Inhaltsbereich
Global atmospheric data from CHAMP and GRACE
NRT-RO
Near-Real Time - Radio Occultation Project: Logo
The research project NRT-RO was funded within the GEOTECHNOLOGIEN programme of BMBF (2005-2008). Contact person is Dr. Jens Wickert.
The primary objective of the proposed research project is the development of a processing system for the derivation of global atmospheric data from remotely-sensed atmospheric measurements from CHAMP and GRACE in near-real-time and their application for the improvement of global numerical weather predictions. Hereby the GPS (Global Positioning System) radio occultation is applied, an innovative geotechnology for remote sensing of the Earth’s atmosphere.
The developed system will be transferred to an operational mode. The use of an appropriate ground infrastructure (Polar satellite receiving station, global GPS ground network) for the provision of the necessary satellite and ground data allows in combination with the developed system a provision of atmospheric data according to the timing requirements of global weather forecast centers in near-real-time. The GPS radio occultation data will be assimilated in real numerical weather predictions of various centers for the first world-wide. Detailed results regarding the impact of the occultation measurements on the quality of the forecasts are expected. Components of this infrastructure (Global and low latency GPS ground network, orbit processing system) are also elements for the scientific CHAMP and GRACE data analysis related to the derivation of properties of the Earth’s gravity field. The entire infrastructure with its elements can also be regarded as a component of a Global Geodetic Observing Systems (GGOS) for monitoring and understanding of geodetic and geodynamic processes and the global change.
In addition a specific practical application of GGOS for the exploration of the “System Earth“ will be demonstrated. Not only the impact of GPS occultation data on the quality of global numerical weather forecasts will be investigated but also it is planned to use them for the improvement of real numerical weather forecasts. Hereby first results of the impact of a small multi-satellite configuration consisting of the CHAMP and GRACE satellites on the Numerical Weather Prediction (NWP) quality are expected.
The main tasks within the proposed project are:
- Development, extension and operation of the necessary ground infrastructure (Polar satellite receiving station, global low-latency GPS ground network, operational satellite orbit and atmospheric processing systems) for CHAMP and GRACE for rapid and continuous provision of GPS radio occultation data with an average delay of 1,5 h between measurement and provision of atmospheric information on a global scale.
- Development of methods and algorithms for the provision of rapid and precise satellite orbits and orbit predictions and for the derivation of precise atmospheric data in near-real-time. Integration of these methods to automated processing systems and transfer to operational mode.
- Development, testing and application of methods for the assimilation of GPS occultation measurements into global NWP models. Operational assimilation of CHAMP and GRACE data into global numerical weather forecasts. Evaluation of the impact of GPS radio occultation data on the quality of the forecasts.