DLG-3 SDTS README FILE:

This directory contains a Spatial Data Transfer Standard (SDTS), 
Topological Vector Profile (TVP) compliant transfer, produced by the 
National Mapping Division of the United States Geological Survey, created 
from digital line graph 3 (DLG-3) data.

STANDARD AUTHORITY:  
        FIPS 173: The Spatial Data Transfer Standard 
        Part 4: Topological Vector Profile, Version 1, December 20, 1993

ISO 8211 CONFORMANCE:
        All files with extension *.DDF are in the ISO 8211 file transfer
        format. All SDTS spatial addresses are expressed in two 32 bit 
        binary sub-fields defined by the ISO8211.  Leader and directory 
        information are dropped whenever possible. Files are Level 2 of
        ISO 8211.
 
CATALOG DIRECTORY MODULE xxxxCATD.DDF:
        Each transfer will contain this catalog directory module which
        contains a listing of every SDTS ISO 8211 file included in the
        transfer.  (xxxx indicates a four-character transfer base which 
        is common to all files in a transfer.)

IDENTIFICATION MODULE xxxxIDEN.DDF:
        This module contains information that describes the overall
        characteristics of the data in a transfer, including
        it geographical domain.  

PURPOSE OF TRANSFER:
        This transfer's purpose is as a sample data set which demonstrates 
        how DLG-3 data is encoded in SDTS.

REFERENCES:
        "DLG-3 SDTS Transfer Description" -- draft document which describes
        SDTS transfers of DLG-3 data, including detailed information on
        each module.  Located in files sdts/datasets/tvp/dlg3/dlg3.wp 
        (Word Perfect) or sdts/datasets/tvp/dlg3/dlg3.ps (Post Script).

POINT OF CONTACT:
        SDTS Task Force               |  Information on SDTS is also
        U.S. Geological Survey        |  available on FTP site
        526 National Center           |  sdts.er.usgs.gov
        Reston, VA 22092              |  (130.11.52.170)
        FAX:  (703) 648-5542          |
        E-MAIL: sdts@usgs.gov         |


TRANSFER CREATION DATE:  
     MAY 9, 1994

THIS DIRECTORY CONTAINS THE FOLLOWING TRANSFER:  
------------------------------------------------------------------------------
Domain:                    WILMINGTON SOUTH, DE-NJ
Theme:                     HYDROGRAPHY
Scale:                     24000
File name base:            HY01
Identification module:     HY01IDEN.DDF
Catalog/Directory module:  HY01CATD.DDF
------------------------------------------------------------------------------

This transfer requires an external data dictionary from the U.S. 
Geological Survey, National Mapping Division, with a 4-character code 
of DLG3, version number 1.00.  This data dictionary can be found in
directory sdts/datasets/tvp/dlg3/masterdd.
