Geomagnetic Sudden Commencement Automatic Detection via MODWT

It is of great importance to develop an algorithm that autodetects sudden commencement (SC) because it could be an indicator of the onset of the geomagnetic storm. A geomagnetic storm is considered as one of the global processes in the ionosphere-thermosphere-magnetosphere system. Automatic detection of SCs is based on multiresolution analysis of a maximal overlap discrete wavelet transform using a Haar wavelet filter. The proposed algorithm is tested on 1-min-resolution data sets collected from magnetic observatories belonging to the International Real-Time Magnetic Observatory Network. Maximum standard deviation of algorithm detection times is observed to be 1 min of the corresponding arrival times published by the National Geophysical Data Center.