Development of a high temperature superconducting magnetic tensor gradiometer for underwater UXO detection

We are developing a magnetic tensor gradiometer for underwater unexploded ordnance (UXO) detection using high-T_c SQUID planar gradiometers. The system will use signals from six planar gradiometers, located on the faces of a hexagonal pyramid, to calculate the full gradient tensor. It will be towed underwater and will need to deal with noise caused by ocean waves, sensor motion and the measurement capsule itself. This paper presents our progress to date on this project including test results of gradiometer performance in laboratory conditions.