Today
I calibrated the tilt sensing OPLEV for SR2, see sr2tmoplevtiltcal.png for the calibration curves.
For pitch, the linear range is ±223 µrad,
while the range for yaw is ±322 µrad, assume that they rougly align with vertical and horizontal axes respectively.
The calibration factors are 0.006501 mm/cnts (vertical) and 0.007532 mm/cnts (horizontal). So the OL2EUL matrix without length sensing is:
| TILT_PIT | TILT_YAW | |
| P | 2.23402062 | 0 |
| Y | 0 | 3.323667101 |
I updated the matrix in MEDM screen.
Similar to SR3, there steering mirror of the OPLEV is not heavily tilted. Hence, this matrix is roughly diagonalized.