Le 18/10/2023 à 17:57, Javier Jimenez Shaw via PROJ a écrit :
Hi
What is the difference between PJ_TYPE_GEODETIC_CRS and
PJ_TYPE_GEOCENTRIC_CRS?
Geocentric is a specialization of Geodetic (not in the standard, but so
common that we have a subtype for it)
In crs-explorer.proj.org <http://crs-explorer.proj.org> you can easily
see how there are no Geodetic systems in EPSG and there are no
Geocentric systems in IAU_2015...
Geodetic CRS in EPSG are geographic 2D, geographic 3D or geocentric. No
weird/unusual geodetic ones
In IAU_2015, there's indeed no geocentric CRS definition. You may get
PJ_TYPE_GEODETIC_CRS for CRS like IAU:19902 "Mercury (2015) / Ocentric"
whose coordinate system is spherical with planetocentric latitude and
longitude. This is close to a geographic CRS, except that you use
-ocentric latitude (angle between the equatorial plane and the point on
the ellipsoid) instead of a -ographic latitude (the angle between the
equatorial plane and the normal to the ellipsoid at the point of interest).
--
http://www.spatialys.com
My software is free, but my time generally not.
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