Figure A1:

The effectiveness of the veto criteria designed to flag h(t) non-stationarity due to the malfunction of the 45MHz driver over a six hour period on September 21, 2015. The top panel shows the witness channel (a monitor for amplitude fluctuations in the signal used to generate the 45 MHz optical sidebands) over a 6 hour period with non-stationary data in h(t). Due to variation in its mean value, a band limited root-mean-square (BLRMS) of this channel over 60 seconds was a better indicator of the targeted behavior, shown in the middle panel. Thresholds of this BLRMS were tested over 11 days during the analysis period for efficiency in identifying periods of high trigger rate in h(t), and the threshold shown in the middle figure was found to be optimal for the analysis time removed. The bottom panel shows Omicron h(t) triggers over the same 6 hour time period. Times removed by the veto are shaded out in gray.