Pilot study: Parasitic and passive radar

The report describes principles and potential applications of PPR (parasitic and passive radar). PPR is a passive technology which - in contrast to traditional radar - is based on using non-cooperative transmitters (e.g. radar-, TVor radio transmitters) as illuminators, wideband receivers, and advanced signal processing methods in order to extract target information. PPR may be combined with electronic support measures (ESM) in an integrated passive sensor system. ESM would contribute several critical functions such as detection, classification and positioning of transmitters. Advantages of PPR include generating all-weather target maps without revealing its presence, without needing a transmission licence, and with a lower cost per unit. Disadvantages are that the technology is more complex than traditional radar and uncertainties regarding the availability of suitable transmitters. Important potential applications of PPR include air surveillance for anti-aircraft units, sea surveillance for submarines and surface vessels, and ground situation picture for army units. Civilian applications are also possible, e.g. traffic monitoring and covert police surveillance. Examples of suitable transmitters are given in the report and important research questions are identified, e.g. suppression of the direct path signal, positioning of transmitters, and clutter suppression using PPR in combination with SAR ("synthetic aperture radar") and GMTI ("ground moving target indication"). There are only a few operational PPR-systems today and the technology is often classified. A literature search has been performed which indicates that PPR-related research has increased during recent years.