Reports until 06:28, Monday 18 February 2019
H1 AOS
jenne.driggers@LIGO.ORG - posted 06:28, Monday 18 February 2019 (46977)
DARM coherence with ASC is low above 25 Hz

The DARM coherence with ASC and LSC is fairly low above 25 Hz, with the exception of DHARD_P having some coherence between 30-40Hz.  We should address this at some point, but it is not a high priority.  So, Danny's suspicions of the extra low frequency noise being due to his ASC change yesterday are exonerated. 

Also, we are not saving any signals from the ADS system, which is now being used to control the pointing of PRM and the SOFT degrees of freedom.  We need to add these in (at least the DOF[3,4,5]_OUT) before ER14.

I don't know if anyone has explicitly written this in the alog, but in the Saturday evening alog (46972) it is noted that while the DARM reference is mostly back to November levels, we're reporting a far smaller BNS range.  I'm quite confident that most of that range loss is due to the broad peak at 180 Hz from the OMC and PZT driver.  We already have plans to address this with the same solution that LLO implemented several months ago (LLO alog 41374 and comments).

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