Analysis of sea spikes in NetRad clutter

In this work our attention is focused on the statistical and spectral analysis of sea clutter spikes recorded by the netted radar system, NetRad, which works in both monostatic and bistatic configurations. Once separated the spikes from the background, we examine their properties, focusing on the spike width and on the interval which separates two consecutive spikes. The spectral properties of the sea spikes are also examined and compared with the background

Bistatic radars: clutter modeling and target detection

In the first part of this work we analyse the sea clutter data collected simultaneously by the bistatic and monostatic nodes of the NetRAD, which is a netted radar system working at S band, whereas the datasets have been collected with four different out-of-plane geometries. Particular attention is paid to characterize the variation of the main statistical and spectral features of the bistatic sea-clutter according to the polarization and the bistatic geometry. The aim of the analyses consists in examining the spikiness of bistatic clutter, compared with the monostatic one, which will be useful for the design of the radar detectors. In the Doppler domain, sea spikes are mainly concentrated within the peak of the clutter spectrum and their presence makes the spectrum wider. These features are examined in this work by a comparison among the Doppler spectra of the total received samples, of the background and of the spikes. From a statistical point of view, the presence of sea spikes is examined by comparing the data histograms with some heavy-tailed distributions and by studying the behaviour of two explicative statistical parameters, such as kurtosis and shape parameter. The statistical distributions of the spike width and of the interval between two subsequent spikes are also analysed. The second part of this work addresses the problem of target detection for bistatic and, in a more general way, multistatic and multiple input - multiple output radars. The adopted algorithm is able to keep constant the false alarm rate, if the disturbance samples associated to each receiver-transmitter pair are distributed according to a Compound-Gaussian model. In particular, the performance of the adopted detection algorithm is analyzed, in order to evaluate the impact of clutter diversity on the detection performance. The results highlight that clutter statistical diversity has a strong impact on the detection performance. In the case of two channels, a significant result is that the same value of the probability of detection is obtained for different couples of the shape parameters associated to the two channels. The performances of both single channel and multichannel detection schemes are evaluated on the sea clutter data collected by the NetRAD nodes, in order to evaluate which channel, between the bistatic and monostatic ones, is more favorable for radar detection. Furthermore, the gain, achieved by using a multistatic detection algorithm, is analyzed

STATISTICAL ANALYSIS OF PASSIVE BISTATIC RADAR CLUTTER

Recently, great interest has been devoted to systems that exploit the signal transmitted by an illuminator of opportunity, a non-cooperative transmitter independent from the receiver. In this thesis work, there is at first a description of the concept and the processing stages of a PCL system, then a discussion of algorithms implemented to remove the direct path interference;finally the statistical analysis of clutter from two passive bistatic radar demonstrators is provided

A radar architecture for joint dynamic spectrum access and target-matched illumination

In this study, we address a simple cognitive architecture to design a radar waveform that fills the gaps in the radio-frequency spectrum and matches the target scattering properties. The metric used to calculate the radar waveform is the Mutual Information between the received signal and the target impulse response. Particular attention is paid to analyse the impact of the properties of the communication signals on the chosen metric, for both ideal and non-ideal cases

Multistatic CFAR detection in non-Gaussian clutter

This work deals with a target detection algorithm for multistatic and multiple input-multiple output radars. The adopted algorithm is able to keep the false alarm rate constant, if the disturbance samples associated to each receiver-Transmitter pair are distributed according to a Compound-Gaussian model. In particular, we analyze the performance of the adopted detection algorithm, in order to evaluate the impact of clutter diversity on the detection performance. To this aim, we simulated the clutter samples by varying the shape parameter of the clutter distribution associated to each receiver-Transmitter pair. The results highlight that clutter diversity has a strong impact on the detection performance. In the case of two channels, i.e.Two receiver-Transmitter pairs, a significant result is that the same value of the probability of the detection is obtained for different couples of the shape parameters associated to the two channels

Performance of the Coherent NAVICO Radar in Heavy Sea Clutter

This Report analyses the performance of the Coherent NAVICO radar system in heavy sea clutter conditions. The performance of the system are analysed in term of Receiver Operating Characteristics (ROC), that is in terms of Probability of False Alarm and Probability of Detection. The Report is organized as follow. Section 1 introduce the Clutter and Target signal models, in particular the heavy coherent sea clutter is modeled with an Auto Regressive process whose samples belong to a coherent K distribution while the target echo is generated according to the well known Swerling I model. Section 2 describe the flow diagram of the coherent NAVICO radar receiver, each block of the receiver flow chart is described and compared with the optimum CFAR detector in Gaussian clutter. The performance of the system are reported in Section 3 while Section 4 describes the Matlab script functions that has been created to model and analyse the system

Statistical Analysis of Bistatic and Monostatic Sea Clutter

In this work, we analyze the sea clutter data collected simultaneously by the bistatic and monostatic nodes of a S-band netted radar system. The analyzed radar system is the NetRad, developed by the University College London (UCL) and the datasets were collected with four different out-of-plane geometries. The aim of the analysis is to compare statistically the behavior of the bistatic and monostatic sea clutter for different geometries. In particular, we focus on the sea spikes, whose presence increases the probability of false alarm of the radar detector. The statistical analysis is carried out by comparing the empirical distribution of sea clutter data with some known heavy-tailed distributions and by studying the behavior of three statistical parameters, the kurtosis the Weibull and K+Noise shape parameter. An algorithm that separates the sea spikes from the Bragg background is implemented, in order to study in-depth the sea spikes statistics. To this aim, we examine the empirical distribution of the spike duration and of the interval between two subsequent spikes. The results of our analyses show that spikiness is higher for low values of the bistatic angle and that bistatic data are generally less spiky than monostatic ones only for horizontal polarization

CoCoNet: Towards coast to coast networks of marine protected areas (From the shore to the high and deep sea), coupled with sea-based wind energy potential

This volume contains the main results of the EC FP7 "The Ocean of Tomorrow" Project CoCoNet, divided in two sections: 1) a set of guidelines to design networks of Marine Protected Areas in the Mediterranean and the Black Seas; 2) a smart wind chart that will allow evaluating the possibility of installing Offshore Wind Farms in both seas. The concept of Cells of Ecosystem Functioning, based on connectivity, is introduced to define natural units of management and conservation. The definition of Good Environmental Status, as defined in the Marine Strategy Framework Directive, is fully embraced to set the objectives of the project, by adopting a holistic approach that integrates a full set of disciplines, ranging from physics to bio-ecology, economics, engineering and many sub-disciplines. The CoCoNet Consortium involved scientist sfrom 22 states, based in Africa, Asia, and Europe, contributing to build a coherent scientific community

CoCoNet: towards coast to coast networks of marine protected areas (from the shore to the high and deep sea), coupled with sea-based wind energy potential

This volume contains the main results of the EC FP7 “The Ocean of Tomorrow” Project CoCoNet, divided in two sections: 1) a set of guidelines to design networks of Marine Protected Areas in the Mediterranean and the Black Seas; 2) a smart wind chart that will allow evaluating the possibility of installing Offshore Wind Farms in both seas. The concept of Cells of Ecosystem Functioning, based on connectivity, is introduced to define natural units of management and conservation. The definition of Good Environmental Status, as defined in the Marine Strategy Framework Directive, is fully embraced to set the objectives of the project, by adopting a holistic approach that integrates a full set of disciplines, ranging from physics to bio-ecology, economics, engineering and many sub-disciplines. The CoCoNet Consortium involved scientist sfrom 22 states, based in Africa, Asia, and Europe, contributing to build a coherent scientific community