The electromagnetic characteristics of UXO using the electromagnetic method

Abstract

In UXO clearance operations, reliable detection is a prerequisite for safe and efficient remediation. This paper investigates a transient electromagnetic (TEM) method for UXO detection, including the optimization of a magnetically coupled transmitting source and the analysis of the electromagnetic responses of UXO targets with different orientations and burial depths. Numerical simulations demonstrate that the proposed single-transmitter, multi-receiver TEM configuration not only enables rapid target localization, but also substantially reduces data volume and processing workload, thereby improving detection efficiency. Based on finite element modeling constrained by the fast localization results, the dependence of target responses on position and attitude is examined in detail. Field experiments show that the temporal evolution trends of the simulated time-domain responses under different orientations are in good agreement with the measured data. In motion-survey mode, the measured line responses allow rapid identification of suspicious locations, while planar responses further resolve the attitude of subsurface anomalies. In fixed-point sounding mode, the initial amplitude of the time-domain response is sensitive to target depth, and the symmetry of the planar response is governed by the inclination angle. These results provide a quantitative basis for the design and optimization of TEM detection systems for UXO.