A novel localization and orientation method of magnetic sensors for magnetic characterization of spacecraft

To achieve the magnetic cleanliness of spacecraft, it is necessary to precisely model the magnetic characteristics of the spacecraft using on-ground magnetic measurement data collected by magnetic sensors. The accuracy of the modeling largely depends on the accurate position and orientation information of magnetic sensors. Therefore, this paper presents a novel localization and orientation method for sensors based on a magnetic beacon to obtain accurate sensor position and orientation. Firstly, the magnetic field generated by the magnetic beacon is characterized by spherical harmonic functions. Therefore, the method proposed in this paper is not limited to dipole-like magnetic beacons. Subsequently, the magnetic beacon was placed on a non-magnetic turntable and rotated through one full circle. The generated magnetic field was measured by sensors whose position and orientation needed to be determined. The deviation between the Fourier coefficients calculated based on the spherical harmonic model and the that obtained based on the test data is used as the objective, and the Particle Swarm Optimization (PSO) algorithm is adopted to calculate the position and orientation. Through simulation and experimental measurement, the accuracy of the algorithm, the localization and orientation ability at short distances, the uniqueness of the solution, and the anti-noise ability were verified, which shows that under the condition of 1 nT Gaussian noise, the standard deviations of the position and orientation obtained from multiple repeated calculations are 1.502 mm and 0.22°, respectively.