IGS article on ITRF2020; NGS new MYCORS update
There is a blurb on the NGS home page informing readers of the new GNSS-only version of the ITRF. NGS will soon compute a MYCORS solution ??Solution 3? to update the US NSRS to be consistent with the new global reference frame.
If you click the blurb??s title, it loads the IGS site (or follow: https://igs.org/ ). Among the many items of interest on this site is a link to the current issue of their newsletter: IGS Constellations (current issue number is four (4)).
This issue includes an article on ITRF 2020 written by Dr Zuheir Altamini. For additional information see his other publications: https://scholar.google.fr/citations?user=Uz7AetAAAAAJ&hl=fr
Lots of other topics are linked from the IGS.org site. Well worth visiting.
- 8 Replies
Some additional info on the IGS contribution to the ITRF:
https://itrf.ign.fr/docs/solutions/itrf2020/IGS-contribution-to-ITRF2020.pdf
Those interested in transformation values between ITRF 2020 and previous versions:
Am I understanding correctly that the translation from ITRF2014 to ITRF2020 is only -1.4mm, -0.9mm, and 1.4mm, and scales at less than a half part-per-billion? I wonder what the noise in those values is. It’s hard to believe that those values can even be realized.
I believe the uncertainties are reported along with the values. There are numerous documents and reports at both the IGS and IERS sites describing their derivations. The US NGS incorporates these transformation values in their HTDP tool.
You might want to review this document: https://nap.nationalacademies.org/catalog/25579/evolving-the-geodetic-infrastructure-to-meet-new-scientific-needs that discusses issues related to meeting the increasing accuracy needs of users trying to understand geophysical phenomena.
I attach copies of the Table of Contents below:
WOW, what a long link. Hope it works.
My reply incorrectly indicated that the uncertainties were shown in the previously posted files.
They are shown in this image:
Source site is:
https://itrf.ign.fr/en/solutions/itrf2020
My answer to the question about the accuracy of the reported parameters and uncertainties is that they are the output of a ??correctly-weighted? adjustment of a ??largish? set of high-quality data observed at continuously operating stable sites with long histories.
Thank you for sharing that. It’s impressive that the error estimates are so low along with the very small transformation from 2014 to 2020.
That paper is worth the read. Thank you.
So is this G2238 in WGS 84 ensemble? Do you use .atx files with PSO (phase center offset), that define IGS20 difference with ITRF2020? Are you going to use new for ITRF2020 PSD model:
I am not sure what you are asking.
Using my best guess I provide the following relevant links:
https://earth-info.nga.mil/index.php?dir=wgs84&action=wgs84
https://igs.org/wg/reference-frame/
https://www.unoosa.org/documents/pdf/icg/2021/ICG15/19.pdf
https://www.unoosa.org/documents/pdf/icg/2022/ICG16/16.pdf
The first link addresses how the NGA??s WGS84 maintains consistency with the ITRF.
The other links address issues including the PCOs.
You may also want to review WGs linked from https://igs.org in particular
HTH,
DMM
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