Characterization of impurities in building materials with SAR

In Germany nearly 64 percent of the common housing stock was built before 1978 mainly without insulation. In light of efforts to reduce German carbon emissions, the government has highlighted the reduction of energy consumption in building heating systems through increased insulation as a strategic goal. Effective Insulation however requires detailed knowledge of a buildings wall structure. Unfortunately, due to the rapid restoration of the German housing stock after the Second World War, building descriptions, in particular of the building fabric were not systematically recorded for houses built prior to 1978. Recently the DLR - Microwaves and Radar Institute - examined the possibility of using microwaves to determine material characteristics of building walls. Experiments showed that Synthetic Aperture Radar (SAR) can provide additional information about the inner structure of the wall in comparison to real aperture radar measurements. This paper gives an overview of the latest investigations into this topic including laboratory measurements of stone structures and measurements of real building materials.