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.
- 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.
- 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:
The Seamless Digital Chart of the World is the preferred base map for the World Language Mapping System (WLMS).