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- Experimental Setup for Radio Characterization of Fire at Microwave FrequenciesPublication . Coimbra, Pedro; Faria, Stefânia; Vala, Mário; Felício, João; Fernandes, Carlos; Leonor, Nuno; Caldeirinha, Rafael; Salema, CarlosWildfires are a recurring phenomenon in many countries around the world, either due to natural causes or negligent human behavior. Emergency communication services used by firefighters at the theater of operations must be highly reliable, in order to ensure the safety and coordination of the teams that are fighting the wildfire, contributing to extinguishing it as quickly as possible with minimum use of resources. Emergency communication networks strongly rely on wireless links that may be impaired by the flames. In this work, we present an experimental setup for characterization of fire at microwave frequencies. Preliminary results show that we are able to extract very low dielectric constant (<1.1) using ultrawideband signals. Moreover, we characterize the attenuation introduced by fire in small-scale scenario. Future work will include the characterization of fire in larger-scale scenarios.
- Radiowave Propagation Modelling of Dual Wildfire Front Spreading over Hilly Terrain at 700 MHzPublication . Faria, Stefânia; Vala, Mário; Coimbra, Pedro; Leonor, Nuno; Felício, João; Fernandes, Carlos A.; Salema, Carlos; Caldeirinha, Rafael F. S.In this paper, a study of a fire front spreading over flat and sloped terrains and how these fire fronts may have impact on radiowave communications are presented. The phenomenon is modelled using Fire Dynamics Simulator (FDS) and the Cold Plasma Model (CPM), using pine needles as fuel heap. Fire parameters such as Heat Release Rate (HRR), Mass Loss Rate (MLR) and fuel consumption are presented and analysed. Attenuation effects at 700 MHz are calculated considering the Full-Stack Model (FSM) and Transmission Line Model (TLM). Simulation results clearly demonstrate that the slope of the terrain profile in the presence of a dual fire front spreading up the hill has significant impact on the additional excess loss of around 2.5 dB, yielding an overall excess loss of 3.5 dB for such a small-scale fire simulation.