Effects of the upper atmosphere on terrestrial and Earth–space communications: Final results of the EU COST 271 Action

Project “Effects of the Upper Atmosphere on Terrestrial and Earth–Space Communications (EACOSs)” was inaugurated as a four-year 271 Action in the Telecommunications and Information Science and Technology domain of the EU COST (Co-operation in the Field of Scientific and Technical Research) in October 2000. It followed two previous successful Actions COST 238 on PRIME (Prediction and Retrospective Ionospheric Modelling over Europe) and COST 251 on IITS (Improved Quality of Service in Ionospheric Telecommunication Systems Planning and Operation). The COST 271 Action (EACOS) has been oriented towards: (i) collection of new ionospheric and plasmaspheric data for now-casting and forecasting purposes, (ii) development of methods and algorithms to predict and to minimise the effects of plasmaspheric–ionospheric perturbations and variations on communications; (iii) perform studies that influence the technical development and the implementation of new communication services, particularly for the GNSS and other advanced Earth–space and satellite-to-satellite applications; and (iv) dissemination and correlation of results, ideas and information which will provide a valuable support to European research centres and industry.This paper reviews the main results achieved in the COST 271 Action concerning in particular a range of the ionospheric space weather issues, specifically: now-casting, forecasting and warning tools, methods and supporting databases for ionospheric propagation prediction; total electron content variations and their use in the reconstruction of plasmaspheric–ionospheric structures as a key parameter for navigation error in GNSS applications and effects of planetary and gravity waves and gradients of the electron density on terrestrial and satellite communications.