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Schlagwörter:
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Zusammenfassung:
Irregularities in the plasma distribution within the Earth's ionosphere are capable of disrupting radio signals transmitted from Global Navigation Satellite Systems (GNSS). These irregularities occur over a variety of spatial scales, from large (several tens of kilometres) down to small (only hundreds of metres). They tend to form predominantly in the high latitude ionosphere, in conjunction with plasma patches and particle precipitation; and in the post-sunset equatorial ionosphere, in conjunction with drifting plasma bubbles. The irregularities are then detectable because they cause temporal fluctuations (or disturbances) in the phase and intensity of satellite radio signals. In particular, radio wave scintillation arises from the propagation through the smaller scale ionospheric irregularities.
GNSS is an important infrastructure infrastructure where such ionospheric irregularities cause degradation in the positioning quality: not only by increasing the positioning error, but by producing outages, as well. This means that applications reliant upon GNSS can be severely affected in the presence of ionospheric irregularities and under adverse space weather conditions. As a result, forecasting and warning is expected to be used to mitigate any disruption to users and applications.
This contribution discusses recent progress in the context of a UK-specific effort, and amongst other tools, in particular aims to compare and contrast different metrics (both novel and traditional) and their potential to enhance measurement and forecasting. The discussion focuses on approaches that are being considered and tested in the framework of the Space Weather Instrumentation, Measurement, Modelling and Risk programme, funded by the UKRI Natural Environment Research Council (NERC).
