When I started the ETMy Charge measurements today, I checked the Aligned state oplev centering. It was WAY off. So, I reset the alignment back to a more recent nominal pointing (based on trends) since yesterday's bootfest set all pointing biases to old values. Note - we should reset to a good IFO pointing across all SUSes ASAP.
However this didn't help much on the Oplev which was out at some -90 in Pitch. The long trend (attached) shows a major drift in the Oplev from ~March 20th to April 13th where it started to flatten out. (Note there is a period of poor alignment for the week after April 13th, and then the pointing is restored, and the flattening out of the Oplev resumes. Unsure of what tipped off the major drift, I checked VEA Temp - all good. A check of the alog around the March 21st date indicated that the "grout work" finished around March 21st. Wow, long grout dry time.
So, time to rezero!
For reference, our OpLev's only exhibited approx 10 urad pitch drift over a couple of week period following the pier grouting work being carried out at LLO (see LLO aLOG entry 17030).