Thanks Even for the quick response. Can I create a CRS as WKT with the ob_tran?
On Wed, 31 May 2023, 00:43 Even Rouault, <[email protected]> wrote: > Javier, > > I suspect you might be able to apply the azimuth by using the infamous > +proj=ob_tran. The tricky part will be to find on which parameter(s) of > ob_tran (o_lat_p, o_lon_p, lon_0) to map it. > > Possibly relevant, there's at least 2 different code implementations > attempting at reproducing the Spilhaus from Esri, which include a azimuth > parameter: > > - cf https://github.com/OSGeo/PROJ/issues/1851#issuecomment-943138537 > > - or > https://github.com/neocarto/bertin/blob/main/src/projections/spilhaus.js > + https://github.com/d3/d3-geo/blob/main/src/rotation.js > > The maths ressemble those of proj=ob_tran > > Even > Le 31/05/2023 à 00:24, Javier Jimenez Shaw a écrit : > > Hi > > Some use cases of Esri "local" projection are arriving to my desk. This > projection works in Esri software, but not in PROJ (obviously also not in > QGIS) > > One example is this WKT1_ESRI > > > PROJCS["Hycroft001",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Local"],PARAMETER["False_Easting",13264.924],PARAMETER["False_Northing",46473.418],PARAMETER["Scale_Factor",1.00025],PARAMETER["Azimuth",15.786],PARAMETER["Longitude_Of_Center",-116.7048269],PARAMETER["Latitude_Of_Center",42.88212865],UNIT["Foot_US",0.3048006096012192]] > > Looking at their documentation, it seems to be this one: > https://desktop.arcgis.com/en/arcmap/latest/map/projections/local.htm > > The biggest difference I see with the Orthographic from PROJ is the Azimut > parameter. I have the impression that the azimut is just a rotation of the > axes, but it is not clear to me in the Snyder book (page 145. If you do not > have it, it is available at https://pubs.er.usgs.gov/publication/pp1395 ) > > Is there are alternative in PROJ? > Does it make sense to add this transformation? > > Thanks > Javier > .___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... .... ._ .__ > > _______________________________________________ > PROJ mailing > [email protected]https://lists.osgeo.org/mailman/listinfo/proj > > -- http://www.spatialys.com > My software is free, but my time generally not. > >
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