In order to maintain consistency with the International Earth Rotation and Reference System Service (IERS) and the International GNSS Service (IGS) reference frames, NGS has been working to implement the new International Terrestrial Reference Frame 2020 (ITRF2020) and IGS20 realizations in the U.S. National Spatial Reference System (NSRS). This will result in updated North American Datum 1983 (NAD 83) coordinates for stations in the NOAA CORS Network (NCN) that are consistent with the existing NAD 83 epoch 2010.0 realization. This update will be called the Multi-Year CORS Solution 3 (MYCS3), and the last time NGS did a similar update was 5 years ago for MYCS2, where you can read more information on the MYCS2 website.
What’s new?
This update to the NSRS is expected to be released later this year. What’s new?
- New coordinate functions for NOAA CORS Network (NCN) stations consistent with ITRF2020
- Datasheets will display new NAD 83 coordinates transformed from ITRF2020 coordinate functions. The new NAD 83 coordinates will remain at reference epoch 2010.0
- Position and Velocity (P&V) files will display coordinates/velocities in both NAD 83 and ITRF2020
- The NGS Online Positioning Users Service (OPUS) will begin processing data with NCN control that is consistent with ITRF2020 at the time of measurement; results will still be transformed to NAD83 at epoch 2010.0.
NGS will share more information, including an upcoming webinar, as the transition date approaches.
Background:
On 2 October 2022, the International Earth Rotation and Reference System Service (IERS) released a new realization of the International Terrestrial Reference Frame called ITRF2020. The new frame supersedes the previous version called ITRF2014. The ITRF2020 release was followed shortly by the release of a new frame realization by the International GNSS Service (IGS) called IGS20 which is closely related to ITRF2020.