Geo-Spacial information is that which references positions on the planet. Examples include map-overlays, Geo-Referenced Photos, political boundary-lines, aerial imagery, way-points and tracks recorded by a GPS device and much more.
Geo-Spacial data comes in many formats, some of the most common are the following:
- GPX - GPX (the GPS Exchange Format) is a light-weight XML data format for the interchange of GPS data (waypoints, routes, and tracks) between applications and Web services on the Internet.
- KML - KML is a file format used to display geographic data in an Earth browser, such as Google Earth, Google Maps, and Google Maps for mobile. KML uses a tag-based structure with nested elements and attributes and is based on the XML standard.
- Shapefile - A format used by ESRI's powerful ArcGIS suite of software.
There are many pieces of software that might be used when working with geo-spacial data, many of which perform specialized functions.
These applications provide a 3D view of the earth that can be rotated and zoomed. They provide a 3D model of the terrain as well as some base data such as satellite imagery, political borders, roads, cities, etc. Often they will also allow for the display of user-created content and possibly even allow the addition and editing of basic content such as points, lines, and polygons.
- Google Earth - http://earth.google.com/
- NASA World Wind - http://worldwind.arc.nasa.gov/
- ArcGIS Explorer - http://www.esri.com/software/arcgis/explorer/
- Microsoft Virtual Earth - http://www.microsoft.com/virtualearth/
Data Editing and Analysis
While some of the virtual globes provide basic editing of geo-spacial data, this software goes further.
- GPS Babel - Software for translating between data formats and reading-from/writing-to GPS devices
- GPS Photo Linker - Add coordinates to photos by matching their timestamp to points in a GPS track-log.
- Geotagger - Add coordinates to photos using GoogleEarth.
- HeyWhatsThat - Displays a panorama of the mountain peaks visible from any point.
- HeyWhatsThat Path Profiler - Will display the elevation profile of a user-created path.
Making use of geo-spacial data
- Flickr - Photo-sharing site allows positioning and display of photos on a map.
- Wikipedia - Articles can be marked with location coordinates and then displayed on a map. Articles with locations specified will also appear in GoogleEarth.
While various survey tools are used for the precise spacial measurement needed for construction and city planning, the primary hardware tool used by individuals for collecting and using geo-spacial information is the Global Positioning System (GPS) receiver. These devices come from a variety of manufactures with a huge range of features and price-points. The most basic have no screen and simply record a 'track' of coordinates and time-stamps as you move about. Others do no recording themselves but just relay coordinates to a computer. Slightly more full-featured (but still basic) units have a small monochromatic screen that may display coordinates, travel speed, travel direction, as well as allow navigation to a pre-recorded location and/or route.
More expensive GPS receivers may include more accurate location (by several meters), color screens, radios, built in maps, driving directions routing, and other features.