This is my question as well, how do antenna calibrations relate to reference frames?
Trying to research that, I found this, https://www.ngs.noaa.gov/ANTCAL/#faq24
"24) Why did so many calibration values change in February 2017?
On 29 January 2017, the IGS released a new reference frame, IGS14; NGS incorporated these changes into our database in February 2017. As part of the IGS14 reference frame, the absolute calibration values for many GNSS satellites and receiver antennas were updated. The absolute calibration value for the AOAD/M_T antenna was also updated with IGS14. Since this antenna is used to convert NGS relative calibrations into absolute (see FAQ12), the values for all "relative to absolute" calibrations also changed. In all, the calibrations for over 450 receiver antennas in the NGS database changed in February 2017. A complete list of antennas which changed with the IGS14 update is here."
which still leaves me with the question, how do antenna calibrations relate to reference frames?
Best regards, Eli