People were having problem with relocking after the maintenance.
IMC VCO tune offset was railing at +-5V whenever COMM PLL was trying to enable slow feedback to IMC. TJ manually disabled it, not sure why this was turned on, it seems like the guardian does not touch this.
When both X and Y were unlocked, it was clear that X arm fringe velocity was much much larger than Y arm just by looking at the camera.
It seems like the EX ISI has been going crazy for the past 2 hours or so (first attachment left). I haven't checked if this is due to ground motion, It seems like the FOM for 0.03-0.1Hz band shows us that there's something going on (but EY looks noisier) (second attachment).
The dominant frequency of the noise is about 1/24 Hz, so the frequency is about right (first attachment right).
As I was talking to Jeff, however, ETMX ISI slowed down. We'll see.
(Update: As we were waiting, we are hit by another quake at around 2:10 or so UTC.)
Attached is a spectra comparing the ground motion between yesterday and today -EX first image, EY second image-. There is certainly 50mHz elevated motion, compared to yesterday.
Although it is strange how large is the ETMX motion on stage 1 at 40mHz, witnessed by the t240. Certainly much more than for EY.
Looking at the transmissibility at EX from ground to stage 1 -image 3- , it seems the motion is much more amplified (compared to yesterday) between hepi and stage 1 in x and y, cf green in 2nd row.
Took 24 hour plots of the ETM-X and ETM-Y ISI CPS X locations covering the time of the problems with ETM-X.
