Time and Frequency Domain Electromagnetic Induction Metal and Landmine Detection and Identification Sensor System

Reference#: P01466

With an estimated 100 million mines and countless millions of acres of land contaminated with unexploded ordnance (UXO) world-wide there is a need for a sensor system and methods that can detect and identify large and small metal objects buried in the soil. In addition, during armed conflict, there is a need for mine detection and neutralization in real-time or near real time. A commonly used sensor for mine and UXO detection is the electromagnetic induction (EMI) metal detector. Conventional EMI detectors using either frequency-domain (FD) or time-domain (TD) eddy current methods can detect small targets at shallow depths and large metal targets at deeper depths. However other metal objects commonly found in the environment form a major problem in identifying mines and create many false alarms. These false alarms cost time and money when trying to clear an area of the real mines. Metal targets need to not only be identified but also classified in real-time.

The Johns Hopkins Applied Physics Laboratory has developed and patented a time-domain electromagnetic target discriminator (ETD) sensor system and method which is capable of measuring the metal target's time decay response based on the physical parameters of the target metal and its environment for identifying the metal target. The ETD sensor system includes a pulse transmitter connected to a receiver via a data acquisition and control system. The Transmitter and receiver include coil configurations for placement in proximity to visual obscured, buried, metal target for inducing eddy currents with in the metal target. The ETD measures the eddy current time decay response of the metal target in order to perform target recognition and classification. The identification process entails comparing the metal target's time decay response with a library of normalized object signatures, e.g., time decay responses and other characteristics.

Patent Status: U.S. patent(s) 6853194 issued. International patents issued.

Dr. G. R. Jacobovitz
Phone: (443) 778-9899