GEODESICPROJ(1) GeographicLib Utilities GEODESICPROJ(1)NAMEGeodesicProj-- perform projections based on geodesics
SYNOPSISGeodesicProj ( -z | -c | -g ) lat0 lon0 [ -r ] [ -e a f ] [ -w ] [ -p
prec ] [ --comment-delimiter commentdelim ] [ --version | -h | --help ]
[ --input-file infile | --input-string instring ] [ --line-separator
linesep ] [ --output-file outfile ]
DESCRIPTION
Perform projections based on geodesics. Convert geodetic coordinates
to either azimuthal equidistant, Cassini-Soldner, or gnomonic
coordinates. The center of the projection (lat0, lon0) is specified by
either the -c option (for Cassini-Soldner), the -z option (for
azimuthal equidistant), or the -g option (for gnomonic). At least one
of these options must be given (the last one given is used).
Geodetic coordinates are provided on standard input as a set of lines
containing (blank separated) latitude and longitude (decimal degrees or
degrees, minutes, seconds); for details on the allowed formats for
latitude and longitude, see the "GEOGRAPHIC COORDINATES" section of
GeoConvert(1). For each set of geodetic coordinates, the corresponding
projected coordinates x, y (meters) are printed on standard output
together with the azimuth azi (degrees) and reciprocal scale rk. For
Cassini-Soldner, azi is the bearing of the easting direction and the
scale in the easting direction is 1 and the scale in the northing
direction is 1/rk. For azimuthal equidistant and gnomonic, azi is the
bearing of the radial direction and the scale in the azimuthal
direction is 1/rk. For azimuthal equidistant and gnomonic, the scales
in the radial direction are 1 and 1/rk^2, respectively.
OPTIONS-z use the azimuthal equidistant projection centered at latitude =
lat0, longitude = lon0. The -w flag can be used to swap the
default order of the 2 coordinates, provided that it appears before
-z.
-c use the Cassini-Soldner projection centered at latitude = lat0,
longitude = lon0. The -w flag can be used to swap the default
order of the 2 coordinates, provided that it appears before -c.
-g use the ellipsoidal gnomonic projection centered at latitude =
lat0, longitude = lon0. The -w flag can be used to swap the
default order of the 2 coordinates, provided that it appears before
-g.
-r perform the reverse projection. x and y are given on standard
input and each line of standard output gives latitude, longitude,
azi, and rk.
-e specify the ellipsoid via a f; the equatorial radius is a and the
flattening is f. Setting f = 0 results in a sphere. Specify f < 0
for a prolate ellipsoid. A simple fraction, e.g., 1/297, is
allowed for f. By default, the WGS84 ellipsoid is used, a =
6378137 m, f = 1/298.257223563.
-w on input and output, longitude precedes latitude (except that, on
input, this can be overridden by a hemisphere designator, N, S, E,
W).
-p set the output precision to prec (default 6). prec is the number
of digits after the decimal point for lengths (in meters). For
latitudes, longitudes, and azimuths (in degrees), the number of
digits after the decimal point is prec + 5. For the scale, the
number of digits after the decimal point is prec + 6.
--comment-delimiter
set the comment delimiter to commentdelim (e.g., "#" or "//"). If
set, the input lines will be scanned for this delimiter and, if
found, the delimiter and the rest of the line will be removed prior
to processing and subsequently appended to the output line
(separated by a space).
--version
print version and exit.
-h print usage and exit.
--help
print full documentation and exit.
--input-file
read input from the file infile instead of from standard input; a
file name of "-" stands for standard input.
--input-string
read input from the string instring instead of from standard input.
All occurrences of the line separator character (default is a
semicolon) in instring are converted to newlines before the reading
begins.
--line-separator
set the line separator character to linesep. By default this is a
semicolon.
--output-file
write output to the file outfile instead of to standard output; a
file name of "-" stands for standard output.
EXAMPLES
echo 48.648 -2.007 | GeodesicProj-c 48.836 2.337
=> -319919 -11791 86.7 0.999
echo -319919 -11791 | GeodesicProj-c 48.836 2.337 -r
=> 48.648 -2.007 86.7 0.999
ERRORS
An illegal line of input will print an error message to standard output
beginning with "ERROR:" and causes GeodesicProj to return an exit code
of 1. However, an error does not cause GeodesicProj to terminate;
following lines will be converted.
SEE ALSO
The ellipsoidal gnomonic projection is derived in Section 8 of C. F. F.
Karney, Algorithms for geodesics, J. Geodesy 87, 43-55 (2013); DOI
<https://dx.doi.org/10.1007/s00190-012-0578-z>; addenda:
<http://geographiclib.sf.net/geod-addenda.html>.
AUTHORGeodesicProj was written by Charles Karney.
HISTORYGeodesicProj was added to GeographicLib, <http://geographiclib.sf.net>,
in 2009-08. Prior to version 1.9 it was called EquidistantTest.
GeographicLib 1.45 2015-09-30 GEODESICPROJ(1)
