J. Kissel for J. Driggers and N. Lecoeuche

After Jenne's re-work of the ISC_LOCK guardian code (see LHO aLOG 51426), we lost lock at 1250407425 (Aug 21 2019 07:23:27 UTC). Niko then loaded the guardian changes (after a few more bug fixes), and ran through the newly minted -- and very slow! -- ENGAGE_SOFT_LOOPS steps which brings the spot positions from centered, out wide in yaw, up in pitch, and then back over in yaw to land back in the old pre-August, "July" spot positions. See LHO aLOG 51433 for Niko's summary of activity.

Other than the length of the ENGAGE_SOFT_LOOPS state, everything seemed to have run smoothly, and is currently running smoothly (though the microseimm and EQ band are pretty high at the moment).

Thus, at the start of this observation segment -- started 1250414457 (Aug 21 2019 09:20:39 UTC) -- now (and hopefully "for good") has the pre-August, "July" O3 spot positions, and we've finally recovered from the initial alignment reference loss.

Sheila and I will be characterizing the IFO today in these reverted spot positions (in similar fashion to LHO aLOG 51393 and LHO aLOG 51394).

I attach BEFORE (first) vs AFTER (second) screenshots of the initial alignment references and spot positions.