Using Service (US):
Air Force (USAF)
The Global Positioning System (GPS) is a constellation of orbiting satellites that provides navigation data to
military and civilian users all over the world. The GPS constellation is designed and operated as a 24-satellite system,
consisting of six orbital planes (with four satellites per plane).
The system is operated and controlled by the 50th Space Wing at Schriever Air Force Base in Colorado.
GPS provides a global, three-dimensional positioning, navigation, and timing information system -
used by the U.S. military for aircraft, artillery, ships, tanks and other weapon systems.
GPS satellites orbit the earth every 12 hours and send continuous navigation signals. Users can receive these signals to calculate time, location and velocity. The GPS signals are so accurate that time can be figured to within a millionth of a second, velocity within a fraction of a mile per hour, and location to within 100 feet.
GPS provides 24-hour navigation services including:
-Extremely accurate, three-dimensional location information
-A global common grid that is easily converted to any local grid
-Passive all-weather operations
-Continuous real-time information
-Support to an unlimited number of users and areas
-Support to civilian users at a slightly less accurate level.
The Evolved Expendable Launch Vehicle (EELV) program supports the launch of GPS satellites from Cape Canaveral Air Station in Florida. GPS satellites are launched into 11,000-mile circular orbits. While orbiting the earth, the current systems transmit signals on two different L-band frequencies. GPS II satellites have a design life of 7.5 years, but many remain operational for as long as 10-12 years or more.
GPS capabilities were put to the test Operations Desert Shield and Desert Storm. Allied troops relied heavily on GPS to navigate the featureless Arabian Desert. During operations Enduring Freedom, Noble Eagle and Iraqi Freedom, GPS contributions increased significantly. During Operation Iraqi Freedom, the GPS satellite constellation allowed the delivery of GPS-guided Joint Direct Attack Munitions (JDAM) with pinpoint precision (to about 10 feet) and with minimal collateral damage.
The newest GPS satellite, the Lockheed Martin
GPS IIIA payload, will deliver significant enhancements,
including a new L1C (civil) Galileo-compatible signal and enhanced M-code earth coverage power.
The GPS IIIA satellites will deliver signals three times more accurate
than current GPS payloads and provide three times more power for military users, while at the same time enhancing design life
and adding a new civil signal - designed to be interoperable with international global navigation satellite systems.
The GPS III production team consists of Lockheed Martin,
and Infinity Systems Engineering.
The three companies will produce the first two of a planned eight GPS IIIA payloads. Initial launch is planned for 2014.
In May 2008, the first GPS III contract was awarded to Lockheed Martin for the development and production of two initial space vehicles (SV-1 and SV-2), with options for up to ten additional SVs. In January 2012, the Air Force awarded Lockheed Martin a $238 million contract for the production of GPS III SV-3 and SV-4. On February 25, 2013, the U.S. Air Force awarded Lockheed Martin two fixed-price contracts totaling $120 million for long lead parts for GPS III satellites SV-5, SV-6, SV-7 and SV-8.
will produce the GPS OCX, which is the next generation Global Positioning System Advanced Control Segment.
The OCX will provide command and control of the GPS IIA, IIR, IIR-M, IIF, and IIIA satellites and replaces the OCX Master Control
Station and Alternate Master Control Station. Also, the OCX upgrades the U.S. Air Force and National Geospatial Intelligence Agency (NGA) monitor stations
and modifies the existing ground antennas. Furthermore, the OCX provides monitoring of all current GPS signals as well as
the new L1C, L2C, L5, and M-Code signals. The Raytheon
production team includes Boeing,
Braxton Technologies, Infinity Systems Engineering, and the Jet Propulsion Laboratory.
In February 2010, the Air Force awarded Raytheon an initial contract of $886 million to develop the new OCX element of the GPS to improve the accuracy and availability of GPS navigation signals. The initial 73-month contract, among other things, calls for development and installation of hardware and software at GPS control stations at Schriever Air Force Base (AFB) in Colorado and Vandenberg AFB in California.
The unit cost of a GPS IIIA satellite is $204.94 million (in 2012).
The GPS constellation provides worldwide positioning, navigation, and precise time to military and civilian users.
FY 12 budget funds will sustain the GPS constellation with the assembly and launch of replenishment satellites. Continues the development and production of the GPS IIIA system (the next generation GPS satellite) as well as development of the ground control system.
Funds in the amount of $492.9 million will purchase two GPS IIIA satellites (SV-5 and SV-6).
Also, FY 13 continues the development of the next generation GPS ground control system GPS OCX.
For more information, click to see the FY 2013 DoD GPS III Budget.
FY 13 also provides funds in the amount of $58.2 million required for Global Positioning System (GPS) Block IIF satellite launch and on-orbit support, including satellite transportation from the factory to the launch site, launch processing and booster integration, launch operations, and on-orbit checkout and operations. For more information, click to see the FY 2013 DoD GPS II Budget.
Source: U.S. Department of Defense (DoD), Lockheed Martin Corp.,
and Raytheon Company
Last Update: February 25, 2013.
By Joakim Kasper Oestergaard (www.kostergaard.com)
Lockheed Martin's GPS Site: GPS Satellite IIIA
Raytheon's GPS Site: OCX Advanced Control System
YouTube: Global Positioning System | YouTube Videos
Brochure: Lockheed Martin GPS IIIA | Brochure
Fact Sheet: Lockheed Martin GPS IIIA | Fact Sheet
Fact Sheet: Raytheon GPS OCX | Fact Sheet
GPS U.S. Defense Budget Charts:
Primary Function: Constellation of satellites that provide navigational data to military and civilian users