Stormy space weather can cause fascinating polar lights in the Earth’s atmosphere but can also damage sensitive electronic systems and solar panels onboard satellites.
In particular solar radiation bursts and Coronal Mass Ejections (CMEs) may perturb density, composition and vertical structure of the ionospheric plasma. Early information on solar wind parameters is obtained from NASA’s ‘Advanced Composition Explorer’ (ACE) spacecraft. DLR Neustrelitz is part of the Real Time Solar Wind (RTSW) monitoring capability of NOAA. The RTSW data are used to provide accurate alerts and warnings of major solar storms with a lead time of about one-hour. The data shall be used to improve forecasts of the ionospheric perturbation degree in near real time.
While travelling through the ionosphere, radio signals are refracted, delayed or scattered. Extreme travel delay may cause range errors of up to 100 metres. Plasma turbulences may cause rapid fluctuations of the signal strength, well known as ionospheric radio scintillations. Radio scintillations occur mostly at high and low latitude regions. During severe space weather events accuracy and safety of GNSS applications may also be impacted at mid-latitude regions such as central Europe.
Correction and/or mitigation of ionospheric propagation effects require the knowledge of the ionosphere state for estimating the impact. Hence, a near real time global monitoring of the ionospheric state and a fast data processing including dissemination of results is required.
Ionospheric “weather maps” are generated in DLR Neustrelitz since GPS became operational in 1995. GPS data were provided via the International GPS service (IGS). Nowadays, global near real time data are obtained via the Real Time Pilot Project of IGS. The derived maps of the total electron content (TEC) of the ionosphere can be used for correcting ionospheric range errors of single frequency GNSS measurements.
DLR operates an own global network of high rate GNSS receivers capable to monitor and process measurements from GPS, GLONASS and Galileo. In addition to ground based measurements also space based data from satellite missions as CHAMP and GRACE contribute to a comprehensive global data basis on the geo-plasma.
Initiated by the former ESA project SWIPPA and the nationally funded project SWACI a number of experiences have been collected for establishing and operating a space weather service focussed on ionospheric issues. Selected data are directly provided to the Space Weather European NETwork (SWENET).
The ‚Ionosphere weather’ services shall provide operators and customers of modern telecommunication and navigation systems newest information on the current and predicted state of regional and global ionospheric conditions for the transionospheric radio link.
For enabling this in highest quality, the comprehensive GNSS data base collected during many years is exploited to study structure and dynamics of the ionosphere. The studies are aiming at developing new monitoring techniques and innovative correction and mitigation tools. To further improve the accuracy in precise GNSS applications down to the sub-centimetre level, a number of studies estimate propagation effects described by higher order terms in the ionospheric refraction index.
Concerning ionospheric perturbations, research is focused on detection, tracing and forecasting of ionospheric perturbations which are closely related to space weather phenomena.