Seamless Digital Chart of the World

An enhanced and updated global GIS basemap

The Seamless Digital Chart of the World (SDCW) is a unique, updated basemap provided in an easy-to-use, seamless GIS format. The SDCW is based on the best currently-available global vector base map, Digital Chart of the World (Vector Smart Map 0, Edition 5 from NGA).

It comes with a variety of enhancements and updates which make it more easily usable, at a broader range of scales, and with better cartographic results than the freely available Digital Chart of the World from which it largely derives.

This data product serves as a high-quality GIS basemap for cartographers and researchers.

Major features

Proprietary adaptation of the Digital Chart of the World in a seamless ESRI shapefile (.shp) data format, eliminating duplicate layers and tile boundary artifacts (see Sample Maps)
Updated country and province polygons (see Sample Maps)
Layer files and project files for ArcView 9.3 and 10.0 that simplify creation of maps with attractive, readable symbology
All features appear in global-extent ESRI shapefiles or file geodatabases - features customarily drawn with borders (countries, states/provinces, inland water areas, etc. are merged across DCW tiles and libraries
First-level political subdivisions (states/provinces) are periodically updated, and country polygons (not included in VMAP 0) are created from the updated subdivisions. Second-level subdivisions have been added for India and China
Inland water areas and watercourse lines have relative-flow attributes, allowing appropriate amounts of water to be shown at different scales and for different cartographic requirements
An improved set of populated place points, ranked by population and with improved names, allows improved symbology, labeling and scale-appropriate display of place

New in Version 10.0.2

Extended set of population-classified cities and towns (approximately 200,000 in a file geodatabase format), with improved name rendering (GNS names with unicode diacritics) - (see Sample Maps)
Internal political borders have been updated for over 60 (40 since version 10.0 countries). Codes and names for over 30 additional provinces were updated. Second-level subdivisions have been added for India, China, and Sri Lanka
Elevation and hillshade raster datasets, 30 arc-second
Kosovo as a country has been separated from Serbia. Some adjustments (reassigning islands to correct countries and adjusting borders) were made to 10 countries
Flow-classified rivers and streams (see below)

The combination of population-classified cities and towns and flow-classified rivers and streams allows use of the SDCW at a wider range of scales than the original DCW. The user can reduce the clutter of smaller towns and streams.

System requirements

GIS software capable of reading ESRI shapefile format (.shp) and file geodatabase format.
Shapefiles have been tested in ESRI's ArcView 8.2, 8.3, and 9.x.
Projects and layers tested in ArcView 9.3 and 10.0.
Sample ArcView project with wizard macro has been tested in ArcView 9.3.
Windows system to run self-extracting .exe installation files. This need not be the computer running the GIS system, but must be able to write data to a location accessible by the GIS system.

All other technical specifications can be found in the following PDF document:

SDCW documentation

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