[Proj] ESRI's standard_parallel_1 for Mercator morphed to latitude_of_origin?

Mikael Rittri Mikael.Rittri at carmenta.com
Fri Oct 12 11:33:16 PDT 2012


Joe,
by "parameter name munging", do you mean in addition to what is done by morphToESRI()
and morphFromESRI() in OGRSpatialReference? Can you give examples?
    Would you agree that for my example, morphFromESRI() makes a hypercorrection
(trying to fix what ain't broken)?
     By the way, I have found the analogous ticket http://trac.osgeo.org/gdal/ticket/3036
for Equidistant Cylindrical. 

Mikael Rittri
Carmenta
Sweden
http://www.carmenta.com

12 okt 2012 kl. 18:41 skrev "Joseph White" <JWhite at terragotech.com>:

> Mikael,
> It's not just you.  In the course of our software, we have to transition
> data back and forth from ESRI to GDAL/OGR, and we have to do some
> parameter name munging to get ESRI to take some of the coordinate system
> data.  
> 
> Joe
> 
> -----Original Message-----
> From: proj-bounces at lists.maptools.org
> [mailto:proj-bounces at lists.maptools.org] On Behalf Of Mikael Rittri
> Sent: Thursday, October 11, 2012 4:43 PM
> To: PROJ.4 and general Projections Discussions
> Subject: [Proj] ESRI's standard_parallel_1 for Mercator morphed to
> latitude_of_origin?
> 
> This question really concerns GDAL/OGR rather than Proj.4, but anyway:
> 
> I have had a problem that I think was caused by 
> 
> http://trac.osgeo.org/gdal/changeset/7542
> 
> which caused the Mercator parameter "standard_parallel_1" in ESRI WKT to
> be renamed to "latitude_of_origin" during conversion to OGC WKT. 
> 
> This makes no sense to me. These are different parameters with different
> semantics, and according to
> http://www.remotesensing.org/geotiff/proj_list/mercator_2sp.html
> both of them are valid parameter names for Mercator (2SP) in OGC WKT.
> 
> So why the renaming? Is the semantics subtly different in the ESRI
> world? 
> Or is this just a bug that has survived because a Mercator seldom has a
> non-zero standard parallel?
> 
> I'd be grateful for comments. 
> 
> Mikael Rittri
> Carmenta
> Sweden
> http://www.carmenta.com
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