Abstract: A method and system for compensating maneuver induced components in the magnetic field sensed by an airborne magnetic detector. The magnetic fields sensed during a series of selected aircraft maneuvers are processed to yield signals representative of the magnetic properties of the aircraft. Subsequently, these signals are combined with signals representative of the aircraft attitude to provide a compensation signal. This compensation signal may be applied directly to the output of the magnetic detector or may be used to drive a set of compensation coils.

Abstract: A smart mine includes a pair of He.sup.3 magnetic sensors exteriorly connected to a head compartment of a mine housing. A torpedo compartment for housing a torpedo completes the mine housing. The head compartment contains the sensor support electronics which includes a phase locked loop means having a pair of digital phase locked loops connected between the sensors and a difference circuit whereby a difference signal representative of the difference between the pair of He.sup.3 magnetic sensors is produced for processing in a signal processor for determining the presence of large ferromagnetic bodies and producing a torpedo firing signal.

Abstract: In marine seismic exploration, it is common for a vessel to tow a streamer, which includes a plurality of pressure sensitive detectors or hydrophones, for the purpose of acquiring seismic signals representative of the underlying structure of the earth. To aid in the interpretation of these seismic signals, it is necessary to know the precise location of the streamer at the time the signals are acquired. Disclosed herein is a method and system for providing a model representative of the location of the streamer relative to the location of the vessel. In one aspect, the system includes an apparatus mounted at the stern of the vessel and coupled to the near end of the streamer. This apparatus is adapted to provide measurements of the yaw and pitch of that portion of the streamer adjacent the vessel. These measurements are employed in the generation of the position model.