Here is some of the data from Saturday's jitter injections (29780), plotted differently.  The main point is that we should be able to reduce the yaw jitter coupling by at least a factor of a few, and this should help the DARM spectrum, but not enough to get the noise a factor of 10 belpw the quantum noise with the current level of jitter.  

• the first attachment is a transfer function from the IMC WFS signals to DCPD sum, which is directly comparable to the transfer functions Evan posted in 25653.  For PIT, the coupling in this measurement was similar to what Evan measured in Febuary, but this coupling was reduced by about 8dB on saturday which should have brought it almost back to the September level. For Yaw, the coupling now a factor of 3-4 higher than it was in the September and Febuary.  
• Since Saturday I have tried moving PR2 PITCH along with the POP offset to reduce the pitch coupling (no sucsess), and moving the POP YAW offset (also nothing).  Soft offsets have not been tried. 
• The last plot has projections from Saturday based on the IMC WFS DC and the ISS PDs, as well as a DARM reference and the GWINC curve from our DARM FOM for reference.  These are from before the PIT coupling was improved, so the situation should be a little better now.