Sheila, Jeff, TVo

We were thinking that comparing TFs between L2 actuators and the oplev sensors on the test masses might be a good idea, however, it wasn't trivial to get a past reference of a driven TF which matches the exact status of our current damping scheme.  

So Sheila suggested that I do a passive low bandwidth, high-averaging TF comparing the NLN states of the suspension before and after the EQ.

- References are the old (2017-06-23 03:00:00) compared to the most recent lock stretch (2017-07-28 03:49:39)

Below are the graphs and .xml files for the TFs, it seems like the pitch DOFs are clearer than Yaw as far as coherence but the ITMs are pretty bad below .6 Hz so it's hard to say something too definitive about that status in the low frequency regime.  However, for the ETMs, we can see that from .1 Hz to 3Hz there hasn't been much change due to the earthquake.