ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-26-243-2008 Automatic detection and tracking of filaments for a solar feature database Aboudarham J. 1 Scholl I. 1 2 Fuller N. 1 Fouesneau M. 3 Galametz M. 3 Gonon F. 3 Maire A. 3 Leroy Y. 3 Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique (LESIA), Observatoire de Paris-Meudon, France International Space University (ISU), Strasbourg, France Ecole Nationale Supérieure de Physique de Strasbourg (ENSPS), Strasbourg, France 26 02 2008 26 2 243 248 Copyright: © 2008 J. Aboudarham et al. 2008 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/26/243/2008/angeo-26-243-2008.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/26/243/2008/angeo-26-243-2008.pdf

A new method for the automatic detection and tracking of solar filaments is presented. The method addresses the problems facing existing catalogs, such as the one developed recently in the frame of the European Grid of Solar Observations (EGSO) project. In particular, it takes into account the structural and temporal evolution of filaments, differences in intensity as seen from one observation to the next, and the possibility of sudden disappearance followed by reappearance. In this study, the problem of tracking is solved by plotting all detected filaments during each solar rotation on a Carrington map and then by applying region growing techniques on those plots. Using this approach, the "fixed" positions of the envelopes in the Carrington system can be deduced. This is followed by a backward tracking of each filament by considering one full solar rotation. The resulting shifted Carrington map then enables one to follow any filament from one rotation to the next. Such maps should prove valuable for studies of the role of filaments in solar activity, notably coronal mass ejections (CMEs).

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