RTK is definitely not using WGS84 (EPSG:4326) (I talked about that here https://youtu.be/M2ck3cAGvhg ) If you are using an NTRIP service, you should check their specs. Could you tell me which NTRIP service are you using? I am working on a open source/data project to gather that kind of information (I will tell more about it in this mailing list when it is more mature) If you are using a based station owned by you, check its specs. It could be something more similar to ITRF.
On Fri, 11 Oct 2024 at 12:27, Nigel Stewart via PROJ <proj@lists.osgeo.org> wrote: > > First of all I think you are being way too unrealistic about what you > can use ChatGPT for. > >If you'd tried the command it's suggested to you, you would know that it > doesn't work. > > It has given you an ill-formed CRS, as well as suggesting you use > deprecated syntax. > > It didn't smell good, I must admit. > > > It would be helpful if you can be more explicit about what you are > trying to do. > > What EPSG-codes are you trying to get a transformation between? > > In a nutshell: > > # to GDA94 / MGA zone 56 > > $ echo "0 0 0" | cs2cs +proj=tmerc +lat_0=-34.0 +lon_0=150.0 +k=1 +x_0=0 > +y_0=0 +datum=WGS84 +units=m +no_defs +type=crs +to 'EPSG:28356' > 222908.70 6233785.28 0.00 > > # to GDA2020 / MGA zone 56 > > $ echo "0 0 0" | cs2cs +proj=tmerc +lat_0=-34.0 +lon_0=150.0 +k=1 +x_0=0 > +y_0=0 +datum=WGS84 +units=m +no_defs +type=crs +to 'EPSG:7856' > 222908.70 6233785.28 0.00 > > # to GDA2020 / MGA zone 56 > > $ echo "222908.70 6233785.28 0.00" | cs2cs 'EPSG:28356' +to > 'EPSG:7856' > 222909.17 6233786.71 0.00 > > Our expectation is that GDA2020 is within a meter or two of GDA94 due to > the tectonic drift of the Australian plate towards the north east. > Our concern is that from these custom transverse mercator projections, > this difference isn't reflected. > We can see the Helmert transformation being applied in the third case, but > not in the first two. > ChatGPT doesn't seem completely off track pointing to EPSG:8048 for GDA94 > to GDA2020 Helmert. > > Our application is RTK-based georeferencing, possibly WGS84 is not > appropriate for our application. > > $ cs2cs > Rel. 6.3.1, February 10th, 2020 > > (But we're seeing similar for our stack using PROJ 9.4.1) > > Thanks in advance, > > - Nigel Stewart > _______________________________________________ > PROJ mailing list > PROJ@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/proj >
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