Modeling of high accuracy local geomagnetic field base on rectangular harmonic analysis

Accurate geomagnetic reference maps are a key point for geomagnetic navigation. The advantage of constructing the geomagnetic filed model using RHA (Rectangular Harmonic Analysis) and then obtaining the geomagnetic reference mapping is discussed. An improved RHA model with linear trend compensating terms is presented for the boundary vibration phenomenon. To overcome the problem of traditional method falling into the local optimum, a MPGA (Multiple-Population Genetic Algorithm) is applied to solve the undetermined constants of model. The simulation experiment is executed by the measured magnetic data. The results show that MPGA is feasible and effective for solving the undetermined constants of RHA model. Compared with traditional RHA model, the improved RHA model has higher fitting accuracy, and can relieve the boundary vibration phenomenon.