MC1 accelerometer has been plugged in. The modecleaner locking has been intermittent today, but I looked at a 15 minute lock in DTT, looking at the STS1 seismometer and both accelerometer triplets. Plot and DTT xml attached.

For the sake of not cluttering up everything with legends, the coherence plots are organized by direction (x, y, z), and include the coherence of each of the three sensors (sts, acc1, acc2) with the IMC control signal and the IMC transmitted RIN. 

Some remarks:

• The 1 Hz pendulum motion is about equal amounts of X and Y, which makes sense, as MC1 and 3 are at an angle
• The ~3 Hz stack motion seems to be entirely in the X direction. Why?
• The bounce/roll bands are strongly coherent with Z motion at MC2. 
• The STS does not appear to have any low frequency advantage over the accelerometers, in terms of coherence, contrary to what I would expect even without a thermal enclosure. 
• The control signal and RIN RMSs are clearly dominated by noise in the 1-3Hz band, where we have reasonable coherence. Good prospects for noise subtraction...