Improving geomagnetic field models for the period 1980-1999 using Orsted data

DOI PDF Web Site Web Site Web Site 参考文献28件

書誌事項

タイトル別名
  • Improving geomagnetic field models for the period 1980-1999 using Ørsted data
  • Improving geomagnetic field models for

この論文をさがす

抄録

The Danish satellite Ørsted is due to be launched in 1998, and should provide, for the first time since the Magsat mission (1979-1980), a dense and global coverage of the Earth's surface with vector measurements of the magnetic field. In this paper, we compare the expected error in the main field models computed for the 1970-1999 time interval using observatory data, with or without the a priori information given by the knowledge of the field at both Magsat and Ørsted epochs. This work is based on the reasonable hypothesis that the main field models derived from Ørsted data will be as accurate as the Magsat models. The a priori information given by the Magsat and Ørsted models is based on a linear behaviour of the rate-of-change of the field throughout this period, plus a noise level which can be estimated as a function of time and degree from past field changes. The expected error in the models computed for the 1980-1999 period with a priori information appears to be significantly smaller than the expected error in the models computed without this information. This result is related to the heterogeneous distribution of the observatories over the Earth surface. Consequently, when the Ørsted data is available, improved models can be computed for the 1980-1999 period particularly in regions without observatory data. This method with a priori information may allow the use of the same set of observatories throughout the entire period. Indeed, our method alleviates the requirement of a very dense data distribution.

収録刊行物

参考文献 (28)*注記

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ