Editorial: Passive radar systems

This IEE Special Issue on passive radar systems coincides with the seventieth anniversary of the first British radar experiment at Daventry in February 1935. The papers in this Special Issue cover the full spectrum of topics currently being researched in the area of passive radar systems. There are papers addressing the use of a variety of transmitters of opportunity -FM radio, digital audio broadcast (DAB), digital video broadcast (DVB), global navigation satellite systems and cell-phone base-stations - plus one paper that looks at detecting targets by radiometry. Other papers examine specific signal processing issues, including the problem of nearby large targets masking smaller more distant targets, improved computational performance for cross-correlation processing and the use of the probability hypothesis density (PHD) tracker to solve the problem of multistatic passive radars with non-directional antennas. Finally, a number of papers look at the issues of performance and deployment modelling and address the problems of optimally siting the radar receivers for passive radar and bearings-only systems and predicting the performance of passive radar systems. A common feature in all the systems described in this Special Issue is the extensive use of digital hardware and software processing and it seems inevitable that in the future we might see the development of passive radar systems that simultaneously exploit a wide range of different transmissions of opportunity.