I have uploaded a brief report on efforts to understand and diagonalize the OSEM sensor readouts on the two quadruple suspensions at LHO.  The BSC8 chamber containing ITMY is now out of vacuum and so further testing on it will not be possible for the near future.  The ETMY will still be under vacuum and is amenable to more testing that should help us understand how to fix the responses of the lower stages of the quad suspension OSEMs.

https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?.submit=Number&docid=t1200442&version=