Products > GDM > Base GDM and Custom Gazetteer

MetaCarta Geographic Data Modules make up the core of MetaCarta products. A GDM is a knowledge base used to identify and disambiguate geographic references, assign latitude/longitude coordinates, and confidence scores and relevance ranking. Each MetaCarta GDM contains linguistic statistics, gazetteer data, and natural language processing (NLP) logic. 

The MetaCarta Base GDM is included with MetaCarta's products and contains more than 7 million unique geometric entities and 13 million name variations for:

  • Cities and towns
  • Administrative divisions (counties, states/provinces, countries)
  • Regions and continents
  • Natural physical features (mountains, bodies of water, canyons, etc.)
  • Certain man-made features (prominent buildings, roads, tunnels, etc.)

The MetaCarta Base GDM features global coverage from sources including NGA GNS, USGS GNIS, and dozens of additional sources.  In addition, it contains location-patterned references including:

  • Relative references (20 miles southeast of New Orleans)
  • Military Grid References System (MGRS), e.g. “36SWF2248402617” means 36° 10'5''N 33° 15'0''E
  • Universal Transverse Mercator (UTM), e.g. “357973N527260E ZONE 38” means 3° 14'19''N 45° 14'43''E
  • Decimal Degrees (including transcription variants)

The MetaCarta Custom Gazetteer allows unique, company- or industry-specific place names to be added to the MetaCarta GSRP. In addition, the Custom Gazetteer provides the means for an administrator to add additional placenames to the Platform for georeferencing.  It can also be used to disable the tagging of placenames from the MetaCarta GDMs.