A High Stability Fluxgate Magnetic Gradiometer For Shallow Geophysical Survey Applications
Abstract
The detection of induced and remanent magnetisation of subsurface features provides a rapid survey technique. Rejection of the unwanted geomagnetic field and its diurnal variations is accomplished by adopting a gradient magnetometer arrangement in which only the difference signal from two magnetometers separated by a short distance is recorded. Resonance type magnetometers offer high sensitivity but at the expense of increased weight. Fluxgate types are lighter but are vector sensing and their performance can be limited by thermally induced mechanical and electronic drift. This paper describes the construction of a one metre separation, vertical component, fluxgate magnetometer which alleviates these problems. The gradient sensors may be combined into multiple sensor arrays to enhance the survey rate. A data logger is also described and survey data acquired during trials and testing are presented.
- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.1176B