Below is the summary of the DQ shift for the week from 2025-07-21 to 2025-07-27
- During this week, the average BNS range was around 150 Mpc, and there were no large variations in the range.
- Except for a few features, the strain spectrogram looked reasonable.
- There was excess noise at the first and second harmonics of the violin modes at the beginning of the locks.
- In addition to persistent lines, there were also lines whose amplitude and frequency varied over time. Most of these features were below 300 Hz. The details of these features are available in the a-log 85984. These lines were identified using the STRAIN_NOLINES channel, and hence some of these lines may be removed/cleaned in the STRAIN_CLEAN channel.
- At the beginning of the locks, sometimes the calibration lines were seen in the STRAIN_NOLINES for a few minutes.
- On a couple of instances, the IFO was locked during earthquakes during which there was excess noise in the 10 -20 Hz band.
- The glitch rates at different Omicron SNRs were mostly consistent throughout the week.
- Most of these glitches were centered around specific frequencies such as 23 Hz, 34 Hz, 46 Hz, etc.
- There were no new and significant features in PEM channels
- Many of the accelerometers and some microphones in the corner station also see similar non-stationary lines in h(t) described above (link to plots in a-log 86010).
- The fscan usually identified 29.969* Hz and 99.9986* Hz comb features.
- The dominant channels in Hveto were usually ASC TRANS, HPI, and ISI from the corner station. However, most days they had a poor use percentage.
The full DQ shift report with day-by-day details is available at https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20250721