Patent ID: 8878538

Claim:
An airborne geophysical surveying system comprising: a receiver coil assembly for towing by an aircraft, the receiver assembly including at least one receiver coil for sensing changes in a magnetic field component of a magnetic field, and a receiver coil orientation sensing system for sensing orientation changes of the receiver coil; and a controller receiving signals representing the sensed changes in the magnetic field component from the receiver coil and the sensed orientation changes from the receiver coil orientation sensing system, and correcting the sensed changes in the magnetic field component to provide a signal that is corrected for noise caused by changing orientation of the receiver coil in a static geomagnetic field, wherein the controller provides the corrected signal by: predicting, in dependence on the signal from the receiver coil orientation system, a resulting signal from the receiver coil, and subtracting the resulting signal from the signal received from the receiver coil.