The Digital Chart of the World (DCW) & Data Quality Project

Index:  Project summary     Project documents     Other DCW online resources

Project Summary

This one year R&D project examined the concepts of data quality as applied to spatial databases. The examination was specifically related to the Digital Chart of the World (DCW). The DCW is the world's most comprehensive 'public domain' GIS database with a nominal scale of 1:1mill. The major data quality aspects examined were positional line accuracy and completeness. The project was carried out by staff and students from the Dept. of Mapping Sciences, Agricultural University of Norway (now: section for geomatics at the Department of Mathematical Sciences and Technology at the Norwegian University of Life Sciences), and staff from UNEP/GRID-Arendal, one of the nodes in the UNEP/GRID network of cooperating environmental data and information centres.

The objectives of the project were:

1. To theoretically examine some data quality characteristics (positional line accuracy and completeness) of spatial databases.
2. To review and summarise present use and quality experiences from DCW users world-wide by means of an Internet based survey.
3. To provide an extensive completeness report of the DCW database using existing material on the DCW and its source map series, the Operational Navigation Charts.

The beneficiaries of the project are intended to be:

1. The GIS community, both data producers and users, both practitioners and academicians, concerned with quality aspects of georeferenced data.
2. In particular, all users of DCW data including UNEP/GRID in general and in particular the GRID centres and co-operating centres using DCW data in various projects.

Institutions and Persons Involved:

This was a joint project between UNEP/GRID-Arendal, a node in the UNEP/GRID network of co-operating environmental data and information centres, and Department of Mapping Sciences, Agricultural University of Norway (now: the section for Geomatics at the Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences).

• Dr. Sindre Langaas, UNEP/GRID-Arendal
• Ass. Professor Håvard Tveite, Department of Mapping Sciences, Norwegian University of Life Sciences
• Christopher G. Smith, UNEP/GRID-Arendal

Project Funding and Period:

The project was funded by the Norwegian Research Council (The GIT Programme), United Nations Environment Programme and the Agricultural University of Norway.

The project period was 01.08.1994 - 30.09.95

Project Documents

We have presented some of the results from this project at the SCANGIS'95 Conference in Trondheim, Norway, June 12-14, 1995.

• Tveite, H. and Langaas, S. 1995. Accuracy Assessments of Geographical Line Data Sets: The Case of the Digital Chart of the World (some errors corrected, PDF, 35kB. A Postscript version, 135700 bytes). In: J.T. Bjorke (ed.) Proceedings from the 5th Scandinavian Research Conference on Geographical Information Systems, 12-14 June 1995, Trondheim, Norway, pages 145-154.
• Langaas, S and Tveite, H. 1995. To Characterise and Measure Completeness of Spatial Data: A Discussion Based on the Digital Chart of the World (DCW) (PDF, 20kB. A Postscript version, 44729 bytes). In: J.T. Bjorke (ed.) Proceedings from the 5th Scandinavian Research Conference on Geographical Information Systems, 12-14 June 1995, Trondheim, Norway, pages 155-161.

Another presentation was given at a joint UNEP/GRID and Consultative Group of International Agricultural Research institutions (CGIAR) workshop on the use of GIS in international agricultural research, held in Arendal, Norway, 8-11 May 1995.

• Langaas, S. 1995. Cartographical Data and Data Quality Issues (PDF, 27kB. A Postscript version, 64998 bytes).

The above three presentations have been compiled into project report no. 1, which can be downloaded in its entirety below. Two other reports have also been published. These should be of particular interest for DCW users world wide.

• Langaas, S. and Tveite, H. 1995. Selected papers from the DCW data quality project (PDF, 80kB. A Postscript version, 341923 bytes). DCW & Data Quality Project Report No.1 /1995, UNEP/GRID-Arendal, Norway, 30 pages.
  To view Abstract, click here.
• Langaas, S. 1995. Completeness of the Digital Chart of the World (DCW) (PDF, 132kB. A Postscript version, 500176 bytes). DCW & Data Quality Project Report No.2 /1995, UNEP/GRID-Arendal, Norway, 75 pages.
  To view Abstract, click here.
• Smith, C.G. and Langaas, S. 1995. A Survey of Digital Chart of the World (DCW) Use and Data Quality (PDF, 40kB. A Postscript version, 109522 bytes). DCW & Data Quality Project Report No.3 /1995, UNEP/GRID-Arendal, Norway, 25 pages.
  To view Abstract, click here.

The above three reports are also available in hard copy format for postage & handling costs. If interested, take a look at the order instructions.

An article on the line quality assessment part of this research has been published in the International Journal of Geographical Information Science.

• Tveite, H., and Langaas, S., 1999, An Accuracy Assessment Method for Geographical Line Data Sets Based on Buffering. International Journal of Geographical Information Science, Vol. 13, No. 1, 1999, pp. 27-47. (link)

We would be very pleased if you wanted to try the method described in this article (this WWW-page includes all the necessary scripts and instructions to apply the method using the ArcInfo GIS). Please inform us if you find the method useful, and/or if you have bug reports.

Other DCW Online Resources

• General DCW info and map examples
  • A good, general description of the Digital Chart of the World. From USGS.
  (being phased out?)
  • Formal Metadata for the Digital Chart of the World (not available anymore? - in accordance with the FGDC Content Standard for Digital Geospatial Metadata). From USGS.
  • DCW description (including short layer descriptions). From ESRI.
  • Short, general description of VMap0 in French (not available anymore? - Carte numérique du monde). From Geomatics Canada.
  • North Caroline State University (NCSU) Libraries DCW overview
• DCW Applications
  • Example 1: Global DEM creation. General description. From USGS.
  • Example 1: Global DEM creation. More detailed and technical description. From Susan Jenson, USGS. (Moved, but where?)
  • Example 1: Global DEM creation. Online access to the DCW derived DEM data. From USGS.
  • Example 2: Global Land-Sea Mask for use in Global Change research. From USGS.
  • Example 3: 3-D visualisation of the Holy Land. From Shane Murion, UK.
  • Example 4: Utilisation of DCW and other public domain datasets in general purpose regional database creation. UNEP/GRID Arendal's Baltic Sea region GIS Database. From UNEP/GRID-Arendal.
  • Example 5: Wilderness Quality Mapping in the Euro-Arctic Barents Region (not available anymore?). From UNEP/GRID-Arendal and National Remote Sensing Centre, UK.
  • Example 6: Opportunities for generalization in the Digital Chart of the World (PDF-file). NCGIA Technical Report 92-2. By F.J. Fico, NCGIA
• DCW data online
  • Digital Chart of the World data server at Pennsylvania State University Libraries in USA. Generates and delivers ARC/INFO Export files (.E00) and shows previews.
  • The Geospatial Engine at NIMA. The VMAP0 and VMAP1 (for parts of the world) CDs can be downloaded (or ordered) in VPF format.
  • Several Arctic DCW Arc/Info coverages can be accessed from the GRID-Arendal public GIS database
  • DCW data from China. From the CITAS project, University of Washington.
  • GIS Data Depot provides DCW, VMAP0 and VMAP1 data (for a fee).
  • DCW data - online (FTP), Manifold format (search for DCW).
• DCW data offline
  • DCW in ARC/INFO format from ESRI: Online ordering (The link seems to be moving around...)
• DCW (VPF) relevant software utilities and standards
  • The DCW was originally produced in the Vector Product Format, a military specification that can also be ordered at this site (search using "vector and product and format")
  • VPFView (v2.1) is software to view DCW/VMAP0 data from the DCW/VMAP0 CD-ROM data set in VPF format
  . It is available for download as a part of the NIMAMUSE software package (at NIMA). Operates on "IBM PC, or compatible microcomputer, as well as SUN UNIX, Silicon Graphics, Hewlett-Packard, and MacIntosh".
  • Software Utility: DCW VPF -> ARC/INFO Ungenerate format (dcw.exe). From COGS ftp repository.
  • Excerpts from the DCW specifications (including a link to the specifications).
  • Excerpts from the VMAP0 specifications (including a link to the specifications).
  • Printed versions of the VMAP, VPF (and DCW) specifications can be bought from Document Center Inc. Search for "VMAP", "VPF"/"Vector Product Format" (or DCW) on www.document-center.com.

The DCW (edition 1) has not been updated since its first release by the DMA (US defense mapping agency) in 1992.
The NIMA (the DMA was merged with several other agencies to form NIMA) has released a second edition of the DCW (called Vector Smart Map level 0, VMAP0). Watch the DMA WWW-pages for information on coming editions (search for VMAP0).

This page was last revised by Håvard Tveite (28. November - 2005). The WWW is constantly changing, please help us and the rest of the GI society by mailing us comments, corrections and suggestions about other on-line DCW resources.