A Comparative Assessment Of Several Dipole-Based Algorithms For The Extraction Of Uxo Target Parameters

With funding from the Office of Naval Research (ONR), the Naval Explosive Ordnance Technology Division (NAVEODTECHDIV), the Strategic Environmental Research and Development Program (SERDP), and the Environmental Security Technology Certification Program (ESTCP), several groups have developed physics-based interpretation software for extracting target parameters from secondary EM fields induced in UXO or other small buried metallic objects. In most cases, the software uses a point dipole with a frequency- or time-dependent polarizability tensor as a model of the EM field. As part of an effort currently being funded by ESTCP to commercialize some of the emerging hardware and software technology for UXO detection and characterization, this paper presents comparative results from the application of 3 different parameter extraction algorithms for EM data based on the dipole model. Although based on a common model, there are significant differences in the respective algorithms. We highlight these differences by applying the algorithms to a common data set. The data were acquired over the Calibration Lanes at the UXO Test Site located at the Yuma Proving Grounds using a new version of the Advanced Ordnance Locator (AOL2), a state-of-the-art time-domain EMI system consisting of 3 orthogonal transmitters and an array of 9 tri-axial receivers.