Detection of Coronal Mass Ejections

Coronal mass ejection (CME) events refer to the appearance of a new, discrete, white-light feature (with outward speed) in a coronagraph. The huge amount of data provided by the pertinent instruments onboard the solar and heliospheric observatory (SOHO) and, most recently, the solar terrestrial relations observatory (STEREO) makes the human-based detection of such events excessively time consuming. Although several algorithms have been proposed to address this issue, there is still lack of universal consensus about their reliability. This work presents a novel method for the detection of CMEs as recorded by the LASCO instruments onboard SOHO. The algorithm we developed is based on level sets and region competition methods, the CMEs texture being characterized by their co-occurrence matrix. The texture information is introduced in the region competition motion equations, and in order to evolve the curve, a fast level set implementation is used.