Data Access
An automatic compiled coronal mass ejection (CME) catalogue based on observations from the Heliospheric Imagers (HIs) onboard NASA's Solar Terrestrial Relations Observatory (STEREO) spacecraft. Using the Computer Aided CME Tracking software(CACTus), CMEs are identified in HI data using an automatic feature-detection algorithm.
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
An automatic compiled coronal mass ejection (CME) catalogue based on observations from the Heliospheric Imagers (HIs) onboard NASA's Solar Terrestrial Relations Observatory (STEREO) spacecraft. Using the Computer Aided CME Tracking software(CACTus), CMEs are identified in HI data using an automatic feature-detection algorithm.
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/Luciano.Rodriguez | |||
| 2. | MetadataContact | spase://SMWG/Person/Olga.Y.Uritskaya |
CACTus was designed to detect CMEs according to their observational definition as "a new, discrete, bright white-light feature in the coronagraphic field-of-view, moving radially outward". Utilizing this definition implies that we have not assumed any physical model while characterizing and detecting CMEs. CACTus detects many more events than are listed in the classical, manually compiled catalogs. While browsing the catalog, you will find many small events that do not correspond to the current classical CME picture. They occur independently, prior to or in the aftermath of a large eruption. In the latter case they are not usually included in the classical catalogs, since they are considered part of the whole eruption.
CME number
first apparition in field of view
principal angle, counterclockwise from North (degrees)
angular width (degrees)
Northernmost propagation angle (degrees),
Southernmost propagation angle (degrees)
median (projected) 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