[Proj] MGRS/USNG support?

Eric Miller EMiller at dfg.ca.gov
Thu May 4 14:34:19 EDT 2006

How difficult would it be to support the Military Grid Reference System (and U.S. National Grid)?  They're basically UTM but as a single alphanumeric string.  It seems it'd be a bit tricky since most of library and console programs act on coordinate pairs.  Basically, support would have to preprocess inputs and postprocess outputs somehow.  I'd imagine there would need to be a flag controlling desired output precision. (unless an existing flag can serve that purpose -w/n/ ?)

Are people:

1) Opposed
2) Supportive
3) Ambivalent
4) Don't care


I guess, for this to work the UTM handling would have to change.  Currently, you have to specify +zone= and +south (as appropriate), but the library should be able to figure that out and report it back in the output.  The user should have the option of forcing a zone or allowing the library to determine it.  Perhaps this is too deep a change?  I don't think it is an uncommon problem that folks might not know what zone a coordinate will fall into.  At least, not until it has been transformed to geodetic coordinates on the same datum/ellipsoid.  Then it's pretty easy to figure out.  So, why can't the library do that for the user?

Eric G. Miller
GIS Analyst
Biogeographic Data Branch
Department of Fish and Game

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