This report summarizes FOI´s research during 2005 on Reconnaisance and Surveillance and Low Observables Technology. The research comprise sensor systems (radar, IR, laser, acoustics), signal processing, data fusion, signature analysis and materials for signature reduction. The extent and the aim off the research are shortly described. Also the national and the international evolution of the area are stated. The research activities, which have been performed in the projects, are described to contents and results.