Internal Vision of GGOS Markus Rothacher GFZ Potsdam GGOS Retreat DGFI in Munich February 15-16, 2006
Contents Motivation Four Levels of Products of the IAG Services: First Level: Raw Data Collection Second Level: Three Pillars of Geodesy Third Level: Integration/Combination Fourth Level: Modeling/Interpretation Conclusions
Motivation Helplessness in the face of natural disasters demonstrates that our knowledge of the Earth s complex system is rather limited.
Eruption of Mount St. Helens: 18.05.1980
Earthquake in Kobe (Japan): 17.01.1995
Tsunami in Sumatra: 26.12.2004 Image before the catastrophy Image after the catastrophy 1 km Indonesia: Banda Aceh Source: DLR
Floods in New Orleans: 30.08.2005 1 km Elbe floods in August 2003
Motivation Helplessness in the face of natural disasters demonstrates that our knowledge of the Earth s complex system is rather limited. Deeper insight into the processes and interactions within this system is one of the most urgent challenges for our society. To monitor changes in the Earth system and the processes causing natural disasters a global Earth observing system has to be established. The geodetic contribution is GGOS. The space geodetic techniques (VLBI, SLR/LLR, GNSS, DORIS), altimetry, InSAR, gravity missions, in-situ measurements etc. allow the monitoring of the Earth system with an unprecedented accuracy (10-9).
Measuring and Modeling the Earth s System Measuring Geometry Space Geodetic C O M B I N A T I O N VLBI SLR/LLR I Sun/Moon N T (Planets) E Atmosphere R A Ocean C T Hydrosphere I O Cryosphere N S Core Earth Rotation GNSS Precession/Nutation, Polar Motion, UT1, LOD DORIS Altimetry InSAR Gravity Gravity Missions Geocenter Gravity field, Temporal variations Terrestrial Techniques Abs./Rel. Earth System Station Position/Motion, Sea Level Change, Deformation Techniques Levelling Information about Earth System Observation Modelling Mantle Influence / Modelling Crust
First Level: Raw Data Collection Guarantee the infrastructure of a GGOS over decades (VLBI, SLR/LLR, GNSS, ), improve coverage, stability Continuous monitoring of the Earth from space with satellite missions (altimetry, gravity, atmosphere, ) Work towards real-time or near real-time data flow and monitoring (e.g., 10-50 Hz GPS data) for early warning systems etc.; pulsating Planet Earth Complement the space geodetic techniques with groundbased and in-situ measurements (regional densification, validation, ). Many geo-hazard phenomena are local or regional (volcanoes, Earthquakes, land slides, tsunamis, floods, ) Develop the necessary data flow, data access and management structures (huge amount of data, fast turn around, )
Satellite Missions Relevant to GGOS Mission Type CHAMP Gravity/ magnetic field/ atmosphere GRACE Gravity (static+ temporal), 2002 2010 GOCE atmosphere Gravity (stationary, high-resolution) 2007 2009 TOPE-POSEIDON Ocean altimetry 1992 2005 Jason-1 Ocean altimetry 2001 2008 ICESAT Ice altimetry 2003 2008 CRYOSAT 2 Ice altimetry 2009 2013??? ERS-2 Altimetry/ climate/ environment 1995 2007 ENVISAT Altimetry/ climate/ environment 2002 2008 TerraSAR- SAR/ InSAR/ atmosphere 2006 2011 SWARM Magnetic field 2009 2014 LAGEOS-1 & 2 Reference system, gravity 1975 - open GPS/GLONASS Navigation/ positioning, orbits, time 1978 - open GALILEO transfer/ Earth rotation, Navigation/ positioning, Mission Duration 2000 2008 2010 - open
Vision of the Future: Pulsating Planet Earth Dense GPS networks everywhere on the Earth (Japan, Plate Boundary Observatory, Europe, ) GPS data processed in realtime with 10-50 Hz GPS seismology Monitoring of the pulsating Planet Earth Courtesy of GSI Japan
Second Level: Three Pillars of GGOS GEOM ETRY GPS, Altimetry, INSAR Remote Sensing Leveling Sea Level REFERENCE SYSTEM S VLBI, SLR, LLR, GPS, DORIS EARTH ROTATION GRAVITY FIELD VLBI, SLR, LLR, GPS, DORIS Classical: Astronomy New: Ringlasers, Gyros Orbit Analysis Satellite Gradiometry Ship-& Airborne Gravimetry Absolute Gravimetry Gravity Field Determination
Second Level: Three Pillars of GGOS Processing of the space geodetic data with an accuracy of a few times 10-10 for all three pillars and a high temporal and spatial resolution Real-time processing of global data Full reprocessing capability for all space geodetic data (VLBI, SLR, DORIS, GNSS, LEOs, ) Consistency between the pillars Operational InSAR and altimetry products for monitoring of the Earth system (volcanoes, land slides, tsunamis, )
Homogeneous Reprocessing of the Global GPS Data Ocean loading, better reference frame Improved ambiguity resolution
Advanced Modeling: Higher-Order Ionosphere Terms Differences with and without higher-order ionosphere terms
Third Level: Integration/Combination Higher and higher level of combination: Site coordinates Site coordinates + Earth orientation parameters Site coordinates + EOPs + troposphere Site coordinates + EOPs + troposphere + gravity field Software Packages capable to process all space geodetic techniques on the observation level, also including LEO data, K-band, altimetry, Combination of InSAR and altimetry with other techniques Full consistency in all the modeling, standards and parameterizations GGOS high-level portal with easy access to all products for all Earth sciences and policy makers (e.g. like Google Earth)
Present and Future Combination Parameter space for a rigorous combination: Parameter Type Atmosphere () () DORIS/ PRARE SLR LLR () () Altimetry () Gravity Field ITRF GPS/ GLON. Earth Rotation ICRF Quasar Coord. (ICRF) Nutation Polar Motion UT1 Length of Day (LOD) Coord.+Veloc.(ITRF) Geocenter Gravity Field Orbits LEO Orbits Ionosphere Troposphere Time/Freq.; Clocks VLBI ()
Present and Future Combination Parameter space for a rigorous combination: Parameter Type Atmosphere () () DORIS/ PRARE SLR LLR () () Altimetry () Gravity Field ITRF GPS/ GLON. Earth Rotation ICRF Quasar Coord. (ICRF) Nutation Polar Motion UT1 Length of Day (LOD) Coord.+Veloc.(ITRF) Geocenter Gravity Field Orbits LEO Orbits Ionosphere Troposphere Time/Freq.; Clocks VLBI ()
Vision 2010: Intergation of 4 Levels into a GGOS 2010: ca. 40 Low Earth Orbiters (LEO) ca. 600 radio sources CHAMP, GRACE-A/B, GOCE 2010: T/P, ERS-1/2, Jason-1, Jason-2, Icesat, Envisat GPS/MET, OERSTED, SAC-C 6 COSMIC, 3 SWARM Dense GPS networks: ca. 10 000 stations 2010: 1200satellites Japan 20 SLR Satellite 1000 Plate Observatory 90constellations MEO Boundary and GEO satellites 2010: ca. Europe GPS 29400 Switzerland GALILEO 30 29 100GLONASS Hz, near real-time 24 3 ZQSS Augmentation systems (GEO)
Fourth Level: Modeling/Interpretation Link the global time series of geodetic parameters to the relevant geophysical models Take into account the relationships between deformation, variations in Earth rotation and gravity field changes (e.g. loading, mass transport, ) Development of comprehensive, numerical Earth models including the interaction between the components of the Earth system Models with the capability to assimilate all space geodetic data and a lot of other geophysical and geoscience data (e.g., on global geophysical fluids) Couple models from oceanography, atmosphere, solid Earth, Highly interdisciplinary task, very challenging
Modeling and Interpretation GEOSPHERE KINEM ATICS OF POINTS Coordinates Velocities ATM OSPHERE Wind, Pressure Distribution HYDROSPHERE Ocean Currents, Ground Water CRYOSPHERE Melting of Pole Caps, Glaciers BIOSPHERE? Geodetic Parameters Geophysical Processes Plate Tectonics, Subduction,Convection,Earth s Core EARTH ROTATION VARIATIONS Polar Motion, UT1 VARIATIONS OF THE EARTH S GRAVITY FIELD Potential Coefficients Change in Vegetation
GGOS: A Huge Task Thank you for your attention!