Shifter: Sumeet Kulkarni

Fellow/Mentor: Ling Sun

Summary:

• Average duty cycle 52.5%. No observing on Sunday. Longest lock period about ~18 hours on Friday.
• BNS Range averaged at 110 MPc. but showed lots of variation and dipped below 100 MPc. on a few instances.
• 48 Hz. spectral line / glitching continued to be visible, grew stronger as the week passed and peaked highest on Saturday. (Plot attached)
• Loud glitches caught throughout by hveto from H1:LSC-POP_A_LF_OUT_DQ with high significance.
• Whistles glitches were seen on all days of observing barring Tuesday and Thursday. They're correlated with motion in IMC-F and we observe a simultaneous increase in variance of the VCO frequency. alog48863
• Slowly wandering lines related to the Squeezer in h(t), first seen on April 21, were seen again on Thursday and Friday. alog48772
• Lost Lock towards the end of the day on Saturday at around 19:00 UTC due to high winds. Despite several attempts, the lock could not be regained on Sunday all the way until the end of the shift. alog48829 alog48830

Complete details can be found at https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20190422.