Theoretical and experimental investigations of microwave signatures for characterization of building structures

In Germany nearly 64 percent of common housing stock was built before 1978 mainly without any insulation. Following the first and second oil crisis in 1973 and 1979 awareness for thermal insulation has grown and corresponding measures successively have been integrated into the building architecture over the next decades. As there exist almost no construction plans about wall structure of buildings for the time before 1979, it is difficult for building managers to identify and realize an adequate insulation for individual buildings. In an ongoing research project by German Aerospace Center (DLR) and University of Applied Sciences (FH) Aachen measurement techniques used for remote sensing, security research and concentrating solar power are tested and developed further to obtain methods that allow for a fast and accurate determination of physical building parameters. DLR - Microwaves and Radar Institute - now examines the possibility of using microwaves to determine material characteristics of building walls, so that efficient thermal insulation for existing non-insulated buildings can be realized. This paper is intended to provide an insight into the basic problem and some first investigations.