1GEODESICPROJ(1) GeographicLib Utilities GEODESICPROJ(1)
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6 GeodesicProj -- perform projections based on geodesics
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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
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 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.
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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 -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 -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 -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 -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 -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 -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 --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 --version
85 print version and exit.
86 -h print usage and exit.
88 --help
90 print full documentation and exit.
91 --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 --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 --line-separator linesep
103 set the line separator character to linesep. By default this is a
104 semicolon.
105 --output-file outfile
107 write output to the file outfile instead of to standard output; a
108 file name of "-" stands for standard output.
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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
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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.
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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>.
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129 GeodesicProj was written by Charles Karney.
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132 GeodesicProj was added to GeographicLib,
133 <https://geographiclib.sourceforge.io>, in 2009-08. Prior to version
134 1.9 it was called EquidistantTest.
135GeographicLib 1.52 2021-06-21 GEODESICPROJ(1)