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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Detection and Tracking of Human Targets using Ultra-Wideband Radar

Östman, Andreas January 2016 (has links)
The purpose of this thesis was to assess the plausibility of using two Ultra- Wideband radars for detecting and tracking human targets. The detection has been performed by two different types of methods, constant false-alarm rate methods and a type of CLEAN algorithm. For tracking the targets, multiple hypothesis tracking has been studied. Particle filtering has been used for the state prediction, considering a significant amount of uncertainty in a motion model used in this thesis project. The detection and tracking methods have been implemented in MATLAB. Tracking in the cases of a single target and multiple targets has been investigated in simulation and experiment. The simulation results in these cases were compared with accurate ground truth data obtained using a VICON optical tracking system. The detection methods showed poor performance when using data that had been collected by the two radars and post-processed to enhance target features. For single targets, the detections were accurate enough to continuously track a target moving randomly in a controlled area. In the multiple target cases the tracker was not able to distinguish the multiple moving subjects.
2

Compact Low-Cost Ultra-Wideband Pulsed-Radar System

Pitcher, Aaron D. January 2019 (has links)
Recently, the advent of the integrated circuits (ICs), the monolithic microwave integrated circuits (MMICs) and the multiprocessing computer technology have provided numerous opportunities to make the radar technology compact and affordable. The ultra-wideband (UWB) technology gives many advantages over the traditional narrowband radar systems due to its high spatial resolution, low susceptibility to interference, superior penetration depths, and increased peak power. However, the ability to digitize and reconstruct the full UWB signal spectrum comes at a considerable cost and size. Ultimately, high-speed sampling rates above 10 giga-samples per second (GSPS) are beyond the abilities of conventional analog-to-digital converters (ADCs). The UWB technology is inaccessible to the end-user for various advanced applications in microwave imaging and detection. The purpose of this work is to provide a low-cost, dual-channel UWB pulsed-radar system that is readily available with a 1:10 system bandwidth. The advancements in low-cost alternatives for compact and portable designs empower many promising UWB applications. Here, the desired bandwidth is from 500 MHz to 5 GHz, which utilizes a fast pulse repetition frequency (PRF) in short-range applications. The preliminary results from the novel Equivalent-Time Sampling Receiver are promising with an equivalent-time sampling rate up to 20 GSPS. Nevertheless, the system design is versatile for bandwidth tuning in order to meet the needs of different applications. This versatility is enabled by: i) selection of the effective sampling rate through the field-programmable gate array (FPGA) programming environment, ii) choice of the receivers' front-end track and hold (T & H) amplifier bandwidth, iii) a collection of different PRFs from the low kilohertz up to 20 MHz, iv) tuning of the pulse generator bandwidth, and v) simultaneous multi-channel capabilities enabling antenna beam-forming, polarization diversity and spatial diversity. The result is a fully functional prototype that costs a fraction of traditional bench-top solutions. / Thesis / Master of Applied Science (MASc)
3

Preliminary Evaluation of the Clinical Value of an Ultra-Wideband Radar Sensor for Heart Assessment / Preliminär Utvärdering av det Kliniska Värdet av en Ultra Wideband Radar för hjärtbedömning

Lundbäck, Kristoffer, Dahn, Leonardo January 2016 (has links)
Heart dysfunction is a worldly widespread problem that currently is one of the leading causes of death. Studies indicate that many deaths related to cardiac dysfunction could have been prevented if discovered early. Contemporarily, ultrasound and electrocardiography are indispensable modalities for diagnostic purposes and analysis of cardiac function. The Ventricorder is an Ultra-Wideband radar sensor manufactured by the Norwegian company Novelda. Ventricorder has been shown to be able detect heart movements and breathing but its actual clinical value remains to be investigated. The Cardiac State Diagram (CSD) is a pre-clinical software tool for visualization of the heart's mechanical function. The CSD is confirmed by pilot studies to be able to constitute a basis for diagnosis and cardiac function assessment. Theoretically, the CSD is well suited to be used with the Ventricorder since the Ventricorder detects small changes over time and information about time events is all that is required for the creation of a CSD. Contemporarily, ultrasound tissue velocity imaging (TVI) is usually used for production of CSDs and in this master thesis we examined if the Ventricorder can be used to produce CSDs. This was done by mainly comparing velocity data from the Ventricorder with velocity data from temporally synchronized apical four-chamber images acquired with ultrasound TVI. The results indicate that there is an apparent correlation between these data sets and the Ventricorder should therefore be able to produce data that could constitute the basis for the production of a CSD. What remain now is to confirm these results statistically with a larger test group and to investigate whether all the time instants needed for the production of a CSD can be identified objectively. / Hjärtdysfunktion är ett värdsligt utbrett problem som ligger bakom många dödsfall varje år. Studier har visat att många dödsfall som är relaterade till hjärtdysfunktion hade kunnat förebyggas om de upptäckts i tid. För närvarande är bland annat ultraljud och EKG oumbärliga metoder för diagnostisering och analys av hjärtfunktion. Ventricorder är en typ av radarsensor som utnyttjar ett brett frekvensspektrum, så kallat Ultra Wideband, och är tillverkad av det norska företaget Novelda. Ventricorder har visat sig kunna detektera exempelvis hjärtrörelser och andning men dess kliniska värde har ännu inte undersökts. Cardiac State Diagram (CSD) är ett prekliniskt mjukvaruverktyg för att visualisera hjärtats mekaniska funktion och som har bekräftats genom pilotstudier att kunna användas som underlag för diagnostik och bedömning av hjärtats funktion. Teoretiskt sett är CSD väl lämpat för att användas med Ventricordern eftersom Ventricordern registrerar små rörelser över tid och just ändringar över tid är precis vad som behövs för att skapa ett CSD. I dagsläget används vanligen vävnadsdoppler (TVI) för produktion av CSD och i denna masteruppsats undersöktes huruvida Ventricorder kan användas för att producera CSD. Detta gjordes genom att jämföra mätdata från Ventricorder med temporalt synkroniserade apikala fyrkammar-bilder framställda med vävnadsdoppler. Resultaten indikerar att det finns en påtaglig korrelation mellan dessa data och att mätdatat från en Ventricorder således bör kunna användas för produktion av CSD. Det kvarstår att bekräfta dessa resultat statistiskt med en större testgrupp och att undersöka om samtliga tidsmarkörer som behövs för produktion av ett CSD kan identifieras objektivt.
4

Development of microwave and millimeter-wave integrated-circuit stepped-frequency radar sensors for surface and subsurface profiling

Park, Joongsuk 17 February 2005 (has links)
Two new stepped-frequency continuous wave (SFCW) radar sensor prototypes, based on a coherent super-heterodyne scheme, have been developed using Microwave Integrated Circuits (MICs) and Monolithic Millimeter-Wave Integrated Circuits (MMICs) for various surface and subsurface applications, such as profiling the surface and subsurface of pavements, detecting and localizing small buried Anti-Personnel (AP) mines and measuring the liquid level in a tank. These sensors meet the critical requirements for subsurface and surface measurements including small size, light weight, good accuracy, fine resolution and deep penetration. In addition, two novel wideband microstrip quasi-TEM horn antennae that are capable of integration with a seamless connection have also been designed. Finally, a simple signal processing algorithm, aimed to acquire the in-phase (I) and quadrature (Q) components and to compensate for the I/Q errors, was developed using LabView. The first of the two prototype sensors, named as the microwave SFCW radar sensor operating from 0.6-5.6-GHz, is primarily utilized for assessing the subsurface of pavements. The measured thicknesses of the asphalt and base layers of a pavement sample were very much in agreement with the actual data with less than 0.1-inch error. The measured results on the actual roads showed that the sensor accurately detects the 5-inch asphalt layer of the pavement with a minimal error of 0.25 inches. This sensor represents the first SFCW radar sensor operating from 0.6-5.6-GHz. The other sensor, named as the millimeter-wave SFCW radar sensor, operates in the 29.72-35.7-GHz range. Measurements were performed to verify its feasibility as a surface and sub-surface sensor. The measurement results showed that the sensor has a lateral resolution of 1 inch and a good accuracy in the vertical direction with less than  0.04-inch error. The sensor successfully detected and located AP mines of small sizes buried under the surface of sand with less than 0.75 and 0.08 inches of error in the lateral and vertical directions, respectively. In addition, it also verified that the vertical resolution is not greater than 0.75 inches. This sensor is claimed as the first Ka-band millimeter-wave SFCW radar sensor ever developed for surface and subsurface sensing applications.
5

Development of microwave and millimeter-wave integrated-circuit stepped-frequency radar sensors for surface and subsurface profiling

Park, Joongsuk 17 February 2005 (has links)
Two new stepped-frequency continuous wave (SFCW) radar sensor prototypes, based on a coherent super-heterodyne scheme, have been developed using Microwave Integrated Circuits (MICs) and Monolithic Millimeter-Wave Integrated Circuits (MMICs) for various surface and subsurface applications, such as profiling the surface and subsurface of pavements, detecting and localizing small buried Anti-Personnel (AP) mines and measuring the liquid level in a tank. These sensors meet the critical requirements for subsurface and surface measurements including small size, light weight, good accuracy, fine resolution and deep penetration. In addition, two novel wideband microstrip quasi-TEM horn antennae that are capable of integration with a seamless connection have also been designed. Finally, a simple signal processing algorithm, aimed to acquire the in-phase (I) and quadrature (Q) components and to compensate for the I/Q errors, was developed using LabView. The first of the two prototype sensors, named as the microwave SFCW radar sensor operating from 0.6-5.6-GHz, is primarily utilized for assessing the subsurface of pavements. The measured thicknesses of the asphalt and base layers of a pavement sample were very much in agreement with the actual data with less than 0.1-inch error. The measured results on the actual roads showed that the sensor accurately detects the 5-inch asphalt layer of the pavement with a minimal error of 0.25 inches. This sensor represents the first SFCW radar sensor operating from 0.6-5.6-GHz. The other sensor, named as the millimeter-wave SFCW radar sensor, operates in the 29.72-35.7-GHz range. Measurements were performed to verify its feasibility as a surface and sub-surface sensor. The measurement results showed that the sensor has a lateral resolution of 1 inch and a good accuracy in the vertical direction with less than  0.04-inch error. The sensor successfully detected and located AP mines of small sizes buried under the surface of sand with less than 0.75 and 0.08 inches of error in the lateral and vertical directions, respectively. In addition, it also verified that the vertical resolution is not greater than 0.75 inches. This sensor is claimed as the first Ka-band millimeter-wave SFCW radar sensor ever developed for surface and subsurface sensing applications.
6

Analysis of Ultra-Wideband Pulse Scattered from Planar Objects

Li, Lin Unknown Date
No description available.
7

Automatic target classification based on radar backscattered ultra wide band signals / Classification automatique des cibles en utilisant les signaux rétrodiffusés par un radar ultra large bande

Khodjet-Kesba, Mahmoud 06 November 2014 (has links)
L’objectif de cette thèse est la classification automatique des cibles (ATC) en utilisant les signaux rétrodiffusés par un radar ultra large bande (UWB). La classification des cibles est réalisée en comparant les signatures des cibles et les signatures stockées dans une base de données. Premièrement, une étude sur la théorie de diffusion nous a permis de comprendre le sens physique des paramètres extraits et de les exprimer mathématiquement. Deuxièmement, des méthodes d’extraction de paramètres sont appliquées afin de déterminer les signatures des cibles. Un bon choix des paramètres est important afin de distinguer les différentes cibles. Différentes méthodes d’extraction de paramètres sont comparées notamment : méthode de Prony, Racine-classification des signaux multiples (Root-MUSIC), l’estimation des paramètres des signaux par des techniques d’invariances rotationnels (ESPRIT), et la méthode Matrix Pencil (MPM). Troisièmement, une méthode efficace de classification supervisée est nécessaire afin de classer les cibles inconnues par l’utilisation de leurs signatures extraites. Différentes méthodes de classification sont comparées notamment : Classification par la distance de Mahalanobis (MDC), Naïve Bayes (NB), k-plus proches voisins (k-NN), Machines à Vecteurs de Support (SVM). Une bonne technique de classification doit avoir une bonne précision en présence de signaux bruités et quelques soit l’angle d’émission. Les différents algorithmes ont été validés en utilisant les simulations des données rétrodiffusées par des objets canoniques et des cibles de géométries complexes modélisées par des fils minces et parfaitement conducteurs. Une méthode de classification automatique de cibles basée sur l’utilisation de la méthode Matrix Pencil dans le domaine fréquentiel (MPMFD) pour l’extraction des paramètres et la classification par la distance de Mahalanobis est proposée. Les résultats de simulation montrent que les paramètres extraits par MPMFD présentent une solution plausible pour la classification automatique des cibles. En outre, nous avons prouvé que la méthode proposée a une bonne tolérance aux bruits lors de la classification des cibles. Enfin, les différents algorithmes sont validés sur des données expérimentales et cibles réelles. / The objective of this thesis is the Automatic Target Classification (ATC) based on radar backscattered Ultra WideBand (UWB) signals. The classification of the targets is realized by making comparison between the deduced target properties and the different target features which are already recorded in a database. First, the study of scattering theory allows us to understand the physical meaning of the extracted features and describe them mathematically. Second, feature extraction methods are applied in order to extract signatures of the targets. A good choice of features is important to distinguish different targets. Different methods of feature extraction are compared including wavelet transform and high resolution techniques such as: Prony’s method, Root-Multiple SIgnal Classification (Root-MUSIC), Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) and Matrix Pencil Method (MPM). Third, an efficient method of supervised classification is necessary to classify unknown targets by using the extracted features. Different methods of classification are compared: Mahalanobis Distance Classifier (MDC), Naïve Bayes (NB), k-Nearest Neighbors (k-NN) and Support Vector Machine (SVM). A useful classifier design technique should have a high rate of accuracy in the presence of noisy data coming from different aspect angles. The different algorithms are demonstrated using simulated backscattered data from canonical objects and complex target geometries modeled by perfectly conducting thin wires. A method of ATC based on the use of Matrix Pencil Method in Frequency Domain (MPMFD) for feature extraction and MDC for classification is proposed. Simulation results illustrate that features extracted with MPMFD present a plausible solution to automatic target classification. In addition, we prove that the proposed method has better ability to tolerate noise effects in radar target classification. Finally, the different algorithms are validated on experimental data and real targets.
8

Clutter Removal in Single Radar Sensor Reflection Data via Digital Signal Processing

Kazemisaber, Mohammadreza January 2020 (has links)
Due to recent improvements, robots are more applicable in factories and various production lines where smoke, fog, dust, and steam are inevitable. Despite their advantages, robots introduce new safety requirements when combined with humans. Radars can play a crucial role in this context by providing safe zones where robots are operating in the absence of humans. The goal of this Master’s thesis is to investigate different clutter suppression methods for single radar sensor reflection data via digital signal processing. This was done in collaboration with ABB Jokab AB, Sweden. The calculations and implementation of the digital signal processing algorithms are made with Octave. A critical problem is false detection that could possibly cause irreparable damage. Therefore, a safety system with an extremely low false alarm rate is desired to reduce costs and damages. In this project, we have studied four different digital low pass filters: moving average, multiple-pass moving average, Butterworth, and window-based filters. The results are compared, and it is ascertained that all the results are logically compatible, broadly comparable, and usable in this context.
9

Bladder Monitoring Using Ultra-Wideband Radar and Vivaldi Antenna

Jonsson, Erica, Kovács, Attila January 2023 (has links)
Millions worldwide cannot tell when their bladder is nearing total capacity. The catheter, a tube to empty the bladder, is a vital part of life for many people. A catheter is, however, not a comfortable option, and it is the most common cause of infection in people staying in hospitals. This thesis aims to make the process more comfortable and non-invasive. The proposed idea is to use a UWB radar system with Vivaldi antennas to monitor the bladder state. Research shows that UWB radars can see a difference between a full and an empty phantom bladder. However, current research that explores the usage of UWB radar systems to monitor the bladder state does not consider regulations other than the ones set by FCC. They also only perform experiments on a phantom bladder. This thesis investigates the practical viability of using a UWB radar system designed per the restricted regulations set by Post- och Telestyrelsen. The thesis includes the design, simulations,manufacturing, and testing of the antennas as well as the radar system. The goal was to test the system in both simulations, with a phantom model and with a human body as a target, to advance the current state of research and determine its practicality forreal-life applications. The simulations showed a significant difference in reflections between full and empty bladders. The measurements from the experiments showed a slight difference in amplitude as well, although not as great as predicted due to a longer pulse. The Vivaldi antennas performed as expected according to both theory and simulations and they should work as desired in further experiments that use a UWB radar to monitor the bladder state per the PTS regulations. This thesis is solely based on an original idea and has not been influenced or derived from any external company.
10

Contribution à la conception d'un système d'identification et de classification de véhicules par les ondes électromagnétiques / Design of a vehicles identification and classification system by using electromagnetic waves

Le, Minh Thuy 27 March 2013 (has links)
Les activités de transport de passagers et de marchandises augmentent sans cesse dans le monde et en particulier dans l'Union Européenne, entre autres au bord des péages. Afin d'améliorer la fluidité et réduire les risques d‘encombrements, une des solutions consiste à rendre les péages plus performants. L'objectif de cette thèse est d'améliorer la performance des systèmes d'identification de véhicules et de contribuer à la conception d'un système de classification des types de véhicules par ondes électromagnétiques pour application au télépéage. Ce système permet un paiement automatique sans arrêt des véhicules. La première partie de la thèse est consacrée à l'étude de deux systèmes d'identification de véhicules : RFID UHF et DSRC. Notre recherche s'est focalisée sur l'augmentation de la distance de communication ainsi que sur la réduction de la taille et du prix du système grâce à 5 nouvelles antennes à bas coûts, très directives et faciles à industrialiser. La deuxième partie est consacrée à l'étude d'un système de classification à distance des différents types de véhicules, basé sur les ondes diffusées par les véhicules. Il détecte la présence d'un véhicule et mesure la distance entre ce véhicule et le système avec une bonne précision. Ce système est basé sur la technique de radar Ultra-Large-Bande. Le signal émis est une impulsion monocyle de très courte durée. Dans cette partie, nous proposons et testons trois méthodes de classification de véhicules dans un environnement proche du milieu routier. / The activities of passenger and goods transport are constantly increasing worldwide and especially in the European Union, including the edge of tolls. To improve the fluidity and reduce the risk of congestion, one of the solutions is automatic toll payments. The objective of this thesis is to enhance the performance of vehicle identification systems and to contribute to develop a design of a classification vehicles system by using electromagnetic waves for free-flow electronic toll collection system application. This system allows an automatic payment without stopping vehicles. The first part of this thesis deals with the study of two vehicle identification systems: UHF RFID and DSRC. Five new antennas were realized with the purpose to increase the communication range as well as to reduce the size and cost of the system. They are high gain and easy to be industrialized. The second part of this thesis is devoted to the study of a classification of different types of vehicles from the scattered waves captured by the system. Three methods of vehicle classification are proposed and tested in the road environment. Such system detects the presence of vehicle and measures the distance between vehicle and itself with a good accuracy. The principle of the system is based on Ultra-Wideband radar technology in which transmitting signal with a very short duration pulse is used.

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