- 著者
- J. M. A. Miranda M. A. Pais I. P. Abreu
- 出版者
- Society of Geomagnetism and Earth, Planetary and Space Sciences
- 雑誌
- Journal of geomagnetism and geoelectricity (ISSN:00221392)
- 巻号頁・発行日
- vol.49, no.2-3, pp.373-386, 1997-02-20 (Released:2011-08-23)
- 参考文献数
- 15
- 被引用文献数
- 1 2
The aim of this study is to analyse the integration of sparse three component magnetic observations from observatories and repeat stations with dense total field values from aeromagnetic data, into a homogeneous description of the magnetic field. The methodology followed implies the independent computation of main and crustal field contributions, each one incorporating the constraints of harmonicity. The crustal anomalous field is calculated for 1980 by digital filtering of the total field values from aeromagnetic surveys; the convolution is made in the spatial domain with space varying coefficient sets to account for the change in direction of the main field. The main field is estimated by updating the DGRF80, whose agreement with the Iberian data has already been demonstrated, with a SCHA model for the secular variation deduced from 360 three component observations over the Iberian Peninsula for the period 1980-1991. The combination of these two contributions permits one to compute magnetic component maps for the 1991.0 epoch that agree, in the least-squares sense, with the observational data while respecting the mathematical characteristics of a potential field. This methodology seems to be an effective way to produce regional estimations of the internal field.