Method and experiment for compensating the interferential magnetic field in underwater vehicle

It is the key technique for underwater geomagnetic navigation to compensate vehicle interferential magnetic field. The essential of interferential field compensation is to estimate model parameters of interferential fields and use the parameters to compute geomagnetic field. The rank-deficient problem will appear with least square method because the distribution of measurement data in gesture space is insufficient. In this paper, the vehicle voyage track is optimized to improve the completeness of measurement data and differential evolution (DE) algorithm is adopted to estimate model parameters of interferential magnetic field. Underwater experiments are carried out to validate the compensation effect. After compensation, the measurement error of geomagnetic field has decreased from more than ten thousands nT to tens of nT. Compared with least-square algorithm, the DE algorithm has better performance in accuracy. The results demonstrate that the proposed method can effectively compensate vehicle interferential field effectively and thus improve measurement accuracy of geomagnetic field for underwater vehicle.