Evaluation of Three-Component Magnetic Sensors for Delineation and Identification of UXO

The data acquired from three-component magnetic sensors are evaluated to determine if the information provided by the additional Hx, Hy, and Hz components improves the detection, delineation, and identification of UXO. The three-component data were acquired under controlled field conditions. Model data were generated with the program MAGMOD, which uses a prolate spheriod and multipole expansion solution to estimate the induced magnetic field external to the spheriod. Comparison of the total magnetic field and individual component plots of the model and field data suggests that the three-component sensors may provide information necessary to better determine the depth and orientation azimuth and dip of the ordnance in the subsurface. At the present time, three-component sensors are not suitable for practicle field applications because of their sensitivity to orientation and levelness. Improper leveling of the sensor can cause a magnitude increase in the variation of the measured magnetic field.