Data Access
The catalog of autonomously detected Flows (Flows are suspicious detections) 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%.
Version:2.7.0
The catalog of autonomously detected Flows (Flows are suspicious detections) 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%.
Role | Person | StartDate | StopDate | Note | |
---|---|---|---|---|---|
1. | Author | spase://SMWG/Person/David.Berghmans | |||
2. | Author | spase://SMWG/Person/Eva.Robbrecht | |||
3. | MetadataContact | spase://SMWG/Person/Olga.Y.Uritskaya |
CACTUS autonomously detects coronal mass ejections (CMEs) in image sequences from LASCO or SECCHI. Flows are suspicious detections, their color in the detectionmap is dark blue. The output of our software is a list of events, similar to the classic catalogs, with principle angle, angular width and velocity estimation for each CME. In contrast to catalogs assembled by human operators, these CME detections by software can be faster, which is especially important in the context of space weather, and possibly also more objective, as the detection criterion is written explicitly in a program.
The CME list is automatically generated by CACTus. There is no human intervention or supervision at this stage. Therefor we ask to use caution when using the data for statistical purposes.
When any of this data is used, please cite one of the following publications:
CME number
onset time, earliest indication of liftoff
duration of liftoff (hours)
principal angle, counterclockwise from North (degrees)
angular width (degrees)
median velocity (km/s)
variation (1 sigma) of velocity over the width of the CME
lowest velocity detected within the CME
highest velocity detected within the CME
II if da>90, III if da>180, IV if da>270, indicating potential halo/partial halo CME