Today I began calibrating the camera servo signals into spot positions. I ran the A2L script at the nominal camera spot positions. Then, I changed the camera offset and waited for the camera servo to converge. Then I remeasured the A2L gain. Using the a2l_lookup function in /opt/rtcds/userapps/release/isc/common/scripts/decoup/BeamPosition the A2L gain can be converted into a spot position in mm. This is a slow process so it will take time to get the conversions for all.
| Camera offset | A2L gain | Conversion | |
| ETMY Pitch | start: -230, end: -231 | start: 5.62, end: 5.92 |
(-23.2 mm - -21.8 mm)/-1ct = 1.4 mm/ct |
| ITMX Pitch | start: -230, end: -231 | start: -0.45, end: -0.56 |
(6.46 mm - 5.96 mm)/-1ct = -0.5 mm/ct |
I continued today following the same process stated above.
(-9.38 mm - -9.93 mm)/ 1ct
= 0.55 mm/ct
(3.90 mm - 5.18 mm) / 1ct
= -1.28 mm/ct
(17.22 mm - 17.84 mm)
= -0.62 mm/ct
I reran the ITMX beam spot calibration following the same method described above, but this time I checked how the beam spot moved on both ITMX and ITMY when I changed the BS camera offset. Turns out, they give the same answer, so that's good.
(6.41 mm - 5.96 mm)/-1 ct
= -0.45 mm/ct
(11.26 mm - 11.70 mm)/ -1ct
= 0.44 mm/ct (-0.44 mm/ct for ITMY)