Ubuntu Manpage: cct - Coordinate Conversion and Transformation

Provided by: proj-bin_9.4.0-1build2_amd64

NAME

       cct - Coordinate Conversion and Transformation

SYNOPSIS

          cct [-cIostvz [args]] +opt[=arg] ... file ...

       or
          cct [-cIostvz [args]] {object_definition} file ...

       Where  {object_definition} is one of the possibilities accepted by proj_create(), provided it expresses a
       coordinate operation

          • a proj-string,

          • a WKT string,

          • an object code (like "EPSG:1671" "urn:ogc:def:coordinateOperation:EPSG::1671"),

          • an object name. e.g. "ITRF2014 to ETRF2014 (1)". In that  case  as  uniqueness  is  not  guaranteed,
            heuristics are applied to determine the appropriate best match.

          • a     OGC     URN     combining     references     for     concatenated    operations    (e.g.    "‐
            urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618")

          • a PROJJSON string. The jsonschema is at https://proj.org/schemas/v0.4/projjson.schema.json

          New in version 8.0.0.

          NOTE:
              Before version 8.0.0 only proj-strings could be used to instantiate operations in cct.

       or
          cct [-cIostvz [args]] {object_reference} file ...

       where {object_reference} is a filename preceded by  the  '@'  character.   The  file  referenced  by  the
       {object_reference} must contain a valid {object_definition}.
          New in version 8.0.0.

DESCRIPTION

cct is a 4D equivalent to the proj projection program, performs transformation coordinate systems on a
set of input points. The coordinate system transformation can include translation between projected and
geographic coordinates as well as the application of datum shifts.

The following control parameters can appear in any order:

-c <x,y,z,t>
Specify input columns for (up to) 4 input parameters. Defaults to 1,2,3,4.

-d <n> New in version 5.2.0.

Specify the number of decimals to round to in the output.

-I Do the inverse transformation.

-o <output file name>, --output=<output file name>
Specify the name of the output file.

-t <time>, --time=<time>
Specify a fixed observation time to be used for all input data.

-z <height>, --height=<height>
Specify a fixed observation height to be used for all input data.

-s <n>, --skip-lines=<n>
New in version 5.1.0.

Skip the first n lines of input. This applies to any kind of input, whether it comes from STDIN, a
file or interactive user input.

-v, --verbose
Write non-essential, but potentially useful, information to stderr. Repeat for additional
information (-vv, -vvv, etc.)

--version
Print version number.

The +opt arguments are associated with coordinate operation parameters. Usage varies with operation.

cct is an acronym meaning Coordinate Conversion and Transformation.

The acronym refers to definitions given in the OGC 08-015r2/ISO-19111 standard "Geographical Information
-- Spatial Referencing by Coordinates", which defines two different classes of coordinate operations:

Coordinate Conversions, which are coordinate operations where input and output datum are identical (e.g.
conversion from geographical to cartesian coordinates) and

Coordinate Transformations, which are coordinate operations where input and output datums differ (e.g.
change of reference frame).

USE OF REMOTE GRIDS

       New in version 7.0.0.

       If the PROJ_NETWORK environment variable is set to ON, cct will attempt to use remote grids stored on CDN
       (Content Delivery Network) storage, when they are not available locally.

       More details are available in the Network capabilities section.

EXAMPLES

       1. The operator specs describe the action to be performed by cct. So the following script

          echo 12 55 0 0 | cct +proj=utm +zone=32 +ellps=GRS80

       will transform the input geographic coordinates into UTM zone 32 coordinates.  Hence, the command

          echo 12 55 | cct -z0 -t0 +proj=utm +zone=32 +ellps=GRS80

       Should give results comparable to the classic proj command

          echo 12 55 | proj +proj=utm +zone=32 +ellps=GRS80

       2. Convert geographical input to UTM zone 32 on the GRS80 ellipsoid:

          cct +proj=utm +ellps=GRS80 +zone=32

       3. Roundtrip accuracy check for the case above:

          cct +proj=pipeline +ellps=GRS80 +zone=32 +step +proj=utm +step +proj=utm +inv

       4. As (2) but specify input columns for longitude, latitude, height and time:

          cct -c 5,2,1,4 +proj=utm +ellps=GRS80 +zone=32

       5. As (2) but specify fixed height and time, hence needing only 2 cols in input:

          cct -t 0 -z 0 +proj=utm +ellps=GRS80 +zone=32

       6. Auxiliary data following the coordinate input is forwarded to the output stream:

          $ echo 12 56 100 2018.0 auxiliary data | cct +proj=merc
          1335833.8895   7522963.2411      100.0000     2018.0000 auxiliary data

       7. Coordinate operation referenced through its code

          $ echo 3541657.3778 948984.2343 5201383.5231 2020.5 | cct EPSG:8366
          3541657.9112    948983.7503  5201383.2482     2020.5000

       8. Coordinate operation referenced through its name

          $ echo 3541657.3778 948984.2343 5201383.5231 2020.5 | cct "ITRF2014 to ETRF2014 (1)"
          3541657.9112    948983.7503  5201383.2482     2020.5000

BACKGROUND

       cct  also  refers  to  Carl  Christian Tscherning (1942--2014), professor of Geodesy at the University of
       Copenhagen, mentor and advisor for a generation of Danish geodesists, colleague and collaborator for  two
       generations  of  global  geodesists,  Secretary General for the International Association of Geodesy, IAG
       (1995--2007), fellow of the American Geophysical Union (1991),  recipient  of  the  IAG  Levallois  Medal
       (2007), the European Geosciences Union Vening Meinesz Medal (2008), and of numerous other honours.

       cct,  or  Christian,  as he was known to most of us, was recognized for his good mood, his sharp wit, his
       tireless work, and his great commitment to the development of geodesy  --  both  through  his  scientific
       contributions,  comprising  more  than  250  publications,  and by his mentoring and teaching of the next
       generations of geodesists.

       As Christian was an avid Fortran programmer, and a keen Unix connoisseur, he would have enjoyed  to  know
       that  his  initials  would  be  used  to  name  a modest Unix style transformation filter, hinting at the
       tireless aspect of his personality, which was certainly one of the reasons he accomplished so  much,  and
       meant so much to so many people.

       Hence, in honour of cct (the geodesist) this is cct (the program).

BUGS

       A  list  of  known bugs can be found at https://github.com/OSGeo/PROJ/issues where new bug reports can be
       submitted to.

HOME PAGE

       https://proj.org/

AUTHOR

       Thomas Knudsen

COPYRIGHT

       1983-2024, PROJ contributors

9.4                                                01 Mar 2024                                            CCT(1)