Since the PEM accelerometers were installed on SQZT 0+7 a couple days ago (in-table locations in 69671), I checked table coherences with some relevant SQZ signals I could think of. A couple interesting finds, but don't totally know what to make of them yet:

• SHG coherences, with OPO TRANS + FC REFL, as well as SQZT0 motion.
  • 200 Hz - 800 Hz - Coherence of SQZ green power with SQZT0 accelerometer from seems slightly higher than I expected? Especially given the high levels of table motion seen in that same frequency band.
  • 1.2 kHz and 1.45 kHz - there seems to be strong coherence of SHG with table motion in these high frequency bands too? And the >1 kHz motion seems to get into our other green signals, like OPO_TRANS and FC_REFL.
  • With OPO ISS running, I guess it stablilizes OPO_TRANS power against the 200-800 Hz fluctuations of SHG green (w/in ISS or OPO loop bandwidths)? But FCGS doesn't have an ISS, so that SHG motion propagates to FC green locking, unlike OPO green locking with ISS.
• CLF coherence with SQZT0 accelerometers ~ 400 Hz, even though CLF_REFL_PD has an ISS running, and the PD is installed on SQZT7. Not totally surprising I guess, but kinda interesting to see it.