slide1 l.
Skip this Video
Loading SlideShow in 5 Seconds..
Online resources for georeferencing PowerPoint Presentation
Download Presentation
Online resources for georeferencing

Loading in 2 Seconds...

play fullscreen
1 / 24

Online resources for georeferencing - PowerPoint PPT Presentation

  • Uploaded on

Online resources for georeferencing http:// Online resources for georeferencing Google Maps Search & directions Free text search, zoom -dependent

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

Online resources for georeferencing

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Online resources for georeferencing


Online resources for georeferencing

google maps
Google Maps
  • Search & directions
    • Free text search, zoom -dependent
    • Directions for travelling by car, bike, public transport and foot
    • Data compiled from different sources
  • Maps
    • Datum: WGS84
    • Views: map, satellite (= aerial photography), terrain, Google Street View + various layers of information
    • Data compiled from different sources (indicated at the bottom of each map)
  • Third Party Plug-ins extend functionality
google maps searching
Google Maps - Searching

Search now with suggestions

google maps viewing
Google Maps - Viewing



Terrain (under ‘More’)

Earth (plug-in required)


Google Maps – Getting coordinates

  • Requires additional widgets or plug-ins
    • Activate LatLng Marker in Google Maps Labs
    • Install a mapplet like GPS Location or Position Finder in ‘My Maps > Browse the directory’. Now deprecated!
    • Use Canadensys LatLong Crosshairs bookmarklet:
  • Use Distance Measurement Tool to measure extent
  • Use My Maps to save markers, create maps, share with others (including kml import)

Google Maps – Getting coordinates

Google Maps Labs

LatLng Marker

Right-click and‘Drop LatLng Marker’

(activate in ‘Labs’ first)


Google Maps – Getting coordinates

Canadensys bookmarklet

Click to toggle


Pan map to change position

Click to get coordinates


Google Maps – Measuring extent

Distance Measurement Tool

(activate in ‘Labs’ first)


Google Earth

  • 3D globe desktop application
  • Same data as Google Maps
    • Datum: WGS84
    • No Map or Terrain view
  • Similar functionalities as Google Maps
    • Search more limited than Google Maps (no suggestions)
    • Right-click and choose ‘Get Info’ for coordinates
    • Use ruler to measure extent
    • Several coordinate formats
    • Numerous information layers (format: kml)


  • Google Maps interface
    • Datum: WGS84 (& NAD27)
    • Map, satellite, hybrid and terrain
    • Topo, DOQ, NEXRAD and Mapnik
    • Free text search not Zoom level-dependent
    • Markers cannot be moved, but new markers can be placed at crosshairs (click ‘Mark’)
    • Several coordinate formats for each marker + heading and distance from crosshairs
    • Saves all markers automatically


  • Worldwide gazetteer for citiesand towns
  • Google Map basemaps
  • Great for hard to find localities, especially outside US
    • Datum: WGS84
    • Search with country or worldwide
    • Provides DMS, DD, UTM coordinates
    • Includes contours (but spotty coverage)
  • Example: Qandahar or Kandahar, AF

GEOnet Names Server (GNS)

  • Worldwide data from NGA andUS BGN
    • NIMA = National Imagery andMapping Agency
    • Datum: WGS84
    • Degrees minutes seconds,precision to nearest minute
    • Feature type
    • Used as a source for many gazetteers
  • For US data, use Geographic Names Information System (GNIS):

Geographical Name Search Service (GNSS)

  • Canadian data by the CanadianGeographical Names Service(CGNS)
    • Datum: NAD83
    • Degrees minutes seconds anddecimal degrees
    • Feature type
  • Full Canadian Geographical Names datasets can be downloaded from GeoBase:

Falling Rain

  • Worldwide gazetteer for citiesand towns
  • Great for hard to find localities,especially outside US
    • Datum: WGS84
    • Degrees minutes (seconds), based on NIMA
    • Browse to find locality (no search)
    • Provides hierarchy, alternative names, topo maps, altitude, weather information and location of nearby towns in nautical miles (nm). Tip: Use Google/Chromey to translate nm into km.
  • Example: Qaryeh-ye Gol`alam, Velayat-e Lowgar, AF
  • You can also check against Statoids:

Getty Thesaurus of Geographic Names (TGN)

  • Worldwide gazetteer byThe Getty
  • Useful for finding alternativeand old names
    • Feature types
    • Geographical hierarchy
    • Coordinates only to minutes (or not at all)! Use recent name and search in Google Maps
  • Example: Big Apple, inhabited place, United States

FuzzyG – JRC Fuzzy Gazetteer

  • Worldwide gazetteer designed for bad spelling!
  • Useful for finding alternative, doubtful spelling,old names
    • Feature types
    • By continent
    • Coordinates only to minutes (or not at all)! Use recent name and search in Google Maps
  • Example: Narobi, Africa


  • UTM = Universal Transverse Mercator
    • Divides earth in 60 UTM zones = 6 degrees per zone
    • Datum: WGS84 and others
    • Notation: Zone Easting Northing = 17N 630084 4833438
    • Zone includes hemisphere (17N) or latitude band (17T): MGRS
    • Default extent: 30m (if recorded with GPS receiver)
    • UTM Calculator:
  • MTM = Modified Tranverse Mercator
    • Used in Canada: zones are 3 degrees, different codes, false easting and scale, etc.
    • UTM/MTM Calculator:

UTM – 17T 630084 4833438 (CN Tower in Toronto)

Equator = 0m northing

4833438m northof equator

Equator = 10,000,000m

false northing for

Southern Hemisphere

Central meridian= 500,000mfalse easting

130084m east ofcentral meridian

Georeferencing workshop - Online resources - 2010.06.05



Public Land Survey System (PLSS)

  • Mainly used in the US West, Midwest and some Southern states in early surveys
  • System of Township-Range-Section (TRS):T13N-R14E-S15, Arizona, Coconino County
  • Graphical Locator:
    • Translates TRS in decimal degrees
    • Datum: NAD27
  • Determine state and meridian (BLM):
  • For extents:

Other Resources

  • GPS Visualizer:
    • Use to translate a file with coordinates into kml or a picture
    • Similar: for publications
  • GeoLocate:
    • Georeferencing desktop and web application
    • Useful for roads and rivers (US only)
  • Statoids:
    • Information about administrative divisions (provinces, counties) and their history, area, population, codes, etc.
    • No coordinates!
    • Similar: CIA World Factbook
  • See for more…