Vehicle Tracking Devices - indicating position via satellite technology..
A system based on satellites that allows a user with a receiver to determine precise coordinates for their location on the earth's surface. These are a primary source of spatial data.
Space-based radio positioning systems that provide 24-hour, three-dimensional position, velocity, and time information to suitably equipped users anywhere on or near the surface of the Earth.
A system of satellites, ground stations, and GPS receivers. Ground stations monitor satellites in "known" positions and triangulation is used to determine such things as latitude and longitude or the location of the vessel or other vehicles.
Uses satellite signals to track the location or position of vehicles or vessels on earth.
Surveying systems which can isolate the position of a point on the earth's surface by making simultaneous observations on several orbiting navigational satellites.
Highly accurate location system which precisely pinpoint surface locations in terms of exact latitude and longitude using hand-held instruments that communicate with orbiting satellites.