Feasibility study and development of a full digital passive radar demonstrator

In the past few years we have witnessed a growing interest in Passive Radars which exploit electromagnetic emissions coming from non-cooperative transmitters for example TV/Radio stations. The main feature of these systems is the absence of a transmitter. This feature, in addition to reduced system costs, makes this kind of equipment hard to intercept. Many demonstrators have been developed in the past decade by Universities, research facilities and private companies, however, we can’t say we have found a solution to fully satisfy the performance and cost requirements. This thesis focuses on the development of a low cost passive radar demonstrator with the aim of achieving a high range resolution exploiting the DVB-T signal as illuminator of opportunity (IO), which should satisfy both cost and performance needs. The study and design of the above mentioned radar demonstrator lead to three main innovative aspects. The first aspect is the realisation of a low cost passive radar demonstrator based on Software Defined Radio (SDR) technologies. In particular the Universal Software Radio Peripherals (USRPs) seems to be a good solution which meets the requirements of scalability and modularity which our system must have, for example the possibility to receive different signals by using the same hardware configured via software. The second aspect is the development of the whole processing chain. A theoretical analysis and experimental validation for every algorithm have been done. In particular, all algorithms developed are independent from the type of illuminator of opportunity chosen. This advantage, in conjunction with the use of a hardware which can be reconfigured via software, makes the entire radar system adaptive to the signal used. The third and final point focuses on the way to obtain a passive radar system which offers high range resolution. Specifically, in this thesis, the possibility of obtaining a high range resolution using adjacent DVB-T channels has been studied. A theoretical analysis, followed by a validation on real data will highlight that the resolution enhancement is proportional to the number of exploited DVB-T channels. The radar’s functionality is tested on different scenarios: maritime and aerial. The experimental results obtained with the demonstrator in both scenarios for different types of targets is proved both the feasibility of our radar system and the actual improvement of range resolution resulting from using multiple DVB-T adjacent channels