It seems like we should put some effort into our oplev damping loops. 

• They need better roll offs, at 10 Hz the noise from these loops is similar to the ASC noise. (screenshot attached)
• We have a resonant gain in the servo which I think is tuned for damping when there is no power in the arms.   
• There is a feature in the ASC signals which seems to come from the ITMY oplev at 3.3 Hz, which is a large part of the RMS of the alingment signals. 

It would be good to use the suspension model to look at our top mass damping loop shape while we have radiation pressure in the arms, as well as the oplev damping and see if we can get better damping out of the top mass.  Next time we have some commisioning time, we could make some measurements before we switch to the low noise ASC to see if we can reshape these loops to have less noise.