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Herraiz, M.
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- PublicationRestrictedDEPTH-DEPENDENT SEISMIC ATTENUATION IN THE GRANADA ZONE (SOUTHERN SPAIN)(1990-10)
; ; ; ; ; ; ;Ibanez, J.; University of Granada, Spain ;Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;De Miguel, F.; University of Granada, Spain ;Herraiz, M.; Universidad Complutense, Madrid, Spain ;Alguacil, F.; University of Granada, Spain ;Morales, J.; University of Granada, Spain; ; ; ; ; Coda-Q estimates for the Granada Basin (Southern Spain) are obtained by analyzing earthquakes occurring within or close to the borders of this area. The data set is composed of 54 earthquakes with local magnitudes ranging between 2.2 and 4.0 and with epicentral distances to the nearest station smaller than 10 km. A single-scattering process is assumed. Coda-Q values obtained show a clear dependence on frequency according to the relationship Q = Qof", where n ranges from 0.81 to 0.89. After removing the main site effects and discussing the possible multiple-scattering influence, the lapse-time dependence is interpreted as due to attenuation variations with depth. This result agrees with the variation of coda Q obtained by using different sets of events with increasing hypocentral depth ranges.199 28 - PublicationRestrictedThe contribution to IHY from the COST296 Action MIERS: Mitigation of Ionospheric Effects on Radio Systems(2009-04)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;De Franceschi, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Alfonsi, Lu.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Altadill, D.; Observatorio del Ebro, Tortosa, Spain ;Bencze, P.; Hungarian Academy of Sciences, Geodetic and Geophysical Research Institute, Sopron, Hungary ;Bourdillon, A.; Institut d'Electronique et de Télécommunications de Rennes, Rennes, France ;Buresova, D.; Institute of Atmospheric Physics, Prague, Czech Republic ;Cander, L. R.; Rutherford Appleton Laboratory, Council for the Central Laboratory of the Research Councils, Oxfordshire, UK ;de la Morena, B.; Instituto Nacional de Tecnica Aerospacial, Torrejon de Ardoz, Spain ;Economou, L.; Intercollege Limassol Campus, Limassol, Cyprus ;Herraiz, M.; Universidad Complutense Madrid, Madrid, Spain ;Kauristie, K.; Finnish Meteorological Institute, Helsinki, Finland ;Lastovicka, J.; Institute of Atmospheric Physics, Prague, Czech Republic ;Pau, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Rodriguez, G.; Universidad Complutense Madrid, Madrid, Spain ;Stamper, R.; Rutherford Appleton Laboratory, Council for the Central Laboratory of the Research Councils, Oxfordshire, UK ;Stanislawska, I.; Space Research Center- Polish Academy of Science, Warsaw, Poland; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The objective of the COST296 Action MIERS (Mitigation of Ionospheric Effects on Radio Systems) is to develop an increased knowledge of the effects imposed by the ionosphere on practical radio systems, and for the development and implementation of techniques to mitigate the deleterious effects of the ionosphere on such systems (http://www.cost296.rl.ac.uk). The COST296 Community contributes to the international efforts of IHY with scientific and outreach activities as well. After the realization of a web site hosted by Istituto Nazionale di Geofisica e Vulcanologia (INGV), developed also to promote the ionospheric physics to the open public, the COST296 Community supported an initiative addressed to the pupils of the primary school of several European Countries: the realization of a school-calendar dedicated to the Sun and to the Sun-Earth connections.352 28 - PublicationOpen AccessWorst cases for an one-hop high frequency link(2002)
; ; ; ; ;Mirò, G.; Atmospheric Sounding Station «El Arenosillo», National Institute of Aerospace Technology, Magazón, Huelva, Spain ;de la Morena, B. A.; Atmospheric Sounding Station «El Arenosillo», National Institute of Aerospace Technology, Magazón, Huelva, Spain ;Radicella, S. M.; Aeronomy and Radiopropagation Laboratory, Abdus Salam ICTP, Trieste, Italy ;Herraiz, M.; Department of Geophysics and Meteorology, Faculty of Physics, Complutense University, Madrid, Spain; ; ; The characterisation of a HF channel by means of monthly electron density profiles can be complemented with a detailed study of radio propagation «worst cases» on situations with extremes conditions of radiopropagation for a given period. These «worst cases» correspond to conditions that can be identified by means of cumulative distributions of the key parameter f0F2. In this paper, the main parameters of the HF channel: time delay, apogee, elevation angle and transmission frequency with mean and extreme conditions are analysed. The method used to characterise the ionospheric channel is based on ray-tracing techniques.131 168 - PublicationOpen AccessIonospheric biases correction for coordinates derived from GPS single point positioning(2005)
; ; ; ; ; ;Gende, M.; Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Argentina ;Mohíno Harris, E.; Departamento de Geofísica y Meteorología, Universidad Complutense de Madrid, Spain ;Brunini, C.; Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Argentina ;Radicella, S. M.; Aeronomy and Radiopropagation Laboratory, The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy ;Herraiz, M.; Departamento de Geofísica y Meteorología, Universidad Complutense de Madrid, Spain; ; ; ; Most GPS users employ low cost receivers. These receivers do not allow users to record the pseudorange that they observe, but the computed coordinates. This work presents an original and simple method to correct ionospheric biases introduced in GPS signals. The originality of this method is based on the fact that no pseudorange is needed to correct the biases, only the calculated coordinates are used. This distinguishes this method from other classic alternatives. This paper evaluates the efficiency of the method with the use of real data.182 493