jeffrey.kissel@LIGO.ORG - posted 10:48, Monday 31 October 2016 - last comment - 13:38, Friday 04 November 2016(31029)
Delightfully Ghoulish SEI Environment Lock Stretch for Characterization
J. Kissel
Admiring the work of the SEI and ASC teams, we've just lost lock on a really impressive lock stretch in which we had ~40 mph winds, ~70th percentile microseism, and a 5.4 Mag earhtquake in the horn of Africa and survived. It would be most excellent it DetChar can compare amplitudes of ISC control signals, check out the beam rotation sensor tilt levels, the ISI platform sensor amplitudes, take a look at optical lever pitch and yaw compared with ASC signals etc.
Start: Oct 31 2016 16:15:05 UTC
End: 17:37-ish UTC
Winds and some ground BLRMS (showing microseism and the earthquake arrival) for this lock stretch. We survived at least one gust over 50mph before losing lock. No one changed seismic configuration during this time.
For the record, the units of the above attached trends (arranged in the same 4-panel format as the plot) are ([nm/s] RMS in band) [none] ([nm/s] RMS in band) [mph] Thus, - the earthquake band trend (H1:ISI-GND_STS_ITMY_Z_BLRMS_30M_100M) shows the 5.3 [mag] EQ peaked at 0.1 [um/s] RMS (in Z, in the corner station, between 30-100 [mHz]), - the microseism (again in Z, in the corner station, H1:ISI-GND_STS_ITMY_Z_BLRMS_100M_300M) is averaging 0.25 [um/s] RMS between 100-300 [mHz] (which is roughly average, or 50th percentile -- see LHO aLOG 22995), and - the wind speed (in the corner station) is beyond the 95th percentile (again, see LHO aLOG 22995) toward the end of this lock stretch, at 40-50 [mph]. Aside from Jordan Palamos' work in LHO aLOG 22995, also recall David McManus' work in LHO aLOG 27688, that -- instead of a side-by-side bar graph, shows a surface map. According to the cumulative surface map, with 50th percentile winds and 95th percentile winds, the duty cycle was ~30% in O1. So, this lock stretch is not yet *inconsistent* with O1's duty cycle, but it sure as heck-fy looks promising.