The ETMX decoupling filters for top mass drive to pitch motion at the test mass are now installed in the appropriate L2P bank (split in two filters in FM1 and FM2), and using a gain of -1 (cf 2nd attached screenshot L2P_medm)
It reduces the pitch motion from length drive by a factor of ~7 @ .44Hz and ~5 @ 1Hz (cf first screenshot ETMX_L2P_testing), comparing the L2P transfer function with/without the filter.
Method :
1) Measured L2P and P2P transfer functions using following templates
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Data/2014-03-17_H1SUSETMX_M0_LtoPY_WhiteNoise_0p1to10Hz.xml
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Data/2014-03-03_H1SUSETMX_M0_PtoPY_WhiteNoise_0p1to10Hz.xml
2) Compared the measurement with model, fitted the measurements, inverted P2P and calculated L2P/P2P using the script LP_decoupling.m located in
/ligo/svncommon/SusSVN/sus/trunk/QUAD/H1/ETMX/SAGM0/Scripts
The fitting and inverting process is summarized in the attached pdf.
Note : There's a factor of 11 between fit and model at DC