FYI, IAS:
Below is the table of the ETM and ITM bias slider offset when the arm was aligned. Xarm data is right after we saw some green fringing (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9064). I'm taking HIFO-Y data for Y arm (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6627) even though HIFO-Y was more than a year after H2 EY was pumped down, as the slider was not calibrated during OAT, the data channels were all H2 so it's hard to track it down using data viewer now, and I don't know how much the output matrix changed (the uncalibrated slider data is still available e.g. here: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=3363).
| EX | IX | EY | IY | |
| PIT urad | 332.5 | 82.8 | -142.7 | 247.5 |
| YAW urad | -3.75 | -55.5 | 197 | -271.5 |
Though EX, IX and IY all needed to be pointed down, EY needed to be pointed up (the slider sign convention is such that a positive PIT offset points the optic down).
Slider calibration is probably 15%-ish good or maybe better based on the measurement of baffle PD positions.
OTOH, the earth radius is about 6400km. The angle between the local vertical of EX and the corner is about 4km/6400km=630urad.
The relation between the gloabl and local coordinate system is defined in T980044.
Again FYI:
We know from the excercise of offloading TMS PIT to HEPI, and then offloading HEPI PIT back to TMS, that the PIT of HEPI doesn't affect the PIT of ETMX much.