1GEODESICPROJ(1)             GeographicLib Utilities            GEODESICPROJ(1)
2
3
4

NAME

6       GeodesicProj -- perform projections based on geodesics
7

SYNOPSIS

9       GeodesicProj ( -z | -c | -g ) lat0 lon0 [ -r ] [ -e a f ] [ -w ] [ -p
10       prec ] [ --comment-delimiter commentdelim ] [ --version | -h | --help ]
11       [ --input-file infile | --input-string instring ] [ --line-separator
12       linesep ] [ --output-file outfile ]
13

DESCRIPTION

15       Perform projections based on geodesics.  Convert geodetic coordinates
16       to either azimuthal equidistant, Cassini-Soldner, or gnomonic
17       coordinates.  The center of the projection (lat0, lon0) is specified by
18       either the -c option (for Cassini-Soldner), the -z option (for
19       azimuthal equidistant), or the -g option (for gnomonic).  At least one
20       of these options must be given (the last one given is used).
21
22       Geodetic coordinates are provided on standard input as a set of lines
23       containing (blank separated) latitude and longitude (decimal degrees or
24       degrees, minutes, seconds); for details on the allowed formats for
25       latitude and longitude, see the "GEOGRAPHIC COORDINATES" section of
26       GeoConvert(1).  For each set of geodetic coordinates, the corresponding
27       projected coordinates x, y (meters) are printed on standard output
28       together with the azimuth azi (degrees) and reciprocal scale rk.  For
29       Cassini-Soldner, azi is the bearing of the easting direction and the
30       scale in the easting direction is 1 and the scale in the northing
31       direction is 1/rk.  For azimuthal equidistant and gnomonic, azi is the
32       bearing of the radial direction and the scale in the azimuthal
33       direction is 1/rk.  For azimuthal equidistant and gnomonic, the scales
34       in the radial direction are 1 and 1/rk^2, respectively.
35

OPTIONS

37       -z lat0 lon0
38           use the azimuthal equidistant projection centered at latitude =
39           lat0, longitude = lon0.  The -w flag can be used to swap the
40           default order of the 2 coordinates, provided that it appears before
41           -z.
42
43       -c lat0 lon0
44           use the Cassini-Soldner projection centered at latitude = lat0,
45           longitude = lon0.  The -w flag can be used to swap the default
46           order of the 2 coordinates, provided that it appears before -c.
47
48       -g lat0 lon0
49           use the ellipsoidal gnomonic projection centered at latitude =
50           lat0, longitude = lon0.  The -w flag can be used to swap the
51           default order of the 2 coordinates, provided that it appears before
52           -g.
53
54       -r  perform the reverse projection.  x and y are given on standard
55           input and each line of standard output gives latitude, longitude,
56           azi, and rk.
57
58       -e a f
59           specify the ellipsoid via the equatorial radius, a and the
60           flattening, f.  Setting f = 0 results in a sphere.  Specify f < 0
61           for a prolate ellipsoid.  A simple fraction, e.g., 1/297, is
62           allowed for f.  By default, the WGS84 ellipsoid is used, a =
63           6378137 m, f = 1/298.257223563.
64
65       -w  toggle the longitude first flag (it starts off); if the flag is on,
66           then on input and output, longitude precedes latitude (except that,
67           on input, this can be overridden by a hemisphere designator, N, S,
68           E, W).
69
70       -p prec
71           set the output precision to prec (default 6).  prec is the number
72           of digits after the decimal point for lengths (in meters).  For
73           latitudes, longitudes, and azimuths (in degrees), the number of
74           digits after the decimal point is prec + 5.  For the scale, the
75           number of digits after the decimal point is prec + 6.
76
77       --comment-delimiter commentdelim
78           set the comment delimiter to commentdelim (e.g., "#" or "//").  If
79           set, the input lines will be scanned for this delimiter and, if
80           found, the delimiter and the rest of the line will be removed prior
81           to processing and subsequently appended to the output line
82           (separated by a space).
83
84       --version
85           print version and exit.
86
87       -h  print usage and exit.
88
89       --help
90           print full documentation and exit.
91
92       --input-file infile
93           read input from the file infile instead of from standard input; a
94           file name of "-" stands for standard input.
95
96       --input-string instring
97           read input from the string instring instead of from standard input.
98           All occurrences of the line separator character (default is a
99           semicolon) in instring are converted to newlines before the reading
100           begins.
101
102       --line-separator linesep
103           set the line separator character to linesep.  By default this is a
104           semicolon.
105
106       --output-file outfile
107           write output to the file outfile instead of to standard output; a
108           file name of "-" stands for standard output.
109

EXAMPLES

111          echo 48.648 -2.007 | GeodesicProj -c 48.836 2.337
112          => -319919 -11791 86.7 0.999
113          echo -319919 -11791 | GeodesicProj -c 48.836 2.337 -r
114          => 48.648 -2.007 86.7 0.999
115

ERRORS

117       An illegal line of input will print an error message to standard output
118       beginning with "ERROR:" and causes GeodesicProj to return an exit code
119       of 1.  However, an error does not cause GeodesicProj to terminate;
120       following lines will be converted.
121

SEE ALSO

123       The ellipsoidal gnomonic projection is derived in Section 8 of C. F. F.
124       Karney, Algorithms for geodesics, J. Geodesy 87, 43-55 (2013); DOI
125       <https://doi.org/10.1007/s00190-012-0578-z>; addenda:
126       <https://geographiclib.sourceforge.io/geod-addenda.html>.
127

AUTHOR

129       GeodesicProj was written by Charles Karney.
130

HISTORY

132       GeodesicProj was added to GeographicLib,
133       <https://geographiclib.sourceforge.io>, in 2009-08.  Prior to version
134       1.9 it was called EquidistantTest.
135
136
137
138GeographicLib 1.52                2021-06-21                   GEODESICPROJ(1)
Impressum