Evaluating the Vulnerability of Several Geodetic GNSS Receivers under Chirp Signal L1E1 Jamming Understanding the factors that might intentionally influence the reception of global navigation satellite system (GNSS) signals can be a challenging topic today. The focus of this research is to evaluate the vulnerability of geodetic GNSS receivers under the use of a lowcost L1E1 frequency jammer. A suitable area for testing was established in Slovenia. Nine receivers from different manufacturers were under consideration in this study. While positioning, intentional 3minute jammings were performed by a jammer that was located statically at different distances from receivers. Furthermore, kinematic disturbances were performed using a jammer placed in a vehicle that passed the testing area at various speeds. An analysis of different scenarios indicated that despite the use of an L1E1 jammer, the GLONASS (Russian: Globalnaya Navigatsionnaya Sputnikovaya Sistema) and Galileo signals were also affected, either due to the increased carriertonoiseratio (CN0) or, in the worst cases, by a lossofsignal. A jammer could substantially affect the position, either with a lack of any practical solution or even with a wrong position. Maximal errors in the carrierphase positions, which should be considered a concern for geodesy, differed by a few metres from the exact solution. The factor that completely disabled the signal reception was the proximity of a jammer, regardless of its static or kinematic mode.

Experimental Demonstration of Ship Target Detection in GNSSBased Passive Radar Combining Target Motion Compensation and TrackbeforeDetect Strategies 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 trackbeforedetect methods to achieve long time integration can be fruitfully exploited in GNSSbased passive radar for the detection of maritime targets. The proposed detection strategy reduces the sensitivity of longtime integration methods to the adopted motion models and can save the computational complexity, making it appealing for realtime implementations. Experimental results obtained in three different scenarios (port operations, navigation in open area, and river shipping) comprising maritime targets belonging to different classes show as this combined approach can be employed with success in several operative scenarios of practical interest for this technology.