Based on their experiences with LTc SQUID sensors, extensively being used in TEM surveys, SUPRACON AG and IPHT (Institute for Physical High technology) of Jena/Germany, manufacturers of both Low Temperature (LTc) - and High Temperature (HTc) SQUIDs, have developed a new HTS SQUID sensor for ground Time Domain Electromagnetic surveys.

The system is cooled using liquid nitrogen and measures the vertical B field. Horizontal components can be added depending on user requests. Using a completely new SQUID electronics design, the noise performance at low frequencies is drastically improved. The system incorporates a cable tester, battery monitor and analogue
signal meter. Symmetric outputs via banana plugs allow the user to connect the sensor to any geophysical receiver. The operational system has an overall weight of 17 kg.

The SQUID electronics, which is mounted directly on top of the cryostat, is tuned automatically using micro processors in the control unit. The built in power supply allows for a 12 hours working day. The noise limited resolution is below 50fT/sqrt(Hz) for frequencies above 100Hz, increasing slightly to <200fT/sqrt(Hz) at 1Hz.

During the past year, Supracon and IPHT have also incorporated significant improvements in their operational airborne Full Tensor Magnetic Gradiometer system, which was deployed on routine surveys during the second half of 2006