SWACI is a research project of DLR supported by the State Government of Mecklenburg-Vorpommern. Radio signals, transmitted by modern communication and navigation systems may be heavily disturbed by space weather hazards. Thus, severe temporal and spatial changes of the electron density in the ionosphere may significantly degrade the signal quality of various radio systems which even may lead to a complete loss of the signal. By providing specific space weather information, in particular now- and forecast of the ionospheric state, the accuracy and reliability of impacted communication and navigation systems shall be improved.

Small scale irregularities of the ionospheric plasma may cause fluctuations of the signal strength of radio waves. The S4-Index is a measure to describe the amplitude- respectively the intensity fluctuations of a signal. The σφ-Index, describes the behaviour of carrier phase fluctuations. Both indices are calculated over a one minute interval.

DLR’s high rate GNSS measurement network ranges from auroral to equatorial latitudes. The measurements are provided in near real time by DLR’s Experimentation and Verification Network (EVnet) [Noack et al., 2004, 2005]. We thank the hosting institutes for supplying the required infrastructure.