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.
-
--comment-delimiter commentdelim
- 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.