Global Positioning System

GPSglobal positioning systemsGlobal Positioning System (GPS)Global Positioning Satelliteglobal positioningGPS systemGPS receiversNAVSTARGPS locationGlobal Positioning Systems (GPS)
The Global Positioning System (GPS), originally NAVSTAR GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Air Force.wikipedia
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GLONASS

Global Navigation Satellite SystemGLONASS GPSGLONASS K
The Russian Global Navigation Satellite System (GLONASS) was developed contemporaneously with GPS, but suffered from incomplete coverage of the globe until the mid-2000s.
It provides an alternative to GPS and is the second navigational system in operation with global coverage and of comparable precision.

Satellite navigation

GNSSnavigation satelliteglobal navigation satellite system
It is a global navigation satellite system (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
, the United States' Global Positioning System (GPS) and Russia's Global Navigation Satellite System (GLONASS) are fully operational GNSSs, with China's BeiDou Navigation Satellite System (BDS) and the European Union's Galileo scheduled to be fully operational by 2020.

Galileo (satellite navigation)

GalileoGalileo positioning systemGalileo project
There are also the European Union Galileo positioning system, and India's NAVIC.
One of the aims of Galileo is to provide an independent high-precision positioning system so European nations do not have to rely on the U.S. GPS, or the Russian GLONASS systems, which could be disabled or degraded by their operators at any time.

Bradford Parkinson

Bradford W. Parkinson
Roger L. Easton of the Naval Research Laboratory, Ivan A. Getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
He is best known as the lead architect, advocate and developer, with early contributions from Ivan Getting and Roger Easton, of the Air Force NAVSTAR program, better known as Global Positioning System.

Roger L. Easton

Roger EastonRoger Easton, Sr.
Roger L. Easton of the Naval Research Laboratory, Ivan A. Getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
Roger Lee Easton, Sr. (April 30, 1921 – May 8, 2014) was an American scientist/physicist who was the principal inventor and designer of the Global Positioning System, along with Ivan A. Getting and Bradford Parkinson.

Gladys West

Dr. Gladys West
The work of Gladys West is credited as instrumental in the development of computational techniques for detecting satellite positions with the precision needed for GPS.
Gladys Mae West (née Brown) (born 1930) is an African American mathematician known for her contributions to the mathematical modeling of the shape of the Earth, and her work on the development of the satellite geodesy models that were eventually incorporated into the Global Positioning System (GPS).

Force multiplication

force multiplierforce multipliersforce-multiplier
Considered vital to the nuclear deterrence posture, accurate determination of the SLBM launch position was a force multiplier.
For example, if a certain technology like GPS enables a force to accomplish the same results of a force five times as large but without GPS, then the multiplier is five.

Geolocation

geo-locationgeolocateGeoIP
It is a global navigation satellite system (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
When satellite navigation (such as GPS) signals are unavailable, geolocation applications can use information from cell towers to triangulate the approximate position, a method that is not as accurate as GPS but has greatly improved in recent years.

United States Naval Research Laboratory

Naval Research LaboratoryU.S. Naval Research LaboratoryNRL
Roger L. Easton of the Naval Research Laboratory, Ivan A. Getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
The Global Positioning System (GPS) was invented at NRL and tested by NRL's Timation series of satellites.

DARPA

Defense Advanced Research Projects AgencyAdvanced Research Projects AgencyARPA
In 1959, ARPA (renamed DARPA in 1972) also played a role in TRANSIT.
ARPA at this point (1959) played an early role in Transit (also called NavSat) a predecessor to the Global Positioning System (GPS).

Satellite constellation

constellationsatellite constellationsconstellations
It used a constellation of five satellites and could provide a navigational fix approximately once per hour.
Examples of satellite constellations include the Global Positioning System (GPS), Galileo and GLONASS constellations for navigation and geodesy, the Iridium and Globalstar satellite telephony services, the Disaster Monitoring Constellation and RapidEye for remote sensing, the Orbcomm messaging service, Russian elliptic orbit Molniya and Tundra constellations, the large-scale Teledesic, Skybridge, and Celestri broadband constellation proposals of the 1990s, and more recent systems such as O3b or the OneWeb proposal.

Decca Navigator System

DeccaDecca NavigatorDecca transmitter
The design of GPS is based partly on similar ground-based radio-navigation systems, such as LORAN and the Decca Navigator, developed in the early 1940s.
Decca was eventually replaced, along with Loran and similar systems, by the GPS during the 1990s.

Differential GPS

DGPSDifferential Global Positioning Systemposition information
The directive was proposed by the U.S. Secretary of Defense, William Perry, in view of the widespread growth of differential GPS services by private industry to improve civilian accuracy. Examples of augmentation systems include the Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlay Service (EGNOS), Differential GPS (DGPS), inertial navigation systems (INS) and Assisted GPS.
A Differential Global Positioning System (DGPS) is an enhancement to the Global Positioning System (GPS) which provides improved location accuracy, in the range of operations of each system, from the 15-meter nominal GPS accuracy to about 1-3 cm in case of the best implementations.

GPS Block IIF

Block IIFGPS IIFGPS IIF SV-1
GPS Block IIF, or GPS IIF is an interim class of GPS (satellite), which are used to keep the Navstar Global Positioning System operational until the GPS Block IIIA satellites become operational.

Timation

In 1967, the U.S. Navy developed the Timation satellite, which proved the feasibility of placing accurate clocks in space, a technology required for GPS.
The results of this program and Air Force Project 621B formed the basis for the Global Positioning System (GPS).

50th Space Wing

50th Tactical Fighter Wing50th Fighter-Bomber Wing50th Fighter Wing
The 50th Space Wing also manages the Global Positioning System.

Assisted GPS

A-GPSaGPSAssisted
Examples of augmentation systems include the Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlay Service (EGNOS), Differential GPS (DGPS), inertial navigation systems (INS) and Assisted GPS.
Assisted GPS or Augmented GPS (abbreviated generally as A-GPS and less commonly as aGPS) is a system that often significantly improves the startup performance—i.e., time-to-first-fix (TTFF)—of a GPS satellite-based positioning system.

Korean Air Lines Flight 007

Korean Air Flight 007KAL 007Korean Airlines Flight 007
After Korean Air Lines Flight 007, a Boeing 747 carrying 269 people, was shot down in 1983 after straying into the USSR's prohibited airspace, in the vicinity of Sakhalin and Moneron Islands, President Ronald Reagan issued a directive making GPS freely available for civilian use, once it was sufficiently developed, as a common good.
In addition, the incident was one of the most important events that prompted the Reagan administration to allow worldwide access to the United States Global Positioning System (GPS).

Air Force Space Command

AFSPCSpace CommandUnited States Air Force Space Command
When speaking with reporter David Martin, commanding General John E. Hyten was able to state that the program was doing its part in keeping the global world of GPS satellites and other important global satellite usage peaceful.

Radio

radio communicationradio communicationswireless
The citation honors them "for the most significant development for safe and efficient navigation and surveillance of air and spacecraft since the introduction of radio navigation 50 years ago."
In radio navigation systems such as GPS and VOR, a mobile receiver receives radio signals from navigational radio beacons whose position is known, and by precisely measuring the arrival time of the radio waves the receiver can calculate its position on Earth.

UGM-27 Polaris

PolarisPolaris missilePolaris missiles
(At the time, the Navy was developing the submarine-launched Polaris missile, which required them to know the submarine's location.) This led them and APL to develop the TRANSIT system.
A predecessor to the GPS satellite navigation system, the Transit system (later called NAVSAT), was developed because the submarines needed to know their position at launch in order for the missiles to hit their targets.

Time transfer

time referencecommon-view GPStime information
It is a global navigation satellite system (GNSS) that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
Examples of a one-way time transfer system are the clock on a church or town building and the ringing of their time-indication bells; time balls, radio clock signals such as LORAN, DCF77 and MSF; and finally the Global Positioning System which uses multiple one-way time transfers from different satellites, with positional information and other advanced means of delay compensations to allow receiver compensation of time and position information in real time.

Transit (satellite)

TransitTransit 1BAN/UYK-1
(At the time, the Navy was developing the submarine-launched Polaris missile, which required them to know the submarine's location.) This led them and APL to develop the TRANSIT system.
The Transit system was made obsolete by the Global Positioning System (GPS), and ceased navigation service in 1996.

Ivan A. Getting

Ivan GettingIvan Alexander GettingDr. Ivan Alexander Getting
Roger L. Easton of the Naval Research Laboratory, Ivan A. Getting of The Aerospace Corporation, and Bradford Parkinson of the Applied Physics Laboratory are credited with inventing it.
Ivan Alexander Getting (January 18, 1912 – October 11, 2003) was an American physicist and electrical engineer, credited (along with Roger L. Easton and Bradford Parkinson) with the development of the Global Positioning System (GPS).

Atomic clock

atomic clocksatomiccaesium clock
The satellites carry very stable atomic clocks that are synchronized with one another and with the ground clocks.
Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.