Reports until 11:27, Tuesday 03 June 2025
H1 DetChar (DetChar)
jane.glanzer@LIGO.ORG - posted 11:27, Tuesday 03 June 2025 (84747)
Glitch rate comparison between O4a and O4b

Attatched to this alog are omicron glitch rate comparions, as a function of frequency and SNR, between O4a and O4b. Here, I used roughly ~ 3425 hours of observing time for O4a and O4b (H1:DMT-ANALYSIS_READY:1 flag). The specific observing times used were:

O4a: 2023-06-24 20:00:00 - 2024-01-17 00:00:00 (~3422 hours observing)

O4b: 2024-04-10 00:00:00 - 2025-01-28 17:00:00 (~3428 hours observing)

The SNR and frequency of the omicron triggers gathered were 7.5 < SNR < 500, and 10 Hz < frequency < 1024 Hz. I find that the glitch rate in O4b is significatly less than O4a. In O4a, there was a lot of non-stationary noise from ~10-50 Hz (see alogs 71005 & 71092), which is why the rate was so high. For frequencies below 50 Hz, the glitch rate per hour went from roughly  ~16.7 in O4a to ~2.5 in O4b. For SNR below 50, the glitch rate per hour went from ~36 per hour in O4a to ~9 per hour in O4b. 

 

Images attached to this report