基于磁梯度测量的磁校准方法OA北大核心CSTPCD

Before aircraft heading measurement by using a tri-axial magnetic sensor or magnetic anomaly detec-tion,magnetic interference calibration of the magnetic sensor is required.In order to avoid the degradation of calibra-tion accuracy due to the short-time fluctuation of the geomagnetic field,an interference calibration method for magnetic sensors using magnetic gradient measurement is proposed based on the geomagnetic field gradient distribution character-istics in near-earth space.A 24-parameter interference model for magnetic interference of the magnetic gradient meas-urement system is established,and a multivariate nonlinear equations is constructed based on multiple arbitrary rota-tions of the ellipsoidal fitting method for a single sensor,then by the solution of the nonlinear system equations using a genetic algorithm with higher region search efficiency.The simulation results show that,compared with the traditional ellipsoidal fitting calibration method,this proposed method overcomes the influence of short-time fluctuations of the geo-magnetic field,and improves the calibration accuracy of the magnetic gradient measurement system,whose differential magnetic gradient measurement error can be calibrated to[1.848 2 1.845 3 1.915 0]T nT.This study provides a relia-ble guarantee for the carrier interference compensation and high-precision measurement of the aero magnetic system.