The German airborne SQUID tensor magnetic gradiometer

The German program was started in 1997 at the Institute for Physical High-Technology (IPHT) with the aim of developing a full airborne superconducting quantum interference device (SQUID) magnetic tensor gradiometer using liquid-helium-based thin-film technology. Since that time the sensor, electronics, data acquisition system, and cryogenics have been developed and tested. The first flight trial of a full tensor gradiometer (6 gradient + 3 magnetometer channels), with ancillary sensors (3-axis accelerometer, current sensors, and a real-time differential GPS) was completed in May 2003. This paper describes the system, provides some preliminary results from that experiment, and describes upcoming improvements.