Classification of unexploded ordnance-like targets with characteristic response in transient electromagnetic sensing

Abstract

Characteristic response parameterized in time-dependent target intrinsic polarizabilities can be used to discriminate unexploded ordnance (UXO) from harmless items. This study explains the measurement, analysis, and classification of UXO-like targets against data collected under laboratory-type conditions with a specially designed transient electromagnetic (TEM) system. After a brief description of the single dipole model and TEM system, the characteristic responses of all UXO-like targets have been measured with an improved long straight solenoid. The influence of the target shape and size on characteristic response is analyzed. Results show that targets of the same shape share similar power law function decay rate at an early time. The larger the target size is, the greater the response will be. The characteristic response for harmless targets decays faster than the UXOs, leading to a considerable difference in a later time, which can be used for target classification. When the characteristic response is parameterized as kt −β e −γ t in 100 ms, targets can be effectively separated with the fitted parameters k, β and γ. However, when fitted in 10 ms, the fitted parameter γ may be thousands of times than the one fitted in 100 ms, resulting in classification failure. The normalized response combined with the fitting parameter β can be used for target classification to overcome the instability of fitted parameter γ in 10 ms. Finally, all UXOs are completely separated from harmless targets within 10 ms. K: Data processing methods; Detection of explosives; Pattern recognition, cluster finding, calibration and fitting methods 1Corresponding author.

Precision Magnetometers for Aerospace Applications: A Review

“…Currently, detailed magnetic observations for geological surveys [ 13 , 14 ], unexploded ordnance detection [ 82 , 83 ], magnetic anomaly detection (e.g., of submarines or sea mines) [ 84 ], and other applications [ 5 , 11 ] are primarily conducted using magnetometers on manned vehicles, be they land-based [ 5 , 85 ], aircraft [ 83 , 86 , 87 ], ships [ 88 , 89 ], or underwater vehicles [ 90 ]. Manned aircraft are relatively large and able to generate significantly higher power than UAVs, making them suitable platforms for high-sensitivity airborne magnetometer solutions, such as the SQUID-based tensor magnetic gradient measurement system “UXOMAX” [ 91 ].…”

Precision Magnetometers for Aerospace Applications

“…Currently, detailed magnetic observations for geological surveys [13,14], unexploded ordnance detection [133,134], magnetic anomaly detection (e.g., of submarines or sea mines) [135], and other applications [5,11] are primarily conducted using magnetometers on manned vehicles, be they land-based [5,136], aircraft [134,137,138], ships [139,140], or underwater vehicles [141]. Manned aircraft are relatively large and able to generate significantly higher power than UAVs, making them suitable platforms for high-sensitivity airborne magnetometer solutions, such as the SQUID-based tensor magnetic gradient measurement system UXOMAX [142].…”

Real-time Detection System for Portable Transient Electromagnetic Unexploded Ordnance

“…In terms of data processing, traditional detection methods usually store measurement data on hardware [4][5][6] . This system employs an ARM+FPGA dual-core system for real-time data acquisition and processing.…”