Trent, Georgia
The new QPD offsets improved the coherence from when the offsets were turned off. However, this new coherence is still lower than coherence from the initial QPD offset values.
See Gabriele's post for more info about the OMC alignment and QPD offsets.
We wanted to look at the coherence between OMC-REFL and DARM with the OMC QPD B offsets on and off. We looked at the coherence between the following channels.
- H1:CAL-DELTAL_EXTERNAL_DQ
- H1:OMC-REFL_A_LF_OUT_DQ
| Trace | Date: UTC | GPS Start Time | Number of Averages | OMC QPD A Pitch Offset | OMC QPD A Yaw Offset | OMC QPD B Pitch Offset | OMC QPD B Yaw Offset | Coherence Ref | Darm Ref |
| Black | 09/03/2024 07:59:49 | 1394006407 | 5325 | -0.15 | 0.2 | 0.04 | -0.14 | 32 |
36 |
| Green | 13/03/2024 10:59:06 | 1394362764 | 1464 | -0.15 | 0.2 | 0 | 0 | 33 | 37 |
| Blue | 12/03/2024 09:07:16 | 1394269654 | 1765 | -0.15 | 0.2 | 0 | 0 | 34 | 38 |
| Red | 13/03/2024 20:28:00 | 1394396898 | 2061 | -0.25 | 0.1 | -0.05 | 0.07 | 35 | 39 |
The blue, green, and red curves have less averages because there was not as long of a time between glitches/losing lock as the black curve.
We took the blue and green curves to determine if there was something else that could have caused the coherence to lower besides turning the offsets off. There is not a significant difference between the blue and green curves so we can conclude that the coherence is lower when the offsets are turned off.
The coherence of all the curves is quite low (<0.1).
The red curve is the coherence with the new QPD offsets and we see that the coherence is still lower than the black curve (the initial QPD offsets).
