The Canadian Geomagnetic Reference Field 1995
The Canadian Geomagnetic Reference Field 1995
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DOI：
10.5636/jgg.49.317
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发表时间：
1997-01-01
期刊：
影响因子：
--
通讯作者：
Newitt, LR
中科院分区：
文献类型：
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作者：
Haines, GV;Newitt, LR
1995 年加拿大地磁参考场 (CGRF) 的制作中引入了多项创新。使用最近开发的主场差异方法同时对长期变化和主场进行建模。时间多项式的次数根据球冠谐波空间次数而变化。进行了修改以允许在分析中使用标量数据以及矢量数据。使用了 CGRF 之前版本中未使用的多个数据集，包括 Project Magnet 数据、FOGS 数据、低层标量航磁数据和标量海洋数据。针对以北纬 65 度、西经 85 度为中心、半径为 30 度的球盖生成了球盖谐波模型。最大空间膨胀指数为 K = 16，最大时间膨胀为 7。CGRF 导致建模区域上的数据误差方差与 IGRF 相比，主场数据低 19%，长期变化数据低 55%。
Several innovations have been introduced in the production of the Canadian Geomagnetic Reference Field (CGRF) for 1995. The secular variation and main field were modelled simultaneously using the recently developed method of main field differences. The degree of the temporal polynomial was varied depending on the spherical cap harmonic spatial degree. Modifications were made to allow the use of scalar, as well as vector, data in the analysis. Use was made of several data sets not used in previous versions of the CGRF, including Project Magnet data, FOGS data, low-level scalar aeromagnetic data, and scalar marine data. A spherical cap harmonic model was produced for a spherical cap of 30 degrees radius centred at 65 degrees N, 85 degrees W. The maximum spatial index of expansion was K = 16, and the maximum temporal expansion was 7. The CGRF results in an error variance to the data over the modelling area that is 19% lower for the main field data and 55% lower for secular variation data than does the IGRF.