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How to Georeference (Documents):

GIS/Georeferencing Tools:

Georeferencing and GIS Data Sources:

Gazetteers:

  • Getty Thesaurus of Geographic Names- Datum WGS84, not derived from NIMA data, do not use for coordinates but for looking at old names / name changes.
  • The Alexandria Digital Library Gazetteer Server - Gazetteer that’s especially useful for historic and variant names. Datum WGS84. Data based on NIMA so precision usually to the nearest minute (when second=59 seconds, round up to the next minute), except for US-based localities and a few other areas/cities, for which it’s to the nearest minute. Original coordinate system= DMS.
  • NIMA GEOnet Names Server (GNS) - The base information for many gazetteers, all of which use a slightly different display. Most useful for narrowing down the available results by administrative levels. Datum WGS84. Precision to the nearest minute (when second=59 seconds, round up to the next minute), except for US-based localities and a few other areas/cities, for which it’s to the nearest second. Original coordinate system= DMS. Can download all data for entire country for GIS applications.
  • FuzzyG - FuzzyG - The Fuzzy Gazetteer - enables you to find geographic features even when you do not know their exact names. Returns a list of similar names. Datum is WGS84 and precision to nearest minute. Original coordinate system Degrees, Minutes, Seconds (DMS). Based on NIMA GeoNET names server data.
  • Falling Rain- gazetteer site that gives foreign localities and distances in nautical miles to nearest place names (formerly Calle.com) - WGS84. Data based on NIMA so precision usually to the nearest minute (when second=59 degrees, round up to the next degree). Original coordinate system= DMS.
  • Maporama-For finding Coordinates for Street Addresses anywhere in the world. Write to them to find datum for map you are using.Coordinate precision to the nearest minute.
  • Mappy Road Guide - for finding or mapping localities in Europe (18 countries). Especially good for roads and street addresses. Does not give coordinates.
  • MultiMap - for finding or mapping localities in Europe, US and Australia. Gives coordinates, datum unknown (at present).
  • Gazetteers of the World and Beyond - National Library of Australia.
  • Canadian Geographic Names -Canadian gazetteer – includes a rough map for each locality. Datum NAD27. Precision to the nearest minute (when second=59 seconds, round up to the next minute). Original coordinate system= DMS.
  • Canadian Centre for Topographic Information - topographic maps of Canada, 1:50,000 and 1:100,000. WGS84 datum.
  • Sources for World Data:

  • Digital Chart of the World- Free downloadable layers for the world. Note that the data is only valid as of 1991/1992. These same datasets plus administrative boundaries are also available at the DIVA-GIS and BioGeomancer gdata site.
  • CIA World Factbook - Useful for information about current political boundaries, and will give you rough coordinates for the center of countries.
  • GIS Data Depot- Downloadable country maps from many sources on one site.
  • Geography Network-returns a list of GIS layers available for your area of interest, from various sources.
  • Berkeley Digital Library Maps - free on-line digital maps of many parts of the world.
  • UT Austin Perry-Castaneda Map Library-Great resource for scanned and online maps.
  • Global Climate Data for Free plus country data & other great stuff from DIVA-GIS.
  • Color Satellite Imagery for Free from NASA and the Applied Science Directorate.
  • Terra Server -for the world. Cool satellite images with coordinates given as you scroll, but the free version’s usefulness is limited.
  • USGS Global GIS- A Digital Atlas of the Planet Earth. From either 1995 or 2000. Provides 1:1 million scale maps in GIS format. Can be used with ArcView (ArcVIEW not required as comes with viewer). WGS84 datum, coordinate precision to 2 decimal places.Available at libraries or can be purchased online for $30 a CD. Provides global coverages of elevation, landcover, seismicity, and resources of minerals and energy.
  • Online Uruguay Maps.
  • Coordinate Tools from the Loumus project for Finland.
  • GBIF -Global Biodiversity Information Facility.
  • Global Topographic Data-DEMs.Free GIS layers. Downloaded layers may need conversion.

    A related document to this site is: Converting GTOPO DEM's to ArcView Format.

    Sources for US Data:

  • USGS Geographic Names Information System (GNIS) US-based gazetteer. Datum NAD27 before Sept 2005. Since Sept 2005 NAD83. Precision to the nearest second.
  • MapTech Terrain Navigator ($99 a state, good for georeferencing the US)- Default Datum is NAD27, coordinate precision is exact, map type is 1:24,000 or 1:100,000. Also recommend Terrain Navigator PRO - has street names and addresses, plus other features.
  • Topo!- similar to Terrain Navigator, use this in calculator as USGS map, NAD 27 or NAD83 (see which one your map is set to), with exact precision. Works with both PC and MACs (unlike Terrain Navigator, but overall TN is easier for searching).
  • Delorme Atlas and Gazetteer-for the United States. Large paper maps, good to use in conjunction with electronic maps. Has road names. Use as USGS 1:150,000, 250,000, etc (see bottom of map for scale). You have to compute your precision by how close you can measure it too (say 1 mm) and convert that to degrees for that scale. Grids are WGS84 datum,original coordinate system degrees, minute, seconds.
  • US National Maps-for the United States. Great for finding streets and features names, has good searching capabilities, can save bookmarks and has a distance tool. Highly recommended. Coordinate precision to the nearest second, datum is reported on the left hand side.
  • MapQuest - for finding or mapping localities, for finding street addresses in the US. Use this link to map coordinates using MapQuest. Datum is WGS84 (NAD83).
  • Topozone- Digital versions of USGS topo maps for the US and Puerto Rico, available in 1:24k/25k, 1:100k, and 1:250k series. Also includes a gazetteer. Great for measuring extents and obtaining coordinates. Datum is NAD27 or NAD83/WGS84, depending on what you set it to. Precision is to the nearest .001 degree for the gazetteer and .0001 for the maps.
  • USPS Post Office Locator-Useful for addresses of post offices, although be wary, as post offices may have moved. Another resource, such as topozone.com, will be needed to locate the coordinates.
  • Terra Server-for the US. Allows you to switch between topo maps and aerial photos for various regions in the United States, and gives the date of the aerial photos. Good for measuring extents and can give you coordinates, but other sites, such as topozone.com, are probably more useful.
  • US Census State & County Maps-Good for political boundary outline maps of the states and counties for reference, but not useful for obtaining coordinates or extents.
  • National Biological Information Infrastructure - NBII, our US representative to GBIF.
  • UT Austin Perry-Castaneda Map Library-Great resource for scanned and online maps, especially for National Parks of the United States.
  • TNRIS or Texas State Demographer - For Texas Maps.
  • USGS NED Shaded Relief Imagery-Free 1:24,000 USGS images that show shaded reliefs.
  • TIGER/Line Census Maps-Free US county layers.
  • University of Colorado GIS Maps - for Colorado.
  • Colorado Geological Survey- GIS maps.
  • Data for California: California Spatial Information Library and California FRAP Data - Free Habitat and Vegetation Data.
  • Historical USGS Maps of Eastern US States- PA, NJ, OH, NY, ME, DE, NH, RI,VT,WV , MZ, MS, CT Free from MapTech.

  • Georeferencing Archives:

    A good resource for any georeferencing questions you may have is the archive of messages sent to the MaNIS and HerpNET email lists.

    1. MaNIS archives. These are both available for anyone to search.
    2. HerpNET archives.

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    If you have suggestions for other websites, contact Carol Spencer.

    Updated C L Spencer 21 Feb 2008