Combined gravity field model EIGEN-6C2 complete to degree and order 1949 from GOCE, GRACE, LAGEOS and surface gravity data, released on December 10, 2012.All of these models can be downloaded from the ICGEM data base at GFZ. A list of available EIGEN models is given below. long-term mean, satellite-only (from combination of GOCE, GRACE, CHAMP and/or LAGEOS tracking data) as well as combined (with terrestrial gravity data) so-called EIGEN (European Improved Gravity model of the Earth by New techniques) gravity field models. Weekly models are only available for releases 04 and 05 and can be downloaded from the ISDC archive.Īdditionally, GFZ – in cooperation with GRGS – derives static, i.e. They offer an increased resolution in time at the expense of decreased resolution in space. Weekly time-series of gravity field models are derived by solving subsets (aligned to GPS weeks) of the monthly normal equation systems. Detailed information about the current release (GFZ RL05) can be found here. Monthly time-series of gravity field models are available for releases 01 till 05. Here you can also find the monthly GRACE SDS newsletter which provides an up to date status of available Level-1 and Level-2 products of the GRACE Science Data System. Different time-series for different releases (along with helpful documentation) are available at the two GRACE archives ISDC and PODAAC. as sets of spherical harmonic coefficients representing the Earth’s potential field for a dedicated time-period. GFZ’s monthly and weekly time-variable GRACE gravity field models are freely distributed in the form of GRACE Level-2 products, i.e. Time-variable gravity field models on monthly and weekly basis These profiles have been operationally (24/7) provided to various numerical weather services. The secondary science objective of the GRACE mission was to obtain about 150 very precise globally distributed vertical temperature and humidity profiles of the atmosphere per day using the GPS radio occultation technique. GRACE has lasted three times as long as originally planned for more than 15 years, but came to an end in October 2017 due to battery problems and running out of fuel. in more than 1700 publications in international peer-reviewed journals or more than 5500 registered users at the GRACE archive ISDC (Information System and Data Center). Thus, during more than 15 years of mission operations GRACE has essentially contributed to a better understanding of system Earth. These measurements are directly coupled to the seasonal and sub-seasonal variations in the continental hydrological cycle, to ice mass loss in the large glacier systems in Greenland or Antarctica, to sea level rise, to long wavelength ocean circulation processes or to the transport of ocean heat to Earth’s poles. Additionally, the twin satellites were interconnected by a K-band microwave link to measure the exact separation distance and its rate of change to an accuracy of better than 0.1 µm/s. The position and velocity of the satellites were measured using onboard GPS antennae and (for validation purposes) SLR retro-reflectors. To consider precise attitude and non-gravitational forces both satellites were equipped with star cameras and accelerometers. The increase in accuracy has been achieved by utilizing two satellites following each other on the same orbital track. The primary science objective of the GRACE mission was to measure the Earth’s gravity field and it’s time variability with unprecedented accuracy. Project management and systems engineering activities are carried out by JPL. Co -Principal Investigator of the mission was Dr. Byron Tapley (UTCSR) and his team are ultimately responsible for developing the flight mission hardware from selection to a launch-ready condition, for accomplishing the scientific objectives and delivering the proposed measurements to the broader Earth science community and general public as expediently as possible. As an innovation, the Principal Investigator Prof. GRACE was selected in 1997 as second mission in NASA's Earth System Science Pathfinder ( ESSP ) program. The mission has been proposed in 1996 jointly by the University of Texas at Austin, Center for Space Research ( UTCSR ), the German Research Centre for Geosciences ( GFZ ) and the Jet Propulsion Laboratories (JPL) in Pasadena. GRACE was a joint project between the National Aeronautics and Space Administration ( NASA ) and the Deutsches Zentrum für Luft- und Raumfahrt ( DLR ). Data, Products, Services GFZ Publications.Transfer and Innovation Sustainability at GFZ Central Workshop.Education and Training Events Archive Earth System Knowledge Platform.Collection of geoscientific experiments.
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