Issue |
EAS Publications Series
Volume 9, 2003
Magnetism and Activity of the Sun and Stars
|
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Page(s) | 117 - 117 | |
DOI | https://doi.org/10.1051/eas:2003093 | |
Published online | 17 November 2003 |
Magnetism and Activity of the Sun and Stars
J. Arnaud and N. Meunier (eds)
EAS Publications Series, 9 (2003) 117
J. Arnaud and N. Meunier (eds)
EAS Publications Series, 9 (2003) 117
Inversion of line profiles using principal component analysis: some practical guidelines
Observatoire de Paris, LESIA, FRE 2461 du CNRS,
92195 Meudon Cedex, France
Modern spectro-polarimeters produce huge amounts of data, and the computing time needed to achieve data inversion is then becoming an important bottleneck for the modelling activity. Recently, an alternative to the traditional non-linear least squares technique has been proposed; it relies on an old technique in multivariate analysis, principal component analysis (PCA), and proves to be much faster than traditional techniques (a gain of two orders of magnitude in computation time is not unusual). We will briefly recall this technique and discuss some means of making it still more robust.
© EAS, EDP Sciences, 2003