[OSRS-PROJ] Older Stateplane Definitions

Craig Bruce csbruce at cubewerx.com
Sat Jul 27 17:58:10 EDT 2002


Paul Ramsey <pramsey at refractions.net> wrote:

> Here are the ESRI coordinate projections as extracted from the online
> list of projections provided in their ArcIMS reference manual.

The definitions of the following coordinate systems are incorrect:

# Nord_de_Guerre <27500>
# NTF_Paris_France_I <27581>
# NTF_Paris_France_II <27582>
# NTF_Paris_France_III <27583>
# NTF_Paris_France_IV <27584>
# NTF_Paris_Nord_France <27591>
# NTF_Paris_Centre_France <27592>
# NTF_Paris_Sud_France <27593>
# NTF_Paris_Corse <27594>

As indicated previously, they are incorrect because the angluar parameters
are actually in Gradians relative to the Paris Prime Meridian but PROJ will
assume that they are in Degrees relative to the Greenwich Prime Meridian.

I'm guessing that this geographic one has the same problem:

# GCS_NTF_Paris <4807>
# GCS_Tananarive_1925_Paris <4810> 
# GCS_Voirol_1875_Paris <4811>
...

There appear be many that don't use Greenwich/Degrees for the angular
parameters, and they're all suspect.

--------------------------+------------------------+--------------------------
Dr. Craig S. Bruce        | Tel: 819-771-8303 x205 |             CubeWerx Inc.
Senior Software Developer |   Home: 613-565-1344   |  Gatineau, Québec, Canada
csbruce at cubewerx.com      | http://www.csbruce.com |  http://www.cubewerx.com/
--------------------------+------------------------+--------------------------
    "Everything should be built from the top down, except the first time."

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