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Reports until 18:14, Sunday 03 February 2019
H1 CAL (CAL, ISC, SUS)
jeffrey.kissel@LIGO.ORG - posted 18:14, Sunday 03 February 2019 - last comment - 10:26, Wednesday 13 February 2019(46754)
H1 SUS ETMX Driver Electronics Measurements Complete 
R. Abbott, J. Kissel

Rich and I measured detailed transfer functions of SUS ETMX's driver electronics today. More details to come, but we were at EX measuring from about 11a to 6p with things disconnected, the SUS ETMX guardian in SAFE, and the SEI chamber guardian in DAMPED. All driver electronics (and associated cabling) suspensions, platforms, and guardians have been restored to nominal functionality.

The raw data can be found here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Common/Electronics/H1/Data/SUSElectronics/ETMX/
    UIM/2019-02-03/
    PUM/2019-02-03/
    TST/2019-02-03/

The file names are only labeled by date, so the key to translate the filenames into useful quadrant / coil and switch state information is found in the measurement notes in each directory,
/ligo/svncommon/CalSVN/aligocalibration/trunk/Common/Electronics/H1/Data/SUSElectronics/ETMX/
    UIM/2019-02-03/2019-02-03_UIMdriver_measurementnotes.txt
    PUM/2019-02-03/2019-02-03_PUMdriver_measurementnotes.txt
    TST/2019-02-03/2019-02-03_ESDLVDriver_measurementnotes.txt
Comments related to this report
jeffrey.kissel@LIGO.ORG - 10:26, Wednesday 13 February 2019 (46927)
Link 

Here's the analog electronics measurement setups for this data.

This time (unlike the 2016 attempt; see the last page of LHO:24725), we tried to cut corners by only driving the coil drivers with single-ended input directly from the SR785 -- so we can avoid having to characterize the details of the differential driver box that has been used previously. This failed, causing (what we believe to be saturations) of the coil driver electronics and wonky unphysical transfer functions. This is especially evident with the PUM driver's switchable "acquire" circuits engaged, and in the UIM driver after the second and third low-pass filters are in engaged. Finally, comparing against measurements taken with the coil driver monitor circuits (LHO:46854) it's dreadfully obvious.

More investigation is required as to what's going on, but sadly those investigations take time that we don't have.
I'm proceeding with attempting to fit a combination of the un-spoiled SR785 data and the less-complete-and-more-complicated monitor circuit data taken with DTT (again, LHO:46854).

The ESD driver measurements (at least) appear to be good enough to move forward, as indicated by the table of results above.
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evan.goetz@LIGO.ORG - 16:02, Monday 04 February 2019 (46773)
Link 

Using the data from Jeff and Rich's measurements, I have fitted the ESD driver electronics. However, I ran into problems when trying to fit the PUM and UIM measurements. The raw output of the transfer function measurements looks unfamiliar to previous measurements and has puzzled Jeff and Rich when I showed it to them.

1) Summary plots from ESD driver measurements and fits
2) Puzzling PUM driver measurements
3) Puzzling UIM driver measurements

Scripts for analysis of the data is located at:
$CALSVN/trunk/Common/Electronics/H1/Scripts/model_ETMX_*_20190203.m
and plots are found at:
$CALSVN/trunk/Common/Electronics/H1/Results/SUSElectronics/ETMX/[UIM,PUM,TST]/2019-02-03/

The fit results for the ETMX ESD driver electronics is given below.
Quadrant                   Low pass [z;p] (Hz)                             Summing node [z;p] (Hz)
-----------------------------------------------------------------------------------------------------------------------
UL        [13.871+/-0.721, 15.668+/-0.748; 2.186, 2.186]       [129.736e3+/-2.818e3; 3.213e3+/-15.78, 31.549e3+/-381.9]
LL        [13.666+/-0.817, 15.570+/-0.850; 2.163, 2.163]       [90.736e3+/-694; 3.177e3+/-7.088, 26.699e3+/-145.6]
UR        [14.9049, 14.9054; 2.2222, 2.2223]                   [93.521e3+/-729; 3.279e3+/-7.534, 26.617e3+/-146.2]
LR        [13.335+/-0.486, 15.861+/-0.513; 2.157, 2.157]       [131.520e3+/-2.867; 3.238e3+/-15.9, 31.618e3+/-380.8]

Note above that the UR quadrant fit looked odd when looking purely at magnitude residuals. We saw that there was about a 1% offset in the band of primary interest (1 Hz - 1 kHz) above ~30 Hz which we attribute to the fact that LISO is attempting to minimize the fit error on both magnitude and phase simultaneously. When fitting purely on magnitude, the discrepancy is greatly reduced, at the cost of a slightly larger wiggle on the phase error (still less than a degree).

These have not yet been installed into the SUS output filter banks, but should be done so at the next opportunity.

We will ruminate on the PUM and UIM measurements and attempt to repeat these, again, at the next opportunity.
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