High-performance SQUID magnetometer system

The QAMT is the latest development of a geophysical prospecting system for high-resolution acquisition of three orthogonal magnetic field components. Due to the innovative readout technique, both dynamic range and signal slew rate could be increased enormously.

This innovation was able to extend the range of applications of geophysical measurement systems to both active (semi-airborne) as well as passive electromagnetics. Here, either currents are actively coupled into the ground or natural excitations (e.g., due to atmospheric activity) are passively utilized to generate geophysical eddy current systems, which are used to acquire the conductivity distribution in the subsurface by airborne magnetic field sensing. These techniques are particularly advantageous in the exploration and characterization of deep-seated or covered deposits.

However, the new technology must satisfy the increased requirements of these applications. In order to move freely in the Earth's magnetic field without losing information due to sensor limitations, the system must provide a wide dynamic range. To detect all possible excitation signals, the sensors must be very fast, which is given by high slew rates. To detect the smallest differences in conductivity, very sensitive sensors with a low noise level are required.