Study On The Compensation Method Of Vehicle Interferential Magnetic Field In UAV Aeromagnetic Survey

Compensation of the carrier interference magnetic field is one key technology in aeromagnetic survey. Sensor heading error and carrier interference magnetic field are considered in the unmanned plane interference magnetic field compensation. These factors are researched theoretically, and an integrated compensation model is established. Scalar and component compensation model are proposed, which are validated by simulation and experiment.Firstly, a linear scalar compensation model of integrated interference magnetic field is proposed, which is obtained from interference magnetic field mathematics model. The compensation parameters are obtained from singular value decomposition(SVD). The compensation precision influence factors are analyzed theoretically, and the simulation result is presented.Secondly, a component compensation model is proposed to overcome the disadvantage of scalar compensation method, because the scalar compensation method is not effective for vector compensation. Carrier attitude and geomagnetic field on geography reference frame are used for component compensation restriction, in which carrier attitude is provided by inertia navigation instrument. The component compensation parameters are calculated by linear correlation when establishing relative relationship between compensation parameter and attitude, and then, carrier interference magnetic field componentsare compensated.Lastly, the scalar and component compensation methods are validated by experiment. The motor equipment and mobile maneuver interference magnetic field of anunmannedplane are measured. A ground experiment is designed, in which a three axis magnetometer is deployed on the unmanned plane, and the interference magnetic field scalar compensation is implemented. After compensation, standard deviation is reduced from 1050 nT to 0.55 nT. In addition, inertia navigation instrument and three axis magnetometer are used for interference magnetic field component compensation. After compensation, standard deviations are reduced from 393.37 nT, 291.28 nT and 524.28 nT to 39.44 nT, 20.44 nT and 38.54 nT respectively. Experiment results demonstrate the effectiveness and correctness of the proposed method.