10/24/2007 Recent published paper using QOCA analysis
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10/30/2005 Published paper using QOCA analysis
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04/06/2003 Air Force Rocket Puts GPS Satellite Into Space CAPE CANAVERAL - An Air Force Boeing Delta 2 rocket carried a Global Positioning System satellite into orbit last week to replace a 13-year-old model that sometimes goes off-line. The satellite joins a GPS network that lets military ships, planes and ground-based personnel, as well as civilians, determine their position with near-pinpoint accuracy anywhere in the world. |
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02/23/2003 First GPS satellite launched 25 years ago The launching of the first Block I Navstar GPS satellite from Vandenberg AFB, Calif., Feb. 22, 1978, marked a quiet revolution in technology. |
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08/30/2002 Published paper using QOCA analysis
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08/12/2002 US allies building their own global positioning system A planned fleet of 30 satellites dedicated to the broadcast of positioning data, Galileo promises to be an updated European equivalent to the familiar US Global Positioning System. Beginning in 2008, Galileo will supplement and improve on the accuracy of existing GPS satellites, serving consumers around the world. In short, Europeans will pay for a new network, while Americans, who use satellite positioning services more than most, will benefit. |
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06/30/2002 Published paper using QOCA analysis
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10/22/2001 Pentagon Denies GPS to Taliban WASHINGTON -- The Pentagon said on Friday that it won't limit the accuracy of positioning information that's beamed to civilian global positioning system (GPS) receivers. The government claims it "now provides civil users a horizontal positioning accuracy of 36 meters, compared to 100-meter accuracy" in the 1995 standard. But as the military campaign against Afghanistan enters its third week, the Defense Department could take steps to limit the usefulness of GPS receivers in the hands of Taliban forces. "We have demonstrated the ability to selectively deny GPS signals on a regional basis, particularly ... when our national security is threatened," said Lt. Jeremy Eggers, a spokesman at Schriever Air Force Base in Colorado. |
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10/17/2001 Published paper using QOCA analysis
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07/13/2001 World most precise clock created (Reuters) Scientists at the National Institute of Standards and Technology in Boulder, Colo., developed a new type of atomic clock that produces about 1 quadrillion "ticks" per second and promises to be far more accurate than the current top standard in time measurement -- cesium-based microwave atomic clocks. |
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05/21/2001 GPS 2R-8 (SVN-45) Launch Postponed The planned launch of SVN-45 (IIR-8) on 16 August 2001 was canceled. Reducing the number of IIR launches now improves the chances of modifying more of the IIR satellites to include a second civil signal on L2 and M-Code on L1 and L2. A GPS IIR satellite is kept at Cape Canaveral at all times to support an emergency launch. An emergency launch is theoretically possible within 60-days of call-up. Of the 28 operational satellites, those that have exhibited performance problems have been positioned to minimize the impact of a failure. |
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05/08/2001 Published paper using QOCA analysis
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02/15/2001 What is WAAS? In order to meet the strict requirements for commercial aircraft navigation the FAA has developed the Wide Area Augmentation System or WAAS. WAAS is a safety-critical navigation system that will provide a quality of positioning information never before available to the aviation community. It is what the name implies, a geographically expansive augmentation to the basic GPS service. The WAAS improves the accuracy, integrity, and availability of the basic GPS signals. This system will allow GPS to be used as a primary means of navigation for enroute travel and non-precision approaches in the U.S., as well as for Category I approaches to selected airports throughout the nation. The wide area of coverage for this system includes the entire United States and some outlying areas such as Canada and Mexico. |
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01/29/2001 NASA's GDGPS (GPSWorld) The National Aeronautics and Space Administration (NASA) is implementing a new Global Differential GPS (GDGPS) system, developed by Jet Propulsion Laboratory (JPL), that provides seamless global real-time positioning at sub-20-cm vertical accuracy and sub-10-cm horizontal accuracy for dual frequency GPS receivers. Such accuracy has previously been available only on a selected local basis, through real-time kinematic (RTK) techniques, which have enabled decimeter-level (and better) real-time GPS-based positioning on a few kilometers local scale. |
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01/06/2001 New GPS M-code being developed The Air Force is developing a new military GPS signal -- called M-code -- at both frequencies (LI and L2) that fits within the currently registered bandwidth, but concentrates most of the energy away from the current civil signal and military signals. M-code enhancements will be made to both Blocks IIRs and IIFs, according to Col. Allan Ballenger, acting deputy director of the NAVSTAR GPS joint program office. |
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12/26/2000 Published paper using QOCA or FONDA as a tool
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05/17/2000 Improvements in GPS performance (Business Wire)Rand McNally, the leading global provider of geographic and travel information, announced today that testing on the company's new Global Positioning System (GPS) hardware has revealed a significant improvement in accuracy since President Clinton recently ordered the military to stop scrambling the satellite signals that power the system. According to the tests, 95 percent of the time GPS users can now expect accuracy to be within 10 meters, instead of the 100 meters prior to Clinton's edict. |
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05/01/2000 SA is gone At midnight of May 1, 2000, the US stopped jamming GPS signals for civilian users, allowing drivers, pilots, skiiers, etc., to get the same level of accuracy as the Pentagon does. |
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04/01/2000 Recent publications which used QOCA analysis
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Created by Danan Dong and maintained by Da Kuang for
Geodynamics and Space Geodesy Group
email: dakuang@jpl.nasa.gov tel:(818)354-8332
03/30/2000