The effects of wind farm installation on the conventional monostatic radar operation have been investigated in previous studies. The interference on radar operation is due to the complex scattering characteristics from the wind turbine structure. This research considers alternative approach for studying and potentially mitigating these negative impacts by adapting the multistatic radar system technique. This radar principle is well known and it is attracting research interest recently, but has not been applied in modelling the wind farm interference on multistatic radar detection and tracking of multiple targets. The research proposes two areas of novelties. The first area includes the simulation tool development of multistatic radar operation near a wind farm environment. The second area includes the adaptation of Range-Only target detection approach based on mathematical and/or statistical methods for target detection and tracking, such as Interval Analysis and Particle Filter. These methods have not been applied against such complex detection scenario of large number of targets within a wind farm environment. Range-Only target detection approach is often considered to achieve flexibility in design and reduction in cost and complexity of the radar system. However, this approach may require advanced signal processing techniques to effectively associate measurements from multiple sensors to estimate targets positions. This issue proved to be more challenging for the complex detection environment of a wind farm due to the increase in number of measurements from the complex radar scattering of each turbine. The research conducts a comparison between Interval Analysis and Particle Filter. The comparison is based on the performance of the two methods according to three aspects; number of real targets detected, number of ghost targets detected and the accuracy of the estimated detections. Different detection scenarios are considered for this comparison, such as single target detection, wind farm detection, and ultimately multiple targets at various elevations within a wind farm environment.

Passive localization of aircraft in flight using signal time of arrival (TOA) poses some unique challenges. The sensors must be deployed in an approximately coplanar configuration, which produces significant vertical uncertainty in the estimated position. This dissertation examines the traditional algorithms used in passive localization. It presents general forms of linear TOA, time difference of arrival (TDOA), angle of arrival (AOA), and frequency difference of arrival (FDOA) equations from the literature and explains how to apply an intuitive geometric interpretation of these equations. It presents two novel algorithms for passive localization. One uses a one dimensional AOA (1AOA) to improve the vertical estimate. The other employs an a priori estimate to approximate the non-linear localization problem as a linear problem and produce a high quality position estimate. A comprehensive survey of the literature is presented. This dissertation provides a summary and classification of passive localization algorithms from the literature with simple descriptions of how the form of the equations relate to their numerical stability. It presents two novel algorithms for passive localization. The hybrid multilateration and triangulation algorithm improves wide area multilateration by using vertical 1AOA to constrain the vertical position. The multilateration with a priori estimates algorithm provides a linear localization method that utilizes previous location estimates.

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Ground penetrating radar (GPR) has been extensively utilized as a highly efficient and non-destructive testing method for infrastructure evaluation, such as highway rebar detection, bridge decks inspection, asphalt pavement monitoring, underground pipe leakage detection, railroad ballast assessment, etc. The focus of this dissertation is to investigate the key techniques to tackle with GPR signal processing from three perspectives: (1) Removing or suppressing the radar clutter signal; (2) Detecting the underground target or the region of interest (RoI) in the GPR image; (3) Imaging the underground target to eliminate or alleviate the feature distortion and reconstructing the shape of the target with good fidelity. In the first part of this dissertation, a low-rank and sparse representation based approach is designed to remove the clutter produced by rough ground surface reflection for impulse radar. In the second part, Hilbert Transform and 2-D Renyi entropy based statistical analysis is explored to improve RoI detection efficiency and to reduce the computational cost for more sophisticated data post-processing. In the third part, a back-projection imaging algorithm is designed for both ground-coupled and air-coupled multistatic GPR configurations. Since the refraction phenomenon at the air-ground interface is considered and the spatial offsets between the transceiver antennas are compensated in this algorithm, the data points collected by receiver antennas in time domain can be accurately mapped back to the spatial domain and the targets can be imaged in the scene space under testing. Experimental results validate that the proposed three-stage cascade signal processing methodologies can improve the performance of GPR system.

Ground penetrating radar (GPR) has been extensively utilized as a highly efficient and non-destructive testing method for infrastructure evaluation, such as highway rebar detection, bridge decks inspection, asphalt pavement monitoring, underground pipe leakage detection, railroad ballast assessment, etc. The focus of this dissertation is to investigate the key techniques to tackle with GPR signal processing from three perspectives: (1) Removing or suppressing the radar clutter signal; (2) Detecting the underground target or the region of interest (RoI) in the GPR image; (3) Imaging the underground target to eliminate or alleviate the feature distortion and reconstructing the shape of the target with good fidelity. In the first part of this dissertation, a low-rank and sparse representation based approach is designed to remove the clutter produced by rough ground surface reflection for impulse radar. In the second part, Hilbert Transform and 2-D Renyi entropy based statistical analysis is explored to improve RoI detection efficiency and to reduce the computational cost for more sophisticated data post-processing. In the third part, a back-projection imaging algorithm is designed for both ground-coupled and air-coupled multistatic GPR configurations. Since the refraction phenomenon at the air-ground interface is considered and the spatial offsets between the transceiver antennas are compensated in this algorithm, the data points collected by receiver antennas in time domain can be accurately mapped back to the spatial domain and the targets can be imaged in the scene space under testing. Experimental results validate that the proposed three-stage cascade signal processing methodologies can improve the performance of GPR system.

This master’s thesis deals with the concept of passive multistatic radar. The radar system exploits WiFi or WiMAX transmitters as the source of radiolocation signal. The transmitters are considered non-cooperative. The master’s thesis evaluates limitations arising from utilization of WiFi or WiMAX signals. A Matlab simulator was created as a part of the thesis, which was used to verify the basic idea behind this concept. Based on the results of real-life simulations, conclusions are suggested towards a possible application of WiFi/WiMAX radar.

<p>Основни допринос дисертације су дефинисани методи истовременог<br />формирања више снопова код пријемника мултистатичког радара. Тиме<br />иста пријемна антена прима сигнале из целе хемисфере уз појачања<br />адекватна величини антене. Показано је да дефинисане методе,<br />примењене на конформне антене омогућавају формирање више<br />стотина снопова са само једним FPGA колом. Приказане су и<br />могућности паралелне обраде оволиког броја примљених радарских<br />сигнала. У пријемнику су обједињене функције претраживања простора<br />и праћења циљева. Процењене су величине простора који се може<br />покрити оваквим системом уз искључиву примену комерцијалне<br />технологије. Дате су методе синхронизације предајника и пријемника<br />засноване на технологији ултраширокопојасних комуникација.<br />&nbsp;</p> / <p>Osnovni doprinos disertacije su definisani metodi istovremenog<br />formiranja više snopova kod prijemnika multistatičkog radara. Time<br />ista prijemna antena prima signale iz cele hemisfere uz pojačanja<br />adekvatna veličini antene. Pokazano je da definisane metode,<br />primenjene na konformne antene omogućavaju formiranje više<br />stotina snopova sa samo jednim FPGA kolom. Prikazane su i<br />mogućnosti paralelne obrade ovolikog broja primljenih radarskih<br />signala. U prijemniku su objedinjene funkcije pretraživanja prostora<br />i praćenja ciljeva. Procenjene su veličine prostora koji se može<br />pokriti ovakvim sistemom uz isključivu primenu komercijalne<br />tehnologije. Date su metode sinhronizacije predajnika i prijemnika<br />zasnovane na tehnologiji ultraširokopojasnih komunikacija.<br />&nbsp;</p> / <p>Main contribution of this dissertation are the new digital beam forming<br />methods, suitable for applicable in multibeam conformal antenna. These<br />methods maintain antenna gain independently of beam positions in whole<br />hemisphere, scanned by the radar. Few hundred beams could be formed by<br />the only one FPGA. Parallel digital signal processing of these beams can be<br />also performed by the only one FPGA. Functions of surveillance and tracking<br />radar are joint in the one receiver. High accuracy in time and frequency<br />synchronization between receiver and transmitter is enabled by UWB.</p>

This thesis focuses on detection algorithms of radar targets, namely on group of techniques for removing of disturbing reflections from static objects - clutter and for suppression of distortion products caused by the phase noise of the transmitter and receiver. Methods for distortion suppression in received signal are designed for implementation in the developed active multistatic radar, which operates in the code division multiplex of several transmitters on single frequency. The aim of the doctoral thesis is to design, implement in tool for technical computing MATLAB and analyze the effectiveness and computational complexity of these techniques on simulated and real data.