We have had issues with RxPD clipping at Y-End Pcal since earlier this year. In light of this clipping we switched to using TxPD instead of RxPD since June 19, 2017.  This clipping introduced a systematic error in the calibrated data before June 19. The mathematical recipe that describes this systematic error is in LHO alog #34153. The comment on the same alog also contains the correction factor that needs to be applied to account for clipping until Jan 22.

The files below contains the correction factor from Jan 22, 2017 02:19:02 UTC to Jun 19, 2017 17:35:22 UTC.  

Correction factor at three calibration line frequencies for all time with 10s interval (the data is obtained from 10s FFT).

 ${CalSVN}/aligocalibration/trunk/Runs/O2/H1/Results/PCAL/O2_RxPD_TxPD_factor_Jan22_Jun20.txt

Correction factor at three calibration line frequencies for science-quality data with 2 minute running average

${CalSVN}/aligocalibration/trunk/Runs/O2/H1/Results/PCAL/O2_RxPD_TxPD_factor_Jan22_Jun20_scienceintent_2minrunningavg.txt (Data)

${CalSVN}/aligocalibration/trunk/Runs/O2/H1/Results/PCAL/O2_RxPD_TxPD_factor_Jan22_Jun20_scienceintent_2minrunningavg.png (Plot)

The script used to produce these correction factors is here:

${CalSVN}/aligocalibration/trunk/Runs/O2/H1/Scripts/PCAL/TxPDRxPD_factor_Jan22_Jun20_2017.m