基于矩谐分析的高精度局部地磁场建模研究

Modeling of High Accuracy Local Geomagnetic Field Base on Rectangular Harmonic Analysis

高精度地磁基准图的绘制是实现地磁导航的关键。本文论述了应用矩谐分析方法进行地磁场建模,进而绘制地磁基准图的优越性。针对边界振荡问题,提出了一种具有线性趋势补偿项的改进矩谐分析模型。为克服传统方法在求解模型待定常数时易陷入局部最优的问题,将多种群遗传算法应用到模型待定常数的求解中。应用实测地磁数据进行了仿真试验。结果表明,应用多种群遗传算法求取矩谐分析模型待定常数的方法是可行有效的;与传统矩谐分析模型相比,改进的矩谐分析模型对地磁场的拟合精度更高,且可以减轻边界振荡现象。

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.