CACTus LASCO level zero CME catalog

The catalog of autonomously detected CMEs in image sequences from LASCO (Large Angle Spectrometric Coronagraph). The crux of the software is the detection of CMEs as bright ridges in (time, height) maps using the Hough transform. The next step employs clustering and morphological closing operations to mark out different CMEs. The output is a list of events, similar to the classic catalogs, with starting time, principle angle, angular width and velocity estimation for each CME. In contrast to catalogs assembled by human operators, these CME detections can be done without any human interference on real-time data 24 h per day (see http://sidc.oma.be/cactus for the real-time output with data covering the last 4 days). Therefore the detection is not only more immediate, but, more importantly, also more objective. Experimental results on real-time data show that the developed technique can achieve excellent results in measuring starting time and principal angle and good results for the angular width and velocity measurement compared to the CMEs listed in the catalog. Its overall success rate is presently about 94%.