1CCT(1) PROJ.4 CCT(1)
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6 cct - Coordinate Conversion and Transformation
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9 cct [ -cIostvz [ args ] ] +opts[=arg] file[s]
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12 cct a 4D equivalent to the proj projection program, performs transfor‐
13 mation coordinate systems on a set of input points. The coordinate sys‐
14 tem transformation can include translation between projected and geo‐
15 graphic coordinates as well as the application of datum shifts.
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17 The following control parameters can appear in any order:
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19 -c <x,y,z,t>
20 Specify input columns for (up to) 4 input parameters. Defaults
21 to 1,2,3,4.
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23 -d <n>
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25 New in version 5.2.0: Specify the number of decimals in the output.
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28 -I Do the inverse transformation.
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30 -o <output file name>, --output=<output file name>
31 Specify the name of the output file.
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33 -t <time>, --time=<time>
34 Specify a fixed observation time to be used for all input data.
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36 -z <height>, --height=<height>
37 Specify a fixed observation height to be used for all input
38 data.
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40 -s <n>, --skip-lines=<n>
41 New in version 5.1.0.
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44 Skip the first n lines of input. This applies to any kind of
45 input, whether it comes from STDIN, a file or interactive user
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48 -v, --verbose
49 Write non-essential, but potentially useful, information to
50 stderr. Repeat for additional information (-vv, -vvv, etc.)
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52 --version
53 Print version number.
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55 The +args arguments are associated with coordinate operation parame‐
56 ters. Usage varies with operation.
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58 cct is an acronym meaning Coordinate Conversion and Transformation.
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60 The acronym refers to definitions given in the OGC 08-015r2/ISO-19111
61 standard “Geographical Information – Spatial Referencing by Coordi‐
62 nates”, which defines two different classes of coordinate operations:
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64 Coordinate Conversions, which are coordinate operations where input and
65 output datum are identical (e.g. conversion from geographical to carte‐
66 sian coordinates) and
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68 Coordinate Transformations, which are coordinate operations where input
69 and output datums differ (e.g. change of reference frame).
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72 1. The operator specs describe the action to be performed by cct. So
73 the following script
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75 echo 12 55 0 0 | cct +proj=utm +zone=32 +ellps=GRS80
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77 will transform the input geographic coordinates into UTM zone 32 coor‐
78 dinates. Hence, the command
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80 echo 12 55 | cct -z0 -t0 +proj=utm +zone=32 +ellps=GRS80
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82 Should give results comparable to the classic proj command
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84 echo 12 55 | proj +proj=utm +zone=32 +ellps=GRS80
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86 2. Convert geographical input to UTM zone 32 on the GRS80 ellipsoid:
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88 cct +proj=utm +ellps=GRS80 +zone=32
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90 3. Roundtrip accuracy check for the case above:
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92 cct +proj=pipeline +proj=utm +ellps=GRS80 +zone=32 +step +step +inv
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94 4. As (2) but specify input columns for longitude, latitude, height and
95 time:
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97 cct -c 5,2,1,4 +proj=utm +ellps=GRS80 +zone=32
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99 5. As (2) but specify fixed height and time, hence needing only 2 cols
100 in input:
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102 cct -t 0 -z 0 +proj=utm +ellps=GRS80 +zone=32
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104 6. Auxiliary data following the coordinate input is forward to the out‐
105 put stream:
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107 $ echo 12 56 100 2018.0 auxiliary data | cct +proj=merc
108 1335833.8895 7522963.2411 100.0000 2018.0000 auxiliary data
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111 cct also refers to Carl Christian Tscherning (1942–2014), professor of
112 Geodesy at the University of Copenhagen, mentor and advisor for a gen‐
113 eration of Danish geodesists, colleague and collaborator for two gener‐
114 ations of global geodesists, Secretary General for the International
115 Association of Geodesy, IAG (1995–2007), fellow of the American Geo‐
116 physical Union (1991), recipient of the IAG Levallois Medal (2007), the
117 European Geosciences Union Vening Meinesz Medal (2008), and of numerous
118 other honours.
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120 cct, or Christian, as he was known to most of us, was recognized for
121 his good mood, his sharp wit, his tireless work, and his great commit‐
122 ment to the development of geodesy – both through his scientific con‐
123 tributions, comprising more than 250 publications, and by his mentoring
124 and teaching of the next generations of geodesists.
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126 As Christian was an avid Fortran programmer, and a keen Unix connois‐
127 seur, he would have enjoyed to know that his initials would be used to
128 name a modest Unix style transformation filter, hinting at the tireless
129 aspect of his personality, which was certainly one of the reasons he
130 accomplished so much, and meant so much to so many people.
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132 Hence, in honour of cct (the geodesist) this is cct (the program).
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135 proj(1), cs2cs(1), geod(1), gie(1)
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138 A list of know bugs can be found at
139 https://github.com/OSGeo/proj.4/issues where new bug reports can be
140 submitted to.
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143 https://proj4.org/
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146 Thomas Knudsen
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149 1983-2018
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1545.2.0 Sep 10, 2018 CCT(1)