V. Bossilkov, L. Dartez

Summary
We gave the simulines calibration injection scheme another go at LHO during this week's commissioning window. In short, the commissioning endeavor was partially successful: we did not lose lock and we were able to gather useful data for the actuation stages and the DARM OLG. However, additional commissioning time is required before we can fully adopt simulines for the regular calibration measurements at LHO.

Objective
The goal of today's session included the following:
1.) Determine whether we can run simulines at LHO reliably without losing lock,
2.) assess the data quality of the recorded simulines hdf5 files and confirm that they can be read and post-processed
3.) evaluate the spacing of the common frequency vector that is used for all measurements
4.) tweak the injection amplitudes and integration length to get a good enough SNR while keeping the amplitudes and integration lengths as low as possible

Code Execution
We ran two trials with injections at different amplitudes: 0.5*A and 0.1*A, where A is the corresponding amplitude typically used for the same injections in DTT. Simulines uses a configuration file in .INI format to inform the various injections of their frequency vectors, amplitudes, and other settings. The two files we used, both of which are located in /ligo/groups/cal/src/simulines/h1_test_settings, are named as follows:

Half the DTT amplitude: settings_h1_0.5.ini
One tenth the DTT amplitude: settings_h1_0.1.ini

These files are contained within the simulines repo as of commit bf25b1b4.

The simulines code was run using the following command from within the repo's simulines directory:
python simulines.py -i ../h1_test_settings/settings_h1_0.5.ini

The terminal output for both runs is attached here. All measurements were placed in /ligo/groups/cal/H1/measurements as they would during a normal pydarm measure execution.

Once recorded, we ran a quick script that Vlad wrote to take a look at each measurement's uncertainty as it compares to those taken with DTT. The script used lives at /ligo/home/louis.dartez/projects/20230705/simulines_commissioning/simulinesUncert_H1.py. This script compares each simulines injection with a corresponding DTT injection. The exact DTT injections used for this initial test run are listed in the script source code (uploaded to this alog for redundancy).

Results
We were able to successfully run simulines for all of the normal calibration measurement sweeps (we did not take any broadband measurements). The table below contains plots comparing the uncertainty from the simulines (SL) injections vs the same using diaggui (DTT). The top plot in each figure shows an overlay of the uncertainty from the SL injection and the DTT injection. The bottom plot contains the residual (SL_unc / DTT_unc). The left and right columns correspond to the 0.5*"DTT Amplitude" and 0.1*"DTT Amplitude", respectively. Each actuation stage is displayed on its own row.



0.5*Ampl
0.1*Ampl
ETMX L1


ETMX L2


ETMX L3






For a first shot at taking a serious look at demo-ing and commissioning the simulines tool at LHO, we have been quite successful. The uncertainty comparisons below tell us that we're able to achieve comparable uncertainty in several parts of the band with a significantly lower amplitude than what we've been using in DTT (this isn't a statement about the tools, rather that it's about time we take a new look at the injection amplitudes). However, we will need to zoom in a bit more and study the data we've already recorded to determine where and by how much to adjust our injection amplitudes to maintain an acceptable coherence for all measurements. 

Unfortunately, we weren't able to plot up any of the usual transfer functions today because of an issue (bug?) that prevented us from processing any of the PCal measurements. Luckily, the data is thought to be processable once a few kinks get ironed out with the simulines processing code. The current theory is that a bug in the recording script caused nonsensical coherence values to be recorded in the hdf5 output files. 

I'm going to continue working with Vlad and the calibration team to get this up and running.

== Relevant Logs ==
simulines was first tried out at LHO (LHO:66284) 

Vlad lays out initial plan for testing simulines at LHO (LHO:70998)