Ricerc@Sapienza

This work brings forward a framework for passive radar imaging of ship targets by exploiting the reflections of navigation satellite signals. The specific objective is taking advantage of the inherent multistatic nature of the system for the ship passive imagery. To this aim, a bistatic image formation stage is first defined. Then, the bistatic images obtained over multiple baselines are mapped in a domain independent on the particular satellite viewing angle.

This article explores the possibility to exploit global navigation satellite systems (GNSS) signals to obtain radar imagery of ships. This is a new application area for the GNSS remote sensing, which adds to a rich line of research about

The paper addresses the exploitation of Global Navigation Satellite Systems (GNSS) as transmitters of opportunity in passive bistatic radar (PBR) systems for maritime surveillance. The main limitation of this technology is the restricted power budget provided by navigation satellites, which makes it necessary to define innovative moving target detection techniques specifically tailored for the system under consideration.

The focus of this paper is on multi-transmitter GNSS passive radar for maritime surveillance. Particularly, working in the range-Doppler domain, the possibility to integrate over long time intervals (required to counteract restricted power budget provided by navigation satellites) the returns from a moving target illuminated by multiple GNSS transmitters is experimentally demonstrated.

This paper considers the possibility to extract features of vessels at sea with a GNSS-based passive radar system. To this purpose, a passive imaging mode has been defined to form bistatic ISAR images of the detected ship. Then, proper range and cross-range scaling factors have been derived, so that relevant features of the target such as its length can be obtained, potentially enabling target recognition procedures.

GNSS-based passive radar has been recently proved able to enable moving target detection in maritime surveillance applications. The main restriction lies in the low Equivalent Isotropic Radiated Power (EIRP) level of navigation satellites. Extending the integration times with proper target motion compensation has been shown to be a viable solution to improve ship detectability, but this involves computational complexity and increasing sensitivity to motion model mismatches.

This work discusses methods and experimental results on passive radar detection of moving ships using navigation satellites as transmitters of opportunity. The reported study highlights as the adoption of proper strategies combining target motion compensation and track-before-detect methods to achieve long time integration can be fruitfully exploited in GNSS-based passive radar for the detection of maritime targets.