ETM_GLITCH tag added to LHO. Code written by Iain Morton.
Closes #219 (closed)
New plugin etm_glitch.py that checks for glitches at LHO in the ETMX_L3 channel in the 2 seconds before lockloss. Tested on LHO and LLO events and with ./test script.
This will check for any glitches prior to lockloss in two steps:
- Is there a glitch that goes above THRESH (3e5) in the GLITCH_SEARCH_WINDOW (2 seconds prior to lockloss)
- Does the channel then remain within LOW_THRESH (1e5) for at least LOW_TIME (60ms). Need this second step to make sure we don't tag earthquakes or other events when the ETM starts swinging and goes outside the threshold.
Iain showed that LHO is seeing this occur in around 15% of NLN locklosses: https://dcc.ligo.org/LIGO-G2401576
Don't think this type of lockloss is an issue for LLO, but will check with @timothy.ohanlon. Could add the plot for LLO if you think that would be useful. Currently only runs for LHO lock losses in state 600 (NLN) and above.
Examples of plot created with and without glitch below.
With ETM_GLITCH tag 1403820932:
No tag 1404524787:
Edited by Camilla Compton