Thomas, TJ, Peter King, Aidan (remotely)

The goal of this measurement is to get the end HWS to sample the ETMs while locked on IR at low power (2 Watts) as a reference and then transition to higher power (29 Watts).

Preparation:

- This morning Peter and I went down to the end stations to install the Hartmann plate on EX and double check that EY's plate was still on.  Both are currently installed.

- The virtual disk that houses the HWS data frames was full so I ran a script that deletes old data, we are currently at 87% full.

-  I automated the misalignment procedure with this script: /ligo/home/thomas.vo/LIGO/AOS/TCS/20170815_ETM_Abs_Meas/Setup_HWS_Ends_Test.py. In order to image just the ETM, we need to input a bias offset to ALS-PZT2 YAW in order to offset the reflection off the ITM, the offsets were determined in aLOG-35979.  For the X-ARM, the bias offsets were correct, but for the Y-ARM the offsets would kick the ETMY reflection off the HWS so we decided to do this move by hand however it was difficult to precisely discern how far off the ITM spot was.

We locked both arms in green and took the lock guardian all the way up to DC_Readout, then I manually opened the shutter on the green beams and ran a misalignment script (see below) and started the HWS code.  However, the code on ETMX crashed in the middle of the test and didn't throw up any warnings but we were able to get ETMY measurements. The data is in /data/H1/ETMY_HWS/1186800000.

- Start time (@ 2 Watts):  15:35:00 PST

- End time (@ 29 Watts): 15:55:00 PST

- Shuttered: 16:10:00 PST