Reports until 17:37, Monday 31 August 2015
H1 CAL (CAL)
craig.cahillane@LIGO.ORG - posted 17:37, Monday 31 August 2015 (21065)
Strain Uncertainty Carpet Plots Developments
C. Cahillane, D, Tuyenbayev, E, Hall

I have discovered the difference between Plot 1 and Plot 7 in aLOG 20974.
To recap, Plot 1 was strain uncertainty calculated from actual ER7 data, and Plot 7 was strain uncertainty calculated from sensing, digital, and actuation transfer functions only.
One issue was the dewhitening filters were incorrect.  Evan taught me to locate the correct filters based on the GPS times and channel names.  (They can be found in /opt/rtcds/lho/h1/chans/filter_archive/h1calcs/  The shortcut terminal command is "chans")
Another issue was I was using only the ASD of DARM_ERR and DARM_CTRL for my calculations, and ignoring the phase information.  I have corrected this in my code, but not in my uncertainty document T1400586.

Below I have replotted the carpet plots from aLOG 20974 in the same order.  Now you can see very good agreement between New Plot 1 and New Plot 7.
The next step is to discover why the data is so glitchy at high frequency.  I believe it is due to interpolation of the data to fit our ER7 transfer function frequency vector.  
Darkhan has been working on the ER8 DARM model and has made every element into an LTI object.  This will make getting the ER8 transfer functions into any frequency vector very easy, so this is the next step for this project.

The step after that is to begin calculating the error bars themselves. I will have to revisit my Mathematica notebooks to recalculate uncertainty in strain magnitude σ_{|h|} and strain phase σ_{φ_h} with phase info from DARM_ERR and DARM_CTRL included.
Non-image files attached to this report