Example: UWB enhanced Microwave Fire Detection

Microwave Fire Detection is a passive detection technique and relies on the increased radiation of hot spots due to PLANK’s law. However, the received microwave power depends both on the objects temperature and the material, namely its surface emissivity. Conducting materials like metallic objects or foils e.g. might hide a hot spot due to blocking of its radiation. In this respect Ultra-Wide Band (UWB) radar measurements might help in some aspects. This active measurement technique could help in detecting areas with metallic objects thus identifying areas being uncovered by passive microwave fire detection. In addition, UWB measurements could lead to a rough characterisation of the objects material with respect to its electrical properties. The paper gives an overview on UWB radar technology and its possible application in the detection and localisation of a fire and shows results from recent experiments of UWB radar measurements of test fires. Unfortunately, UWB radar measurements are influenced by the incidence angle at the point of contact of waves and object in addition to the surface roughness. The paper describes concepts how to treat such influences