http://hdl.handle.net/2122/100 Search the Channel search http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/4035 Title: Positioning errors during space weather - Event of October 2003 <br/> <br/>Authors: Alfonsi, Lu.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; De Franceschi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Romano, V.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Aquino, M.; Institute of Engineering Surveying and Space Geodesy (IESSG), The University of Nottingham; Dodson, A.; Institute of Engineering Surveying and Space Geodesy (IESSG), The University of Nottingham <br/> <br/>Abstract: The article describes the measurements made by ISACCO during the superstorm of October 2003 used to assess the positioning errors affecting GNSS users and their correlation with the occurrence of observed levels of scintillation. http://hdl.handle.net/2122/4034 Title: Interobl: An interactive software tool for displaying and scaling oblique ionograms <br/> <br/>Authors: Pezzopane, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Abstract: By analyzing an oblique ionogram several characteristics, such as LOF, MOF, FMUF, FHLOF, FLLOF, and 2FMOF, can be found. These characteristics are important both for ionospheric studies and for terrestrial communication purposes, as they give information about the sky wave communication conditions in the High Frequency (HF) radio spectrum. A RCS-5B sweeping HF receiver for oblique sounding was installed at Chania (Crete, Greece, 35.71N, 24.01E) in April 2005 to perform a radio link with Inskip (UK, 53.51N, 2.51W). The receiver, able to record the sounding only as a binary file, was not equipped with a tool to display and scale the recorded trace. This work describes software that is able to do this, consequently increasing the speed of the scaling phase performed by the operator. The usefulness of this software for validating FMUF prediction models is also shown. http://hdl.handle.net/2122/3982 Title: Space weather and RF communications: Monitoring and modelling <br/> <br/>Authors: Cander, Lj. R.; Rutherford Appleton Laboratory, Space Science & Technology Department, Radio Communications Research Unit, Chilton, Didcot, Oxon OX11 0QX, UK; Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia <br/> <br/>Abstract: At the beginning of the new millennium, ionospheric physics and its application in new technologies are at a point of significant change and new development. Ionospheric studies in the past found application in the traditional areas of broadcast and terrestrial radio communications. It has become clear, in recent years, that an understanding of the ionosphere, as a part of the upper atmosphere, is central to the design of many modern communication, navigation and positioning systems. An important additional role has also been recognized in the areas of space weather science and services. This issue of the Journal of Atmospheric and Solar-Terrestrial Physics collects selected contributions presented at the Solar-Terrestrial Sciences session ST14 on "Space weather and RF communications: monitoring and modelling" held during the first General Assembly of the European Geosciences Union (Nice, France, 25–30 April 2004). <br/> <br/>Description: Preface to Journal of Atmospheric and Solar-Terrestrial Physics 67 (2005) http://hdl.handle.net/2122/3981 Title: Evaluation of the performance of the real-time updated simplified ionospheric regional model for the European area <br/> <br/>Authors: Tsagouri, I.; National Observatory of Athens, Institute for Space Applications and Remote Sensing, Palaia Penteli 15236, Greece; Zolesi, B.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Belehaki, A.; National Observatory of Athens, Institute for Space Applications and Remote Sensing, Palaia Penteli 15236, Greece; Cander, Lj. R.; Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK <br/> <br/>Abstract: The increasing demand for upper-atmosphere nowcasting services for operational applications reveals the need for a realistic mapping of the ionosphere over Europe in real-time and especially during storm periods. To meet this need, a real-time updating method of simplified ionospheric regional model (SIRM) with autoscaled ionospheric characteristics observed by four European Digital Portable Sounders (DPS) ionosondes was recently developed. SIRM belongs to the group of ionospheric models for the standard vertical incidence (VI) ionospheric characteristics such as the critical frequency of the ionospheric F2 layer foF2 and the propagation factor M(3000)F2, which oversimplify a number of the ionospheric phenomena of real significance for radio communications applications showing satisfactory performance for median ionospheric condition description in restricted area of mid-latitudes. As a step forward, the rapid conversion of real-time data from four European digisondes to the driving parameters of the SIRM was introduced as the real-time SIRM updating (SIRMUP). In SIRMUP approach, the values of the ionospheric characteristics from first-guess model parameters at measurement points are combined with real-time measurements. The reliability of the real-time SIRM update method has already been tested in terms of the foF2 for various ionospheric conditions and the simulation results were very promising. In this paper, the simulation tests are continued in order to investigate the efficiency of the SIRMUP method in mapping the propagation conditions over Europe as they are expressed by the propagation factor M(3000)F2. In general, the results demonstrate that SIRMUP procedure has the potential to be used in real time for nowcasting the standard ionospheric characteristics over Europe, for operational applications.