Re: OGC blog post summarising Web-mapping misalignment problem
Roger Oberholtzer <[email protected]>
| Newsgroups | gmane.comp.gis.proj-4.devel |
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| Message-ID | <CANkOqwPsG+YV7xpDH=tVvLQMoRwmg+3yr_p9uwR7OOOscMi-hw@mail.gmail.com> |
On Thu, Aug 22, 2019 at 3:23 PM Duncan Agnew <[email protected]> wrote: > > I can only speak to ITRF, but the changes in this come mostly from there being longer time series and more stations. Motion > of the Earth's center of mass is at the sub-cm level--and at this level there are actual motions of the ground that enter in, from > loading by water changes, or by postglacial rebound. That said, if your country is all on one plate, and your national authority > has defined a CRS moving with that plate (a plate-fixed system) then that is probably the one to use, since it maximizes the future > relevance of a value that doesn't include an epoch. But I'm still not 100% clear how to define my source WGS84 lat/longs from my GNSS receiver when doing this. How best to know which WGS84 to use? The local CRS cannot know this. Or so it seems to me. -- Roger Oberholtzer _______________________________________________ PROJ mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/proj