Evaluation of Target Picking Methods for Magnetic Data
SCIENCE APPLICATIONS INTERNATIONAL CORP (SAIC) CARY NC
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Due to the large numbers up to tens of thousands of possible targets identified in nominal UXO surveys, efficient and reliable machine-aided target pickers should be used to identify targets for subsequent characterization. When selecting anomalies, the goal is to identify all anomalous features that may be caused by UXO while minimizing operator time and eliminating operator bias. To facilitate advanced physics-based modeling, however, the target pickers should also be able to select data appropriate to the target, i.e., to outline or estimate the anomalies spatial extent. The current approach to target selection is either manual identification or amplitude thresholding. The former is time intensive, not clearly defined, and prone to operator bias. The latter is sensitive to noise and is prone to over- or under-picking unless judicious oversight is exercised. Neither approach provides measures for estimating the footprint of the anomaly. The impact to the DoD is obvious. Systematic, fast, and robust target pickers can save money and produce a defensible target list compared to the current methods. This project evaluated four automatic target pickers against the manual method and transitioned them to the user community via Oasis montajTM by building custom Geosoft ExecutablesGX. Oasis montajTM is a geophysical data processing and visualization package developed and marketed by Geosoft Incorporated. The four automatic target pickers were 1a wavelet-based detection algorithm, 2clustering positive and negative peaks, 3a dipole-based matched filter, and 4analytic signal. The demonstration was broken up into two phases. The first phase used a 60 dipole synthetic data set to explore the parameter space and optimize the algorithms for the four automatic target pickers. The result of phase 1 was a set of starting parameters that was used in phase 2. The second phase applied the target pickers to 7 magnetic data sets using the parameters output from phase 1.
- Target Direction, Range and Position Finding
- Ammunition and Explosives