[gdal-dev] Add Mercator_variant_A method?

[Jukka Rahkonen]

Brad Hards <bradh <at> frogmouth.net> writes:


> The problematic part is that "PROJECTION" definition. I was originally
going to 
> argue it should be Mercator_1SP, but it looks like the EPSG decided to change 
> it (in EPSG::2010.058) to this new "Mercator_variant_A" form, and keep the 
> "Mercator_1SP" form as an alias.

Here is a link to a report that at this moment (2015-04-07) makes query to
EPSG database v. 8.6.5

http://www.epsg-registry.org/report.htm?type=selection&entity=urn:ogc:def:method:EPSG::9804&reportDetail=short&style=urn:uuid:report-style:default-with-code&style_name=OGP%20Default%20With%20Code&title=Method%209804%20Mercator%20variant%20A

Guidance note document that is asked to be used as an ultimate reference is
http://www.iogp.org/pubs/373-07-2.pdf

I felt that document somehow heavy to read but it appears in many places
that "Mercator variant A" is the primary name since October 2010. This
section is from page 34 (of 143)

"Three variants of the Mercator projection are recognised ,
differentiated by the parameters used in the projection definition : 

Variant A, also known as Mercator (1SP ). The projection is defined
with the equator as the single standard parallel, with scale factor on
the equator also defined. False grid coordinates are applied at the
natural origin of the projection, the intersection of the equator and
the longitude of o rigin. See figure 3 below . In the few cases in
which the Mercator projection is used for terrestrial applications or
land mapping, such as in Indonesia prior to the introduction of the
Universal Transverse Mercator, this is the normal method of definition."

-Jukka Rahkonen-