We have moved our interferometer spot positions back to those we had before the change on the ~1st of August. See alog 51262 for a summary of why several indicators that the July spots were better for the IFO.
We have done this by modifying the powerup A2L spot position gains in the lscparams guardian file, so that we will still acquire lock with the beams roughly centered on the optics, but once we start engaging the soft loops we change the A2L gains and go to the final 37W spots, then power up.
Also, I have reverted the OMC ASC QPD setpoints back to their values from the July time, undoing alog 50973. Hopefully we will see a marked reduction in the number of low frequency glitches. The OMC ASC setpoints were saved in both observe and safe snap files.
Jenne and I were assuming Sheila's modification to the ISC_LOCK guardian were successful, but alas -- a typo meant that we are still using the Aug positions for this observing stretch starting at2019-08-20 23:01 UTC. The game plan will be to - not move the spot positions today - fix the code, reload it - walk operators through the "if it breaks lock, here's how lock acquisition will look" scenarios, or - if we don't lose lock, Sheila and I will walk the spot positions to July at 37W tomorrow morning to execute the as-planned commissioning activity. OMC ASC offsets are still reverted to July though.