On Thu, Jan 9, 2025 at 4:53 PM Even Rouault <even.roua...@spatialys.com> wrote:
> > > Regarding the pipeline, it could be a bad copy-paste or garbled by > > ChatGPT 😀. > > I wouldn't trust ChatGPT to come with geodesic-relevant pipelines... If > you aren't really sure about what you are doing, you'd better let PROJ > infer a reasonable pipeline. > Actually it was not ChatGPT what created this pipeline. I pasted a proper pipeline to it and it helped me to generate SO question, so it may have garbled it. Anyway a proper pipeline I use for years is: +proj=pipeline +step +inv +proj=krovak +lat_0=49.5 +lon_0=24.8333333333333 +alpha=30.2881397527778 +k=0.9999 +x_0=0 +y_0=0 +ellps=bessel +step +inv +proj=hgridshift +grids=Slovakia_JTSK03_to_JTSK.gsb +step +proj=krovak +lat_0=49.5 +lon_0=24.8333333333333 +alpha=30.2881397527778 +k=0.9999 +x_0=0 +y_0=0 +ellps=bessel +step +inv +proj=krovak +lat_0=49.5 +lon_0=24.8333333333333 +alpha=30.2881397527778 +k=0.9999 +x_0=0 +y_0=0 +ellps=bessel +step +proj=push +v_3 +step +proj=cart +ellps=bessel +step +proj=helmert +x=485.021 +y=169.465 +z=483.839 +rx=-7.786342 +ry=-4.397554 +rz=-4.102655 +s=0 +convention=coordinate_frame +step +inv +proj=cart +ellps=WGS84 +step +proj=pop +v_3 +step +proj=webmerc +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 It is the official pipeline provided by our national cartography office, together with Slovakia_JTSK03_to_JTSK.gsb file. Without this pipeline the offset varies up to more than 10 meters. With the pipeline the transformed geotata matches that from state office's WMS 🙂 BTW ChatGPT helped me in solving this problem a lot. Without it I would maybe just gave it up as it is a hobby project. And more generally, people posting issues/questions written partially or > totally written by generative "IA" should really mention it to set > expectations to readers > Thank you. I've just learned that even the pipeline was not the cause (but could be) 🙂 -- Martin Ždila
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