CartConvert -- convert geodetic coordinates to geocentric or local
cartesian
CartConvert [ -r ] [ -l lat0
lon0 h0 ] [ -e a f ] [ -w ] [
-p prec ] [ --comment-delimiter commentdelim ] [
--version | -h | --help ] [ --input-file
infile | --input-string instring ] [
--line-separator linesep ] [ --output-file
outfile ]
Convert geodetic coordinates to either geocentric or local
cartesian coordinates. Geocentric coordinates have the origin at the center
of the earth, with the z axis going thru the north pole, and the
x axis thru latitude = 0, longitude = 0. By default,
the conversion is to geocentric coordinates. Specifying -l
lat0 lon0 h0 causes a local coordinate system to be
used with the origin at latitude = lat0, longitude =
lon0, height = h0, z normal to the ellipsoid and
y due north.
Geodetic coordinates are provided on standard input as a set of
lines containing (blank separated) latitude, longitude
(decimal degrees or degrees, minutes and seconds), and height above
the ellipsoid (meters); for details on the allowed formats for latitude and
longitude, see the "GEOGRAPHIC
COORDINATES" section of GeoConvert(1). For each set of
geodetic coordinates, the corresponding cartesian coordinates x,
y, z (meters) are printed on standard output.
- -r
- perform the reverse projection. x, y, z are given on
standard input and each line of standard output gives latitude,
longitude, height. In general there are multiple solutions
and the result which minimizes the absolute value of height is
returned, i.e., (latitude, longitude) corresponds to the
closest point on the ellipsoid.
- -l lat0 lon0
h0
- specifies conversions to and from a local cartesion coordinate systems
with origin lat0 lon0 h0, instead of a geocentric
coordinate system. The -w flag can be used to swap the default
order of the 2 geographic coordinates, provided that it appears before
-l.
- -e a f
- specify the ellipsoid via the equatorial radius, a and the
flattening, f. Setting f = 0 results in a sphere. Specify
f < 0 for a prolate ellipsoid. A simple fraction, e.g., 1/297,
is allowed for f. By default, the WGS84 ellipsoid is used, a
= 6378137 m, f = 1/298.257223563.
- -w
- toggle the longitude first flag (it starts off); if the flag is on, then
on input and output, longitude precedes latitude (except that, on input,
this can be overridden by a hemisphere designator, N, S,
E, W).
- -p prec
- set the output precision to prec (default 6). prec is the
number of digits after the decimal point for geocentric and local
cartesion coordinates and for the height (in meters). For latitudes and
longitudes (in degrees), the number of digits after the decimal point is
prec + 5.
- set the comment delimiter to commentdelim (e.g., "#" or
"//"). If set, the input lines will be scanned for this
delimiter and, if found, the delimiter and the rest of the line will be
removed prior to processing and subsequently appended to the output line
(separated by a space).
- --version
- print version and exit.
- -h
- print usage and exit.
- --help
- print full documentation and exit.
- --input-file
infile
- read input from the file infile instead of from standard input; a
file name of "-" stands for standard input.
- --input-string
instring
- read input from the string instring instead of from standard input.
All occurrences of the line separator character (default is a semicolon)
in instring are converted to newlines before the reading
begins.
- --line-separator
linesep
- set the line separator character to linesep. By default this is a
semicolon.
- --output-file
outfile
- write output to the file outfile instead of to standard output; a
file name of "-" stands for standard output.
echo 33.3 44.4 6000 | CartConvert
=> 3816209.60 3737108.55 3485109.57
echo 33.3 44.4 6000 | CartConvert -l 33 44 20
=> 37288.97 33374.29 5783.64
echo 30000 30000 0 | CartConvert -r
=> 6.483 45 -6335709.73
An illegal line of input will print an error message to standard
output beginning with "ERROR:" and causes
CartConvert to return an exit code of 1. However, an error does not
cause CartConvert to terminate; following lines will be
converted.
The algorithm for converting geocentric to geodetic coordinates is
given in Appendix B of C. F. F. Karney, Geodesics on an ellipsoid of
revolution, Feb. 2011; preprint
<https://arxiv.org/abs/1102.1215>.
CartConvert was written by Charles Karney.
CartConvert was added to GeographicLib,
<https://geographiclib.sourceforge.io>, in 2009-02. Prior to 2009-03
it was called ECEFConvert.