First CHAMP Mission Results for Gravity, Magnetic and Atmospheric Studies, 2003

In 1995, the German Space Agency DARA selected the CHAllenging Minisatellite Payload (CHAMP) mission for development under a special support programme for the space industry in the new states of the unified Germany, with the Principal Investigator and his home institution GFZ Potsdam being ultimately responsible for the success of all mission phases. After three years of spacecraft manufactur­ ing and testing, the satellite was injected successfully into its final, near circular, almost polar and low altitude (450 km) orbit from the cosmodrome Plesetsk in Russia on July 15, 2000. After a nine month commissioning period during which all spacecraft systems and instruments were checked, calibrated and validated, the satellite has been delivering an almost uninterrupted flow of science data since May 2001. Since this date, all science data have been made available to the more than 150 selected co-investigator teams around the globe through an international Announcement of Opportunity. The scientific goals of the CHAMP mission are to gain a better understanding of dynamic processes taking place in the Earth's interior and in the space near Earth. These goals can be achieved by improved observation of the Earth's gravity and magnetic fields and their time variability with high-performance on-board instru­ mentation and by exploring the structure of the Earth's atmosphere and ionosphere through radio occultation measurements.

I Orbit and Earth Gravity Field.- CHAMP Orbit and Gravity Instrument Status.- On Board Evaluation of the STAR Accelerometer.- Determination of CHAMP Accelerometer Calibration Parameters.- CHAMP Accelerometer and Star Sensor Data Combination.- CHAMP Clock Error Characterization.- Determination of the CHAMP GPS Antenna with Respect to Satellite’s Mass Center.- Spaceborne GPS for POD and Earth Science.- The CHAMP Orbit Comparison Campaign.- CHAMP Orbit Determination with GPS Phase-Connected, Precise Point Positioning.- Kinematic and Dynamic Determination of Trajectories for Low Earth Satellites Using GPS.- CHAMP Double-Difference Kinematic POD with Ambiguity Resolution.- Approaches to CHAMP Precise Orbit Determination.- STAR Accelerometer Contribution to Dynamic Orbit and Gravity Field Model Adjustment.- Impact of Different Data Combinations on the CHAMP Orbit Determination.- CHAMP Rapid Science Orbit Determination — Status and Future Prospects.- Orbit Predictions for CHAMP — Development and Status.- Thermospheric Events in CHAMP Precise Orbit Determination.- New Global Gravity Field Models from Selected CHAMP Data Sets.- First Insight into Temporal Gravity Variablility from CHAMP.- CHAMP Gravity Field Recovery with the Energy Balance Approach.- Preliminary Analysis of CHAMP State Vector and Accelerometer Data for the Recovery of the Gravity Potential.- CHAMP Precise Orbit Determination and Gravity Field Recovery.- Gravitational Field Modelling from CHAMP-Ephemerides by Harmonic Splines and Fast Multipole Techniques.- Evaluation of Geoid Models with GPS/Levelling Points in Sweden and Finland.- Geophysical Impact of Field Variations.- CHAMP, Mass Displacements and the Earth’s Rotation.- CHAMP Gravity Anomalies over Antarctica.- Assimilation of Altimeter and Geoid Data into a Global Ocean Model.- Total Density Retrieval with STAR.- II Earth Magnetic Field.- CHAMP ME Data Processing and Open Issues.- Ion Drift-Meter Status and Calibration.- CO2 — A CHAMP Magnetic Field Model.- Decadal and Subdecadal Secular Variation of Main Geomagnetic Field.- Modelling the Earth’s Magnetic Field: Wavelet Based and Standard Methods.- Improved Parameterization of External Magnetic Fields from CHAMP Measurements.- Monitoring Magnetospheric Contributions using Ground-Based and Satellite Magnetic Data.- Unraveling the Magnetic Mystery of the Earth’s Lithosphere: The Background and the Role of the CHAMP Mission.- A Comparison of Global Lithospheric Field Models Derived from Satellite Magnetic Data.- Mapping the Lithospheric Magnetic Field from CHAMP Scalar and Vector Magnetic Data.- Improving the Definition of Cratonic Boundaries Utilizing the Lithospheric Magnetic Field derived from CHAMP Observations.- Crustal Magnetisation Distribution Deduced from CHAMP Data.- Multiscale Downward Continuation of CHAMP FGM-Data for Crustal Field Modelling.- CHAMP Enhances Utility of Satellite Magnetic Observations to Augment Near-Surface Magnetic Survey Coverage.- Comparing Magsat, Ørsted and CHAMP Crustal Magnetic Anomaly Data over the Kursk Magnetic Anomaly, Russia.- CHAMP, Ørsted and Magsat Magnetic Anomalies of the Antarctic Lithosphere.- Separation of External Magnetic Signal for Induction Studies.- Two-Dimensional Spatiotemporal Modelling of Satellite Electromagnetic Induction Signals.- Night-Time Ionospheric Currents.- Multiscale Determination of Radial Current Distribution from CHAMP FGM-Data.- Ionospheric Currents from CHAMP Magnetic Field Data — Comparison with Ground Based Measurements.- Mapping of Field-Aligned Current Patterns during Northward IMF.- Field-Aligned Currents Inferred from Low-Altitude Earth-Orbiting Satellites and Ionospheric Currents Inferred from Ground-Based Magnetometers — Do They Render Consistent Results?.- III Neutral Atmosphere and Ionosphere.- GPS Radio Occultation with CHAMP.- Validation and Data Quality of CHAMP Radio Occultation Data.- Global Climate Monitoring based on CHAMP/GPS Radio Occultation Data.- Initial Results on Ionosphere/Plasmasphere Sounding based on GPS Data Obtained On Board CHAMP.- Backpropagation Processing of GPS Radio Occultation Data.- Combination of NOAA16/ATOVS Brightness Temperatures and the CHAMP Data to get Temperature and Humidity Profiles.- An Improvement of Retrieval Techniques for Ionospheric Radio Occultations.- Validation of Water Vapour Profiles from GPS Radio Occultations in the Arctic.- Comparison of DMI-Retrieval of CHAMP Occultation Data with ECMWF.- The Assimilation of Radio Occultation Measurements.- Status of Ionospheric Radio Occultation CHAMP Data Analysis and Validation of Higher Level Data Products.- NWP Model Specific Humidities Compared with CHAMP/GPS and TERRA/MODIS Data.- Analysis of Gravity Waves from Radio Occultation Measurements.- GPS Atmosphere and Ionosphere Methods used on Ørsted Data and Initial Application on CHAMP Data.- Combining Radio Occultation Measurements with Other Instruments to Map the Ionospheric Electron Concentration.- Vertical Gradients of Refractivity in the Mesosphere and Atmosphere Retrieved from GPS/MET and CHAMP Radio Occultation Data.- Observation of Reflected Signals in MIR/GEO and GPS/MET Radio Occultation Missions.- Assimilation Experiments of One-dimensional Variational Analyses with GPS/MET Refractivity.- Monitoring the 3 Dimensional Ionospheric Electron Distribution based on GPS Measurements.- Comparison of Three Different Meteorological Datasets (ECMWF, Met Office and NCEP).- Radio Occultation Data Processing at the COSMIC Data Analysis and Archival Center (CDAAC).- Verification of CHAMP Radio-Occultation Observations in the Ionosphere Using MIDAS.- Approach to the Cross-Validation of MIPAS and CHAMP Temperature and Water Vapour Profiles.- Author Index.- Keyword Index.