SQUID technology for geophysical exploration

Abstract

This paper summarizes the results of our latest successful tests with a full tensor LTS SQUID magnetic airborne gradiometer system on platforms such as a helicopter and a fixed wing aircraft, as originally reported on by Stolz et al. (Stolz 2006). The system incorporates planar‐type SQUID gradiometers. It allows standard profile work without any constraints. In mobile applications the gradient resolution at low frequencies is mostly dominated by motion noise caused by the imperfect suppression of variations of the homogeneous magnetic Earth's field. Therefore, strong disturbances appear when the gradiometer is tilted in the homogenous Earth's magnetic field. These signals, caused by the too low CMRR (common mode rejection ratio) can be drastically decreased, by in house developed software utilizing data of a SQUID magnetometer triple.