Bistatic radar-based methods for air surveillance are of interest for the future realization of flexible radar systems with long-term survivability (non-transmitting receiver sub systems), ability to use existing transmitters, and ability to detect lowsignature targets. Analyses, simulations and trials performed within the project are aimed at improving the understanding of bistatic radars systems and the possibilities and constraints of this type of radar systems. This work reports wider trends in and critical factors for the realization of bistatic radar systems, a model developed for simulation of scenarios involving bistatic and multistatic radar systems, and results from radar trials performed with existing transmitters for ground-based digital television and radio, respectively. Bistatic radar capability is assessed to be best suited for use together with other surveillance capabilities, preferably in multi-function sensor systems that can also be used for other purposes, such as signal intelligence or conventional monostatic radar.