The lAG International Symposium on Gravity, Geoid, and Space Missions 2004 (GGSM2004) was lield in the beautiful city of Porto, Portugal, from 30 August to 3 September 2004. This symposium encompassed the themes of Commission 2 (Gravity Field) of the newly structured lAG, as well as interdisciplinary topics related to geoid and gravity modeling, with special attention given to the current and planned gravi- dedicated satellite missions. The symposium also followed in the tradition of mid-term meetings that were held between the quadrennial joint meetings of the International Geoid and Gravity Commissions. The previous mid-term meetings were the International Symposia on Gravity, Geoid, and Marine Geodesy (Tokyo, 1996), and Gravity, Geoid, and Geodynamics (Banff, 2000). GGSM2004 aimed to bring together scientists from different areas in the geosciences, working with gravity and geoid related problems, both from the theoretical and practical points of view. Topics of interest included the integration of heterogeneous data and contributions from satellite and airborne techniques to the study of the spatial and temporal variations of the gravity field. In addition to the special focus on the CHAMP, GRACE, and GOCE satellite missions, attention was also directed toward projects addressing topographic and ice field mapping using SAR, LIDAR, and laser altimetry, as well as missions and studies related to planetary geodesy.
Table of ContentsSession 1.- Initial results from retracking and reprocessing the ERS-1 geodetic mission altimetry for gravity field purposes.- Space-borne gravimetry: determination of the time variable gravity field.- Satellite clusters for future gravity field missions.- A Preliminary Gravitational Model to Degree 2160.- Stochastic model validation of satellite gravity data: A test with CHAMP pseudo-observations.- Analysis of J2-Perturbed Relative Orbits for Satellite Formation Flying.- GOCE Gravity Field Processing.- GRACE Gradiometer.- Modelling the Earth’s gravity field using wavelet frames.- Numerical Velocity Determination and Calibration Methods for champ Using the Energy Balance Approach.- Upward Continuation of Ground Data for GOCE Calibration/Validation Purposes.- Global Gravity Field Solutions Based on a Simulation Scenario of GRACE SST Data and Regional Refinements by GOCE SGG Observations.- Effect of geopotential model errors on the projection of GOCE gradiometer observables.- Comparison of some robust parameter estimation techniques for outlier analysis applied to simulated GOCE mission data.- Comparison of outlier detection algorithms for GOCE gravity gradients.- Using the EIGEN-GRACE02S Gravity Field to Investigate Defectiveness of Marine Gravity Data.- Determination of gravity gradients from terrestrial gravity data for calibration and validation of gradiometric GOCE data.- Session 2.- Evaluation of Airborne Gravimetry Integrating GNSS and Strapdown INS Observations.- Network Approach versus State-space Approach for Strapdown Inertial Kinematic Gravimetry.- The Airborne Gravimeter Chekan-A at the Institute of Flight Guidance (IFF).- Numerical investigation of downward continuation methods for airborne gravity data.- Session 3.- Status of the European Gravity and Geoid Project EGGP.- Merging a Gravimetric Model of the Geoid with GPS/Levelling data : an Example in Belgium.- The Antarctic Geoid Project: Status Report and Next Activities.- First Results from new High-precision Measurements of Deflections of the Vertical in Switzerland.- Error Propagation with Geographic Specificity for Very High Degree Geopotential Models.- Gravity Data Base Generation and Geoid Model Estimation Using Heterogeneous Data.- A new strategy for processing airborne gravity data.- Multiresolution representation of a regional geoid from satellite and terrestrial gravity data.- A Study on Two-boundary Problems in Airborne Gravimetry and Satellite Gradiometry.- Local Geoid Computation by the Spectral Combination Method.- On the incorporation of sea surface topography in establishing vertical control.- A New Gravimetric Geoidal Height Model over Norway Computed by the Least-Squares Modification Parameters.- On the Accuracy of Vertical Deflection Measurements Using the High-Precision Digital Zenith Camera System TZK2-D.- TERRA: A feasibility study on local geoid determination in Bolivia with strapdown inertial airborne gravimetry.- Artificial Neural Network: A Powerful Tool for Predicting Gravity Anomaly from Sparse Data.- Session 4.- Photon Counting Airborne Laser Swath Mapping (PC-ALSM).- Evaluation of SRTM3 and GTOPO30 Terrain Data in Germany.- Multiscale Estimation of Terrain Complexity Using ALSM Point Data on Variable Resolution Grids.- Session 5.- A comparison of different isostatic models applied to satellite gravity gradiometry.- Session 6.- Spectral Analysis of Mean Dynamic Ocean Topography From the GRACE GGM01 Geoid.- Interannual to decadal sea level change in south-western Europe from satellite altimetry and in-situ measurements.- Space-time analysis of sea level in the North Atlantic from TOPEX/Poseidon satellite altimetry.- Mean Sea Level and Sea Level Variation Studies in the Black Sea and the Aegean.- Modelling Future Sea-level Change under Green-house Warming Scenarios with an Earth System Model of Intermediate Complexity.- Crossover Adjustment of New Zealand Marine Gravity Data, and Comparisons with Satellite Altimetry and Global Geopotential Models.- Session 7.- Results of the International Comparison of Absolute Gravimeters in Walferdange (Luxembourg) of November 2003.- A New Small Cam-Driven Absolute Gravimeter.- Absolute Gravity Measurements in Australia and Syowa Station, Antarctica.- Unified European Gravity Reference Network 2002 (UEGN02) Status 2004.- Determination of gravity anomalies from torsion balance measurements.- Session 8.- Decadal Ocean Bottom Pressure Variability and its Associated Gravitational Effects in a Coupled Ocean- Atmosphere Model.- Gravity Changes in the Fennoscandian Uplift Area to be Observed by GRACE and Absolute Gravimetry.- Recovery of global time-variations of surface water mass by GRACE geoid inversion.- Seasonal Gravity Field Variations from GRACE and Hydrological Models.- Mass redistribution from global GPS timeseries and GRACE gravity fields: inversion issues.- The Fennoscandian Land Uplift Gravity Lines 1966–2003.- Temporal Gravity Variations in GOCE Gradiometric Data.- Estimating GRACE Aliasing Errors.- Methods to Study Co-seismic Deformations Detectable by Satellite Gravity Mission GRACE.- The gradiometric-geodynamic boundary value problem.- Relation between the geological conditions and vertical surface movements in the Pannonian basin.- Modelling gravity gradient variation due to water mass fluctuations.