I spent some time this evening measuring OLTFs of our beamsplitter loops and the SRC pointing loops. We might find it helpful to refer back to these measurements when trying to reconstruct the ASC later.

As a reminder, the beamsplitter loops the 36 MHz AS WFS. The SRC pointing loops use the ASC QPD as a sensor, and feed signal to both SR2 and SRM (in such a way as to be decoupled from the 36 MHz SRM loop).

The beamsplitter OLTFs seem pretty straightforward; the UGFs are about 2 Hz for pitch and 3 Hz for yaw.

The SRC pointing loops seem to show complex plant dynamics, so it is difficult to quote a single UGF. There are UGFs ranging from 0.5 Hz to 3 Hz or so. Presumably another UGF in each loop exists at some frequency below the plant dynamics, as with the differential hard loops.

Between Jenne and me, I believe we have either OLTF measurements or step response measurements for all the ASC loops except the four soft loops.