Geographic coordinate systems
Wikipedia: Geographic coordinate systems
A geographic coordinate system is a coordinate system that enables every location on the Earth to be specified by a set of numbers or letters, or symbols...A common choice of coordinates is latitude, longitude and elevation.
|Longitude and Latitude.||-3.106849||51.015344|
|Eastings and Northings.||322454||124580|
Points, lines, and polygons
Typically when dealing with geo-spatial data, this will be in the form of Points, Lines, and Polygons.
- Points - Individual locations made up of a single coordinate set e.g. a Library.
- Lines - Linear features made up of coordinates e.g. a Road
- Polygons - Bounded areas (shapes) made up of coordinates e.g. a County Council.
Geocoding and reverse-geocoding
Geocoding and reverse geocoding are ways of matching address and location data with geo-coordinates.
- Geocoding: Address -> Geo-coordinates. Example: Putting a library on a map from it's address.
- Reverse geocoding: Geo-coordinates -> Address. Example: taking coordinates retrieved from GPS to determine current location.
The traditional way of working with GIS data is through Desktop applications
- ESRI ArcDesktop - World leader for GIS software
- MapInfo - Acquired by Pitney Bowes Business Insight
- Quantum GIS - Open Source option. Brilliant.
Download and install: Quantum GIS