I realized today that our updates to the inverse sensing FOTON filter would yield slightly incorrect DARM FOM curve in DTT, especially in the ~5 kHz range. This is because the DARM FOM DTT template has a calibration that corrects for "warping" from a correct inverse sensing filter compared to what we are able to install in the front end using an IIR filter. I updated the H1_DARM_FOM.xml file with this new calibration and committed the changes to the SVN.

This curve was computed using the following script located in the calibration SVN:
aligocalibration/trunk/Runs/O3/H1/Scripts/darm_FOM_calibration.py

Attached is a figure showing comparison with the old curve (with slightly incorrect calibration) to the new curve (with correct calibration).

Also attached is the current DARM FOM DTT template calibration transfer function that is now being applied to H1:CAL_DELTAL_EXTERNAL_DQ (columns are frequency, magnitude (dB), phase (deg.)).