About the Potential of GPS Radio Occultation Measurements for Exploring the Ionosphere

The GPS radio occultation technique onboard LEO satellites such as CHAMP is a rather simple and relatively inexpensive tool for profiling the ionospheric electron density from satellite orbit heights down to the bottomside. The paper addresses capabilities of the ionospheric radio occultation (IRO) technique for globally monitoring the ionosphere on a routine basis to derive value added data products and study various ionospheric processes including perturbations. A model assisted retrieval technique, operational data processing and validation of vertical electron density profiles are also discussed. These profiles may not only be used to validate ionospheric models, they provide also a good data basis for developing new models of key ionospheric parameters such as the critical frequency foF2, the peak height hmF2 and the scale height Hs. Such models are helpful to improve retrieval procedures and tomographic reconstruction techniques. Due to the operational data processing capabilities the data products may contribute to space weather monitoring.