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Percorrer por autor "Fernandes, Carlos A."

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  • A Framework for the Analysis of Wildfire Effects in Emergency Communication Systems
    Publication . Leonor, Nuno; Fernandes, Carlos A.; Salema, Carlos; Caldeirinha, Rafael
    This paper aims at the development of a simulation framework to enhance the quality, performance and the resilience of the emergency radio communication systems during a wildfire event. To this extent, this research work includes several studies that will contribute for the better understanding of the propagation effects on radio signals under fire environments, the development of a fire-front building up model, the development of a radio propagation tool to obtain coverage maps based on relevant models for propagation in rural areas, particularly in highly dense forest areas, taking into account the topography and clutter in the radio path and the integration of wildfire build up models into the radio propagation tool for an all encompassing radio coverage tool to aid ground forces in realtime with identification of radio exclusion zones in real-time as fire-front develops.
    2018-11Comunicação em conferência Acesso aberto Ver mais
  • Radiowave Propagation Modelling of Dual Wildfire Front Spreading over Hilly Terrain at 700 MHz
    Publication . 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.
    2021-02Comunicação em conferência Acesso restrito Ver mais