Map Projection Software

Public Domain

There are several sources of public domain cartographic software that perform cartographic projections as well as other geodetic computations such as compute geodesic distances (Great Circles) and datum transformations.


General Cartographic Transformation Package

or GCTP is one of the oldest systems. It is a package of FORTRAN procedures that provide forward and inverse projection of about 23 cartrographic projections. It is the "official" system of the National Mapping Division (NMD) of the US Geological Survey. It also provides conversion of State Plane Coordinate System. It is documented with *.txt, *.ps and word processor files as well as hard copy manuals.
It was available via ftp from: as file public/amdahl/gctpv2.dat. This link was not functioning at last try but:

It is also available from:
Phone: 1-800-USA-MAPS Fax: (703) 648-5548

For software questions and assistance contact:
Mike Linck
Phone: (703) 648-4667 Fax: (703) 648-4722
U.S. Geological Survey
510 National Center
Reston, VA 22092
Note: there is a great deal of other information at this ftp site described in *readme* files in the various directories. Also assorted DOS procedures.

A C-language (K&R style) version of GCTP

developed at the EROS Data Center. It provides the same projection services as GCTP as well as about a half dozen additional projections.

It is available from ftp site: as file pub/software/gctpc/gctpc.tar.Z

The material is documented with *.txt and PostScript files. Indications in readme's indicate that due to funding, maintenance and support for gctpc has stopped although a Q&A email address is given.

Note: the above file is *very* long (~11Mb) due to test data and would requires about 40Mb to uncompress and 80Mb to run the test procedures. An extraction of this distribution is available on: as file pub/misc/GCTP-II.tar.Z . It takes less than 1Mb for installation.


system written in ANSI-POSIX C provides three application programs (proj, nad2nad, and geod) as well as an easy to use library for use in user-written application programs. More than 110 forward projections are provided and inverses are available for most (all commonly used ones). NADCON datum conversion program is supplied as well as complete support for SPCS and several international grid systems. Illustrated documentation is supplied as three PostScript files.

Available at: http:/

NOTICE for MSDOS users the MSDOS Release 4.3.3 of the PROJ.4 system has been placed in the above site.

For comment or help, contact:

Gerald (Jerry) I. Evenden
P.O. Box 1027
N.Falmouth, MA 02556-1027

Note: variants of *proj* are used in the GRASS system.

The National Geodetic Survey (NOAA/NGS)

Provides many FORTRAN procedures and DOS programs for cartographic projections as well as datum conversions and other geodetic information.

National Geodetic Information Center
Phone: (301)713-3242;
Mon-Fri 7 a.m.-4:30 p.m. Eastern Time.

The NGS Homepage provides electronic access to it's database, offering most NGS software *free of charge*. or for a listing of PC Software and available manuals

NIMA, The National Imagery and Mapping Agency

has been incorporated the Defense Mapping Agency as of October 1, 1996 and is also a source of considerable cartographic software and information. Unlike the NMD/USGS and NGS, NIMA information is international in scope. Some products (mostly maps) are sold through the USGS.
MADTRAN or Mapping Data Transformation Software program is available from
NIMA's Mapping, Charting and Deodesy Utility Software Environment (MUSE) is a standard suite of software that can be used to access DMA digital data sets and wortk with standard DMA datum transformations and coordinate conversions. Currently it is only available via the USGS for $7.75 at 303-202-4000 or
Box 25286
Denver Federal Center
Denver, CO 80225

From Sol Katz

(, a notice of some sources for UTM conversions on ( quickbasic src/exe for lat/lon to/from utm and other stuff
ll2utm.f77 a f77 subroutine for lat/lon to utm conversion
There are some other interesting files on this ftp site (GIE).
Gerald (Jerry) I. Evenden Internet:
voice: (508)563-6766 Postal: P.O. Box 1027
fax: (508)457-2310 N.Falmouth, MA 02556-1027


MicroCAM is a microcomputer-based program designed for use in the instruction of computer assisted cartography and for the production of small-scale thematic maps.

MicroCAM is public domain and may be spread throughout the land. The AAG charges for the diskettes involved and the extended user's manual written by others. MicroCAM for Windows (Version 1.3) or DOS (Version 4.0) is available for download via anonymous ftp at the United States Military Academy at under the DOS or WINDOWS subdirectories.

Cost: $7 for the Reference Manual and/or $5 for the Guide for Users. Available through Microcomputer Specialty Group (MSG) of the AAG or contact: Dr. Paul S. Anderson,

Dr. Anderson's home page will soon provide updates on MicroCAM capabilities and applications.

GMT-3 The Generic Mapping Tools

GMT, at, is a collection of ~50 UNIX tools that allow users to manipulate data sets, including filtering, trend fitting, gridding, projecting, etc. and produce Encapsulated Postscript File (EPS) illustrations. GMT supports 20 common map projections. GMT is developed and maintained by Paul Wessel and Walter H.F. Smith.


The GeoConverter is Mac shareware for converting between Lat/Long and UTM using the Clarke 1866 ellipsoid. Priced at $6 and availble via ftp from sumex or umich.


TransNAD (3.1 MB) - from Wessex Inc. at is a Windows freeware utility that translates ArcView (shape) and MapInfo (MIF) mapping files between the old NAD27 and the new NAD83. Click on the FREE link at the site to locate this software.

Commercial Software


Terra Data Incorporated, founded in 1990, is located in Croton-On-Hudson, NY. Terra Data develops, markets and supports Geocart, the map projections program for the Macintosh. Geocart enable users to create maps and display, print or export them for use with other applications. The company also sells a line of high resolution data bases for use with Geocart.

The Geographic Calculator

"Comprehensive Coordinate Conversion and Geodetic Calculation Software"

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Last updated 9/26/97 by Karen Mulcahy -