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基于CHAMP卫星的矢量磁测数据,结合最新的IGRF12模型,并假设所有CHAMP卫星的网格测点位于同一高度(307.69km),基于498个测点,建立了2010.0年中国地区要素X、Y、Z和总强度F的卫星磁异常球冠谐(SCH2010)模型,建模前利用CM4模型移除了外源场。模型极点位于36°N和104°E,球冠半角为30°。通过比较△X、△Y、△Z以及X、Y、Z的均方偏差(RMS)的数值变化,确定截断阶数Kmax=9为合适的截断阶数。结合IGRF12所建立的卫星高度的中国地磁参考场(CGRF2010)模型与CM4模型具有较好的一致性,分析比较了基于SCH2010模型与类似磁异常模型的地面磁异常分布,发现各要素磁异常的强度与分布高度一致。通过比较F在不同高度处的磁场分布,发现SCH2010模型在不同高度的估算都符合地磁场的变化规律。比较发现SCH2010与CM4模型的空间变化率一致性较好。所建模型相较于其它区域拟合模型而言,可反映地磁场的更多细节,但球冠谐模型本身及建模过程为两个误差源。
Based on the CHMA satellite-based vector magnetic data and the latest IGRF12 model, and assuming that all CHAMP satellites are located at the same height (307.69km), based on 498 measurement points, the Chinese elements X, Y, Z and total intensity F of the satellite magnetospheric spherical anomalous spherical harmonic (SCH2010) model, CM4 model was used to remove the exogenous field before modeling. The pole of the model is located at 36 ° N and 104 ° E and the ball and socket half angle is 30 °. The cutoff order Kmax = 9 is determined to be a suitable cutoff order by comparing the numerical variations of the mean square deviations (RMS) of ΔX, ΔY, ΔZ and X, Y, Z. The geomagnetic reference field (CGRF2010) model based on satellite altitude established by IGRF12 is in good agreement with CM4 model. The distribution of ground magnetic anomalies based on SCH2010 model and similar magnetic anomaly models is analyzed and compared. The strength of magnetic anomalies Consistent with the distribution. By comparing the distribution of F field at different heights, it is found that the estimation of SCH2010 model at different altitudes is in accordance with the variation of geomagnetic field. The spatial variation rates of SCH2010 and CM4 were found to be more consistent. Compared with other regional fitting models, the proposed model can reflect more details of the geomagnetic field. However, the spherical cap model itself and the modeling process are two error sources.