Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of the National Science Foundation.NASA / JPL ** German Aerospace Center ** German Research Center for Geosciences ** University of Texas Instead, the mission uses a microwave ranging system to accurately measure changes in the speed and distance between two identical spacecraft flying in a polar orbit about 220 kilometers (140 mi) apart, 500 kilometers (310 mi) above Earth. Any errors in the subtracted signals will be present in the residual GRACE groundwater signal.There are a handful of different groups having the expertise to generate gravity field data from the GRACE instrument data, and each dataset is somewhat different depending on the choices made during the data processing.

GPS data of COSMIC and GRACE: potential enhancement from COSMIC-2’s GPS and SLR data Cheinway Hwang 1, Shin-Fa Lin1,2, Yan-Ti Chen , Tzu-Pang Tseng3, and B. F. Chao4 1Dept of Civil Engineering, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan 2National Space Organization, 9 Prosperity 1st Road, Hsinchu, Taiwan 3GPS Science and Application … Launched 17 March 2002, Gravity Recovery and Climate Experiment (GRACE) twin satelliteshe Gravity Recovery and Climate Experiment (GRACE) twin satellites made detailed measurements of Earth's gravity field and improved investigations about Earth's water reservoirs, over land, ice and oceans. This results in an underestimation of errors in the data.##Swenson, Sean & National Center for Atmospheric Research Staff (Eds). The satellites were separated by 220 km and could detect changes smaller than a micrometer per second in relative velocity. h�bbd```b``�� �� �d� �OA��*�T~&�A�j �dT�b�l�5{��)�M ���DJ��H�) Rc��+�����^F����f�0 j�W GRACE measured gravity by relating it to the distance between the twin satellites. Therefore, it was decided in mid-October to decommission the GRACE-2 satellite and end GRACE's science mission.The GRACE-FO mission, a collaboration between NASA and The orbit and design of GRACE-FO is very similar to its predecessor.The GRACE-FO satellites obtain electricity from gallium arsenide solar cell array panels covering the outside of each satellite.GRACE-FO will continue to monitor Earth's gravity and climate. GPS Data • GRACE data are generated from degree-2 and higher Stokes Coefficients, i.e. This is particularly important for … The GRACE and GPS derived results show that significant seasonal variations occur at 40 regional continuous GPS stations of the Crustal Movement Observation Network of China (CMONOC). The key partners were the University of Texas Center for Space Research (CSR), the GeoForschungsZentrum (GFZ) Potsdam, and the Jet Propulsion Laboratory (JPL).GRACE measured gravity by relating it to the distance between the twin satellites. These datasets contain much less measurement error, and appear quite clean. snow or groundwater, one must use independent data to remove the other components of the mass budget. no reference frame • to make the GPS data consistent with the GRACE data, we need to remove the degree-1 terms from the GPS data (or add degree-1 terms to the GRACE data) • we use the GRACE+ocean model degree-1 [Swenson et al., 2008] to determine degree-1 displacements at each GPS … The satellites use a precise microwave ranging system to measure the distance between themselves due to gravitational acceleration. 6 shows the correction maps with a res- olution of 1 1 in an antenna-fixed coordinate system. endstream endobj startxref Various types of observations, such as space-borne Global positioning system (GPS) code and phase data, accelerometer data, K-band range and range-rate data, and ground-based satellite laser ranging data of the CHAllenging Minisatellite Payload (CHAMP) and GRAvity Climate Experiment (GRACE) satellite missions, are used together with ground-based GPS code and phase data … 123 0 obj <>/Filter/FlateDecode/ID[<2A5CF04A5F5D795B02A07E508BD5EF2A><8994E1A157B6B54A8F0366967140EF85>]/Index[103 40]/Info 102 0 R/Length 104/Prev 2383578/Root 104 0 R/Size 143/Type/XRef/W[1 3 1]>>stream To use GRACE to constrain a subset of the vertical mass budget, e.g.

What are some of the strategies for making optimal use of these data?GRACE is sensitive to *all* mass changes, and thus measures the vertically integrated change in mass. Perhaps the biggest differences are apparent in the "constrained" or regularized solutions, in which the filtering is applied during the gravity field determination step. The monthly gravity anomalies maps generated by GRACE are up to 1,000 times more accurate than previous maps, substantially improving the accuracy of many techniques used by GRACE chiefly detected changes in the distribution of water across the planet. %%EOF