Patent ID: 8584586

Claim:
A method implemented using a computer for degaussing a marine vessel having degaussing coils associated therewith, the method comprising: in a test facility, measuring a first impulse response, said first impulse response being the offboard sensor response of the vessel to an impulse of the ambient magnetic field, said first impulse response being indicative of a first roll frequency dependency, said first roll frequency dependency being the dependency, on the roll frequency of the vessel, of the induced signature of the vessel; in a test facility, measuring a second impulse response, said second impulse response being the offboard sensor response of the degaussing coils to an impulse of electrical current applied to the degaussing coils, said second impulse response being indicative of a second roll frequency dependency, said second roll frequency dependency being the dependency, on the roll frequency of the vessel, of the induced signature of the degaussing coils; calculating, for a spectrum of the ambient magnetic field, a roll-frequency-dependency offset, said roll-frequency dependency offset being the amount of electrical current to be applied to the degaussing coils that results in zero sum of said first roll frequency dependency and said second roll frequency dependency; in real time onboard the vessel, measuring the ambient magnetic field; and in real time onboard the vessel, applying to the degaussing coils said roll-frequency-dependency offset corresponding to the ambient magnetic field measured in real time onboard the vessel.