readme

开源投影系统 Cartographic Projections library originally written by Gerald Evenden then of the USGS. The

                      @(#)README	4.4 93/09/26 GIE REL"

The files in this directory are support data for PROJ.4 programs
as well as test scripts for testing proj installation.

File Contents:

README  --- This file

proj_def.dat --- basic default file used by proj.

epsg    --- Translation of EPSG GCS/PCS codes into PROJ.4 via init= mechanism.

nad27   --- North American Datum 1927 for "init=" definition of
			State Plane Coordinate Systems (SPCS).

nad83   --- North American Datum 1983 for "init=" definition of SPCS.

GL27    --- Great Lakes Survey grids, NAD27

world   --- Proj specifications for several international grid systems.

nad.lst --- Reference list of SPCS States and NGS datum identifiers

nad2bin.c   --- C program to convert above ASCII files into binary
				files usable by program nad2nad.  Compiled and used in
				install script only.

install     --- Unix shell (sh) script to install nad2nad file and proj
				init files.  Read beginning for usage instructions.

test27      --- Unix shell (sh) scripts to test installation of
test83          proj and nad27/nad83 init files.  These scripts
                expect release 4 proj to reside in ../src.

pj_out27    --- Comparison files for above test procedures.
pj_out83

The following NADCON conversion files are distributed in separate,
uncompressed distibution file(s).

       Ascii source (in delta format) of grid data to convert geographic
	   coordinates from NAD27 to NAD83
alaska.lla.Z   --- Alaska
conus.lla.Z    --- Conterminous U.S.
hawaii.lla.Z   --- Hawaii
prvi.lla.Z     --- Puerto Rico, Virgin Is.
stgeorge.lla.Z --- St. George Is, Alaska
stlrnc.lla.Z   --- St. Lawrence Is., Alaska
stpaul.lla.Z   --- St. Paul Is., Alaska

       Ascii source (in delta format) of grid data for high precision
	   conversion of geographic coordinates from NAD83 to NAD83
FL.lla.Z    --- Florida
MD.lla.Z    --- Maryland
TN.lla.Z    --- Tennessee
WI.lla.Z    --- Wisconsin
WO.lla.Z    --- Washington, Oregon, N. California

	Other grid shift files
ntv1_can.dat	--- Canadian NTv1 grid shift file (NAD27-->NAD83)