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QOCA related news

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10/24/2007    Recent published paper using QOCA analysis
  • Serpelloni, E.,R. Burgmann, M. Anzidei, P. Baldi, B. Mastrolembo Ventura,and E. Boschi, Strain accumulation across Messina Straits and kinematics of Sicily and Calabria from GPS data and dislocation modeling, ScienseDirect, doi: 10.1016/j.epsl.2010.08.005, 2010.
  • Gan, W. J., P. Zhang, Z. K. Shen, Z. Niu, M. Wang, Y. Wan, D. Zhou and J. Cheng, Present-day crustal motion with the Tibetan Plateau inferred from GPS measurements, J. G. R., 112(B08426), doi:10.1029/2005JB004120, 2007.
  • Serpelloni, E.,G. Vannucci, S. Pondrelli, A. Argnani, G. Casula, M. Anzidei, P. Baldi, and P. Gasperini, Kinematics of the Western Africa-Eurasia plate boundary from focal mechanisms and GPS data, Geophys. J. Int, doi: 10.1111/j.1365-246X.2007.03367, 2007.
  • Calais, E., L. Dong, M. Wang, Z. Shen, and M. Vergnolle, Continental deformation in Asia from a combined GPS solution, Geophys. Res. Lett, 33, L24319, doi:10.1029/2006GL028433, 2006.
  • Stich, D., E. Serpelloni, F. L. Mancilla, and J. Morales, Kinematics of the Iberia-Maghreb plate contact from seismic moment tensors and GPS observations, Tectonophysics, 426, 295-317, 2006.
  • Dong, D., P. Fang, Y. Bock, F. Webb, L. Prawirodirdjo, S. Kedar, and P. Jamason, Spatiotemporal filtering using principal component analysis and Karhunen-Loeve expansion approaches for regional GPS network analysis, J. G. R., 111(B03405), doi:10.1029/2005JB003806, 2006.
  • Miyazaki, S., P. Segall, J. J. McGuire, and T. Kato, Spatial and temporal evolution of stress and slip rate during the 2000 Tokai earthquake, J. G. R., 111(B03409), doi:10.1029/2004JB003426, 2006.

10/30/2005    Published paper using QOCA analysis
  • Hammond, W. C. and W. Thatcher, Northwest Basin and Range tectonic deformation observed with the Global Positioning System, 1999-2003, J. G. R., 110(B10405), doi:10.1029/2005JB003678, 2005.
  • Serpelloni, E., Anzidei, M., Baldi, P., Casula, G. and Galvani, A.,Crustal velocity and strain-rate fields in Italy and surrounding regions: new results from the analysis of permanent and non-permanent GPS networks. Geophysical Journal International 161(3), 861-880. doi:10.1111/j.1365-246X.2005.02618.x, 2005.
  • Hammond, W. C. and W. Thatcher, Contemporary tectonic deformation of the Basin and Range province, western United States: 10 years of observation with the Global Positioning System J. G. R., 109(B08403), doi:10.1029/2003JB002746, 2004.
  • Pondrelli, S., C. Piromallo, and E. Serpelloni, Convergence vs. retreat in Southern Tyrrhenian Sea: Insights from kinematics, Geophys. Res. Lett., 31, L06611, doi:10.1029/2003GL019223, 2004.
  • Pietrantonio, G. and F. Riguzzi, Three-dimensional strain tensor estimation by GPS observations: methodological aspects and geophysical applications, Journal of Geodynamics, 38, 1-18, doi:10.1016/j.jog.2004.02.021, 2004.
  • Savage, J. C., W. Gan, W. H. Prescott, and J. L. Svarc, Strain accumulation across the Coast Ranges at the latitude of San Francisco, 1994-2000 J. G. R., 109(B03413), doi: 10.1029/2003JB002612, 2004
  • Savage, J. C., J. L. Svarc, and W. H. Prescott, Interseismic strain and rotation rate in the northeast Mojave domain, eastern California, J. G. R., 109(B02406), doi: 10.1029/2003JB002705, 2004
  • Savage, J. C., J. L. Svarc, and W. H. Prescott, Near-field postseismic deformation associated with the 1992 Landers and 1999 Hector Mine, California, earthquakes, J. G. R., 108(B9), doi: 10.1029/2002JB002330, 2003
  • Dong, D., Seasonal vertical variations from GPS-derived site position time series, Proceedings of "Workshop on the State of GPS Vertical Positioning Precision: Separation of Earth Processes by Space Geodesy", Luxembourg, 2003
  • Miyazaki, S., J. J. McGuire, and P. Segall, A transient subduction zone slip episode in southwest Japan observed by the nationwide GPS array, J. G. R., 108(B2), doi: 10.1029/2001JB000456, 2003

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.

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.

08/30/2002    Published paper using QOCA analysis
  • Wang, M., Z.K.Shen, et al., Contemporary Crustal Deformation of Chinese Continent and Tectonic Block Model, Science in China(series D), 2002, supp.(in Chinese)
  • Serpelloni E., et al., Combination of permanent and non-permanent GPS networks for the evaluation of the strain-rate field in the central Mediterranean area. In press on Bull. Geof. Theo. Appl., 2002
  • Serpelloni E., et al., Geodetic deformation in the centeral-southern Apennines (Italy) from repeated GPS surveys, Annals of Geophysics 44(3), 627-647, 2001
  • Anzidei M., et al., Insight into present-day crustal motion in the central Mediterranean area from GPS surveys, Geiphys. J. Int. 146, 98-110, 2001

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.

06/30/2002    Published paper using QOCA analysis
  • Zhang, F. P., et al., Seasonal vertical crustal motions in China detected by GPS, Bulletin of Science (in Chinese), 47, #18, 1370-1377, 2002
  • Svarc, J. L., J. C. Savage, W. H. Prescott, and A. R. Ramelli: Strain accumulation and rotation in western Nevada, 1993-2000, J. G. R., 107, B5, ETG 2-1 - ETG 2-11, 2002
  • Svarc, J. L., J. C. Savage, W. H. Prescott, and M. H. Murray: Strain accumulation and rotation in western Oregon and southweatern Washington, J. G. R., 107, B5, ETG 1-1 - ETG 1-7, 2002
  • Dong, D., P. Fang, Y. Bock, M. K. Cheng, and S. Miyazaki: Anatomy of apparent seasonal variations from GPS-derived site position time series, J. G. R., 107, B4, ETG 9-1 - ETG 9-16, 2002
  • Shen et al.: Crustal deformation along the Altyn Tagh fault system, western China, from GPS, J. G. R., 106, 30607-30622, 2001

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.

10/17/2001    Published paper using QOCA analysis
  • Gan, W. and W. H. Prescott: Crustal deformation rates in central and eastern U.S. inferred from GPS, Geophy. Res. Lett., 28, 3733-3736, 2001
  • Savage, J. C., J. L. Svarc, and W. H. Prescott: Strain accumulation near Yucca Mountain, Nevada, 1993-1998, J. G. R., 106, 16483-16488, 2001

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.

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.

05/08/2001    Published paper using QOCA analysis
  • Miyazaki, S. and K. Heki: Crustal velocity field of southwest Japan: subduction and arc-arc collision, J. G. R., 106, 4305-4326, 2001
  • Prescott, W. H., et al.: Deformation across the Pacific-North America plate boundary near San Francisco, California, J. G. R., 106, 6673-6682, 2001

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.

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.

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.

12/26/2000    Published paper using QOCA or FONDA as a tool
  • Gan, W., et al.: Strain accumulation across the Eastern California Shear Zone at latitude 36 30', J. G. R., 105, 16229-16236, 2000
  • Prawirodirdjo, L., et al.: One century of tectonic deformation along the Sumatran fault from triangulation and Global Positioning System surveys, J. G. R., 105, 28343-28361, 2000

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.

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.

04/01/2000    Recent publications which used QOCA analysis
  • Hager, B. H., et al.: Reconciling rapid strain accumulation with deep seismogenic fault planes in the Ventura basin, California, J. G. R., 104, 25207-25219, 1999
  • Savage, J. C., et al.: Deformation across the forearc of the Cascadia subduction zone at Cape Blanco, Oregon, J. G. R., 105, 3095-3102, 2000
  • Shen, Z. K., et al.: Contemporary crustal deformation in east Asia constrained by Global Positioning System measurements, J. G. R., 105, 5721-5734, 2000

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