Active Detection of Small UXO-Like Targets Through Measuring Electromagnetic Responses With a Magneto-Inductive Sensor Array

The mission of detecting and locating unexploded ordnance (UXO) such as the landmine, the improvised explosive devised, etc., is still a challenge to be overcome. In this paper, a new active approach for UXO detection through measuring electromagnetic (EM) response with a magnetic sensor is proposed. To further enhance the magnetic field strength of the UXO, a current-carrying coil is employed to produce a time-varying or steady magnetic field, and a magnetic field modeling of the solenoid structure is built to select optimal coil parameters. To realize three-dimensional imaging, a magnetic field measurement array of $3\times3$ tri-axial magneto-inductive (MI) sensors is constructed, and its major electrical characteristics are evaluated. Finally, a test platform is developed, and the experimental results indicate that the proposed method can detect a plastic anti-personnel UXO down up to a depth of 20.1 cm, improving 50% approximately when compared with a commercial metal detector.