Shifter: Beverly Berger

LHO fellows: Karl Toland, Vaishali Adya

For complete results see https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20170413.

• Observing time was (82.0% + 99.6% + 89.7% + 70.4%) /4 = 85.4% with BNS ranges typically 65 - 70 Mpc.
• Glitchgrams showed excessive (but low SNR) glitching in the 50-100 Hz band. This started on 7 April and was very strong on 10 April through 13 April and faded on subsequent days.
• "Tower" glitches in the 50-100 Hz band were present most days (see attached figures - h(t) spectrogram, spectrogram closeup).
• The ETMX Oplev was a frequent hVeto winner.
• Also a winner, but typically in a later round were Mainsmon channels. There appeared to be glitching at 60 Hz.
• One of the local oscillators had a peculiar time series on the Summary pages.
• The line voltage spectrum showed a variable feature at around 12 Hz.