Attached are plots of the time-dependent calibration correction factors as computed by the GDS calibration pipeline for GPS times 1126003432-1126011584 (Fri Sep 11 03:43:35 PDT 2015 - Fri Sep 11 05:59:27 PDT 2015). The derivation of these factors and their meaning is described in DCC-T1500377. The channel names correspond to the factors as such: GDS-CALIB_F_CC: frequency of coupled cavity pole - average value ~ 350 Hz GDS-CALIB_KAPPA_C: time-dependent scale factor for the sensing - average value ~ 1.07 - expected average value = 1 GDS-CALIB_KAPPA_A_IMAGINARY: imaginary part of time-dependent scale factor for the total actuation - average value ~ -0.01 - expected average value = 0 GDS-CALIB_KAPPA_A_REAL: real part of time-dependent scale factor for the total actuation - average value ~ 1.01 - expected average value = 1 GDS-CALIB_KAPPA_PU_IMAGINARY: imaginary part of time-dependent scale factor for the PUM/UIM stages of actuation - average value ~ 0.03 - expected average value = 0 GDS-CALIB_KAPPA_PU_REAL: real part of time-dependent scale factor for the PUM/UIM stages of actuation - average value ~ 1.07 - expected average value = 1 GDS-CALIB_KAPPA_TST_IMAGINARY: imaginary part of time-dependent scale factor for the TST stage of actuation - average value ~ 0.05 - expected average value = 0 GDS-CALIB_KAPPA_TST_REAL: real part of time-dependent scale factor for the TST stage of actuation - average value ~ 1.0 - expected average value = 1.0 These values indicate some (O(5%)) differences in gain between the current calibration models and the IFO. We expect this level of difference for kappa_tst and kappa_c. However, we anticipated kappa_pu to be closer to the expected average values. This discrepancy is still being investigated.
I recomputed the factors for this time period using the "fudge factor" described in alog 21479. The new computed factors match with those for the later times in Sudarshan's alog (#21479). See attached plots. (Note: The units on the f_cc plot are Hz on the y-axis. Sorry for the confusion in the labeling.)