22 research outputs found

    Ionospheric Monitoring and Modeling Applicable to Coastal and Marine Environments

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    Ionospheric monitoring and modeling in costal and marine environment is reviewed and characterized in terms of state of art, global, regional, and local issues across different domains of solar-terrestrial conditions for practical applications. Their effects on critical technological systems are either controlled by the Earth’s ionosphere, as in telecommunications and information systems, or simply influenced by its variability, as in trans-ionospheric radio communication, and navigation systems. The evolution of long-distance high-frequency (HF) communications and then still the actuality of HF radio links especially for the coast environment, maritime services, and aeronautical applications, for control and emergency services, for communications equally important in case of great islands and remote areas, for economic reasoning and easy management, and for efficient backup in case of cyber threats are discussed. Some preferred methods for a proper assessment of HF networks have been identified, and examples of existing long-term prediction and near real-time nowcasting in ionospheric space weather modeling to be used, particularly in the Mediterranean area, are presented along with contemporary references

    COST 271 Action - Effects of the upper atmosphere on terrestrial and Earth-space communications: introduction

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    2) ( 1 ) Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy ( 2 ) Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, U.K. The COST 271 Action («Effects of the Upper Atmosphere on Terrestrial and Earth-space Communications») within the European ionospheric community has the objectives, embodied in the Memorandum of Understanding (MoU): to study the influence of upper atmospheric conditions on terrestrial and Earth-space communications, to develop methods and techniques to improve ionospheric models over Europe for telecommunication and navigation applications and to transfer the results to the appropriate Radiocommunication Study Groups of the International Telecommunication Union (ITU-R) and other national and international organizations dealing with the modern communication systems. This introductory paper summarises briefly the background and historical context of COST 271 and outlines the main objectives, working methods and structure. It also lists the participating countries and institutions, the Management Committee (MC) Meetings, Workshops and Short-term Scientific Missions. In addition, the paper discusses the dissemination of the results and the collaboration among the participating institutions and researchers, before outlining the content of the Final Report

    The COST 271 Action: conclusions and the way ahead

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    A brief summary is given of the major achievements of the COST 271 Action. New challenges have been identified that open the way for a proposal, which is outlined, for a follow-on to the COST 271 Action within the COST Telecommunications, Information Science and Technology framework

    Ionospheric Ground-based Measurement Networks

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    Within-the-hour variability: levels and their probabilities

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    The study of foF2 data measured every 5-min and of TEC measurements made every 10-min shows that the within-the-hour variability is different in the two parameters. Deciles of this variability for foF2 and for TEC are determined together with the probabilities of exceeding a given level of variability. Furthermore, considering hourly values, it is found that the variability in TEC is like an «intrinsic noise» throughout the day of the order of less than 5% of the hourly value; but at sunrise and often at sunset large values take place. A seasonal dependence is evident. Besides, a within-the-hour variability in foF2 is always present with large values at sunrise or sunset depending on the season, and also during disturbed ionospheric conditions

    Near Earth space plasma monitoring under COST 296

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    This review paper presents the main achievements of the near Earth space plasma monitoring under COST 296 Action. The outputs of the COST 296 community making data, historical and real-time, standardized and available to the ionospheric community for their research, applications and modeling purposes are presented. The contribution of COST 296 with the added value of the validated data made possible a trusted ionospheric monitoring for research and modeling purposes, and it served for testing and improving the algorithms producing real-time data and providing data users measurement uncertainties. These value added data also served for calibration and validation of space-borne sensors. New techniques and parameters have been developed for monitoring the near Earth space plasma, as time dependent 2D maps of vertical total electron content (vTEC), other key ionospheric parameters and activity indices for distinguishing disturbed ionospheric conditions, as well as a technique for improving the discrepancies of different mapping services. The dissemination of the above products has been developed by COST 296 participants throughout the websites making them available on-line for real-time applications

    Nowcasting, forecasting and warning for ionospheric propagation: tools and methods

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    The paper reviews the work done in the course of the COST 271 Action concerned with the development of tools and methods for forecasting, nowcasting and warning of ionospheric propagation conditions. Three broad categories of work are covered. First, the maintenance and enhancement of existing operational services that provide forecast or nowcast data products to end users; brief descriptions of RWC Warsaw and the STIF service are given. Second, the development of prototype or experimental services; descriptions are given of a multi-datasource system for reconstruction of electron density profiles, and a new technique using real-time IMF data to forecast ionospheric storms. The third category is the most wide-ranging, and deals with work that has presented new or improved tools or methods that future operational forecasting or nowcasting system will rely on. This work covers two areas - methods for updating models with prompt data, and improvements in modelling or our understanding of various ionospheric-magnetospheric features - and ranges over updating models of ionospheric characteristics and electron density, modelling geomagnetic storms, describing the spatial evolution of the mid-latitude trough, and validating a recently-proposed technique for deriving TEC from ionosonde observations

    Total electron content - A key parameterin propagation: measurement and usein ionospheric imaging

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    The paper reports on a series of studies carried out within the COST 271 Action relating to the measurement and use of Total Electron Content (TEC) of the ionosphere over North West Europe. Total electron content is a very important parameter for the correction of propagation effects on applied radio systems so that it is vital to have confidence in the experimental measurements and the resultant products derived as aids for the practical user. Comparative investigations have been carried out using TEC values from several different sources. It was found that in general there was broad statistical agreement between the data sets within the known limitations of the techniques, though discrepancies were identified linked to steep ionospheric gradients at the onset of geomagnetic storm disturbance and in the vicinity of the main trough. The paper also reviews recent progress in the development of tomographic inversion techniques that use total electron content measurements to image the ionosphere as an aid to various radio systems applications

    Ionospheric Ground-based Measurement Networks

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