A Ground-Bas Ed Squid Magnetometer

Over the past five years, our group has focused on development of airborne magnetic and electromagnetic systems for mapping and detection of unexploded ordnance (UXO). Among these projects is one involving testing and development of a high temperature airborne Superconducting Quantum Interference Device (SQUID) tensor magnetometer. In association with the airborne SQUID development, we are conducting tests of the SQUID as a ground-based instrument for UXO mapping and detection. The ground-based SQUID is mounted on a man-portable litter with ancillary instrumentation mounted on a cart and connected by an umbilical. High-temperature SQUIDs use liquid nitrogen as the cryogen, which is more convenient than the helium-cooled lowtemperature devices. Preliminary data from the ground-SQUID prototype show good agreement with cesium vapor total magnetic field data along a test line. Noise frequencies and levels appear manageable and we anticipate that specialized processing should make it possible to extract more details about UXO items from their tensor magnetic properties.