We have seen fringe wrapping due to our alingment drives to the OMC, which could be because the pitch drive really moves the OMC input coupler in the longitudnal direction.  To test this we can see if we can get rid of the fringe wrapping caused by a pitch drive by sending some of the pitch drive to the suspension longitudnal drive.  

I made an attempt to diagonalize the OMC drive for pitch.  First I drove the LOCK_P filter bank in the OMC SUS with 3000 counts at 0.2 Hz, producing the dark purple reference in the attached plot.  Then I adjusted the P2L gain to reduce the velocity.  The light purple trace shows the frequency of the shelf being reduced from 45 Hz to just over 20 Hz, so about a factor of 2 reduction in velocity.  

The OMC sus model doesn't send the signals from the OMC ASC through the driveAling matrix.  It would be nice to re-route them through driveAlign to make this easier.  For now I've added matrix elements to the OMC ASC DOF2TT matrix to send the pitch signals to the sus longitudnal.  This could be fine tuned more, but we lost lock as I was trying to fine tune the coefficient.  Hopefully leaving these elements in the matrix will reduce the glitches due to scattered light from the OMC.