Inhalt des Dokuments
Climatological and Space Weather related features of the Ionosphere
- Illustration of the German geoscience satellite CHAMP applying the radio occultation technique to analyze the earth’s atmosphere.
- © S. Kamal (DLR) base on picture from NASA/NOAA
Fakultät VI - Planen Bauen Umwelt, Technischen Universität Berlin
The ionosphere is the ionized part of the earth’s upper atmosphere, ranging from approximately 60 km to 1000 km height. Due to its electrical conductivity, the ionosphere influences the terrestrial and trans-ionospheric propagation of radio waves. This in turn has an effect on radio communication as well as satellite based navigation.
Radio occultation (RO) is one of the most effective space based remote-sensing techniques for exploring planetary atmospheres. By tracking the signals of Global Navigation Satellite Systems (GNSS), such as GPS, GLONASS, Galileo or BeiDou from low earth orbiting (LEO) satellites in limb-viewing geometry, it enables a continuous and global monitoring of the earth's ionosphere and neutral atmosphere.
The state of the ionosphere is affected by several geophysical properties. For example, particle precipitation of magnetospheric origin causes an additional ionization of the ionosphere in the auroral zone at E-layer heights. This significantly affects high frequency (HF) signal propagation. Electron density profiles, derived from GNSS based ionospheric radio occultation (IRO) measurements in the polar region sometimes have their maximum density at E-layer height. Such an ionization structure is called E-layer dominated ionosphere (ELDI) as introduced in . In the project, climatological and space weather related characteristics, such as geophysical conditions and spatio-temporal distributions of ELDI-related ionospheric processes as well as high-latitude ionospheric disturbances will be evaluated. Therefore, space-based IRO measurements aboard LEO satellites will be used in coordination with ground-based ionospheric measurements from ionosondes and EISCAT radars. The findings will serve as the basis for the development of an empirical model to describe ELDI properties which will be integrated into the Neustrelitz Electron Density Model (NEDM).
This project runs in cooperation with the German Aerospace Center (DLR) in Neustrelitz: https://www.dlr.de/dlr/desktopdefault.aspx/tabid-10260 
 Mayer, C. and N. Jakowski, Enhanced E layer Ionization in the Auroral Zones Observed by Radio Occultation Measurements Onboard CHAMP and Formosat-3/COSMIC, Annales Geophysicae, 27, 1207-1212, 2009