NAME¶
ConicProj -- perform conic projections
SYNOPSIS¶
ConicProj (
-c |
-a )
lat1 lat2 [
-l
lon0 ] [
-k k1 ] [
-r ] [
-e a
f ] [
-p prec ] [
--comment-delimiter
commentdelim ] [
--version |
-h |
--help ] [
--input-file infile |
--input-string instring ] [
--line-separator linesep ] [
--output-file outfile
]
DESCRIPTION¶
Perform one of two conic projections geodesics. Convert geodetic coordinates to
either Lambert conformal conic or Albers equal area coordinates. The standard
latitudes
lat1 and
lat2 are specified by that the
-c
option (for Lambert conformal conic) or the
-a option (for Albers equal
area). At least one of these options must be given (the last one given is
used). Specify
lat1 =
lat2, to obtain the case with a single
standard parallel. The central meridian is given by
lon0. The longitude
of origin is given by the latitude of minimum (azimuthal) scale for Lambert
conformal conic (Albers equal area). The (azimuthal) scale on the standard
parallels is
k1.
Geodetic coordinates are provided on standard input as a set of lines containing
(blank separated)
latitude and
longitude (decimal degrees or
degrees, minutes, seconds). For each set of geodetic coordinates, the
corresponding projected easting,
x, and northing,
y, (meters)
are printed on standard output together with the meridian convergence
gamma (degrees) and (azimuthal) scale
k. For Albers equal area,
the radial scale is 1/
k. The meridian convergence is the bearing of
the
y axis measured clockwise from true north.
Special cases of the Lambert conformal projection are the Mercator projection
(the standard latitudes equal and opposite) and the polar stereographic
projection (both standard latitudes correspond to the same pole). Special
cases of the Albers equal area projection are the cylindrical equal area
projection (the standard latitudes equal and opposite), the Lambert azimuthal
equal area projection (both standard latitude corresponds to the same pole),
and the Lambert equal area conic projection (one standard parallel is at a
pole).
OPTIONS¶
- -c
- use the Lambert conformal conic projection with standard parallels
lat1 and lat2.
- -a
- use the Albers equal area projection with standard parallels lat1
and lat2.
- -l
- specify the longitude of origin lon0 (degrees, default 0).
- -k
- specify the (azimuthal) scale k1 on the standard parallels (default
1).
- -r
- perform the reverse projection. x and y are given on
standard input and each line of standard output gives latitude,
longitude, gamma, and k.
- -e
- specify the ellipsoid via a f; the equatorial radius is
a and the flattening is 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. (Also, if f > 1,
the flattening is set to 1/ f.) By default, the WGS84 ellipsoid is
used, a = 6378137 m, f = 1/298.257223563.
- -p
- set the output precision to prec (default 6). prec is the
number of digits after the decimal point for lengths (in meters). For
latitudes and longitudes (in degrees), the number of digits after the
decimal point is prec + 5. For the convergence (in degrees) and
scale, the number of digits after the decimal point is prec +
6.
- --comment-delimiter
- 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
- read input from the file infile instead of from standard input; a
file name of "-" stands for standard input.
- --input-string
- 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
- set the line separator character to linesep. By default this is a
semicolon.
- --output-file
- write output to the file outfile instead of to standard output; a
file name of "-" stands for standard output.
EXAMPLES¶
echo 39.95N 75.17W | ConicProj -c 40d58 39d56 -l 77d45W
=> 220445 -52372 1.67 1.0
echo 220445 -52372 | ConicProj -c 40d58 39d56 -l 77d45W -r
=> 39.95 -75.17 1.67 1.0
ERRORS¶
An illegal line of input will print an error message to standard output
beginning with "ERROR:" and causes
ConicProj to return an
exit code of 1. However, an error does not cause
ConicProj to
terminate; following lines will be converted.
AUTHOR¶
ConicProj was written by Charles Karney.
HISTORY¶
ConicProj was added to GeographicLib,
<
http://geographiclib.sf.net>, in version 1.9.