Dissertationen zum Thema „Radar acquisition“
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1
Modise, Stephen Karabo. „Development of a real time radar acquisition system“. Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/7704.
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Includes bibliographical references.The Geosonde radar system, developed for use in bore holes, includes a data acquisition system. Development is currently being conducted by the Radar Remote Sensing Group at the University of Cape Town and Stellenbosch University. This thesis describes the development of a real time operating system and an overall upgrade of basic interfaces to the Geosonde system. The current system employs the use of an embedded MS-DOS operating system and supports basic user control and data exporting over a serial line. The objectives of this thesis are to perform major upgrades on the system by introducing an XML based form of network control and NTP synchronization of the processing board. As a result, an investigation into the adequacy of MS-DOS as a target operating system, bearing in mind the intended upgrades, was carried out. Taking into consideration the failings of MS-DOS as far as the system requirements are concerned, an investigation into available real time executives was conducted and a decision based on the requirements was made. Embedded GNU/Linux was chosen as the target software platform. The software design of the application shows all the necessary design issues considered. The implementation phase of the thesis describes all the tools necessary to implement the embedded Linux system and all the components necessary to meet the needs of the Geosonde system. The network and serial interfaces were tested and shown to be fully functional. The XML based control in particular offers a more flexible and more platform independent solution than the serial interface.
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Montes, Felix G. „Digital data acquisition for laser radar for vibration analysis“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA350185.
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Thesis (M.S. in Applied Physics) Naval Postgraduate School, June 1998.Thesis advisor(s): Robert C. Harney, D. Scott Davis. "June 1998." Includes bibliographical references (p. 45-46). Also available online.
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Ehrman, Lisa M. „Automatic target recognition using passive radar and a coordinated flight model“. Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131128/unrestricted/ehrman%5Flisa%5Fm%5F200405%5Fms.pdf.
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4
Saintenoy, Albane. „Radar geologique : acquisition de donnees multi-deports pour une mesure multi-parametres“. Paris 7, 1998. http://www.theses.fr/1998PA077144.
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Le radar geologique est un appareil susceptible d'imager les contrastes des parametres electromagnetiques presentes par un milieu. Les trois parametres apparaissant dans les equations de maxwell sont, la permittivite electrique, la conductivite electrique et la permeabilite magnetique. Il n'est pas evident que les contrastes de chacun de ces parametres soient distinguables a partir de l'etude des donnees reflexion de radar geologique. Les parametres electromagnetiques sont positifs non-nuls. Leurs valeurs observees dans les milieux terrestres conduisent naturellement a l'introduction de parametres logarithmiques. L'analyse d'une heterogeneite dans un milieu homogene, lineaire et isotrope, soumis a un champ electromagnetique incident apprend plusieurs choses. Tout d'abord, contrairement a l'intuition, les effets magnetiques sont aussi importants que les effets electriques. Par ailleurs, les anomalies de permittivite electrique logarithmique seule ont le meme comportement que celles de conductivite electrique logarithmique seule. En champ lointain, un contraste ponctuel dans les proprietes electriques d'un milieu, reagit comme un petit dipole electrique dans la direction du champ electrique incident. Par contre, un contraste ponctuel dans les proprietes magnetiques seules, reagit comme un petit dipole magnetique. Pour aborder le probleme inverse, il est plus interessant de decrire un milieu par son impedance effective logarithmique et sa vitesse effective logarithmique. Car, une image radar obtenue en mode monostatique est une image directe des contrastes d'impedance effective. Et, une image radar obtenue avec un assez grand deport contient de l'information sur les contrastes de vitesse effective. Ces deux conclusions sont illustrees par la simulation de l'amplitude du champ diffracte en champ lointain par une anomalie petite devant la longueur d'onde du champ incident, en tenant compte des diagrammes de rayonnement du point diffractant et des antennes emettrice et receptrice, ainsi que de la dispersion geometrique. Les developpements theoriques suggerent l'acquisition de donnees experimentales dans une cuve pleine d'eau. Malgre des difficultes (niveau de bruit trop important et intervalle de deport trop faible), ces donnees montrent qu'il est envisageable de determiner experimentalement les diagrammes de rayonnement des antennes, et valident les simulations.
5
Zhang, Guifu. „Detection and imaging of targets in the presence of clutter based on angular correlation function /“. Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/6085.
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6
Booth, Adam David. „Acquisition and Processing of Three-Dimensional, Multi-Offset Archaeological Ground Penetrating Radar Data“. Thesis, University of Plymouth, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494128.
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7
Kingston, Derek Bastian. „Decentralized control of multiple UAVs for perimeter and target surveillance /“. Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2057.pdf.
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8
Käll, Daniel, und Emelie Lannerhjelm. „Design and Development of Data Acquisition/Processing and Communication Interface for Radar Front-End“. Thesis, Linköpings universitet, Fysik och elektroteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133208.
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This thesis follows the design process of a back end. The purpose of this back end is to interface a radar front end, developed by Acreo Swedish ICT, and stream its digitalized output to a PC using Universal Serial Bus (USB) 3.0. The front end, which acts as a basis for this project, is a Frequency Modulated Continuous Wave (FMCW) radar which is connected to the back end by a header. The header connects the digitalized radar signals, together with two SPI-buses and a few GPIO pins. Thus, enabling configuration and set up of the front end board via a PC. The result of the thesis is a data acquisition board that can be used to interface with the front end. The implemented back end features an FPGA to handle the ADC data from the front end, so the board has DSP capabilities, but can also stream the raw radar data. The FPGA is connected to a USB 3.0 controller through a 32-bit parallel interface. The configuration of the front end, via the produced board, is verified in its functionality and can be controlled by a PC using a simple GUI. Commands are sent through the USB 3.0 controller to a front end controller which handles the communication. Since getting the hardware functional has been the main objective of the thesis, the project has been deemed to be successful. The final result is a back end radar prototype, which has the requested core hardware functionalities. In addition to this, the prototype has the capacity to act as a platform for further expanding its functionality after a hand over of the project to Acreo Swedish ICT.
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James, Russell W., und James C. Bevier. „ACQUISITION AND DISTRIBUTION OF TSPI DATA USING COTS HARDWARE OVER AN ETHERNET NETWORK“. International Foundation for Telemetering, 2003. http://hdl.handle.net/10150/607477.
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International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaThe Western Aeronautical Test Range (WATR) operates the ground stations for research vehicles operating at the NASA Dryden Flight Research Center (DFRC). Recently, the WATR implemented a new system for distributing Time, Space, and Position Information (TSPI) data. The previous system for processing this data was built on archaic hardware that is no longer supported, running legacy software with no upgrade path. The purpose of the Radar Information Processing System (RIPS) is to provide the ability to acquire TSPI data from a variety of sources and process the data for subsequent distribution to other destinations located at the various DFRC facilities. RIPS is built of commercial, off the shelf (COTS) hardware installed in Personal Computers (PC). Data is transported between these computers on a Gigabit Ethernet network. The software was developed using C++ with a modular, object-oriented design approach.
10
Joshi, Sujay S. „Multi-Target Tracking via Nonlinear Least Squares Using Doppler Measurements from a Passive Radar System“. Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14576.
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A passive radar systems opportunistic ability to exploit ambient radio signal reflections makes it ideal for covert target tracking. This strategy, referred to as passive covert radar (PCR) or passive coherent location (PCL), typically exploits FM radio or television signals from powerful local transmitters. In addition to covertness, the absence of a dedicated transmitter helps reduce costs and overall system complexity. While a variety of measurements can be used to estimate a targets position and velocity, such as time difference of arrival (TDOA) and direction of arrival (DOA), this thesis focuses on using only Doppler shift measurements to estimate a targets state.
The work presented in this thesis examines the use of Doppler shift measurements from multiple receivers to solve the target tracking and association problem. A nonlinear least squares error (NLSE) estimation technique, called the Levenberg-Marquardt (L-M) algorithm, is used to determine a targets state (position, velocity) from these Doppler shift measurements. More than one target state can potentially produce identical Doppler shift profiles. In a single-receiver, single-target scenario, it is shown that three additional ghost targets caused by symmetry produce the same Doppler shift response. These ghosts may make state estimation impossible if receive antennas are not physically positioned to block out ghost targets. While the NLSE technique tends to give an accurate solution in one quadrant, three other solutions will symmetrically exist in each of the remaining three quadrants. The addition of either another receiver or another measurement (such as DOA) is needed to break this quadrant ambiguity. This thesis considers adding multiple receivers to accurately associate and track multiple targets. Two target association methods (sequential and simultaneous) are developed, and their computational requirements and accuracy are compared. A grid-aided L-M search technique is investigated in an attempt to provide a better initial target state guess to these association and tracking algorithms.
The analysis and simulation results suggest it is feasible to perform multi-target association and tracking using Doppler shift as the sole measurement. Both of the proposed methods gave optimal target association and converged to reasonably accurate state estimates in most of the Monte Carlo runs.
11
Judkins, Phillip Edward. „Making vision into power : Britain's acquisition of the world's first radar-based integrated air defence system 1935 - 1941“. Thesis, Cranfield University, 2008. http://hdl.handle.net/1826/2577.
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This thesis represents the first application of a current conceptual model of defence acquisition to analyse the historical process, the 1935 - 1941 British acquisition of an integrated air defence system pivoted upon the innovative technology of radar. For successful acquisition of a military capability, the model posits that balanced attention must be focused acoss eight 'lines of developmen' - not only equipment, but also doctrine and concepts, logistics, structures, personnel, organisation, training and information with an overarching requirement for interoperability. This thesis contrasts what turned out to be a successful acquisition, of radar to achive air interception capability by day in the Battle of Britain, with less successful acquisition, or radar to achieve the same capability at night, where an effective system arrived too late to ward off the Blitz. The results establish the validity of the model and its attendant lines of development concepts, and furnish new insights into acquisition processes and military history. Acquisition lessons are derived for the capability-based involvement of industry, for the experience and personality necessary for key managers at different 'life stages' of an acquisition and for the avoidance of over-rapid 'dysfunctional diffusion' of innovative technologies. Historical insights for the Battle of Britain include the sub-optimal performance, for trivial reasons, of key South Coast radars, and the critical importance of the human elements of the radar-based air defence system. For the Blitz, airborne radar hardware has previously been identified as a key problem, whereas research here exposes the greater need for accurate ground control radar, the sound selection and training of pilots and operators in new tactics, and provision of equipment maintainers and test gear. New evidence illustrates that pursuit of an alternative to radar significantly delayed the optimal solution, and throws fresh light both on personalities and on development process management.
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Judkins, P. E. „Making vision into power : Britain's acquisition of the world's first radar-based integrated air defence system 1935 - 1941“. Thesis, Cranfield University, 2008. http://hdl.handle.net/1826/2577.
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This thesis represents the first application of a current conceptual model of defence acquisition to analyse the historical process, the 1935 - 1941 British acquisition of an integrated air defence system pivoted upon the innovative technology of radar. For successful acquisition of a military capability, the model posits that balanced attention must be focused acoss eight 'lines of developmen' - not only equipment, but also doctrine and concepts, logistics, structures, personnel, organisation, training and information with an overarching requirement for interoperability. This thesis contrasts what turned out to be a successful acquisition, of radar to achive air interception capability by day in the Battle of Britain, with less successful acquisition, or radar to achieve the same capability at night, where an effective system arrived too late to ward off the Blitz. The results establish the validity of the model and its attendant lines of development concepts, and furnish new insights into acquisition processes and military history. Acquisition lessons are derived for the capability-based involvement of industry, for the experience and personality necessary for key managers at different 'life stages' of an acquisition and for the avoidance of over-rapid 'dysfunctional diffusion' of innovative technologies. Historical insights for the Battle of Britain include the sub-optimal performance, for trivial reasons, of key South Coast radars, and the critical importance of the human elements of the radar-based air defence system. For the Blitz, airborne radar hardware has previously been identified as a key problem, whereas research here exposes the greater need for accurate ground control radar, the sound selection and training of pilots and operators in new tactics, and provision of equipment maintainers and test gear. New evidence illustrates that pursuit of an alternative to radar significantly delayed the optimal solution, and throws fresh light both on personalities and on development process management.
13
Lillrose, Micah Alexander. „High-Speed Data Acquisition and FPGA Detected Pulse Blanking System for Interference Mitigation in Radio Astronomy“. BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1177.
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Radio astronomy is the discipline dedicated to the study of celestial emissions in the radio band from a few MHz to 300 GHz. In recent years, spurious emissions from man-made devices that operate at these frequencies have made detection of astronomical signals difficult. These harmful RF transmissions are called radio frequency interference (RFI). One strategy to remove RFI is to apply spatial filtering using an array antenna. This thesis documents the development of a high-speed data acquisition system used to record data from 7- and 19-element phased array feeds. The system supports synchronous sampling over all channels and streams data to disk allowing spatial filtering to be applied in post-processing. The development of a time blanking RFI mitigation system was also developed as part of this thesis. Time blanking is a strategy to remove radar interference by blanking the time intervals corrupted by radar transmissions. The two blanking strategies are time window blanking and detected pulse blanking. This thesis documents the design and implementation of a detected pulse blanking system built using FPGAs. The system employs complex signal processing techniques to detect and excise radar transmissions in real time. This FPGA RFI mitigation system is the first to use a matched filter in pulse detection. Successful radio frequency interference mitigation is demonstrated by removing simulated radar interference from a sinusoidal tone.
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Spaulding, Timothy J. (Timothy James) 1979. „Tools for evolutionary acquisition : a study of Multi-Attribute Tradespace Exploration (MATE) applied to the Space Based Radar (SBR)“. Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/82703.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2003.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Statement of responsibility on t.p. reads: 2nd Lieutenant Timothy J. Spaulding, USAF.
Includes bibliographical references (p. 139-142).
by Timothy J. Spaulding.
S.M.
15
Quek, M. „The development of four hotel companies in the UK, 1979-2004“. Thesis, Oxford Brookes University, 2007. https://radar.brookes.ac.uk/radar/items/a6057a2a-4402-4384-81d5-84036508280b/1/.
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The evolution of big business in manufacturing and some service industries, together with the role played in this by merger and acquisition (M&A) activity has been thoroughly researched and is well documented. However, despite' the increasing economic and social importance of the UK hotel industry, its development has been largely neglected. Therefore, this thesis set out to explore the development of big business in the hotel industry through the study of M&A activities. This study employs the multiple case study approach (four UK hotel companies), using M&A theory as the theoretical framework; extensive historical secondary data and semi-structured interviews were carried out for the study, covering a period of 26 years. The analysis was conducted by synthesising data with the M&A theory, in terms of two levels, organisational motives and macro environmental factors. The findings confirm those in the existing literature on what is encompassed by the term big business and the part played by M&A activity in the creation of big business. They also suggest that in the hotel industry the acquisition of brand name and brand rights is an important motive, one which has been neglected in the general M&A literature discussion. These findings added several new dimensions to big business concepts, through illuminating the role of brand and brand right acquisition in the context of the UK hotel industry. This thesis confirms the utility of deploying the wide range and large quantity of publicly available historical secondary information, which is rarely used. In addition, the application of a qualitative and longitudinal approach, applied to management theory, has broadened the research agenda in the study of hotel business, business history and business management theory.
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Brousseau, Christian. „Définition, Réalisation et Tests d'un radar VHF Multifréquence et Multipolarisation - Projet MOSAR“. Phd thesis, Université Rennes 1, 1995. http://tel.archives-ouvertes.fr/tel-00085136.
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Nous présentons dans cette thèse la définition, la réalisation et les tests d'un radar V.H.F. multifréquence et multipolarisation, travaillant dans une gamme allant de 20 à 100 MHz. Ce système dénommé M.O.S.A.R. (Maquette Orientée pour un Système d'Analyse de Résonances) a pour objectif la mesure des sections efficaces radars d'avions dans cette gamme de fréquence, afin de fournir l'ensemble des connaissances qui permettront de concevoir un futur radar opérationnel, destiné à la détection et à l'identification des cibles aériennes.
Dans un premier temps, nous définissons les caractéristiques principales du système, telles que la largeur de l'impulsion émise, la période de récurrence, le nombre de fréquences utilisées, ... . Ensuite, nous construisons un radar à impulsions, monostatique, cohérent, commandé par ordinateur, capable de mesurer et d'enregistrer les signaux rétrodiffusés par des avions. Ce système emploie deux réseaux d'antennes différents pour l'émission et la réception, chacun de ces réseaux utilisant respectivement quatre antennes log-périodiques dipolaires. Les informations relatives aux cibles (amplitude, phase et fréquence Doppler) sont ensuite extraites par une analyse spectrale non linéaire haute résolution.
Nous évaluons les performances du radar et précisons les limites du système. Enfin, des résultats expérimentaux sont présentés et confirment les choix dans la définition et la réalisation du radar.
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Rao, Raghunandan M. „Enhancing Performance of Next-Generation Vehicular and Spectrum Sharing Wireless Networks: Practical Algorithms and Fundamental Limits“. Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/99796.
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Over the last few decades, wireless networks have morphed from traditional cellular/wireless local area networks (WLAN), into a wide range of applications, such as the Internet-of-Things (IoT), vehicular-to-everything (V2X), and smart grid communication networks. This transition has been facilitated by research and development efforts in academia and industry, which has resulted in the standardization of fifth-generation (5G) wireless networks. To meet the performance requirements of these diverse use-cases, 5G networks demand higher performance in terms of data rate, latency, security, and reliability, etc. At the physical layer, these performance enhancements are achieved by (a) optimizing spectrum utilization shared amongst multiple technologies (termed as spectrum sharing), and (b) leveraging advanced spatial signal processing techniques using large antenna arrays (termed as massive MIMO). In this dissertation, we focus on enhancing the performance of next-generation vehicular communication and spectrum sharing systems.
In the first contribution, we present a novel pilot configuration design and adaptation mechanism for cellular vehicular-to-everything (C-V2X) networks. Drawing inspiration from 4G and 5G standards, the proposed approach is based on limited feedback of indices from a codebook comprised of quantized channel statistics information. We demonstrate significant rate improvements using our proposed approach in terrestrial and air-to-ground (A2G) vehicular channels.
In the second contribution, we demonstrate the occurrence of cellular link adaptation failure due to channel state information (CSI) contamination, because of coexisting pulsed radar signals that act as non-pilot interference. To mitigate this problem, we propose a low-complexity semi-blind SINR estimation scheme that is robust and accurate in a wide range of interference and noise conditions. We also propose a novel dual CSI feedback mechanism for cellular systems and demonstrate significant improvements in throughput, block error rate, and latency, when sharing spectrum with a pulsed radar.
In the third contribution, we develop fundamental insights on underlay radar-massive MIMO spectrum sharing, using mathematical tools from stochastic geometry. We consider a multi-antenna radar system, sharing spectrum with a network of massive MIMO base stations distributed as a homogeneous Poisson Point Process (PPP) outside a circular exclusion zone centered around the radar. We propose a tractable analytical framework, and characterize the impact of worst-case downlink cellular interference on radar performance, as a function of key system parameters. The analytical formulation enables network designers to systematically isolate and evaluate the impact of each parameter on the worst-case radar performance and complements industry-standard simulation methodologies by establishing a baseline performance for each set of system parameters, for current and future radar-cellular spectrum sharing deployments.
Finally, we highlight directions for future work to advance the research presented in this dissertation and discuss its broader impacts across the wireless industry, and policy-making.Doctor of Philosophy
The impact of today's technologies has been magnified by wireless networks, due to the standardization and deployment of fifth-generation (5G) cellular networks. 5G promises faster data speeds, lower latency and higher user security, among other desirable features. This has made it capable of meeting the performance requirements of key infrastructure such as smart grid and mission-critical networks, and novel consumer applications such as smart home appliances, smart vehicles, and augmented/virtual reality. In part, these capabilities have been achieved by (a) better spectrum utilization among various wireless technologies (called spectrum sharing), and (b) serving multiple users on the same resource using large multi-antenna systems (called massive MIMO). In this dissertation, we make three contributions that enhance the performance of vehicular communications and spectrum sharing systems. In the first contribution, we present a novel scheme wherein a vehicular communication link adapts to the channel conditions by controlling the resource overhead in real-time, to improve spectral utilization of data resources. The proposed scheme enhances those of current 4G and 5G networks, which are based on limited feedback of quantized channel statistics, fed back from the receiver to the transmitter. In the second contribution, we show that conventional link adaptation methods fail when 4G/5G networks share spectrum with pulsed radars. To mitigate this problem, we develop a comprehensive signal processing framework, consisting of a hybrid SINR estimation method that is robust and accurate in a wide range of interference and noise conditions. Concurrently, we also propose a scheme to pass additional information that captures the channel conditions in the presence of radar interference, and analyze its performance in detail. In the third contribution, we focus on characterizing the impact of 5G cellular interference on a radar system in shared spectrum, using mathematical tools from stochastic geometry. We model the worst-case interference scenario, and study the impact of the system parameters on the worst-case radar performance. In summary, this dissertation advances the state-of-the-art in vehicular communications and spectrum sharing, through (a) novel contributions in protocol design and (b) development of mathematical tools for performance characterization.
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Zebiri, Aniss. „Estimation de la dynamique à partir de l'assimilation d'images radars multi-échelles : application à la prévision des taux de précipitation à courte échéance, à partir des images radars“. Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS094.
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La prévision du taux de précipitations occupe une place particulière, compte tenu de leur impact direct sur l'économie. Ces prévisions permettent, d’une part, d’anticiper les contraintes environnementales et d’optimiser par exemple la gestion des ressources en eau, et, d’autre part, d'anticiper les risques d’inondations. L'objectif de ces travaux est d'améliorer la prévision à court terme de taux de précipitation de l'algorithme Rain Nowcast (RN) qui fournissait auparavant des prévisions pertinentes pour un horizon temporel de 30 minutes. Une approche multi-échelle a été proposée qui permet de fusionner deux types de données radars, de résolutions spatiales différentes afin d'augmenter l'horizon temporel de prévision tout en garantissant une prévision de qualité en terme de localisation et quantité de précipitation. Nous proposons deux algorithmes multi-échelles , le premier est séquentiel «Sequential Motion RN» : une estimation globale avec les données régionales pour guider une estimation locale avec des données locales. Le second est parallèle «Parallel Motion RN»: utilisation simultanée des données locales et régionales. Deux autres méthodes dédiées à la prévision sont proposées : l'hypothèse de vent géostrophique, consiste à corriger la sous-estimation de l'intensité du mouvement pour les structures peu contrastées dans les images radars. La deuxième méthode : la correction d’histogramme, consiste à corriger l’effet de lissage causé par le schéma numérique en utilisant une technique largement décrite dans la littérature, pour corriger les mesures de pluviométrie estimées à partir d’images radarThe forecast of precipitation takes a special place, in view of their direct economic impact. These forecasts allow, on the one hand, to anticipate environmental constraints and optimise, for example, the management of water resources, and, on the other hand, to anticipate flood risks. The aim of this study is to improve the nowcasting of precipitation rate of the Rain Nowcast (RN) algorithm that previously provides relevant forecasts for a time horizon of 30 minutes. A multi-scale approach is suggested to merge two types of radar data, with different spatial resolutions, in order to increase the time horizon of the forecast while ensuring a forecast of quality in terms of both location and quantity of precipitation. We propose two multi-scales algorithms, the first one is sequential "Sequential Motion RN" : a globale estimation with regional data to guide a local estimation with local data. The second is parallel "Parallel Motion RN": using both local and regional data simultaneously. Two other methods dedicated to forecast have been proposed: geostrophic wind hypothesis, which involves correcting the underestimation motion intensity for low contrast structures in radar images. The second method: histogram correction, which involves correcting the smoothing effect caused by the numerical scheme by using a widely described technique in literature, to correct raingauge measurements estimated from radar images
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Merelle, Vincent. „Concept de radars novateurs pour la vision à travers les milieux opaques“. Thesis, La Rochelle, 2018. http://www.theses.fr/2018LAROS017/document.
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La « vision » à travers les milieux opaques (murs, cloisons, décombres, ou plus généralement tout milieu qui occulte la vision humaine) est l’un des problèmes clefs du contrôle et de la sécurité. Il apparaît à l’heure actuelle un réel besoin de disposer de dispositifs d’observation à travers ces milieux pour des applications tant militaires (lors des assauts, des prises d’otages, etc.) que civiles (recherche de personnes enfouies dans des décombres, dans un incendie, etc). Les avancées sur cette problématique ont conduit à mettre en place des systèmes radars à très courte portée, opérationnels pour la détection et le tracking de personnes dans des environnements simples. Cependant ils nécessitent que les cibles soient en déplacement afin de les différencier des objets statiques. Cette limitation constitue un défaut majeur pour un certain nombre de scénarii réels où des personnes, par stratégie ou par contrainte, restent immobiles. Ces travaux de thèse visent à explorer les mécanismes de détection de personnes statiques par le biais de leurs micro-mouvements, e.g. des mouvements induits par le thorax lors de la respiration. Nous avons étudié - d’un point de vue théorique - les principes physiques sous-jacents à la détection de ces micro-mouvements par radar UWB impulsionnel à partir du mécanisme Doppler impulsionnel. Ce dernier s’appuie sur des mesures consécutives des phases des impulsions réfléchies. La compréhension de ce phénomène a permis de définir une architecture radar impulsionnelle et de la positionner, en termes de contributions, au regard des différents radars UWB proposés dans la littérature : le FMCW et le radar de bruit. Deux dispositifs radars ont servi de support à ce travail. Le premier, de type démonstrateur académique, repose sur l’utilisation d’un oscilloscope rapide pour numériser les impulsions UWB de 3 à 6 GHz de bande. Il a permis de mettre en place une chaîne de traitement complète de vision à travers les murs. Le second dispositif est un prototype radar développé autour d’une plateforme de numérisation ultra-rapide (100 Gsps par échantillonnage équivalent) de fréquence de rafraîchissement très élevée (100 Hz). Il est construit autour d’un FPGA, d’un ADC rapide (1,25 GHz) et d’un T&H très large bande (18 GHz). Il permet ainsi la détection des micro-mouvements par traitement Doppler impulsionnel"Vision" through opaque environments (walls, partitions, rubble, or any environment that obscures human vision) is one of the key issues of control and security. Advances on this issue have led to operational shortrange radar systems for people detection and tracking in simple environments. However, most of them require the targets to move in order to differentiate them from static objects. This requirement constitues a major shortcoming for a certain number of real scenarios where people, by strategies or by constraints, remain motionless. Hence, this thesis aims to explore the mechanisms of detection of static people through their micro-movements, e.g. movements induced by the thorax during breathing. We have studied - from a theoretical point of view - the physical principles underlying the detection of these micro-movements by pulsed UWB radar with the pulsed Doppler phenomenon, which relies on consecutive measurements of the reflected pulses phases. The understanding of this phenomenon made it possible to define a radar architecture and to position it, in terms of contributions, with regard to the different UWB radars proposed in the literature : the FMCW and the noise radar. Two radar devices served as support for this work. An academic demonstrator based on the use of a fast oscilloscope to digitize the pulses. It allowed to set up a complete processing chain for the application of vision through the walls. The second device is a radar prototype developed around a high-speed scanning platform (100 Gsps perequivalent sampling) with a very high refresh rate (100 Hz). This prototype is built around an FPGA, a fast ADC (1.25 GHz) and a very wide band T&H (18 GHz). This thereby enables to detect micro-movements by pulsed Doppler processing
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Touati, Nadjah. „Optimisation des formes d'ondes d'un radar d'aide à la conduite automobile, robustes vis-à-vis d'environnements électromagnétiques dégradés“. Thesis, Valenciennes, 2015. http://www.theses.fr/2015VALE0031/document.
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Divers radars sont développés pour des besoins d’aide à la conduite automobile de sécurité mais aussi de confort. Ils ont pour but de détecter la présence d’obstacles routiers afin d’éviter d’éventuelles collisions. La demande actuelle en termes de capteurs radars pour l’automobile connaît une croissance importante et les technologies employées doivent garantir de bonnes performances dans un environnement dégradé par les signaux interférents des autres utilisateurs. Dans cette thèse, nous nous intéressons au développement d’un système radar performant en tout lieu et en particulier dans un contexte multi-utilisateurs. A ce propos, nous proposons de nouvelles formes d’ondes qui se basent sur la combinaison des codes fréquentiels de Costas et d’autres techniques de compression d’impulsion en exploitant les signaux de Costas modifiés. La conception adoptée permet, grâce à la diversité introduite, de synthétiser un nombre important de formes d’ondes. Nous avons, ensuite, exploité deux approches d’estimation des paramètres des cibles. La première, plutôt classique, se base sur le traitement Doppler dans un train d’impulsions cohérent. La deuxième, récente dans le domaine automobile, se base sur la technique dite de « Compressed Sensing ». Une adaptation de ces algorithmes pour les signaux proposés a été discutée dans des environnements bruités et multi-cibles. L’ensemble de ces travaux contribue à explorer de nouvelles formes d’ondes, autres que celles utilisées dans les radars actuels et à proposer un traitement innovant en réception, adapté aux radars en général et à l’automobile en particulierSeveral driver assistance radars are developed for security and comfort requirements. Their goal is among others to detect the presence of obstacles for collision avoidance. The current demand in terms of automotive radar sensors experience a significant growth and the technologies being employed must ensure good performances especially in an environment degraded by interfering signals of other users. In this thesis, we are interested in developing a radar system which is effective in all situations especially in a multi-user context. For this purpose, we propose novel radar waveforms based on the combination of frequency hopping Costas codes and other pulse compression techniques, using modified Costas signals. The design approach allows to synthesize a significant number of waveforms, thanks to the high diversity introduced. Afterwards, we have exploited two estimation of target parameters approaches. The first one, quite classic, is based on Doppler processing in a coherent pulse train. The second one, recent in the automotive field , is based on the Compressed sensing techniques. An adaptation of these algorithms to proposed signals is discussed in noisy and multi-target environments. All these works contribute in one hand to explore novel radar waveforms, complement to those currently used in automotive radars and in another hand to propose an innovative processing at the receiver level, suited to radar applications in general and automotive ones in particular
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Lutz, Pascale. „Acquisitions multi-modes en radar géologique de surface“. Pau, 2002. http://www.theses.fr/2002PAUU3009.
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L'imagerie de la subsurface par radar géologique de surface peut être significativement améliorée à partir d'acquisitions multi-modes. Des prospections utilisant plusieurs configurations d'antennes ont permis de déduire des informations sur la sensibilité des structures vis-à-vis de la polarisation de l'onde incidente, leurs propriétés à modifier cette polarisation et leurs localisations en trois dimensions. A partir de ces données, des pseudo-sections à faible degré directionnel ou à mode d'acquisition neutre ainsi que des cartes du facteur de dépolarisation ont été établies. Des études polarimétriques ont permis de souligner le lien entre les propriétés des réflecteurs à modifier la polarisation de l'onde incidente et des phénomènes inhabituels perturbateurs au niveau de sections en point milieu commun en mode TE. Des sections relatives à un réseau directif d'émetteurs déphasés ont également été reconstituées à partir de données acquises en point de réception commun. Suite à l'orientation du faisceau dans différentes directions, la localisation des réflecteurs est plus précise, la profondeur d'investigation maximale est augmentée et le rapport "maximum de l'enveloppe sur minimum de l'enveloppe" est amélioré. En vue de la création d'un véritable antenne réseau [5-50] MHz en émission, des antennes-éléments ont été réalisées. Ces dernières fonctionnent correctement en réception ; elles permettront d'atteindre l'objectif final. Les travaux de recherche actuels consistent en la conception du générateur à transistors à avalanche qui les alimenteraGround penetrating radar images can be signifiquently improved by multi-mode recordings. Surveys using several configurations of the antennas allow to deduce information on the incident wave sensitivity of the structures, their 3-D location and their depolarizing properties. Pseudo-sections characterized by a low degree of directionality or by a neutral acquisition mode have been computed from these multi-configuration datas, as well as maps of the polarization match factor. Polarimetric surveys have underlined the link between interface depolarization and unusual disturbing phenomena on TE mode common mid point gathers. Sections relative to a directive array of phase-shifted transmitters have been reconstructed from common receiver gathers. The beam adjusting towards several directions allows to a more precise reflector location, a greater maximal investigation depth and improvement concerning the " envelope maximum to envelope minimum ratio ". With the aim to carry out an actual array of transmitters in the [5-50] MHz range, single-element antennas have been built. These latters work properly as receivers and will allow to achieve our final aim. At present, the study consists in the design of the avalanche transistor generator
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Lasne, Yannick. „Imagerie radar basse fréquence pour l'exploration des zones arides terrestres et martiennes : détection de l'humidité du sous-sol et cartographie de la paléo-hydrologie“. Toulouse 3, 2005. https://tel.archives-ouvertes.fr/tel-00180231.
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Ces travaux de recherche proposent une approche expérimentale pour étudier les capacités de l'imagerie radar basse fréquence pour la détection des zones humides dans le sous-sol des régions arides terrestres et martiennes et la cartographie géologique de leur proche subsurface. En particulier, l'analyse phasimétrique d'images SAR (bande L) de la Dune du Pyla nous a permis de mettre en évidence un comportement particulier de la différence de phase copolaire, lié à la présence d'une zone humide dans la subsurface. Afin d'interpréter et de modéliser ce phénomène, nous avons développé un modèle analytique de diffusion simple, de type IEM, complété par une expression analytique du terme de diffusion par réflexion multiple. Simulant avec succès le phénomène observé, notre modèle confirme que le signal de phase est généré par le profil d'humidité des structures enfouies occasionnant une composante de diffusion par réflexion multiple. Il a également été montré que ce signal de phase copolaire permet la détection d'interfaces humides à des profondeurs plus importantes que celles autorisées par l'analyse des indicateurs radiométriques classiques. Participant au programme Terrestrial Analog to Mars de la NASA, nous avons également travaillé à la définition des performances d'un système SAR orbital en bande P pour la détection d'humidité dans la proche subsurface de la planète Mars, au moyen de la phase radar. Incluant un terme de diffusion de volume, notre précédent modèle IEM montre que la présence d'hétérogénéités dans les premiers mètres de la croûte martienne pourrait altérer les performances de la différence de phase copolaire pour la détection d'humidité en terme de profondeur d'investigation. Néanmoins, nos résultats de simulations indiquent qu'un tel système SAR, exploitant la phase copolaire, autoriserait la détection de l'humidité et son suivi à l'échelle saisonnière jusqu'à des profondeurs de 3 mètres dans les régions présentant un contexte géologique favorable i. E. Une faible concentration de diffuseurs de surface et de proche subsurface. Au-delà de la détection d'humidité des sols, nous avons également cherché à mettre en évidence l'apport de l'imagerie radar pour les applications de cartographie d'interfaces géologiques à grande échelle au moyen de systèmes radar orbitaux. L'analyse polarimétrique de données SIR-C/X-SAR pour la Mauritanie a permis de montrer le potentiel de l'imagerie radar basse fréquence pour la détection de structures géologiques de surface ainsi que pour la cartographie de la paléo-hydrologie de la proche subsurface en contexte aride. En particulier, nos résultats ont montré que les données polarimétriques fournissent non seulement des éléments d'information sur les mécanismes de diffusion mis en jeu, mais permettent également de différencier les structures de surface par la rugosité qu'elles occasionnent, des structures de subsurface par la diffusion de volume qu'elles génèrentThese research tasks propose an experimental approach to study the capabilities of low frequency radar imagery for the detection of moisture in the first few meters of the terrestrial and Martian arid areas and the geological cartography of their close subsurface. In particular, the phasimetric analysis of L-band SAR images of the Pyla Dune (France) made it possible to highlight a particular behaviour of the copolarized phase difference, related to the presence of buried wet structures in the subsurface. In order to interpret and to model this phenomenon, we developed an analytical single-scattering model based on the IEM, supplemented by an analytical expression of the multiple scattering term. Simulating successfully the studied phenomenon, our model confirms the phase signal being generated by the moisture profile of hidden structures because of the multiple scattering component. It was also shown that this particular phase signature allows the detection of wet interfaces at depths more significant than those authorized by the analysis of the traditional radiometric indicators. Taking part in the program Terrestrial Analog to Mars of NASA, we also worked with the definition of the performances of an orbital P-band SAR system for detecting moisture in the upper few meters of the planet Mars, by means of the copolarized phase difference. Including a volume scattering term, our preceding IEM model shows that the presence of heterogeneities in the first meters of the Martian crust could deteriorate the performances of the copolar phase signal for the detection of moisture in term of depth of investigation. Nevertheless, our results of simulations indicate that such a SAR system, exploiting the copolar radar phase, would authorize the detection of moisture and its follow-up on a seasonal scale until some 3 meters depths in the areas presenting a favourable geological context i. E. A weak concentration of surface and subsurface scatterers. .
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Lasne, Y. „Imagerie radar basse fréquence pour l'exploration des zones arides terrestres et martiennes : détection de l'humidité du sous-sol et cartographie de la paléohydrologie“. Phd thesis, Université Paul Sabatier - Toulouse III, 2005. http://tel.archives-ouvertes.fr/tel-00320160.
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Ces travaux de recherche proposent une approche expérimentale pour étudier les capacités de l'imagerie radar basse fréquence pour la détection des zones humides dans le sous-sol des régions arides terrestres et martiennes et la cartographie géologique de leur proche subsurface. En particulier, l'analyse phasimétrique d'images SAR (bande L) de la Dune du Pyla nous a permis de mettre en évidence un comportement particulier de la différence de phase copolaire, lié à la présence d'une zone humide dans la subsurface. Afin d'interpréter et de modéliser ce phénomène, nous avons développé un modèle analytique de diffusion simple, de type IEM, complété par une expression analytique du terme de diffusion par réflexion multiple. Simulant avec succès le phénomène observé, notre modèle confirme que le signal de phase est généré par le profil d'humidité des structures enfouies occasionnant une composante de diffusion par réflexion multiple. Il a également été montré que ce signal de phase copolaire permet la détection d'interfaces humides à des profondeurs plus importantes que celles autorisées par l'analyse des indicateurs radiométriques classiques. Participant au programme Terrestrial Analog to Mars de la NASA, nous avons également travaillé à la définition des performances d'un système SAR orbital en bande P pour la détection d'humidité dans la proche subsurface de la planète Mars, au moyen de la phase radar. Incluant un terme de diffusion de volume, notre précédent modèle IEM montre que la présence d'hétérogénéités dans les premiers mètres de la croûte martienne pourrait altérer les performances de la différence de phase copolaire pour la détection d'humidité en terme de profondeur d'investigation. Néanmoins, nos résultats de simulations indiquent qu'un tel système SAR, exploitant la phase copolaire, autoriserait la détection de l'humidité et son suivi à l'échelle saisonnière jusqu'à des profondeurs de 3 mètres dans les régions présentant un contexte géologique favorable i.e. une faible concentration de diffuseurs de surface et de proche subsurface. Au-delà de la détection d'humidité des sols, nous avons également cherché à mettre en évidence l'apport de l'imagerie radar pour les applications de cartographie d'interfaces géologiques à grande échelle au moyen de systèmes radar orbitaux. L'analyse polarimétrique de données SIR-C/XSAR pour la Mauritanie a permis de montrer le potentiel de l'imagerie radar basse fréquence pour la détection de structures géologiques de surface ainsi que pour la cartographie de la paléo-hydrologie de la proche subsurface en contexte aride. En particulier, nos résultats ont montré que les données polarimétriques fournissent non seulement des éléments d'information sur les mécanismes de diffusion mis en jeu, mais permettent également de différencier les structures de surface par la rugosité qu'elles occasionnent, des structures de subsurface par la diffusion de volume qu'elles génèrent.
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Lasne, Yannick. „Imagerie radar basse fréquence pour l'exploration des zones arides terrestres et martiennes : détection de l'humidité du sous-sol et cartographie de la paléohydrologie“. Phd thesis, Université Paul Sabatier - Toulouse III, 2005. http://tel.archives-ouvertes.fr/tel-00180231.
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Ces travaux de recherche proposent une approche expérimentale pour étudier les capacités de l'imagerie radar basse fréquence pour la détection des zones humides dans le sous-sol des régions arides terrestres et martiennes et la cartographie géologique de leur proche subsurface. En particulier, l'analyse phasimétrique d'images SAR (bande L) de la Dune du Pyla nous a permis de mettre en évidence un comportement particulier de la différence de phase copolaire, lié à la présence d'une zone humide dans la subsurface. Afin d'interpréter et de modéliser ce phénomène, nous avons développé un modèle analytique de diffusion simple, de type IEM, complété par une expression analytique du terme de diffusion par réflexion multiple. Simulant avec succès le phénomène observé, notre modèle confirme que le signal de phase est généré par le profil d'humidité des structures enfouies occasionnant une composante de diffusion par réflexion multiple. Il a également été montré que ce signal de phase copolaire permet la détection d'interfaces humides à des profondeurs plus importantes que celles autorisées par l'analyse des indicateurs radiométriques classiques. Participant au programme Terrestrial Analog to Mars de la NASA, nous avons également travaillé à la définition des performances d'un système SAR orbital en bande P pour la détection d'humidité dans la proche subsurface de la planète Mars, au moyen de la phase radar. Incluant un terme de diffusion de volume, notre précédent modèle IEM montre que la présence d'hétérogénéités dans les premiers mètres de la croûte martienne pourrait altérer les performances de la différence de phase copolaire pour la détection d'humidité en terme de profondeur d'investigation. Néanmoins, nos résultats de simulations indiquent qu'un tel système SAR, exploitant la phase copolaire, autoriserait la détection de l'humidité et son suivi à l'échelle saisonnière jusqu'à des profondeurs de 3 mètres dans les régions présentant un contexte géologique favorable i.e. une faible concentration de diffuseurs de surface et de proche subsurface. Au-delà de la détection d'humidité des sols, nous avons également cherché à mettre en évidence l'apport de l'imagerie radar pour les applications de cartographie d'interfaces géologiques à grande échelle au moyen de systèmes radar orbitaux. L'analyse polarimétrique de données SIR-C/XSAR pour la Mauritanie a permis de montrer le potentiel de l'imagerie radar basse fréquence pour la détection de structures géologiques de surface ainsi que pour la cartographie de la paléo-hydrologie de la proche subsurface en contexte aride. En particulier, nos résultats ont montré que les données polarimétriques fournissent non seulement des éléments d'information sur les mécanismes de diffusion mis en jeu, mais permettent également de différencier les structures de surface par la rugosité qu'elles occasionnent, des structures de subsurface par la diffusion de volume qu'elles génèrent.
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Fromenteze, Thomas. „Développement d'une technique de compression passive appliquée à l'imagerie microonde“. Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0061/document.
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Ces travaux portent sur le développement d'une technique de compression appliquée à la simplification des systèmes d'imagerie dans le domaine microonde. Cette approche repose sur le développement de composants passifs capables de compresser les ondes émises et reçues, autorisant ainsi une réduction du nombre de modules actifs nécessaires au fonctionnement de certaines architectures de radars. Ce principe est basé sur l'exploitation de la diversité modale présente dans les composants développés, le rendant compatible avec l'utilisation de très larges bandes passantes. Plusieurs preuves de concept sont réalisées au moyen de différents composants étudiés dans cet ouvrage, permettant d'adapter cette technique à de nombreuses spécifications d'architectures et de bandes passantesThis work is focused on the development of a compressive technique applied to the simplification of microwave imaging systems. This principle is based on the study of passive devices able to compress transmitted and received waves, allowing for the reduction of the hardware complexity required by radar systems. This approach exploits the modal diversity in the developed components, making it compatible with ultra wide bandwidth. Several proofs of concept are presented using different passive devices, allowing this technique to be adapted to a large variety of architectures and bandwidths
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Kwon, Ki Hoon. „Optimizing ECM techniques against monopulse acquisition and tracking radars“. Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26140.
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Velmurugan, Rajbabu. „Implementation Strategies for Particle Filter based Target Tracking“. Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/14611.
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This thesis contributes new algorithms and implementations for particle filter-based target tracking. From an algorithmic perspective, modifications that improve a batch-based acoustic direction-of-arrival (DOA), multi-target, particle filter tracker are presented. The main improvements are reduced execution time and increased robustness to target maneuvers. The key feature of the batch-based tracker is an image template-matching approach that handles data association and clutter in measurements. The particle filter tracker is compared to an extended Kalman filter~(EKF) and a Laplacian filter and is shown to perform better for maneuvering targets. Using an approach similar to the acoustic tracker, a radar range-only tracker is also developed. This includes developing the state update and observation models, and proving observability
for a batch of range measurements.
From an implementation perspective, this thesis provides new low-power and real-time implementations for particle filters. First, to achieve a very low-power implementation, two mixed-mode implementation strategies that use
analog and digital components are developed. The mixed-mode implementations use analog, multiple-input translinear element (MITE) networks to realize nonlinear functions. The power dissipated in the mixed-mode implementation of a particle filter-based, bearings-only tracker is compared to a digital implementation that uses the CORDIC algorithm to realize the nonlinear functions. The mixed-mode method that uses predominantly analog components is shown to provide a factor of twenty improvement in power savings compared to a digital implementation. Next, real-time implementation strategies for the batch-based acoustic DOA tracker are developed. The characteristics of the digital implementation of the tracker are quantified using digital signal processor (DSP) and field-programmable gate array (FPGA) implementations. The FPGA implementation uses a soft-core or hard-core processor to implement the Newton search in the particle proposal stage. A MITE implementation of the nonlinear DOA update function in the tracker is also presented.
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LIU, SHUO-ZHANG, und 劉碩彰. „A transportable VHF radar system:signal processing and data acquisition“. Thesis, 1992. http://ndltd.ncl.edu.tw/handle/09368294663011701240.
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Burgess, Norman Keith. „A high speed radar data acquisition and processing system for an experimental monopulse tracking radar“. Thesis, 1994. http://hdl.handle.net/10539/21786.
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A project report submitted to the Faculty of Engineering,
University of the Witwatersrand,
in partial fulfilment of the requirements for the degree of
Master of Science in Engineering.
Johannesburg, April 1994.This project report describes the development of a high speed data acquisition and processing system (DAPS) for an experimental monopulse tracking radar at the Division of Manufacturing and Aeronautical Systems Technology (Aerotek), of CSIR. The system development involved replacement of existing data acquisition hardware and software with an enhanced, PC based, integrated high speed data acquisition system. The system is used for radar acceptance testing, radar monitoring during trials and capture of large volumes of data for off-line processing to pursue research into the phenomenology of radar cross section. The work performed during the execution of this project represents an effort in three technology areas. These are Digital hardware design of custom interface hardware for the ISA bus as implemented on most PC's. This was not a major aim of the project, but was required in the absence of suitable hardware. Formal software specification and design using the real time extensions of Hatley and Pirbhai to the Yourdon and de Marco data flow analysis methodology. The existing software had not been designed using any formal method, and suffered a lack of documentation throughout all phases of the development. The way this project was undertaken has served as an exercise in following the approach, which resulted in a product which is better documented and more maintainable. There are elements of total quality management that are still missing though. • Quality management during software development. At the time of commencement of the project there was no formal commitment to software quality management at Aerotek. Commitment to IS09000 accreditation in future has required that a solid quality ethic and management system be instituted. Current software development follows this approach. A discussion of the topic appears in the conclusion. The DAPS has been in use for approximately two years now. With continued minor modification to meet new user requirements, it has successfully enhanced the usability of the radar system during trials and measurements with the SAAF.
MT2017
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Anderson, Michael Glen 1979. „Design of multiple frequency continuous wave radar hardware and micro-Doppler based detection and classification algorithms“. Thesis, 2008. http://hdl.handle.net/2152/4000.
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Micro-Doppler is defined as scattering produced by non-rigid-body motion. This dissertation involves the design of a multiple frequency continuous wave (MFCW) radar for micro-Doppler research and detection and classification algorithm design. First, sensor hardware is developed and tested. Various design tradeoffs are considered, with the application of micro-Doppler based detection and classification in mind. A diverse database of MFCW radar micro-Doppler signatures was collected for this dissertation. The micro-Doppler signature database includes experimental data from human, vehicle, and animal targets. Signatures are acquired from targets with varying ranges, velocities, approach angles, and postures. The database is analyzed for micro-Doppler content with a focus on its application to target classification. Joint time-frequency detection algorithms are developed to improve detection performance by exploiting noise-spreading and the micro-Doppler phenomenon. Following detection algorithm development, this dissertation covers the design of micro- Doppler feature extraction, feature selection, and classification algorithms. Feature selection is performed automatically via a Fisher score initialized sequential backward selection algorithm. Classification is performed using two distinct approaches: a generative statistical classification algorithm based on Gaussian mixture models (GMMs) and a discriminative statistical classification algorithm based on support vector machines (SVMs). Classifier performance is analyzed in detail on a micro-Doppler signature database acquired over a three-year period. Both the SVM and GMM classifiers perform well on the radar target classification task (high accuracy, low nuisance alarm probability, high F-measure, etc.). The performance of both classifiers is remarkably similar, and neither algorithm dominates the other in any performance metric when using the chosen feature set. (However, the difference between SVM and GMM classification accuracy becomes statistically significant when many redundant features are present in the feature set.) The accuracy of both classifiers is shown to vary as a function of approach angle, which physically corresponds to the angular dependence of micro-Doppler. The results suggest that overall classifier performance is more sensitive to feature selection than classifier selection (with GMM being more sensitive to redundant features than SVM). Both classifiers are robust enough to handle human targets attempting to evade detection by either army crawling or hands-and-knees crawling.text
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Dell'Aglio, Domenico Antonio Giuseppe. „Synthetic Aperture Radar for Natural Hazards Observation: from Acquisition Geometry to Applications to Landslides“. Tesi di dottorato, 2020. http://www.fedoa.unina.it/13098/1/DellAglio_PhD_Thesis.pdf.
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The research topics of this Thesis are related to the remote sensing field using Synthetic Aperture Radar (SAR) data. The research activities started from the idea that remote sensing techniques and applications play a key rule in the Earth observation. Especially nowadays, where the effects of climate change on our life is more and more evident. Starting from this general statement, three research topics were identified and investigated.
The first one concerns the SAR acquisition modes. In particular, we present a unified formulation able to express SAR raw signals for any acquisition geometry. This formulation is then used to show that raw signals simulation of extended scenes can be achieved taking also accounting for sensor trajectory deviations.
The second topic has been conducted during the 2019, under the aegis of the Progressive Systems Srl. The focus of my specific research activity has been to evaluate a preliminary multi-temporal analysis of Sentinel-1 data for the monitoring of subsidence phenomena on two selected target: the Fiumicino Airport and the Brumadinho dam.
The third topic can be considered complementary to the second one. In this case, the suitability of space-borne SAR Sub-Pixel Offset Tracking technique for the long-term monitoring of landslides in vegetated areas has been investigated. In particular, the case study of the Slumgullion landslide (Colorado, US) has been explored.
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Frenzel, Francis. „Acquisition Of 3D Ground-Penetrating Radar Data by an Autonomous Multiagent Team in Support of In-situ Resource Utilization“. Thesis, 2010. http://hdl.handle.net/1807/25584.
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This dissertation details the design and development of a mobile autonomous platform from which to conduct a 3D ground-penetrating radar survey. The system uses a three-rover multiagent team to perform a site-selection activity during a lunar analog mission. The work took place beginning in 2008 and culminated in a final field test on Mauna Kea in Hawaii. This demonstration of autonomous acquisition of 3D ground-penetrating radar in a space robtic application is promising not only for in-situ resource utilization, but also for the concept of multiagent teaming.