The calibration uncertainty envelopes reported in this data release have been used for all event specific analysis reported in GWTC-1.
Each event-specific file contains a column defining the frequency series for which the calibration uncertainty was evaluated, as well as columns providing the median amplitude and phase deviations and the associated 1-sigma uncertainty bounds. For a set of perfectly calibrated data, all amplitude values (both median and 1-sigma bounds) would be equal to 1.0 whereas the phase values (both median and 1-sigma bounds) would be equal to 0.0. All phase values are given in units of radians.
Note that the frequency series given in these files is much more sparse than the frequency series used for the general analysis in GWTC-1, when the analysis required access to intermediate frequency values those were evaluated through a linear interpolation between the measurements provided.
The file GWTC1_example.ipynb is an ipython notebook that shows how these calibration uncertainty envelope files can be read in, interpolated, and plotted.
For the LIGO data, the calibration envelopes were evaluated following the methods described in [62, 63] whereas the Virgo calibration uncertainties are described in [65].
The method with which these calibration uncertainties are incorporated into the analysis presented in GWTC-1 is described in [96].
{The references below follow the same numbering as in the GWTC-1 paper}
[62] Craig Cahillane et al. (LIGO Scientific Collaboration), “Calibration uncertainty for Advanced LIGO’s first and second observing runs,” Phys. Rev. D 96, 102001 (2017), arXiv:1708.03023 [astro-ph.IM]
[63] Aaron Viets et al., “Reconstructing the calibrated strain signal in the Advanced LIGO detectors,” Class. Quant. Grav. 35, 095015 (2018), arXiv:1710.09973 [astro-ph.IM]
[65] F. Acernese et al. (Virgo), “Calibration of Advanced Virgo and Reconstruction of the Gravitational Wave Signal h(t) during the Observing Run O2,” Class. Quant. Grav. 35, 205004 (2018), arXiv:1807.03275 [gr-qc]
[96] Will M Farr, Ben Farr, and Tyson Littenberg, “Modelling Calibration Errors In CBC Waveforms,” https://dcc.ligo.org/LIGO-T1400682/public (2014), Tech. Rep. LIGO-T1400682 (LIGO Scientific Collaboration and Virgo Collaboration)