Experimental Seaborne Passive Radar

Abstract

Passive bistatic radar does not emit energy by itself but relies on the energy emitted by illuminators of opportunity, such as radio or television transmitters. Ground-based passive radars are relatively well-developed, as numerous demonstrators and operational systems are being built. Passive radar on a moving platform, however, is a relatively new field. In this paper, an experimental seaborne passive radar system is presented. The radar uses digital radio (DAB) and digital television (DVB-T) for target detection. Results of clutter analysis are presented, as well as detections of real-life targets.

DAB Signal Preprocessing for Passive Coherent Location

“…Finally, we investigate their influence on the quality of bistatic velocity/range plots with PCL detection results obtained from real signals acquired in the field. We show that two of the presented methods eliminate the periodical artifacts from the bistatic velocity/range plots reported in [ 12 ]. The main contribution of this work is a novel, simple yet effective algorithm of received signal preprocessing in the temporal domain (at the DAB frame level) that improves the readability of bistatic velocity/range images obtained from DAB-illuminated PCL in cases of extended integration time (i.e., much longer than 96 ms).…”

“…For the experiments described in this paper, DAB signals acquired during APART-GAS 2019 campaign [ 11 , 12 ] have been employed. The illuminating transmitter was localized near Koszalin, Poland, and operated at a VHF frequency of 216.84 MHz with an Effective Radiated Power (ERP) level of 3.2 kW and vertical polarization.…”

“…The performance calculations and initial trials of DAB-illuminated PCL are presented in [ 4 , 9 , 10 ]. The results of experiments with DAB signals acquired during the NATO campaign APART-GAS 2019 (Active Passive Radar Trials Ground-based, Airborne, Sea-borne) in Poland [ 11 ] showed encouraging results in detecting airplanes of different sizes flying in the range up to 20 km [ 12 ] from the moving PCL platform [ 13 ]. However, due to the time-domain properties of the DAB signal, there were periodical artifacts sometimes visible in bistatic velocity/range plots that obscure the images with detection results.…”

“…However, due to the time-domain properties of the DAB signal, there were periodical artifacts sometimes visible in bistatic velocity/range plots that obscure the images with detection results. Examples of such images are shown in [ 12 ] and in Figure 1 as a reference. These disturbances appeared with an integration time extended to 5 s. They were repeated on the bistatic velocity axis with a period ≈ 14.3 m/s that is strictly related to the signal’s wavelength ( = 1.37 m for the received DAB center frequency: 218.64 MHz) and the DAB transmission frame duration [ 14 , 15 ] ( = 96 ms) …”

Locating Ships Using Time Reversal and Matrix Pencil Method by Their Underwater Acoustic Signals

“…These methods do not detect the vessels without the required components of the system, including irregular ships. This problem has been addressed with methods such as sonar, radar and arrays of passive sensors that receive information from reflected waves coming from an active source [21][22][23]. In recent years, passive location methods include: time of arrival (TOA), direction of arrival (DOA), and Matched field processing (MFP) [24], which in some cases, may have problems due to the presence of non-homogeneous media [25].…”