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proj - forward cartographic projection filter invproj - inverse cartographic projection filter

proj[-bceEfiIlmorsStTvVwW[args] ] [+args] file[s]invproj[-bceEfiIlmorsStTwW[args] ] [+args] file[s]

Projandinvprojperform 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:-bSpecial option for binary coordinate data input and output through standard input and standard output. Data is assumed to be in system typedoublefloating point words. This option is to be used whenprojis asonprocess and allows bypassing formatting operations.-iSelects binary input only (see-boption).-Ialternate method to specify inverse projection. Redundant when used withinvproj.-oSelects binary output only (see-boption).-taAspecifies 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).-estringStringis an arbitrary string to be output if an error is detected during data transformations. The default value is: *\t*. Note that if the-b,-ior-ooptions are employed, an error is returned as HUGE_VAL value for both return values.-Ecauses the input coordinates to be copied to the output line prior to printing the converted values.-l[p|P|=|e|u|d]idList projection identifiers with-l,-lpor-lP(expanded)that can be selected with+proj.-l=idgives expanded description of projectionid.List ellipsoid identifiers with-le,that can be selected with+ellps,-lulist of cartesian to meter conversion factors that can be selected with+unitsor-ldlist of datums that can be selected with+datum.-rThis options reverses the order of the expected input from longitude-latitude or x-y to latitude-longitude or y-x.-sThis options reverses the order of the output from x-y or longitude-latitude to y-x or latitude-longitude.-SCauses estimation ofmeridinalandparallelscale factors,areascale factor andangulardistortion,andmaximumandminimumscale 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.-mmultThe cartesian data may be scaled by themultparameter. When processing data in a forward projection mode the cartesian output values are multiplied bymultotherwise the input cartesian values are divided bymultbefore inverse projection. If the first two characters ofmultare 1/ or 1: then the reciprocal value ofmultis employed.-fformatFormatis aprintfformat 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|W]nNis the number of significant fractional digits to employ for seconds output (when the option is not specified,-w3is assumed). When-Wis employed the fields will be constant width and with leading zeroes.-vcauses 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-Toption.-VThis option causes an expanded annotated listing of the characteristics of the projected point.-visimpliedwiththisoption.-Tulow,uhi,vlow,vhi,res[,umax,vmax]This option creates a set of bivariate Chebyshev polynomial coefficients that approximate the selected cartographic projection onstdout.The valueslowandhidenote the range of the input where theuorvprefixes apply to respective longitude-x or latitude-y depending upon whether a forward or inverse projection is selected.Resis an integer number specifying the power of 10 precision of the approximation. For example, aresof -3 specifies an approximation with an accuracy better than .001.Umax,andvmaxspecify maximum degree of the polynomials (default: 15). See also:fproj(1).The+argsrun-line arguments are associated with cartographic parameters and usage varies with projection and for a complete description seeCartographicProjectionProceduresfortheUNIXEnvironmentAUsersManual)and supplementary documentation for Release 4. Additional projection control parameters may be contained in two auxiliary control files: the first is optionally referenced with the+init=file:idand the second is always processed after the name of the projection has been established from either the run-line or the contents of+initfile. The environment parameterPROJ_LIBestablishes the default directory for a file reference without an absolute path. This is also used for supporting files like datum shift files. One or morefiles(processed in left to right order) specify 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 fromstdin.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 consistent with the ellipsoid major axis or sphere radius units. Output geographic coordinates will be in DMS (if the-wswitch is not employed) and precise to 0.001" with trailing, zero-valued minute-second fields deleted.

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 112°W. 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

Theprojprogram is limited to converting between geographic and projection coordinates within one datum. Thecs2csprogram operates similarly, but allows translation between any pair of definable coordinate systems, including support for datum translation. Thenad2nadprogram provides for translation between NAD27 and NAD83 (also available in cs2cs)inaconvenientmanner.Thegeodprogram provides the ability to compute geodesic (Great Circle) computations.

cs2cs(1U),nad2nad(1U),geod(1U),pj_init(3U),CartographicProjectionProceduresfortheUNIXEnvironmentAUsersManual,(Evenden, 1990, Open-file report 90-284).MapProjectionsUsedbytheU.S.GeologicalSurvey(Snyder, 1984, USGS Bulletin 1532).MapProjectionsAWorkingManual(Snyder, 1988, USGS Prof. Paper 1395).AnAlbumofMapProjections(Snyder & Voxland, 1989, USGS Prof. Paper 1453).

http://www.remotesensing.org/proj 2000/03/21 Rel. 4.4 PROJ(1)