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

Mikael Rittri Mikael.Rittri at carmenta.com
Thu Oct 11 15:42:36 EST 2012

This question really concerns GDAL/OGR rather than Proj.4, but anyway:

I have had a problem that I think was caused by 


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 
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

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