High Frequency infrasound are produced generally by explosion, aircraft, storm or lightning…(Campus and Christie, 2010). High frequency infrasound signals are detected by I33MG at the azimuth around 39°. To perform the study, IMS infrasound data from I33MG and I19DJ are processed by mean of PMCC method. After investigation these events are correlated with oceanic storms in the Indian Ocean. In this area, lightning flashes, halo and sprite happen frequently (Christian et al., 2003, Chen et al., 2008) as well as surf events. These events are located at far as 3000 km from I33MG. Frequency of I33MG detections are less than 4 Hz and less than 2 Hz for I19DJ detections. Sources of these events would be strong for having high frequency signal detected for a long distance.
Characterize unknown events in order to better identify potential CTBTO relevant event and enhance infrasound station detectability.