Before ER7 we noticed that we have a better signal for damping the ETMX roll mode in AS 45Q yaw than in pitch. Durring the vent we added a matrix to the ASC model to allow switching. On Friday Nic found that the old settings for damping ETMX roll (using AS45Q PIT) were not working, so he found some settings that worked using DARM err alog 19561.
Today I needed to damp ETMX roll again, so I tried using AS45 Yaw, this worked well, with a phase of -90 degrees relative to the settings we had for pitch (so we use bp 13.9, -60degrees, -30 degrees, -100dB and a gain of 60). I also attempted to damp ITMX and ETMY using AS 45 Yaw (which has better SNR for these as well).
While these settings seemed to work for each individual optic, when I turned all three on and left them on simultaneously for several minutes, they rang up all the modes.
| ETMY | ETMX | ITMY | ITMX | |
| Frequency [Hz] | 13.816 | 13.889 | 13.93 | 13.978 |
| Filters | FM3(-100dB) FM4 (bp13.9) | FM2(-60deg)FM3(-100dB)FM4(bp13.9)FM7 (-30deg) | FM1(+60deg) FM3(-100dB) FM4(bp13.9) |
?? |
| Gain | -50 | 60 | -80 |
Reminder, the nominal settings for bounce and roll damping (with AS pit) can be found in alog18614.
