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Reports until 17:39, Thursday 26 June 2025
H1 SUS
oli.patane@LIGO.ORG - posted 17:39, Thursday 26 June 2025 (85369)
Script to show difference in SUS noise before vs after SatAmp swap

In preparation for the SatAmp swap (ECR E2400330), I've written a script that allows us to easily compare the noise performance between satellite amplifier swaps. It takes in a suspension name, ifo, and two gpstimes, grabs the DAMP IN data for all dofs, regresses out the ISI GS13 noise, and then compares the leftover noise between the two gps times.

We wanted to have the script divide out the loop suppression, and Jeff looked into which suspensions we've taken valid open loop TFs for (85289). Some suspensions have valid OLTF measurements, so from those we were able to export the loop suppression to divide out (and are saved in the suspension's Data folders), but others don't have valid measurements, so I made it so if there is a valid measurement, it will divide it out from the regressed sensor noise data, otherwise it'll just show the regressed.

Here is an example of the suspension noise before and after a satellite amplifier swap for SR3 that was done at LLO last summer (72417). There was no loop suppression for us to divide out here, so the plots just show the DAMP IN and the leftover sensor noise.

Here is another example for LHO PR3. This one is only meant to be an example of the plots with the loop suppression removed, as the sat amp is the same for both gps times. There is some weirdness around where the peaks were supposed to be removed by the loop suppression - some dofs still show thin peaks. The loop suppression didn't remove them correctly, and we think this might be because the loop suppression assumes a SISO loop, but we might have cross coupling that then is not accounted for when we are dividing by the loop suppression.

The script is located in /ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/damp_regression_compare.m, and is a function so it can be called from somewhere else. It has been committed as r12362.

The data that's pulled for the gps time and timespan for the sus dofs and chamber GS13s takes a while to grab the first tme, so I had it save the data in the respective suspension Data folders (ex. /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Data/dampRegress_H1PR3_M1_1405123218_1200.mat). Then if you need to run that gps time + span again it'll get the data right away.

The results get saved in the suspension's Results folder (ex. /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/PR3/SAGM1/Results/allDampRegressCompare_H1SUSPR3_M1_NoiseComparison_1405123218vs1433376018-1200.pdf).
 

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