Pattern recognition techniques and the measurement of solar magnetic fields

Arturo Lopez Ariste; David E. Rees; Hector Socas-Navarro; Bruce W. Lites

doi:10.1117/12.447163

1 November 2001 Pattern recognition techniques and the measurement of solar magnetic fields

Arturo Lopez Ariste, David E. Rees, Hector Socas-Navarro, Bruce W. Lites

Proceedings Volume 4477, Astronomical Data Analysis; (2001) https://doi.org/10.1117/12.447163
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

Measuring vector magnetic fields in the solar atmosphere using the profiles of the Stokes parameters of polarized spectral lines split by the Zeeman effect is known as Stokes Inversion. This inverse problem is usually solved by least-squares fitting of the Stokes profiles. However least-squares inversion is too slow for the new generation of solar instruments (THEMIS, SOLIS, Solar-B, ...) which will produce an ever-growing flood of spectral data. The solar community urgently requires a new approach capable of handling this information explosion, preferably in real-time. We have successfully applied pattern recognition and machine learning techniques to tackle this problem. For example, we have developed PCA-inversion, a database search technique based on Principal Component Analysis of the Stokes profiles. Search is fast because it is carried out in low dimensional PCA feature space, rather than the high dimensional space of the spectral signals. Such a data compression approach has been widely used for search and retrieval in many areas of data mining. PCA-inversion is the basis of a new inversion code called FATIMA (Fast Analysis Technique for the Inversion of Magnetic Atmospheres). Tests on data from HAO's Advanced Stokes Polarimeter show that FATIMA isover two orders of magnitude faster than least squares inversion. Initial tests on an alternative code (DIANNE - Direct Inversion based on Artificial Neural NEtworks) show great promise of achieving real-time performance. In this paper we present the latest achievements of FATIMA and DIANNE, two powerful examples of how pattern recognition techniques can revolutionize data analysis in astronomy.

Citation Download Citation

Arturo Lopez Ariste, David E. Rees, Hector Socas-Navarro, and Bruce W. Lites "Pattern recognition techniques and the measurement of solar magnetic fields", Proc. SPIE 4477, Astronomical Data Analysis, (1 November 2001); https://doi.org/10.1117/12.447163

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available