jenne.driggers@LIGO.ORG - posted 02:42, Thursday 13 August 2015 - last comment - 10:43, Thursday 13 August 2015(20498)
A2L run
I ran Hang's latest A2L script (see aLog 20013), after the realignment work that was done tonight (Sheila is writing up her entry as I type).
We stil have excess noise at low frequency, but maybe there's a bit less than when I started the script? The noise we're seeing is totally non-stationary, so it's hard to say. Certainly the A2L didn't eliminate it.
I checked the results of the latest a2l run. It seemed that the decoupling worked only for ETMX pitch and ITMX pitch, and the optimal gains changed only by 7% and 2%. On the other hand, it failed for ETMY pitch and ITMX yaw. I attached a worked result and a failed one for comparison.
By examining the results, the bad ones had a flatter slope and were more likely to have "outliers". We thus might be able to get a better result by increasing the steps between two measurements, or increase the number of gains to be measured. Nonetheless, it seemed to also indicate that we were already near the optimal spot that such an linear, single frequecy decoupling could achieve...