[M. Wade, A. Viets]

I've produced new filters for use in the GDS calibration pipeline.  They can be found in the calibration SVN at:

aligocalibration/trunk/Runs/PreER13/GDSFilters/H1GDS_1225558818.npz

They were produced from SVN revision 6011 and these parameters files:

• aligocalibration/trunk/Runs/O3/H1/params/modelparams_H1_2018-10-04.conf
• aligocalibration/trunk/Runs/O3/H1/params/H1_TDparams_1225558818.conf

The first parameters file above is based on modelparams_H1_20181004.py, found in the same directory.  I made this parameters file to be compatible with the old Matlab DARM model code, since the filter generation code in pyDARM is not yet ready.  Most of the measurement files were able to be read in, the exceptions being these files:

• aligocalibration/trunk/Common/pyDARM/H1aa.mat.  
• aligocalibration/trunk/Common/pyDARM/H1susdata.mat

These files were replaced by the ones used at the end of O2, referred to in aligocalibration/trunk/Runs/O2/H1/params/2017-01-24/modelparams_H1_2017-01-24.conf.  Note: the filters previously in use (as of 2018-11-06) were based on this parameters file.

These filters also have improvements to the high-pass filters, intended to get rid of the spectral leakage noted in LHO aLOG 44997.

The first three plots attached show comparisons of the filters to the frequency-domain models.  The last plot is a transfer function comparing GDS-CALIB_STRAIN to the front-end's CAL-DELTAL_EXTERNAL_DQ.