This map was compiled from data obtained as a result of an aeromagnetic survey carried out by Fugro Airborne Surveys using a Cessna Caravan aircraft. A 0.005 nT sensitivity split-beam cesium vapour magnetometer was mounted in the tail boom of the survey aircraft.
The survey operations were carried out from March 7 to May1, 2003. The nominal traverse line spacing was 800 m with control lies at 2.4 km spacing at a nominal terrain clearance of 200 m. A preplanned flight surface was calculated for this survey to minimize the control line and traverse line altitude differences. Flight path was recovered using a post flight differential Global Positioning System, combined with a vertically mounted video camera.
After editing the survey data, the intersections of the control and traverse lines were established and differences in the magnetic values were computer analysed and manually checked to obtain the level network. The levelled total field values were then interpolated to a 200 m grid. The International Geomagnetic Reference Field has not been removed from the magnetic total field.