GIS Coordinate Formats

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Description

There are several systems in which coordinates can be expressed, and in some of these system coordinated can be written in different ways.

Valid expressions

All of the following are valid expressions for geographical coordinates:

   40:26:46.302N 079:58:55.903W
   40°26′46″N 079°58′56″W
   40d 26′ 46″ N 079d 58′ 56″ W
   40.446195N 79.982195W
   40.446195, -79.982195
   40.446195,-79.982195
   40° 26.7717, -79° 58.93172
   N40:26:46.302 W079:58:55.903
   N40°26′46″ W079°58′56″
   N40d 26′ 46″ W079d 58′ 56″
   N40.446195 W79.982195

Differences:

  • Three different systems:
    • Decimal degree
    • DMS (Degree Minute Second)
    • MinDec (Degrees and Minutes with decimal point)
  • Separators for DMS, :, d or °,",'
  • Latitude/Longitude separated by space or comma
  • - or W/S
  • N, E, S, W at different positions

Possible problems

  • Missing data or wrong data:
    • Missing coordinates have been set to 0.
    • Latitude/Longitude swapped
    • Latitude equal to Longitude
    • Non-coordinate expression or meta-information
  • Usage of another coordinate system
  • Usage of a specific grid
  • Language-specific expressions: O for East

Web Services or own tool

Canadensys offers a webservice for DMS to Decimal conversion [1]. That tool does, however, not recognize any of the expressions listed above.