SUBROUTINE LL2UTM( LON, LAT, Z, X, Y ) SUBROUTINE UTM2LL( X, Y, Z, LON, LAT ) REAL X ! UTM easting in meters REAL Y ! UTM northing in meters INTEGER Z ! UTM zone REAL LON ! East longitude in decimal degrees REAL LAT ! North latitude in decimal degrees
LL2UTM()
and UTM2LL()
use the
(FIPS-standard) USGS National Mapping Division's General
Cartographic Transformation Package routine
GTPZ0()
to do coordinate
conversion between LAT-LON and UTM coodinates.
Note that except for Cray vector machines (Y-MP, C-90, T-90,
J-90), inputs are 4-byte REAL
single precision
(unlike the double precision used internally by
GCTP
). Calculations for which precision is
important should use GCTP
directly; further note that
by default, LL2UTM()
and UTM2LL()
use
the GRS 1980 spheroid to represent the surface of the Earth
(which may be important to know for high-precision calculations).
See also USGS package
GCTP
,
geodetic-sphere selection routines
SETSPHERE, INITSPHERES,
and SPHEREDAT
,
and the I/O API wrapper-routines for
Lambert/Lat-Lon/Mercator/Stereographic/UTM
coordinate conversion, etc.
USE M3UTILIO
(See sample programs LATLON or PRESZ for usage examples.)
Up: Coordinate and Grid Related Routines
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