This report summarizes FOI´s research during 2006 on Sensors and Low Observables Technology. The research comprise sensor systems (optronics, radars, multifunctional sensors, combined sensors), signal processing, mine reconnaissance, and low observables technology. The research is to a large extent performed in international col-aboration. Main efforts in sensor research are on ground situation reconnaissance and combinations of sensors to achieve best performance. Gradually research efforts are increased on urban terrain. The programme on low observables technology has main point in modelling. It also includes research on materials and methods for the optimization of protection measures. The extent and the aim off the research are shortly described. Also, the national and the international R&D in the area are stated. The research activities are described to contents and results.