jennifer.wright@LIGO.ORG - posted 12:42, Thursday 07 March 2024 - last comment - 14:35, Monday 18 March 2024(76188)
OMC_LOCK guardian updated
Ryan S, Jennie W, Camilla
Camilla noticed the OMC_LOCK guardian was failing to find the carrier resonance during the ISC_LOCK guardian state.
Ryan discovered this was due to the triplet (1 45MHz peak either side of the carrier) that the OM_LOCK guardian looks for was not being found by scipy.find_peaks() as the carrier resonance are bellow 9 counts which is its threshold. So we changed the 'height' threshold of find_peaks to 7 on line 327 of OMC_LOCK guardian and commited this change.
We also changed the OMC_LOCKED guardian state at line 511 to look for OMC-DCPD_SUM_OUTPUT to be more than 7 instead of 10.
I think it is reasonable that we had to make this change as the OMC is probably not well aligned as the OMC scan the other day showed we had a lot of HOM content in the beam.
Since OMC (and overall IFO) alignment has improved, we are now seeing good transmission on the OMC DCPDs as we were in O4a, so I've reverted the above threshold changes in the OMC_LOCK Guardian.