Research on Geomagnetic-Navigation-Oriented Geomagnetic Field Modeling Methods

摘要

In the recent years,geomagnetic navigation has become more and more popular. As a passive and autonomous navigation technique, geomagnetic navigation method has advantages of low cost, strong anti-jamming, none accumulative error, high concealment and navigation accuracy. Geomagnetic model, which is the main means to describe geomagnetic field, provides reference for geomagnetic navigation, and it has become the cornerstone of geomagnetic navigation technique. Starting from spherical harmonic analysis, we review the modeling methods with global support (Poisson wavelets) and then bring the focus on regional method with local support (spherical caps harmonic analysis, polynomial method, et al). According to the requirement of geomagnetic navigation, we establish evaluation index in order to determine the performance of different geomagnetic models. Using the World Magnetic Model (WMM) data, we build spherical harmonics model and wavelets model of global geomagnetic field; using the data computed from NGDC-720 model up to order 29, we build polynomial model and Poisson wavelet model of regional geomagnetic field. Evaluation index of different models is computed. According to the computed evaluation index, the theoretical characteristics, applicable conditions, advantages and disadvantages of different modeling approaches are compared. The conclusion from the paper will provide reference for geomagnetic navigation when geomagnetic field model is selected.