I am sure that you are- all familiar with Airborne Magneto- meter Surveying so I shall-spend only a brief moment describing the instrument and techniques and the remainder of the allotted time-on-modern-application-of the instrument._x000D_
The Airborne Magnetometer used by Aero Service in AUstralia- was designated by Gulf Research and implements the saturable-core flux-gate--principle. The first magnetometers developed'were magnetic-balances and depended on the counter-torque principle but these required a stable platform and hence are not applicable to airborne surveying. Other methods include the induction methods, the Hall Effect methods, magneto-striction methods., Deflectioh. of,free.electrons, the proton-precession methods._x000D_
Some: of these are applicable to airborne surveying. As a matter of-fact the nuclear precession magnetometer is the one generally used in the Satellites because it has been miniaturized most successfully._x000D_
The Gulf Magnetometer is the one most generally used in mineral and petroleum exploration because its sensitivity is sufficient for the problem and-data and instrument techniques have been worked out and standardized.