From 2e104e092578347de11208e9a3a80a3bf711265d Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Fri, 25 Sep 2020 22:53:38 +0200 Subject: Implement ellipsoidal formulation of +proj=ortho (fixes #397) - Map ESRI 'Local' to +proj=ortho when Scale_Factor = 1 and Azimuth = 0 - Map ESRI 'Orthographic' to a PROJ WKT2 'Orthographic (Spherical)' which maps to +proj=ortho +f=0 to froce spherical evaluation --- docs/source/operations/projections/ortho.rst | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'docs/source') diff --git a/docs/source/operations/projections/ortho.rst b/docs/source/operations/projections/ortho.rst index 2e8de9ca..2d0e08a8 100644 --- a/docs/source/operations/projections/ortho.rst +++ b/docs/source/operations/projections/ortho.rst @@ -10,7 +10,7 @@ around a given latitude and longitude. +---------------------+--------------------------------------------------------+ | **Classification** | Azimuthal | +---------------------+--------------------------------------------------------+ -| **Available forms** | Forward and inverse, spherical projection | +| **Available forms** | Forward and inverse, spherical and ellipsoidal | +---------------------+--------------------------------------------------------+ | **Defined area** | Global, although only one hemisphere can be seen at a | | | time | @@ -31,6 +31,12 @@ around a given latitude and longitude. proj-string: ``+proj=ortho`` + +.. note:: Before PROJ 7.2, only the spherical formulation was implemented. If + wanting to replicate PROJ < 7.2 results with newer versions, the + ellipsoid must be forced to a sphere, for example by adding a ``+f=0`` + parameter. + Parameters ################################################################################ @@ -40,6 +46,8 @@ Parameters .. include:: ../options/lat_0.rst +.. include:: ../options/ellps.rst + .. include:: ../options/R.rst .. include:: ../options/x_0.rst -- cgit v1.2.3