M. Ball
I have been modeling angle to length cross-coupling in the quad suspensions. Since I am leaving Hanford, I have prepared a sample Matlab script that covers some of the key modeling I did. It is located in /ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/asc_angle_to_DARM.m
More details of my modeling work can be found in G1901481-v2.