Improving Detection and Discrimination of Buried Metallic Objects in Magnetic Geologic Settings by Modeling theBackground Soil Response

摘要

Magnetic soils are a major source of false positives when searching for unexploded ordnance with electromagnetic induction sensors. In adverse areas up to 30% of identified electromagnetic induction anomalies have been attributed to geology. In the presence of magnetic soil, sensor movement and surface topography can cause anomalies in the data that have similar size and shape to those from compact metallic targets. In areas where the background geological response is small relative to the response of metallic targets, electromagnetic induction data can be inverted for the dipole polarization tensor. However, spatially correlated noise from the presence of a geologic background greatly reduces the accuracy of dipole polarization estimates. In this presentation we examine the effects of sensor movement on the measured EM response of a magnetic background signal. We demonstrate how sensor position and orientation information can be used to model the background soil response and improve estimates of a target's dipole polarization tensor.