Glossary of Terms
- Atomic clock
- A precision clock that depends for
its operation on an electrical oscillator regulated by the natural
vibration frequencies of a beam of cesium atoms.
- Control segment
- The five ground stations that
continually check the satellites for proper function.
- The science and technology of gathering,
analyzing, interpreting, distributing and using geographical
- Geographic Information Systems (GIS)
- Technology that analyzes, stores, and displays both spatial (altitude,
political boundaries, etc.) and non-spatial (population,
etc.) data about a place.
- Global Positioning System (GPS)
- A navigational
system using satellite signals to fix the location of a receiver
on or above the earth's surface.
- GPS Receiver
- Electronic equipment that passively receives GPS signal for processing. A
receiver may be hand-held or permanently mounted on a vehicle.
- Angular distance north or south from
the earth's equator measured through 90 degrees.
- The arc or portion of the earth's
equator intersected between the meridian of a given place and
the prime meridian and expressed either in degrees or in time.
- The method of determining position, course, and distance
- A manufactured object or vehicle intended to orbit the
earth, the moon, or another celestial body.
- An instrument for measuring angular
distances used especially in navigation to observe altitudes
of celestial bodies.
- Space segment
- The 24 satellites, each in its own orbit 11,000 miles
above the Earth, that are responsible for signaling precise location
and time data.
- Sending a fake GPS signal.
- User segment
- The handheld (or mounted) receivers
that process the signals from GPS satellites (space segment). This
segment gives the user the actual data in terms of location,