This report summarizes FOI´s research during 2008 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. Space services are also included. The research is to a large extent performed in international collaboration. Main efforts in sensor research are on ground situation reconnaissance, combinations of sensors and sensor data fusion in order to achieve new and improved capability in urban terrain. The programme on low observables technology comprises signature modelling and research on materials and methods for the optimization of protection measures. Knowledge concerning sensors and target and environment are essential in the development of simulastion tools for systems performance assessments. The sextent 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.