Vehicle detection and localization using Unattended Ground Magnetometer Sensors

This analysis was completed as part of a larger Modeling and Simulation effort to estimate algorithm-level Measures of Performance (MOP), such as the probability of detection (PD) and the probability of identification (PID) of a vehicle or person transiting through an area of interest. The present work focuses on MOPs for Unattended Ground Magnetometer Sensors, which may be used to detect passing vehicles and estimate their bearing relative to the magnetometer position. In the first phase of the analysis, we concentrate on the probability of detection as a function of vehicle speed and distance (i.e., point of closest approach (CPA)) from the sensor. In the second phase, we try to localize the vehicle by extracting its relative bearing with respect to the magnetometer from the two orthogonal induced magnetic field measurements. The derivations are based on the assumption that a road vehicle may be approximated as a prolate homogeneous ellipsoid, as well as the assumption of uniform linear motion. Results show that, for speeds below 30 MPH, the maximum detection ranges (for PD = 0.5) are on the order of 40 meters for two-axis fluxgate magnetometers and for the operational parameters used in this analysis.