[OSRS-PROJ] Older Stateplane Definitions ???

[Craig Bruce]

Gerald Evenden <gerald.evenden at verizon.net> wrote:

> The later, proj, definitioin is not in error unless one assumes that
> the Greenwich origin is used.

In all likelihood, this is what everyone will assume.  Why would
they assume otherwise?  Most users will never even see the parameter
definitions.  It's best to avoid special cases.

> To use Greenwich data with proj one can merge the 2.33 correction into
> the lon_0 factor.

The units also need to be translated from Gradians.  The 55° latitude
figure goes through the middle of Great Britain and is nowhere near France.
Translated, it would be 49.5°, which at least goes through France.

The programs that have extracted this information from the POSC EPSG
database which defines them need to be modified to interpret the EPSG
information in its full legal complexity.  (These same bugs have probably
cropped up in countless other systems because the EPSG tables are so
difficult to use.)

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Dr. Craig S. Bruce        | Tel: 819-771-8303 x205 |             CubeWerx Inc.
Senior Software Developer |   Home: 613-565-1344   |  Gatineau, Québec, Canada
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