The GRASS program m.ll2u performs the reverse operation, converting geographic coordinates to UTM coordinates.
The list of spheroids available is somewhat dynamic. At the time of this release, available spheroids included: airy, australian, bessel, clark66, everest, grs80, hayford, international, krasovsky, wgs66, wgs72, and wgs84 (see table below).
This command can be run either non-interactively or interactively. The user can run the program non-interactively by entering desired flag settings and parameter values on the command line using the following format:
Alternately, the user can simply type:
on the command line. In this case, the user will be prompted for parameter values and flag settings through the standard interface described in the manual entry for parser.
Input can be entered from the keyboard or from an input file.
In either case, input should be entered with one UTM easting and northing
pair pe
.fi
If the user sets the -r flag, m.u2ll will expect the order of the
coordinates to be reversed, and stated as northing, easting pairs,
rather than as easting, northing pairs. This is useful for passing
ASCII GRASS vector (/dig) files, whose coordinates are stated as
northing, easting pairs, directly through m.u2ll.
Similarly, the user can elect to send output to an output file or (by default)
to standard output (the user's terminal screen).
Example input and output are shown below (see EXAMPLE).
Program flag settings and parameters have the following meanings.
AVAILABLE SPHEROIDS
where the input file utm.infile contains the following easting and northing
UTM coordinate values and zone designations:
See m.ll2u for a brief discussion of spheroids.
The UTM zone designation determines on what area of the earth
a point is found. The same UTM coordinates will be found
in each different UTM zone. Look at the marginalia of your source map
to determine into which UTM zone your UTM coordinates fall.
Although the user can permissibly omit specification of a UTM zone
when running this program under a UTM data base LOCATION,
it is safer to specify it (see DESCRIPTION, above).
m.u2ll converts the first pair of coordinates on each line of input
and leaves anything else on the line alone.
If a line begins:
then the xxxxxx.xx xxxxxxx.xx UTM coordinate pair is converted to a longitude,
latitude pair. Any other information appearing on the line is left alone.
If the line doesn't begin with a pair of coordinates in the above format,
then the line is left as it is.
For bessel, airy, everest, and wgs66 ellipsoid parameter values, see:
For wgs84 parameter values, see:
Also read GRASS User's Reference Manual entries for:
Flags:
Parameters:
Options: airy, australian, bessel, clark66, everest, grs80, hayford,
international, krasovsky, wgs66, wgs72, wgs84
Options: 1-60
(The on-line listing includes only the spheroid names.)
(The on-line listing includes only the spheroid names.) |
Spheroid: | Semi-major axis | Eccentricity sqrd (e),| Commonly used for:
| (Equatorial Radius) | Flattening (f), |
| (a): | or Polar Radius (b): |
---------------+---------------------+-----------------------+-------------
airy | a=6377563.396 | e=.006670540 |
australian | a=6378160 | f=1/298.25 | Australia
bessel | a=6377397.155 | e=.006674372 | Japan
clark66 | a=6378206.4 | b=6356583.8 | N. America
everest | a=6377276.345 | e=.0066378466 | India, Burma
grs80 | a=6378137 | f=1/298.257 |
hayford | a=6378388 | f=1/297 |
international | a=6378388 | f=1/297 | Europe
krasovsky | a=6378245 | f=1/298.3 |
wgs66 | a=6378145 | f=1/298.25 | worldwide coverage
wgs72 | a=6378135 | f=1/298.26 | worldwide coverage
wgs84 | a=6378137 | f=1/298.257223563 | worldwide coverage
EXAMPLE
Assume the user has input the command:
237740.85 2167292.10
238740.00 2167000.00
239000.00 2167100.00
237100.00 2166000.00
end
Output would then be sent to the output file ll.outfile,
containing the below longitude and latitude coordinate values:
166:02:25.645137W 70:27:46.615528S
166:00:53.237056W 70:27:59.692673S
166:00:27.23258W 70:27:57.454281S
166:03:41.428895W 70:28:25.61617S
end
NOTES
Users can add information to the ellipsoid parameter definition file on their
systems (located in $GISBASE/etc/ellipse.table) to add spheroids not now
among those supported by GRASS.
FILES
See ellipsoid parameter definition file in $GISBASE/etc/ellipse.table.
SEE ALSO
For australian, clark66, grs80, hayford, international, krasovsky, and wgs72
ellipsoid parameters, see:
John P. Snyder, Map Projections - A Working Manual,
U.S. Government Printing Office, Washington DC, 1989.
U.S. Geological Survey Professional Paper 1395; from Table 1, p.12.
Thomas O. Seppelin, The Department of Defense World
Geodetic System 1972, presented at the International
Symposium on Problems Related to the Redefinition of
North American Geodetic Networks, Fredericton, New
Brunswick, Canada in May, 1974; see Table 9, p.35.
U.S. Naval Oceanographic Labs.
d.label
d.points
d.sites
d.where
m.datum.shift
m.gc2ll
m.ll2gc
m.ll2u
parser
AUTHOR
Michael Shapiro, U.S.Army Construction Engineering
Research Laboratory