【摘要】 为了实现地磁导航在近地轨道卫星上的应用,需要解决传统的高斯球谐函数递推法在计算地磁场强度时存在方法复杂、计算量大、实时性难以保证等问题.针对上述问题,提出一种用地球磁场估计函数代替球谐函数的地磁场强度计算方法.该方法利用伪地心下的磁偶极子模型代替主磁场模型,通过多项式拟合离线得到高度范围内固定经纬度网格点的伪中心距系数,进而利用插值法和偶极子模型得到任意点的地磁场强度.仿真结果表明,轨道高度为300~500 km,经纬度网格间隔为0.5°时,地球磁场估计函数法的导航精度与地球主磁场模型WMM精度一致的同时,降低了计算负担,提高了算法计算效率.更多还原

【Abstract】 To realize the application of geomagnetic navigation on the low orbit satellite, the complexity, enormous calculation, poor real time ability of traditional Gaussian spherical harmonica function should be solved before being used to calculate the geomagnetic vector. A geomagnetic field approximation function, Geomagnetic Field Approximation Functions(GFAF), is proposed to replace the spherical harmonic function. Dipole model under a pseudo-centers is utilized to replace the main geomagnetic model in GFAF method. And the coefficient of pseudo-center of different latitude-longitude grid is obtained by polynomial fit method. Finally, the geomagnetic field vector of any position can be achieved using different, interpolation algorithm. A simulation test is carried out under the condition that the increment of latitude and longitude is 0.5° and the orbital height is from 300 to 500 km. The results show that the navigation accuracy of GFAF method is the same to that of geomagnetic field model. However, GFAF method effectively decreases the cost of computing and and improves the calculation efficiency.更多还原