1 / 22

Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)

Graphics files in directories: d:<br>icoprojGOCEgraphics* d:<br>icoprojGOCEGranadaIIreportgraphics d:imagesgeo. Gravity Field and Steady-State Ocean Circulation Explorer (GOCE). Issues of Concern. Ice Sheet Melting. Earthquakes &amp; volcanic activities. Thermohaline

raquel
Download Presentation

Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Graphics files in directories: d:\nico\proj\GOCE\graphics\* d:\nico\proj\GOCE\GranadaIIreport\graphics d:\images\geo Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)

  2. Issues of Concern Ice Sheet Melting Earthquakes & volcanic activities Thermohaline ocean circulation & heat transport Sea level change Global unification of height system

  3. International Programme • International Lithosphere Programme (ILP) • Int. Decade of Natural Disaster Reduction (IDNDR) • International Association of Geodesy (IAG) • World Climate Research Programme (WCRP) • - GEWEX • - WOCE/CLIVAR • - GCOS/GOOS • - ACSYS/CLIC • International Geosphere/Biosphere Program (IGBP) • - LOICZ • Intergovernmental Oceanographic Commission (IOC) • - GLOSS Earthquakes and Volcanic Activities Global Unification of Height System Thermohaline Ocean Circulation and Transport of Heat. Ice Sheet Melting Sea Level Change

  4. Research Goals • Solid Earth Physicsanomalous density structure of lithosphere and upper mantle • Oceanographydetermination of dynamic ocean topography • Ice Sheetsimproved knowledge of ice sheet balance • Geodesyunified height systems, “levelling by GPS” • and from the above improved Sea Level Change Studies

  5. Mission Objectives • determine the Earth’s gravity field with an accuracy of • 1 mgal (1 mgal = 10-5 m/s2 ) • determine the geoid (= equipotential surface for a hypothetical ocean at rest) with an accuracy of 1 cm • achieve this at length scales down to L = 100 km • (degree and order 200)

  6. Presentation Outline • Mission Rationale • Science & Application • Mission Design • Performance • Conclusions

  7. Mission Rationale Limitations of Existing Gravity Field Data • terrestrial gravity anomalies • large unsurveyed areas, heterogeneous data, offsets and biases • geoid mapping via satellite altimetry • not acceptable for oceanography • satellite orbit analysis • - only large spatial scales are satisfactory - heterogeneous data • - error correlation

  8. gravdensBGI.gif Mission Rationale Incomplete Data Coverage

  9. ALTIMETRY terrain GEOID geoid_altim2.ppt Mission Rationale Limitation with Satellite Altimetry

  10. egm.bw.eps Mission Rationale Signal Accuracy versus Spatial Scales

  11. Mission Rationale Spaceborne Gravity Field Methods • Satellite-to-Satellite Tracking in High-Low Mode • SST-hl • Satellite-to-Satellite Tracking in Low-Low Mode • SST-ll • Satellite Gravity Gradiometry • SGG

  12. GPS - satellites 3-D accelerometer Earth mass anomaly sst_hl.eps Mission Rationale SST - hl SST - hl

  13. GPS - satellites SST - hl Earth mass anomaly sst_ll.eps Mission Rationale Combined SST - ll and SST - hl SST - ll

  14. GPS - satellites SGG Earth mass anomaly gradiometry.eps Mission Rationale Combined SGG and SST - hl SST - hl

  15. Mission Rationale Gravity Field Satellite Design Criteria • Orbit as low as possible and near polar • Uninterrupted tracking in 3-D • Isolation of gravitational signal • Amplification of gravitational signal by principle of differentiation

  16. Mission Rationale GOCE versus Design Criteria • Orbit altitude 250 km and sun-synchronous (inc.= 96.5˚) • Uninterrupted and 3-D high-low tracking with GPS satellites relative to ground network • Drag-free system and elimination of residual drag common mode rejection • Gravity signal amplification by gradiometry (differential accelerometry) • in addition: all component gradiometer

  17. goce_eqn.jpg Mission Rationale Full Tensor Gradiometer Measurements acceleration differentiation gravity gradient angular acceleration angular velocities

  18. satellit.ppt Mission Rationale Instrument Concept angular forces translational forces * GPS/GLONASS SST -hl star sensors * A B GRAVITY GRADIOMETER measures: GRAVITY GRADIENTS angularaccelerations common mode accelerations angularcontrol dragcontrol

  19. CGG_fill_bw.eps CGG_plainx.eps CGG_overlayx.eps Mission Rationale Uniqueness SGG achieves highest attainable resolution SGG and SST-ll are complementary

  20. vik.bw.eps Mission Rationale The 3-D structure of the Gravity Field

  21. Mission Rationale The 3 -D structure of the Error Coefficient

  22. GIGGOS.doc (.eps) Mission Rationale The Interdisciplinary Research Solid Earth Physics Earth System Model - ocean - ice sheet - lithosphere - mantle - core Geodesy Sea Level Change Cryosphere Oceanography

More Related