Interferometric inverse synthetic aperture radar experiment using an interferometric linear frequency modulated continuous wave millimetre-wave radar

D. Felguera-Martín,1 J.-T. González-Partida,1 P. Almorox-González,1 M. Burgos-García,1 and B.-P. Dorta-Naranjo2 1Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Grupo de Microondas y Radar. Departamento de Señales, Sistemas y Radiocomunicaciones, Madrid, Spain 2Universidad de Las Palmas de Gran Canaria, Departamento de Señales y Comunicaciones, Las Palmas de Gran Canaria, Spain An interferometric linear frequency modulated continuous wave (LFMCW) millimetre-wave radar is presented, along with the results of an experiment conducted to study the feasibility of using it in a future millimetre-wave interferometric inverse synthetic aperture radar (InISAR) system. First, a description of the radar is given. Then, the signal processing chain is described, with special attention to the phase unwrapping technique. The interferometric phase is obtained by unwrapping the prominent target's phase in each antenna using a sliding frame processing technique. Cell migration issues in this method are also addressed. Simulations were carried out to illustrate and assess the processing chain and to show the effects of multipath echoes on the height measurement. In the real experiment, the range, speed and height of a moving target were tracked over consecutive inverse synthetic aperture radar (ISAR) image frames, verifying the performance of the whole system

Risk Assessment and Mitigation at Copahue Volcano

"Risk assessment" is a relatively new concept in Argentina, since the veryfirst hazard map was only recently constructed on the basis of the 1992 eruption of Copahue volcano (Patagonia). Copahue is considered a very active volcanic system since 13 eruptive events have been recognized overthe last 260 years. Most the events are phreatic and phreato-magmatic withVEI ≤ 2; nevertheless such eruptions represent a threat for thecommunities living in the surrounding areas of the emission centre, not only because of pyroclastic flows and tephra fall (the nearby villages,Caviahue and Copahue, have so far only experienced ash fallout), but also due to the possible formation of mud flows and flank collapse triggered by the volcanic activity. Owing to the frequent eruptions of Copahue, the most recent ones (2000, 2012) showed an increasing explosive character, hazard survey actions, such as thematic maps and contingency plans areconstantly, though slowly, modified. The risk assessment described in this chapter calls for the implementation of the monitoring network in the Argentina side of the volcano, since the only currently active seismic stations (OVDAS) are located in the Chilean side of the volcanic edifice, Copahue volcano lying at the border between the two countries.Moreover, the Chilean observatory adopts criteria of alert levels, which are distinctly different with respect to those of Argentina Civil Defense,producing misleading information to the population. The villages of Copahue and Caviahue are regarded as extremely vulnerable to possible future eruptions if larger magnitude events should occur. A review of the presently available potential hazard map, an improvement of people's education about the volcanic risks and a more interactive cooperation between the Chilean and Argentina scientific and administrative institutions are some of the immediate counter measures to be taken into account before a new explosive phase at Copahue.Fil: Caselli, Alberto Tomás. Universidad Nacional de Rio Negro. Sede Alto Valle. Laboratorio de Estudio y Seguimiento de Volcanes Activos.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Liccioli, Caterina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Tassi, Franco. Università degli Studi di Firenze; Itali