed was processed with correlative stack to strengthen the amplitude and improve signal-noise-ratio (SNR) using the synthetic aperture imaging (SAI). The data of different detection directions on one surveying point in MTEM were imaged as aperture data, which would highlight weak abnormality and improve SNR. In addition, the application effect of SAI was testified with the in-site advanced detection in roadway using MTEM. The results showed that the SAI of the MTEM could improve SNR of the electrical interface information and highlight the geometrical resolution to increase exploration accuracy. The technique is significant theoretically and practically in accurate advanced detection of aquifer structure by MTEM.