PROJ(1) PROJ PROJ(1)

NAME

proj - Cartographic projection filter

SYNOPSIS

proj [-beEfiIlmorsStTvVwW] [args]] ([+opt[=arg] ...] | {crs}) file
...

invproj [-beEfiIlmorsStTvVwW] [args]] ([+opt[=arg] ...] | {crs})
file ...

DESCRIPTION

proj and invproj perform respective forward and inverse conversion of
cartographic data to or from cartesian data with a wide range of
selectable projection functions.

invproj may not be available on all platforms; in this case use proj
-I instead.

The following control parameters can appear in any order

-b Special option for binary coordinate data input and output
through standard input and standard output. Data is assumed to
be in system type double floating point words. This option is
to be used when proj is a child process and allows bypassing
formatting operations.

-d <n>

New in version 5.2.0: Specify the number of decimals to round to in
the output.


-i Selects binary input only (see -b).

-I Alternate method to specify inverse projection. Redundant when
used with invproj.

-o Selects binary output only (see -b).

-t<a> Where a specifies a character employed as the first character
to denote a control line to be passed through without
processing. This option applicable to ASCII input only. (# is
the default value).

-e <string>
Where string is an arbitrary string to be output if an error
is detected during data transformations. The default value is
a three character string: *\t*. Note that if the -b, -i or -o
options are employed, an error is returned as HUGE_VAL value
for both return values.

-E Causes the input coordinates to be copied to the output line
prior to printing the converted values.

-l<[=id]>
List projection identifiers that can be selected with +proj.
proj -l=id gives expanded description of projection id, e.g.
proj -l=merc.

-lp List of all projection id that can be used with the +proj
parameter. Equivalent to proj -l.

-lP Expanded description of all projections that can be used with
the +proj parameter.

-le List of all ellipsoids that can be selected with the +ellps
parameters.

-lu List of all distance units that can be selected with the
+units parameter.

-r This options reverses the order of the expected input from
longitude-latitude or x-y to latitude-longitude or y-x.

-s This options reverses the order of the output from x-y or
longitude-latitude to y-x or latitude-longitude.

-S Causes estimation of meridional and parallel scale factors,
area scale factor and angular distortion, and maximum and
minimum scale factors to be listed between <> for each input
point. For conformal projections meridional and parallel
scales factors will be equal and angular distortion zero.
Equal area projections will have an area factor of 1.

-m <mult>
The cartesian data may be scaled by the mult parameter. When
processing data in a forward projection mode the cartesian
output values are multiplied by mult otherwise the input
cartesian values are divided by mult before inverse
projection. If the first two characters of mult are 1/ or 1:
then the reciprocal value of mult is employed.

-f <format>
Where format is a printf format string to control the form of
the output values. For inverse projections, the output will
be in degrees when this option is employed. The default format
is "%.2f" for forward projection and DMS for inverse.

-w<n> Where n is the number of significant fractional digits to
employ for seconds output (when the option is not specified,
-w3 is assumed).

-W<n> Where n is the number of significant fractional digits to
employ for seconds output. When -W is employed the fields will
be constant width with leading zeroes.

-v Causes a listing of cartographic control parameters tested for
and used by the program to be printed prior to input data.

-V This option causes an expanded annotated listing of the
characteristics of the projected point. -v is implied with
this option.

The +opt run-line arguments are associated with cartographic
parameters. Additional projection control parameters may be
contained in two auxiliary control files: the first is optionally
referenced with the +init=file:id and the second is always processed
after the name of the projection has been established from either the
run-line or the contents of +init file. The environment parameter
PROJ_DATA establishes the default directory for a file reference
without an absolute path. This is also used for supporting files like
datum shift files.

New in version 9.3.0: {crs} is one of the possibilities accepted by
:c:proj_create(), provided it expresses a projected CRS, like a WKT
string, an object code (like "EPSG:32632") a PROJJSON string, etc.
The projection computed will be those of the map projection implied
by the transformation from the base geographic CRS of the projected
CRS to the projected CRS.


One or more files (processed in left to right order) specify the
source of data to be converted. A - will specify the location of
processing standard input. If no files are specified, the input is
assumed to be from stdin. For ASCII input data the two data values
must be in the first two white space separated fields and when both
input and output are ASCII all trailing portions of the input line
are appended to the output line.

Input geographic data (longitude and latitude) must be in DMS or
decimal degrees format and input cartesian data must be in units
consistent with the ellipsoid major axis or sphere radius units.
Output geographic coordinates will be in DMS (if the -w switch is not
employed) and precise to 0.001" with trailing, zero-valued
minute-second fields deleted.

EXAMPLE

The following script

proj +proj=utm +zone=12 -r <<EOF
45d15'33.1" 111.5W
45d15.551666667N -111d30
+45.25919444444 111d30'000w
EOF

will perform UTM zone 12 forward projection. The default
+ellps=GRS80 is used as no +ellps was specified. The geographic
values of this example are equivalent and meant as examples of
various forms of DMS input. The x-y output data will appear as three
lines of:

460770.43 5011865.86

This other example

proj EPSG:6421 -V <<EOF
-120 35.8
EOF

Will perform the projection of the coordinates in "NAD83(2011) /
California zone 4" (EPSG:6421) into its geographic system,
"NAD83(2011)", showing the expanded annotated listing. The output
will appear as:

#Lambert Conformal Conic
# Conic, Sph&Ell
# lat_1= and lat_2= or lat_0, k_0=
# +proj=lcc +lat_0=35.3333333333333 +lon_0=-119 +lat_1=37.25 +lat_2=36
# +x_0=2000000 +y_0=500000 +ellps=GRS80
#Final Earth figure: ellipsoid
# Major axis (a): 6378137.000
# 1/flattening: 298.257222
# squared eccentricity: 0.006694380023
Longitude: 120dW [ -120 ]
Latitude: 35d48'N [ 35.8 ]
Easting (x): 1909606.87
Northing (y): 552253.58
Meridian scale (h) : 1.00004382 ( 0.004382 % error )
Parallel scale (k) : 1.00004382 ( 0.004382 % error )
Areal scale (s): 1.00008765 ( 0.008765 % error )
Angular distortion (w): 0.000
Meridian/Parallel angle: 90.00000
Convergence : -0d35'47.714" [ -0.59658715 ]
Max-min (Tissot axis a-b) scale error: 1.00004 1.00004

OTHER PROGRAMS

The proj program is limited to converting between geographic and
projected coordinates within one datum.

The cs2cs program operates similarly, but allows translation between
any pair of definable coordinate reference systems, including support
for datum translation.

SEE ALSO

cs2cs(1), cct(1), geod(1), gie(1), projinfo(1), projsync(1)

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

Gerald I. Evenden

COPYRIGHT

1983-2024, PROJ contributors

9.5 01 Dec 2024 PROJ(1)