Since the lock was so stable, I could not avoid measuring the DARM open loop for calibration purpose tonight. I have tuned the excitation amplitudes of the 4-1200 Hz DARM OLTF template because some frequency points had too high excitation causing saturation on ETMY DACs. Also for completeness, I have taken a Pcal sweep as well. I will analyze the data later.
The dtt files can be found at:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER10/H1/Measurements/DARMOLGTFs/2016-09-15_H1_DARM_OLGTF_4to1200Hz.xml
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER10/H1/Measurements/PCAL/2016-09-15_H1_PCAL2DARMTF_4to1200Hz.xml
I have processed the data that I took.
Since in the end the calibration filter I got was close to what Evan H. installed (29796) within several % above 100 Hz, we diecided not to re-update the calibration filters for now.
[Fitting Results]
I have used Craig's optical spring function (T1600278) which uses f_s and Q to characterize the low frequency behavior of DARM. Also, the uncertainty was derived based on the covariance matrix from an mcmc sampling (28302). I have already loaded the calibration filters in CAL-CS which are in FMs 2 and 3 of DARM_ERR, but as I wrote above, we are not going to use this and keep using Evan H's filter for now until we assess the actuator functions. See the first attachement for comparison. This measurement suggests slightly worse shot noise above 100 Hz. The latest filter is 7% worse at 1kHz with repspect to the filter that are currently in. Also, for a comparison purpose, I plotted the old calibration filter from ER9 which higher than the latest two filters by about 20-30% across the entire frequency.
[Some data and scripts]
I have used Evan G's DARM code to extract the sensing function. The script is available at:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Scripts/DARMOLGTFs/extractOptResp.m
The data are available at
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/DARMOLGTFs/2016-09-15_H1_DARM_OLGTF_A_ETMYL3LOCKIN2_B_ETMYL3LOCKIN1_tf.txt
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/DARMOLGTFs/2016-09-15_H1_DARM_OLGTF_A_ETMYL3LOCKIN2_B_ETMYL3LOCKIN1_coh.txt
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/DARMOLGTFs/2016-09-15_H1_DARM_OLGTF_A_ETMYL3LOCKIN2_B_ETMYL3LOCKEXC_tf.txt
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/DARMOLGTFs/2016-09-15_H1_DARM_OLGTF_A_ETMYL3LOCKIN2_B_ETMYL3LOCKIN1_coh.txt
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/PCAL/2016-09-15_H1_PCAL2DARMTF_4to1200Hz_A_PCALRX_B_DARMIN1_tf.txt
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER10/H1/Measurements/PCAL/2016-09-15_H1_PCAL2DARMTF_4to1200Hz_A_PCALRX_B_DARMIN1_coh.txt
The fitting code (written in python notebook) is attached.