<p>This invention concerns airborne geophysical surveys and the processing of vector magnetic data from those surveys to remove the aircraft effect. Coefficients representing the permanent and induced magnetic effects are calculated from data obtained during a calibration flight, with reference to the aircraft coordinate system. Then an airborne geophysical survey flight is conducted, and the permanent and induced magnetic effects are removed from the survey flight data in the aircraft coordinate system. The corrected survey flight data is rotated into the NED coordinate system, and the eddy-current effect is removed from the corrected survey data in the NED coordinate system.</p>
