stefan.ballmer@LIGO.ORG - posted 14:06, Monday 05 November 2018 - last comment - 08:36, Tuesday 06 November 2018(45013)
H1 quiet stretch
Attached is the DARM spectrum, DARM coherence with some auxiliary channels, and the LSC auxiliary error point spectra for a quiet stretch on Saturday: 1225344730 (Nov 4 2018 05:31:52 UTC). Note that - compared to Aug 21 2015, PRCL has an excess noise bump up to 60Hz, and an increased high frequency flat noise level (I hesitate to call it shot noise). That bleeds slightly over to SRCL. Hoverer, the linear noise coupling, at least below 30Hz, is dominated by SRCL. Gabriele might also post a bruco for this stretch. Also note that this is from the same lock as Shaila's noise budget (alog 44998)
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I re-ran Kiwamu's OMC DCPD cross-correlation template on this quiet lock stretch (it is hard to find enough time between the big DARM glitches to get a useful number of averages). See attached: blue is the DARM spectrum, and red is the correlated noise. I updated the calibration in this template to match the TF calibration of the DARM FOM DTT template.
A quick by-eye comparison of this and the O1 and O2 cross correlated noise: it looks like we are currently somewhere in between.
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BruCo scan available at https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1225344730/