1CCT(1)                               PROJ                               CCT(1)
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3
4

NAME

6       cct - Coordinate Conversion and Transformation
7

SYNOPSIS

9          cct [-cIostvz [args]] +opt[=arg] ... file ...
10
11       or
12          cct [-cIostvz [args]] {object_definition} file ...
13
14       Where  {object_definition} is  one  of  the  possibilities  accepted by
15       proj_create(), provided it expresses a coordinate operation
16
17          • a proj-string,
18
19          • a WKT string,
20
21          • an object  code  (like  "EPSG:1671"  "urn:ogc:def:coordinateOpera‐
22            tion:EPSG::1671"),
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24          • an  object  name. e.g. "ITRF2014 to ETRF2014 (1)". In that case as
25            uniqueness is not guaranteed, heuristics are applied to  determine
26            the appropriate best match.
27
28          • a  OGC  URN combining references for concatenated operations (e.g.
29            "‐
30            urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,co‐
31            ordinateOperation:EPSG::1618")
32
33          • a     PROJJSON     string.     The      jsonschema      is      at
34            https://proj.org/schemas/v0.4/projjson.schema.json
35
36          New in version 8.0.0.
37
38
39          NOTE:
40              Before  version 8.0.0 only proj-strings could be used to instan‐
41              tiate operations in cct.
42
43       or
44          cct [-cIostvz [args]] {object_reference} file ...
45
46       where {object_reference} is a filename preceded by the  '@'  character.
47       The file referenced by the {object_reference} must contain a valid {ob‐
48       ject_definition}.
49          New in version 8.0.0.
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51

DESCRIPTION

53       cct is a 4D equivalent to the proj projection program, performs  trans‐
54       formation  coordinate  systems on a set of input points. The coordinate
55       system transformation can include translation between projected and ge‐
56       ographic coordinates as well as the application of datum shifts.
57
58       The following control parameters can appear in any order:
59
60       -c <x,y,z,t>
61              Specify  input  columns for (up to) 4 input parameters. Defaults
62              to 1,2,3,4.
63
64       -d <n> New in version 5.2.0.
65
66
67              Specify the number of decimals to round to in the output.
68
69       -I     Do the inverse transformation.
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71       -o <output file name>, --output=<output file name>
72              Specify the name of the output file.
73
74       -t <time>, --time=<time>
75              Specify a fixed observation time to be used for all input data.
76
77       -z <height>, --height=<height>
78              Specify a fixed observation height to  be  used  for  all  input
79              data.
80
81       -s <n>, --skip-lines=<n>
82              New in version 5.1.0.
83
84
85              Skip the first n lines of input. This applies to any kind of in‐
86              put, whether it comes from STDIN, a file or interactive user in‐
87              put.
88
89       -v, --verbose
90              Write  non-essential,  but  potentially  useful,  information to
91              stderr.  Repeat for additional information (-vv, -vvv, etc.)
92
93       --version
94              Print version number.
95
96       The +opt arguments are associated with coordinate operation parameters.
97       Usage varies with operation.
98
99       cct is an acronym meaning Coordinate Conversion and Transformation.
100
101       The  acronym  refers to definitions given in the OGC 08-015r2/ISO-19111
102       standard "Geographical Information -- Spatial  Referencing  by  Coordi‐
103       nates", which defines two different classes of coordinate operations:
104
105       Coordinate Conversions, which are coordinate operations where input and
106       output datum are identical (e.g. conversion from geographical to carte‐
107       sian coordinates) and
108
109       Coordinate Transformations, which are coordinate operations where input
110       and output datums differ (e.g. change of reference frame).
111

USE OF REMOTE GRIDS

113       New in version 7.0.0.
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115
116       If the PROJ_NETWORK environment variable is set to ON, cct will attempt
117       to  use  remote grids stored on CDN (Content Delivery Network) storage,
118       when they are not available locally.
119
120       More details are available in the Network capabilities section.
121

EXAMPLES

123       1. The operator specs describe the action to be performed  by  cct.  So
124          the following script
125
126          echo 12 55 0 0 | cct +proj=utm +zone=32 +ellps=GRS80
127
128       will  transform the input geographic coordinates into UTM zone 32 coor‐
129       dinates.  Hence, the command
130
131          echo 12 55 | cct -z0 -t0 +proj=utm +zone=32 +ellps=GRS80
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133       Should give results comparable to the classic proj command
134
135          echo 12 55 | proj +proj=utm +zone=32 +ellps=GRS80
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137       2. Convert geographical input to UTM zone 32 on the GRS80 ellipsoid:
138
139          cct +proj=utm +ellps=GRS80 +zone=32
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141       3. Roundtrip accuracy check for the case above:
142
143          cct +proj=pipeline +proj=utm +ellps=GRS80 +zone=32 +step +step +inv
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145       4. As (2) but specify input columns for longitude, latitude, height and
146          time:
147
148          cct -c 5,2,1,4 +proj=utm +ellps=GRS80 +zone=32
149
150       5. As  (2) but specify fixed height and time, hence needing only 2 cols
151          in input:
152
153          cct -t 0 -z 0 +proj=utm +ellps=GRS80 +zone=32
154
155       6. Auxiliary data following the coordinate input is forward to the out‐
156          put stream:
157
158          $ echo 12 56 100 2018.0 auxiliary data | cct +proj=merc
159          1335833.8895   7522963.2411      100.0000     2018.0000 auxiliary data
160
161       7. Coordinate operation referenced through its code
162
163          $ echo 3541657.3778 948984.2343 5201383.5231 2020.5 | cct EPSG:8366
164          3541657.9112    948983.7503  5201383.2482     2020.5000
165
166       8. Coordinate operation referenced through its name
167
168          $ echo 3541657.3778 948984.2343 5201383.5231 2020.5 | cct "ITRF2014 to ETRF2014 (1)"
169          3541657.9112    948983.7503  5201383.2482     2020.5000
170

BACKGROUND

172       cct also refers to Carl Christian Tscherning (1942--2014), professor of
173       Geodesy at the University of Copenhagen, mentor and advisor for a  gen‐
174       eration of Danish geodesists, colleague and collaborator for two gener‐
175       ations of global geodesists, Secretary General  for  the  International
176       Association  of  Geodesy, IAG (1995--2007), fellow of the American Geo‐
177       physical Union (1991), recipient of the IAG Levallois Medal (2007), the
178       European Geosciences Union Vening Meinesz Medal (2008), and of numerous
179       other honours.
180
181       cct, or Christian, as he was known to most of us,  was  recognized  for
182       his  good mood, his sharp wit, his tireless work, and his great commit‐
183       ment to the development of geodesy -- both through his scientific  con‐
184       tributions, comprising more than 250 publications, and by his mentoring
185       and teaching of the next generations of geodesists.
186
187       As Christian was an avid Fortran programmer, and a keen  Unix  connois‐
188       seur,  he would have enjoyed to know that his initials would be used to
189       name a modest Unix style transformation filter, hinting at the tireless
190       aspect  of  his  personality, which was certainly one of the reasons he
191       accomplished so much, and meant so much to so many people.
192
193       Hence, in honour of cct (the geodesist) this is cct (the program).
194

SEE ALSO

196       proj(1), cs2cs(1), geod(1), gie(1), projinfo(1), projsync(1)
197

BUGS

199       A     list     of     known     bugs     can      be      found      at
200       https://github.com/OSGeo/PROJ/issues  where new bug reports can be sub‐
201       mitted to.
202

HOME PAGE

204       https://proj.org/
205

AUTHOR

207       Thomas Knudsen
208
210       1983-2023
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2159.2.1                             Jun 1, 2023                           CCT(1)
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