An EventBased Verification Scheme for the RealTime Flare Detection System at Kanzelhöhe Observatory 

Werner Poetzi Submitted: 20180621 02:37
In the framework of the Space Situational Awareness program of the European Space Agency (ESA/SSA), an automatic flare detection system was developed at Kanzelhöhe Observatory (KSO). The system has been in operation since mid2013. The event detection algorithm was upgraded in September 2017. All data back to 2014 was reprocessed using the new algorithm. In order to evaluate both algorithms, we apply verification measures that are commonly used for forecast validation. In order to overcome the problem of rare events, which biases the verification measures, we introduce a new eventbased method. We divide the timeline of the Hα observations into positive events (flaring period) and negative events (quiet period), independent of the length of each event. In total, 329 positive and negative events were detected between 2014 and 2016. The hit rate for the new algorithm reached 96% (just five events were missed) and a falsealarm ratio of 17%. This is a significant improvement of the algorithm, as the original system had a hit rate of 85% and a falsealarm ratio of 33%. The true skill score and the Heidke skill score both reach values of 0.8 for the new algorithm; originally, they were at 0.5. The mean flare positions are accurate within ±1 heliographic degree for both algorithms, and the peak times improve from a mean difference of 1.7±2.9 minutes to 1.3±2.3 minutes. The flare start times that had been systematically late by about 3 minutes as determined by the original algorithm, now match the visual inspection within 0.47±4.10 minutes.
Authors: Pötzi W., Veronig A., Temmer M.
Projects: Other

Publication Status: published
Last Modified: 20180621 13:33


