PROJ(1) PROJ PROJ(1)
NAME
proj - Cartographic projection filter
SYNOPSIS
proj [-beEfiIlmorsStTvVwW] [args]] [+opt[=arg] ...] file ...
invproj [-beEfiIlmorsStTvVwW] [args]] [+opt[=arg] ...] file ...
DESCRIPTION
proj and invproj perform respective forward and inverse conversion of
cartographic data to or from cartesian data with a wide range of se-
lectable 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 for-
matting operations.
-d <n>
New in version 5.2.0: Specify the number of decimals 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 op-
tions 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 param-
eter. 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 pa-
rameters.
-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 lon-
gitude-latitude or x-y to latitude-longitude or y-x.
-s This options reverses the order of the output from x-y or longi-
tude-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 projec-
tions 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 out-
put 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 as-
sumed).
-W<n> Where n is the number of significant fractional digits to employ
for seconds output. When -W is employed the fields will be con-
stant 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 charac-
teristics of the projected point. -v is implied with this op-
tion.
The +opt run-line arguments are associated with cartographic parame-
ters. 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 con-
tents of +init file. The environment parameter PROJ_LIB establishes the
default directory for a file reference without an absolute path. This
is also used for supporting files like datum shift files.
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 deci-
mal 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 pre-
cise to 0.001" with trailing, zero-valued minute-second fields deleted.
EXAMPLE
The following script
proj +proj=utm +lon_0=112w +ellps=clrk66 -r <<EOF
45d15'33.1" 111.5W
45d15.551666667N -111d30
+45.25919444444 111d30'000w
EOF
will perform UTM forward projection with a standard UTM central merid-
ian nearest longitude 112W. 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:
460769.27 5011648.45
OTHER PROGRAMS
The proj program is limited to converting between geographic and pro-
jected 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 sub-
mitted to.
HOME PAGE
https://proj.org/
AUTHOR
Gerald I. Evenden
COPYRIGHT
1983-2021
8.2.1 Jan 1, 2022 PROJ(1)
Generated by dwww version 1.14 on Fri Jan 24 06:18:17 CET 2025.