[ESRI-L] SUM: Spherical Transverse Mercator -- May 13 2003 

Thanks to Bob Kucks at USGS and Melita Kennedy at ESRI for insight on 
this one. The Magnetic Aomaly map of North America uses the Decade of 
North American Geology (DNAG) basemap projection. The DNAG projection 
uses a datum called STM1987. Am not sure I've got it completely right, 
but the following seems to work within the coarseness of the 2km cell 
size of the raster grids. Arc/Info's project command uses a Clarke1866 
spheroid by default when an input datum is not specified. 

input 
projection utm 
units meters 
zone 15 
parameters 
output 
projection transverse 
units meters 
spheroid sphere 
parameters 6371204 6371204 
0.926 
-100 0 0 
0 0 0 
0 
0 
end 

