Measurement Trials of Radiowave Propagation Through Pinus Pinaster Fuel Bed Under Fire

This paper presents results of a measurement campaign conducted to evaluate the impact of forest fires on radiowave propagation. A total mass of 3.4 kg of Pinus Pinaster needles was used as fuel heap and it was uniformly placed in a triangular shape bed, above a metallic table. The ignition sources were two wool yarns soaked in diesel, allocated in two sides of the triangle, with different incident angles, in order to generate two independent fire fronts that will suffer a junction after some seconds. The excess loss introduced by fire was evaluated for a 5 GHz bandwidth, from 3 to 8 GHz. A multipath analysis is also presented in order to detect the variations on signal level, for the dominant components during transmission.