Global Positioning Systems (GPS)
Through the use of a GPS, locations can be identified and measured. These measurements require a reference system, so comparisons can be made between locations. Locations of points collected from a GPS can be imported into a GIS and combined with other data (e.g., elevation data) as illustrated in the diagram below. Once these data are in a GIS environment, other non-spatial data – called attribute data (e.g., soil moisture measurements) can be added to these points.