We investigated O4a data using the Omicron, which is a trigger generator. We applied the Omicron to the strain data of KAGRA’s O4a data, using data during 2023/5/24 10:00:03 ~ 5/24 11:00:03 (UTC) and 2023/5/24 22:29:00 ~ 5/24 23:29:00 (UTC).
We found that there were long-term stable triggers around 400 Hz. This characteristic noise were reported in the past klog (https://klog.icrr.u-tokyo.ac.jp/osl/?r=29026 , https://klog.icrr.u-tokyo.ac.jp/osl/?r=25372).
So We focused on 300-500 Hz. We found that the frequency is around 360 Hz.
