Shifter: Beverly Berger

LHO Fellow: Evan Goetz

Summary:

• Observing 79.4% of the time including maintenance (Monday 88%, Tuesday 67.7%, Wednesday 72.7%). In non-noisy periods, the BNS range was typically 68 Mpc. However, such periods were not common during this DQ shift. In noisy periods discussed in subsequent bullets, the range was typically about 60 Mpc.
• On 20 Mar UTC, severe glitching at 10 Hz was found to be associated most strongly with glitching in the ETMY Oplev. On 22 Mar UTC, alog 34988 from Sheila reported that the Oplev damping filters were changed to reduce their noise at 10 Hz to below the DARM noise level. This has appeared to fix the problem of the 10 Hz glitching in h(t).
• Truck traffic on Rte 10 continues to be an issue. Each day saw an increase in seismic noise at about 12:00 UTC (note the move of this feature from 13:00 after the shift to DST). Convoys of trucks passed during the late hours of 20 Mar UTC. This traffic s problematic because it leads to excess noise around 100 Hz. The convoys were not apparent on subsequent days.
• An alog ( 34999) from Jim Warner noted that the ASC had become noise at about the right time. A later comment ( 35003) from Andy to this alog showed that the behavior seemed to correlate with bad behavior of the ITMY Oplev. At issue is the excitement of longitudinal modes associated with the frequency 0.43 Hz. A subsequent alog ( 35023) and further comment by Jenne and Sheila discuss the different channels that see the 0.43 Hz activity, note that the oplev, especially ITMY seem to be mplicated and suggest reverting to the state before the 10 Hz glitching was fixed. This was done but the ASC issues remain. A line of glitches appeared at about 3.3 kHz in apparent coincidence with this behavior. a known line at the same frequency shows glitching at about 0.43 Hz. See alog comment ( 35044) for more detials. 
• RF45 noise: At about 21:32 UTC, there were indications that RF45 noise had returned. The IFO was not in observing but failed to lock. After some time, the disturbance went away. Some suggestions to try to track down a cause were given. See alog ( 35013) for details. Regrettably, RF45 noise returned on 23 Mar UTC (see alog 35028). 
• Jeff Kissel added a comment to the Summary pages for 22 Mar: The front end's time dependent correction factors at the beginning of this UTC day are bogus because the calculation's filter bank history was not cleared properly until about ~1 hr after the 2017-03-21 calibration measurement suite (see LHO aLOG 34984).

Details may be found at https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20170320.