PROJ(1)PROJ(1)NAMEproj - forward cartographic projection filter
invproj - inverse cartographic projection filter
SYNOPSISproj [ -bceEfiIlmorsStTvVwW [ args ] ] [ +args ] file[s]
invproj [ -bceEfiIlmorsStTwW [ args ] ] [ +args ] file[s]
DESCRIPTION
Proj and invproj perform respective forward and inverse
transformation of cartographic data to or from cartesian
data with a wide range of selectable projection functions.
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 float
ing point words. This option is to be used when
proj is a son process and allows bypassing format
ting operations.
-i Selects binary input only (see -b option).
-I alternate method to specify inverse projection.
Redundant when used with invproj.
-o Selects binary output only (see -b option).
-ta A specifies a character employed as the first char
acter to denote a control line to be passed through
without processing. This option applicable to
ascii input only. (# is the default value).
-e string
String is an arbitrary string to be output if an
error is detected during data transformations. The
default value is: *\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[p|P|=|e|u|d]id
List projection identifiers with -l, -lp or -lP
(expanded) that can be selected with +proj. -l=id
gives expanded description of projection id. List
ellipsoid identifiers with -le, that can be
selected with +ellps, -lu list of cartesian to
meter conversion factors that can be selected with
+units or -ld list of datums that can be selected
with +datum.
-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-longi
tude.
-S Causes estimation of meridinal 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 meridinal and parallel scales factors
will be equal and angular distortion zero. Equal
area projections will have an area factor of 1.
-f format
Format is a printf format string to control the
form of the output values. For inverse projec
tions, the output will be in degrees when this
option is employed. If a format is specified for
inverse projection the output data will be in deci
mal degrees. The default format is "%.2f" for for
ward projection and DMS for inverse.
-[w|W]n
N is the number of significant fractional digits to
employ for seconds output (when the option is not
specified, -w3 is assumed). When -W is employed
the fields will be constant width and 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. Should not be used with the
-T option.
-V This option causes an expanded annotated listing of
the characteristics of the projected point. -v is
implied with this option.
-T ulow,uhi,vlow,vhi,res[,umax,vmax]
This option creates a set of bivariate Chebyshev
polynomial coefficients that approximate the
selected cartographic projection on stdout. The
values low and hi denote the range of the input
where the u or v prefixes apply to respective lon
gitude-x or latitude-y depending upon whether a
forward or inverse projection is selected. Res is
an integer number specifying the power of 10 preci
sion of the approximation. For example, a res of
-3 specifies an approximation with an accuracy bet
ter than .001. Umax, and vmax specify maximum
degree of the polynomials (default: 15). See also:
fproj(1).
The +args run-line arguments are associated with carto
graphic parameters and usage varies with projection and
for a complete description see Cartographic Projection
Procedures for the UNIX Environment--A User's Manual ) and
supplementary documentation for Release 4.
Additional projection control parameters may be contained
in two auxilliary 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 estab
lished from either the run-line or the contents 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) spec
ify the source of data to be transformed. 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 format and input cartesian data must be in units con
sistent 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 +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 meridian nearest longitude 112W. The geographic
values of this example are equivalent and meant as exam
ples 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 geo
graphic and projection coordinates within one datum.
The cs2cs program operates similarly, but allows transla
tion between any pair of definable coordinate systems,
including support for datum translation.
The nad2nad program provides for translation between NAD27
and NAD83 (also available in cs2cs) in a convenient man_
ner.
The geod program provides the ability to compute geodetic
(Great Circle) computations.
SEE ALSOcs2cs(1U), nad2nad(1U), geod(1U),
Cartographic Projection Procedures for the UNIX Environ_
ment--A User's Manual, (Evenden, 1990, Open-file report
90-284).
Map Projections Used by the U. S. Geological Survey (Sny
der, 1984, USGS Bulletin 1532).
Map Projections--A Working Manual (Synder, 1988, USGS
Prof. Paper 1395).
An Album of Map Projections (Snyder & Voxland, 1989, USGS
Prof. Paper 1453).
HOME PAGE
http://www.remotesensing.org/proj
2000/03/21 Rel. 4.4 PROJ(1)
