Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!portal!cup.portal.com!truett
From: truett@cup.portal.com (Truett Lee Smith)
Newsgroups: comp.graphics
Subject: Re: X=525120,Y=893580 map coordinates
Message-ID: <36117@cup.portal.com>
Date: 21 Nov 90 05:31:50 GMT
References: <1990Nov20.142756.1109@vax5.cit.cornell.edu>
Organization: The Portal System (TM)
Lines: 11

If those coordinates are from a map like I had to generate some years ago,
they are in meters from a reference longitude and the equator for a trans-
verse Mercator projection, which is what the metric military maps use.  So
you have to know the reference longitude, whether or not the equator or some
other crossing latitude is the zero in that direction, and the reference
geoid to do the calculations.  Turns out to involve elliptic integrals of
standard form which can be found in the tables.  Look in a book on the 
subject of "geodesy" for the details.

Truett Smith, Sunnyvale, CA
truett@cup.portal.com  OR  truett@tdd.sj.nec.com