地磁基准图分辨率对地磁导航精度的影响分析

The geomagnetic anomaly field has rich spatial features and is stable over time. The matching navigation based on geomagnetic field information has attracted much attention. However, the current acquisition of high-precision magnetic field data in oceanic areas faces the problems of high acquisition costs and difficulty of data collection in some areas. As a result, sparse magnctometry data are usually used to construct geomagnetic maps. The accuracy of geomagnetic matching navigation is closely related to the geomagnetic reference map. To investigate the specific requirement of geomagnetic matching navigation for the resolution of the geomagnetic reference map, six different resolutions of 50 m, 100 m, 200 m, 500 m, 1 000 m, and 2 000 m geomagnetic maps are first obtained by interpolation and sampling. Then, the magnetic contour matching (MAGCOM) algorithm and the iterative closest contour point (ICCP) algorithm are used as matching algorithms to analyze the results of matching navigation under geomagnetic reference maps of different resolutions by using the simulation and measured data. The results show that under specific inertial bias and different speeds, interpolating the geomagnetic map resolution from 500 m to 200 m and 100 m brings about a certain degree of improvement in navigation accuracy, and the improvement does not exceed 50%. Meanwhile, under the simulation conditions, the matching error is close to the inertial error when using geomagnetic maps interpolated up to 50 m.