LL2UTM(1)						      General Commands Manual							 LL2UTM(1)

NAME

       ll2utm - Convert latitude/longitude geographical coordinates to UTM coordinates

SYNOPSIS

       ll2utm [-L] | [latitude longitude [nad27 | nad83 | wgs84]]

DESCRIPTION

       This  program  uses  Redfearn's	formulas to convert a given latitude and longitude into the equivalent Universal Transverse Mercator (UTM)
       coordinates.  (This operation is often referred to as projection, since it projects a curved surface onto a flat plane.)  The  input  lati-
       tude  and longitude must be in decimal degrees.	Latitudes south of the equator are negative, and longitudes west of the prime meridian are
       negative.  UTM is intended for use in the latitude range from 80S to 84N.  The program will accept input outside of this  range,  but  will
       print a warning message.

       The  output  takes  the form of a single line, containing the UTM "x" value, the UTM "y" value, and the UTM zone, separated by white space.
       The "x" value includes the normal 500,000 false easting.  The "y" value includes the normal 10,000,000 false northing, if the point  is	in
       the southern hemisphere.  Points in the southern hemisphere are flagged by making the zone number negative.

       If you provide just the "-L" option, the program will print some license information and exit.

       Projections,  and  inverse  projections, depend on defining an ellipsoid that approximates the shape of the earth (the reference ellipsoid)
       and defining reference coordinates (the datum) that allow measurements to be made.  Different choices of the ellipsoid and datum can  yield
       projections  that  differ  by  tens  of meters.	There are a wide variety of choices, due to both the historical progression of measurement
       technology, and the desire to maximize accuracy over a given region (such as North America, or one of the United States).

       This program defaults to the North American Datum of 1927 (NAD-27) with the Clarke Ellipsoid of 1866, since these appear to be  appropriate
       for  much  of  the  freely-available data.  The data are apparently in the process of being converted to the Geodetic Reference System 1980
       (GRS-80) ellipsoid and NAD-83.  If you come across such data, you can specify "nad83" on the command line.  The GTOPO30 data use the  World
       Geodetic System 1984 (WGS-84) ellipsoid, which can be invoked by specifying "wgs84" on the command line.

SEE ALSO

       The utm2ll(1) command provides the inverse conversion.

								   Jul 24, 2001 							 LL2UTM(1)