GPS Basic Information

GPS or Global Positioning System is a fullyIt is also used in marking targets as hostile and
functional Global Navigation Satellite System. Thisenables the precision guided munitions to allow
system uses an artificial constellation of 24them engage these targets with high accuracy.
medium Earth orbit satellites. These satellitesAir to Ground roles of military aircrafts use GPS
transmit microwave signals, thus enabling a GPSto find targets. GPS also allows targeting for
receiver to determine its location, speed, directionmilitary weapons like ICBMs, Cruise missiles,
and time. This system was developed by Unitedprecision guided missile. Artillery based projectiles
States Department of Defense and was namedare embedded with GPS receivers and can
as NAVSTAR GPS which was given by Mr. Johnwithstand forces up to 12,000G. These are used
Walsh. NAVSTAR is not an acronym, as is widelyfor 155 mm Howitzers. Any Downed pilot can be
believed.easily located if he has GPS receiver. It is widely
This satellite constellation is managed by Unitedused by military for reconnaissance and mapping.
States Air Force 50th Space Wing. The cost isSome GPS satellites also have nuclear detonation
approximately 750 US dollars every year, includingdetectors.
the maintenance cost, replacement, research andGPS helps civilians a lot in surveying and navigation.
development. After shoot down of Korean AirIts ability to calculate local speed and orientation is
Lines Flight 007 in the year 1983, a directive wasextremely useful. Time transfer is possible
issued which made the GPS available for civilianbecause of its capability to synchronize clock. A
use and has been used extensively since then. Itwidely used example of use of GPS is CDMA
has become a very useful tool for making maps,digital cell phone. Each base uses a GPS timing
surveying landscapes, commerce and manyreceiver to synchronize the codes with different
scientific uses. It also provides time referencebase stations and thus making it easy inter-cellular
which can be used in many applications whichhand off and thus support emergency phone calls
include study of earthquake andand other many applications. GPS equipment has
telecommunication network synchronization.also revolutionized tectonics by measuring the
A GPS receiver simply calculates the distancefault motion during earthquakes.
between itself and three more GPS satellite. EachThe two GPS developers, Ivan Getting and
satellite has an atomic clock in it continuallyBradford Parkinson have received national
transmits certain data containing its exact time,academy of Engineering Charles Stark Draper
location of the transmitting satellite and theprize during year 2003. Roger L Easton received
almanac. The receiver then measures theNational Medal for technology on February 13,
reception time of the signal. Thus the distance to2006. Other similar tracking systems are Beidou,
each satellite is known. Knowing three suchwhich has been developed by China and is
distances, a trilateration is formed. By using aproposed to be expanded into COMPASS; Galilieo,
fourth satellite, need for a clock at receiver iswhich is been developed by European Union along
avoided.with many other countries like India and China;
The Global Positioning System is used in a varietyGLONASS, which is been developed by Russia is
of Military and Civilian Applications. It allows soldiersfully available in partnership with India; IRNSS is
find their objectives in a dark or completelyIndia`s proposed regional system and QZSS which
unfamiliar territory and coordinate troophas been proposed by Japan.
movement and supplies. GPS receivers whichThis article is under GNU FDL license and can be
military personnel use are called Commanders anddistributed without any previous authorization
Soldier Digital Assistants. A combination of GPSfrom the author. However the author's name and
and communication through radio enables real timeall the URLs (links) mentioned in the article and
vehicle tracking.biography must be kept.