jeffrey.kissel@LIGO.ORG - posted 09:48, Monday 09 September 2019 - last comment - 12:46, Friday 13 September 2019(51819)
NEW, MORE ACCURATE CALIBRATION MODEL BEING INSTALLED NOW
YES THIS WILL DROP THE FRONT-END COMPUTED BNS RANGE, because we're improving the accuracy of the real-time pipeline in order to better matrch the current IFO (more power than when it was last updated, no detuning, good spot positions, SRCL offset, accounting for new UIM boost, etc.) Should be done in an hour or three. When we come back in to OBSERVATION READY, the new model will be in place. See details of the model in LHO aLOG 51784, and references there in. The decision point to change the model is documented in LHO aLOG 51782, which has yet more references and explanation.
Reference Model values at calibration line frequencies (aka "EPICs records") for this model update have been generated and installed. /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O3/H1/Results/CALCS_FE/ epicsrecords_model-H1_20190909_created-20190909.txt In doing so, I've created the script /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O3/H1/Scripts/CALCS_FE/ python3.5 createEPICS_for_20190909.py rev 8397. and modified it and computeDARM.py to be able to write the EPICs records to file separately from actually pushing it to the front-end. /ligo/svncommon/CalSVN/aligocalibration/trunk/Common/pyDARM/src/ computeDARM.py rev 8399I've used the broadband injection made just after the model update to do a comparison of calibration accuracy with different levels of time-dependent corrections applied, using the new model. This is similar to the analysis done in LHO aLOG 51794. The attached plot has 4 versions of offline calibration, each with different TDCF corrections applied, as indicated in the plot legend. The 5th (red) curve is from the online GDS data (C00). The previous conclusions are still supported by this data: 1) We should not be correcting for SRC time dependence; and 2) We should not be applying the imaginary parts of the actuation kappas. Note the large errors caused by applying corrections for SRC time dependence. This may be due to the fact that the model value of f_s is zero, causing numerical instability when applying time-dependent corrections.
This plot, as well as text files with the data, are available in the calibration SVN here:
aligocalibration/trunk/Runs/O3/H1/Measurements/FullIFOSensingTFs/DCS_BB_plots
The values of the TDCFs used by the GDS and DCS calibration pipelines to produce the calibrated data during this broadband injection were:
For the C00 data (this can be seen on the summary page for that day, just after 18 UTC):
For the DCS data (very similar, but not quite identical):