To see the other types of publications on this topic, follow the link: System calibration and tracking.
Dissertations / Theses on the topic 'System calibration and tracking'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'System calibration and tracking.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Lindén, Erik. "Calibration in deep-learning eye tracking." Licentiate thesis, KTH, Reglerteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295566.
Full textAbstract:
Personal variations severely limit the performance of appearance-based gaze tracking. Adapting to these variations using standard neural network model adaptation methods is difficult. The problems range from overfitting, due to small amounts of training data, to underfitting, due to restrictive model architectures. In this thesis, these problems are tackled by introducing the SPatial Adaptive GaZe Estimator (\spaze{}). By modeling personal variations as a low-dimensional latent parameter space, \spaze{} provides just enough adaptability to capture the range of personal variations without being prone to overfitting. Calibrating \spaze{} for a new person reduces to solving a small optimization problem. \spaze{} achieves an error of \ang{2.70} with \num{9} calibration samples on MPIIGaze, improving on the state-of-the-art by \SI{14}{\percent}. In the introductory chapters the history, methods and applications of eye tracking are reviewed, with focus on video-based eye tracking and the use of personal calibration in these methods. Emphasis is placed on methods using neural networks and the strengths and weaknesses of how these methods implement personal calibration.QC 20210528
2
Horii, M. Michael. "A Predictive Model for Multi-Band Optical Tracking System (MBOTS) Performance." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579658.
Full textAbstract:
ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NVIn the wake of sequestration, Test and Evaluation (T&E) groups across the U.S. are quickly learning to make do with less. For Department of Defense ranges and test facility bases in particular, the timing of sequestration could not be worse. Aging optical tracking systems are in dire need of replacement. What's more, the increasingly challenging missions of today require advanced technology, flexibility, and agility to support an ever-widening spectrum of scenarios, including short-range (0 − 5 km) imaging of launch events, long-range (50 km+) imaging of debris fields, directed energy testing, high-speed tracking, and look-down coverage of ground test scenarios, to name just a few. There is a pressing need for optical tracking systems that can be operated on a limited budget with minimal resources, staff, and maintenance, while simultaneously increasing throughput and data quality. Here we present a mathematical error model to predict system performance. We compare model predictions to site-acceptance test results collected from a pair of multi-band optical tracking systems (MBOTS) fielded at White Sands Missile Range. A radar serves as a point of reference to gauge system results. The calibration data and the triangulation solutions obtained during testing provide a characterization of system performance. The results suggest that the optical tracking system error model adequately predicts system performance, thereby supporting pre-mission analysis and conserving scarce resources for innovation and development of robust solutions. Along the way, we illustrate some methods of time-space-position information (TSPI) data analysis, define metrics for assessing system accuracy, and enumerate error sources impacting measurements. We conclude by describing technical challenges ahead and identifying a path forward.
3
Cole, Gareth Douglas. "Design of an automated calibration device for electromagnetic tracking systems." Online access for everyone, 2007. http://www.dissertations.wsu.edu/Thesis/Spring2007/g_cole_050107.pdf.
Full text
4
Ide, Ichiro, Kenji Yamashiro, Daisuke Deguchi, Tomokazu Takahashi, Hiroshi Murase, Kazunori Higuchi, and Takashi Naito. "Automatic calibration of an in-vehicle gaze tracking system using driver's typical gaze behavior." IEEE, 2009. http://hdl.handle.net/2237/13967.
Full text
5
Elliott, Richard A. "A user interactive calibration program for an object tracking system using a triaxial accelerometer." Honors in the Major Thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1799.
Full textAbstract:
A major method in object tracking systems and other inertial measurement devices resolves around the use of one, two, or three axis accelerometers. A leader in the field such devices is Microstrain Incorporated. They have developed a three axis accelerometer that uses a three axis magnetic sensor array to compute the pitch, roll, and yaw of a compact inertial measurement unit. In researching such devices, it became apparent that data collected using such units is extremely sensitive both to local magnetic fields and human interactions with the devices. It is therefore of great importance to ensure the device or devices are properly calibrated. In the construction of an effective calibration program, it is necessary to measure and zero out even minor discrepancies, as even small misalignments have deleterious effects on device performance.Bachelors
Engineering and Computer Science
Computer Engineering
6
Aykin, Murat Deniz. "Efficient Calibration Of A Multi-camera Measurement System Using A Target With Known Dynamics." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609798/index.pdf.
Full textAbstract:
Multi camera measurement systems are widely used to extract information about the 3D configuration
or &ldquostate&rdquo
of one or more real world objects. Camera calibration is the process of pre-determining all the remaining optical and geometric parameters of the measurement system which are either static or slowly varying. For a single camera, this consist of the internal parameters of the camera device optics and construction while for a multiple camera system, it also includes the geometric positioning of the individual cameras, namely &ldquo
external&rdquo
parameters. The calibration is a necessary step before any actual state measurements can be made from the system. In this thesis, such a multi-camera state measurement system and in particular the problem of procedurally effective and high performance calibration of such a system is considered. This thesis presents a novel calibration algorithm which uses the known dynamics of a ballistically thrown target object and employs the Extended Kalman Filter (EKF) to calibrate the multi-camera system. The state-space representation of the target state is augmented with the unknown calibration parameters which are assumed to be static or slowly varying with respect to the state. This results in a &ldquo
super-state&rdquo
vector. The EKF algorithm is used to recursively estimate this super-state hence resulting in the estimates of the static camera parameters. It is demonstrated by both simulation studies as well as actual experiments that when the ballistic path of the target is processed by the improved versions of the EKF algorithm, the camera calibration parameter estimates asymptotically converge to their actual values. Since the image frames of the target trajectory can be acquired first and then processed off-line, subsequent improvements of the EKF algorithm include repeated and bidirectional versions where the same calibration images are repeatedly used. Repeated EKF (R-EKF) provides convergence with a limited number of image frames when the initial target state is accurately provided while its bidirectional version (RB-EKF) improves calibration accuracy by also estimating the initial target state. The primary contribution of the approach is that it provides a fast calibration procedure where there is no need for any standard or custom made calibration target plates covering the majority of camera field-of-view. Also, human assistance is minimized since all frame data is processed automatically and assistance is limited to making the target throws. The speed of convergence and accuracy of the results promise a field-applicable calibration procedure.
7
Alqahtani, Faleh Mohammed A. "Three-dimensional facial tracker using a stereo vision system." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/131825/1/Faleh%20Mohammed%20A_Alqahtani_Thesis.pdf.
Full textAbstract:
This thesis develops an algorithm enabling accurate tracking of human faces, precise estimation of head poses, efficient resolution of occlusions and improved depth perception under different lighting conditions. The system also utilises two stereo cameras that have the ability to track movements across six degrees of freedom, thereby accounting for pose variations. The system can address circumstances in which facial features are no longer discernible, as the results demonstrate increased accuracy in real-time estimation of head poses and facial landmark features. It can also precisely map facial features in different head poses, making it extremely robust for applying 3D facial tracking solutions.
8
Manat, Namith N. "System for Tracking of Surgical Tools and Assessment of Surgical Skills Using Continuously Adaptive Mean Shift Methodology." VCU Scholars Compass, 2005. http://scholarscompass.vcu.edu/etd_retro/56.
Full textAbstract:
A tracking system that serves as a tool for tracking the movement of surgical instruments has been developed. The system tracks color markers on the surgical instruments. The Continuously Adaptive Mean Shift (CAMSHIFT) methodology was employed for tool tracking and a total distance traversed by the surgical instrument of interest was calculated. Two cameras were used to record the motion of the tool and the software developed was used to track the movement of markers on the tools over subsequent frames. The information thus derived from the two views of cameras was used to calculate the three dimensional coordinates of the location of the marker on the instrument and subsequently the distance traversed. MATLAB, which is a commercial software package, was used to implement the tool tracking algorithm and for developing the GUI (Graphic User Interface). Data was collected using Commercial off the shelf (COTS) camera hardware and processing was done on a 2.2 GHz, 512 MB RAM Intel Pentium 4 computer.
9
Narasimhan, Ramakrishnan Akshra. "Design and Evaluation of Perception System Algorithms for Semi-Autonomous Vehicles." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595256912692618.
Full text
10
Dogan, Gozde. "Development Of A 3-camera Vision System And The Saddle Motion Analysis Of Horses Via This System." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610877/index.pdf.
Full textAbstract:
One of the purposes of this study is to develop a vision system consisting of 3 inexpensive, commercial cameras. The system is intended to be used for tracking the motion of objects in a large calibration volume, typically 6.5 m. wide and 0.7 m. high. Hence, a mechanism is designed and constructed for the calibration of the cameras.
The second purpose of the study is to develop an algorithm, which can be used to obtain the kinematic data associated with a rigid body, using a vision system. Special filters are implemented in the algorithm to identify the 3 markers attached on the body. Optimal curves are fitted to the position data of the markers after smoothing the data appropriately. The outputs of the algorithm are the position, velocity and acceleration of any point (visible or invisible) on the body and the angular velocity and acceleration of the body. The singularities associated with the algorithm are also determined.
Using the vision setup and the developed algorithm for tracking the kinematics of a rigid body, the motions of the saddles of different horses are investigated for different gaits. Similarities and differences between horses and/or gaits are analyzed to lead to quantitative results. Using the limits induced by the whole body vibration of humans, for the first time in the world, daily, allowable riding time and riding distances are determined for different horses and gaits. Furthermore, novel, quantitative horse comfort indicators are proposed. Via the experiments performed, these indicators are shown to be consistent with the comfort assessment of experienced riders.
Finally, in order to implement the algorithms proposed in this study, a computer code is developed using MATLAB®.
11
Liu, Junbin. "Distributed low-power image processing in wireless sensor networks for intelligent video surveillance applications." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/63311/1/Junbin_Liu_Thesis.pdf.
Full textAbstract:
Distributed Wireless Smart Camera (DWSC) network is a special type of Wireless Sensor Network (WSN) that processes captured images in a distributed manner. While image processing on DWSCs sees a great potential for growth, with its applications possessing a vast practical application domain such as security surveillance and health care, it suffers from tremendous constraints. In addition to the limitations of conventional WSNs, image processing on DWSCs requires more computational power, bandwidth and energy that presents significant challenges for large scale deployments. This dissertation has developed a number of algorithms that are highly scalable, portable, energy efficient and performance efficient, with considerations of practical constraints imposed by the hardware and the nature of WSN. More specifically, these algorithms tackle the problems of multi-object tracking and localisation in distributed wireless smart camera net- works and optimal camera configuration determination.
Addressing the first problem of multi-object tracking and localisation requires solving a large array of sub-problems. The sub-problems that are discussed in this dissertation are calibration of internal parameters, multi-camera calibration for localisation and object handover for tracking. These topics have been covered extensively in computer vision literatures, however new algorithms must be invented to accommodate the various constraints introduced and required by the DWSC platform.
A technique has been developed for the automatic calibration of low-cost cameras which are assumed to be restricted in their freedom of movement to either pan or tilt movements. Camera internal parameters, including focal length, principal point, lens distortion parameter and the angle and axis of rotation, can be recovered from a minimum set of two images of the camera, provided that the axis of rotation between the two images goes through the camera's optical centre and is parallel to either the vertical (panning) or horizontal (tilting) axis of the image.
For object localisation, a novel approach has been developed for the calibration of a network of non-overlapping DWSCs in terms of their ground plane homographies, which can then be used for localising objects. In the proposed approach, a robot travels through the camera network while updating its position in a global coordinate frame, which it broadcasts to the cameras. The cameras use this, along with the image plane location of the robot, to compute a mapping from their image planes to the global coordinate frame. This is combined with an occupancy map generated by the robot during the mapping process to localised objects moving within the network.
In addition, to deal with the problem of object handover between DWSCs of non-overlapping fields of view, a highly-scalable, distributed protocol has been designed. Cameras that follow the proposed protocol transmit object descriptions to a selected set of neighbours that are determined using a predictive forwarding strategy. The received descriptions are then matched at the subsequent camera on the object's path using a probability maximisation process with locally generated descriptions.
The second problem of camera placement emerges naturally when these pervasive devices are put into real use. The locations, orientations, lens types etc. of the cameras must be chosen in a way that the utility of the network is maximised (e.g. maximum coverage) while user requirements are met. To deal with this, a statistical formulation of the problem of determining optimal camera configurations has been introduced and a Trans-Dimensional Simulated Annealing (TDSA) algorithm has been proposed to effectively solve the problem.
12
Arico, Mario. "Robotic Comanipulation as a Tangible Interface for Assistance to Laparoscopic Surgery." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS252.
Full textAbstract:
L’objectif de cette thèse est de développer une plateforme robotique pour l’assistance à la cœlioscopie. Nous focalisons l’attention sur l’utilisation de l’outil chirurgical comme une interface tangible : l’outil devient un pointeur 3D pour la manipulation d’objets virtuels insérés dans la scène chirurgicale et affichés sur les images endoscopiques (i.e., un plan virtuel pour délimiter une zone). Pour cela, nous étudions la précision du système de navigation pour l’estimation de la pose de la caméra (pour le retour visuel) et de l’outil (pour le retour haptique). Tout d’abord, nous proposons une méthode de calibration des paramètres extrinsèques de la caméra grâce à plusieurs vues d’un objet sphérique. Cette approche, que l’on appelle Perspective-n-Spheres, améliore localement la précision par rapport aux méthodes existantes. Ensuite, nous améliorons le suivi de la pointe de l’outil grâce à une approche hybride, qui compare deux sources indépendantes de suivi (par images et par capteur optique externe), et utilisons cette redondance pour optimiser localement l’estimation de la position. Enfin, nous implémentons et testons deux outils d’assistance chirurgicale : un laser virtuel et une pince virtuelle. Le laser virtuel aide à l’exécution des tâches de pointage en affichant en temps réel la position de la pointe projetée sur la surface contentant les cibles. Ce laser facilite l’orientation correcte de l’outil dès son insertion, même si ce dernier n’est pas visible sur les images. La pince virtuelle permet le contrôle automatique de l’endoscope en manipulant directement l’outil : la caméra suit la pointe et la maintient dans une position constante dans l’imageThe objective of this thesis is the development of a robotic assistant for Minimally Invasive Surgery. In particular, we explore the use of the surgical instrument as a tangible interface, whereby the physical tool becomes a 3D Surgical Pointer to manipulate artificial virtual contents (e.g., virtual planes to delimit safe zones) populating the surgical scene and overlaid on the endoscopic images. To enable the use of the instrument as a tangible interface, we study the tracking accuracy of the surgical system to recover the camera pose (for visual feedback), and the instrument pose (for haptic feedback). First, we propose a calibration method to estimate the extrinsic camera parameters from multiple poses of the spherical object. This approach, called Perspective-n-Spheres, improves the local reconstruction accuracy compared to the existing calibration methods. Second, we propose to improve the tracking accuracy of the instrument end-effector thanks to a hybrid tracker, which compares two independent tracking sources (images and external optical tracker) and uses this redundancy to locally optimize the position estimate. Third, we develop and test two examples of tool-driven guidance tools: the virtual laser and the virtual grasper. The virtual laser facilitates reaching tasks by overlaying on the images the position of the tool tip projection of the target surface. This visual aid helps the user to correctly orient the tool even when it is not visible on the images. The virtual grasper enables the automatic control of the endoscope motion by manipulating the tool: the endoscope follows the tool tip to maintain its position constant in the image frame
13
Benarab, Djamel-Eddine. "Suivi automatique de nageurs à partir des séquences vidéo : application à l'analyse des performances." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0089/document.
Full textAbstract:
Dans le but d’améliorer les performances des nageurs professionnels, nous avons développé, en collaboration avec la Fédération Française de Natation, un système automatique de suivi à base des séquences vidéo. Pour ce faire, nous proposons un nouveau système de prise de vue 8K adapté au milieu aquatique et permettant un calibrage du bassin. Celui-ci établit le lien entre les coordonnées pixels et métriques permettant, entre autres, d’extraire le couloir concerné pour effectuer les différents traitements. Afin d’initialiser le suivi, il est nécessaire de localiser le nageur. Pour cela, nous proposons d’utiliser une approche a contrario pour détecter le mouvement, puis l’approche Scaled Composite JTC pour localiser précisément la tête du nageur. Ensuite, nous implémentons et adaptons les techniques de suivi de la littérature, notamment celles basées sur la corrélation NL-JTC, les histogrammes de couleur, les motifs binaires locaux (LBP) et les histogrammes de gradient orienté (HOG). Suite aux différentes limitations de ces techniques, nous proposons de nouvelles approches optimisées basées principalement sur la fusion de données. Tout d’abord, nous développons l’approche multipiste constituée de plusieurs pistes de suivi, où chacune représente l’une des techniques de suivi citées précédemment. Ensuite, un choix basé sur l’histogramme de couleur est effectué afin de choisir la meilleure décision parmi celles offertes par chaque piste. Cette approche a significativement amélioré les résultats mais ceux-ci restent insuffisants pour l’étude des performances. Dans ce sens, nous proposons une nouvelle approche par fusion dynamique qui consiste à fusionner le plan de corrélation NL-JTC et le plan de scores couleurs dans le but d’extraire une description plus riche de la cible (forme + couleur). Cette approche a montré de très bons résultats dans le cas où la cible à suivre est visible mais reste très sensible aux occultations de celle-ci. Afin de résoudre cette difficulté, nous améliorons l’approche proposée en suivant simultanément la tête et le maillot de bain du nageur. Cette approche multizone permet, grâce à un critère de décision complexe, de retrouver la zone occultée à l’aide de la zone visible. Enfin, une étude de performances a été menée et les résultats obtenus ont permis de valider ce système. En particulier, nous nous sommes intéressés aux mesures de vitesse cyclique, intra-cyclique et instantanée, afin d’étudier et améliorer les performances des nageursSwimming Federation), an automatic tracking approach using video sequences. To do this, we propose a new 8K shooting system adapted to the aquatic environment and allowing a pool calibration. This establishes the link between pixel and metric coordinates, which allows among others, to extract the concerned lane to carry out the different treatments. In order to initialize the tracking, it is necessary to localize the swimmer. For this, we propose to use an a contrario approach to detect movement, then the Scaled Composites JTC approach to precisely localize the swimmer’s head. Afterwards, we implement and adapt several tracking techniques well-known in the literature, namely those based on the NL-JTC correlation, color histograms, Local Binary Patterns (LBP) and histograms of oriented gradient (HOG). Given the various limitations of these techniques, we propose new optimized approaches based primarily on data fusion. First, we develop a multitracking approach consists of several tracks, where each track represents one of the tracking techniques mentioned above.Then, a choice based on the color histogram is made to select the best decision among those offered by each track. This approach has significantly improved the results, but it remains insufficient for the performance analysis. Therefore, we propose a new dynamic fusion approach that combines NL-JTC correlation plane and color scores plane in order to generate a richer description of the target (form + color). This approach has shown very good results in the case where the target is visible but it is still sensitive to occlusions. To solve this problem, we improve this proposed approach by tracking simultaneously the head and the swimsuit of the athlete. This multi related targets approach enables, through a complex decision criterion, to find the occluded zone based on the visible one. Finally, a performance study is conducted and the results have validated the system. In particular, we were interested in cyclical, intra-cyclical and instantaneous speed measurements, to study and improve the swimmers’performance
14
Rameau, François. "Système de vision hybride à fovéation pour la vidéo-surveillance et la navigation robotique." Thesis, Dijon, 2014. http://www.theses.fr/2014DIJOS031/document.
Full textAbstract:
L'objectif principal de ce travail de thèse est l'élaboration d'un système de vision binoculaire mettant en oeuvre deux caméras de types différents. Le système étudié est constitué d'une caméra de type omnidirectionnelle associée à une caméra PTZ. Nous appellerons ce couple de caméras un système de vision hybride. L'utilisation de ce type de capteur fournit une vision globale de la scène à l'aide de la caméra omnidirectionnelle tandis que l'usage de la caméra mécanisée permet une fovéation, c'est-à-dire l'acquisition de détails, sur une région d'intérêt détectée depuis l'image panoramique.Les travaux présentés dans ce manuscrit ont pour objet, à la fois de permettre le suivi d'une cible à l'aide de notre banc de caméras mais également de permettre une reconstruction 3D par stéréoscopie hybride de l'environnement nous permettant d'étudier le déplacement du robot équipé du capteurThe primary goal of this thesis is to elaborate a binocular vision system using two different types of camera. The system studied here is composed of one omnidirectional camera coupled with a PTZ camera. This heterogeneous association of cameras having different characteristics is called a hybrid stereo-vision system. The couple composed of these two cameras combines the advantages given by both of them, that is to say a large field of view and an accurate vision of a particular Region of interest with an adjustable level of details using the zoom. In this thesis, we are presenting multiple contributions in visual tracking using omnidirectional sensors, PTZ camera self calibration, hybrid vision system calibration and structure from motion using a hybrid stereo-vision system
15
SZENBERG, FLAVIO. "SCENE TRACKING WITH AUTOMATIC CAMERA CALIBRATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2001. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=6519@1.
Full textAbstract:
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOÉ cada vez mais comum, na transmissão de eventos esportivos pelas emissoras de televisão, a inserção, em tempo real, de elementos sintéticos na imagem, como anúncios, marcações no campo, etc. Geralmente, essa inserção é feita através do emprego de câmeras especiais, previamente calibradas e dotadas de dispositivos que registram seu movimento e a mudança de seus parâmetros. De posse destas informações, é simples inserir novos elementos na cena com a projeção apropriada. Nesta tese, é apresentado um algoritmo para recuperar, em tempo real e sem utilizar qualquer informação adicional, a posição e os parâmetros da câmera em uma seqüência de imagens contendo a visualização de modelos conhecidos. Para tal, é explorada a existência, nessas imagens, de segmentos de retas que compõem a visualização do modelo cujas posições são conhecidas no mundo tridimensional. Quando se trata de uma partida de futebol, por exemplo, o modelo em questão é composto pelo conjunto das linhas do campo, segundo as regras que definem sua geometria e dimensões. Inicialmente, são desenvolvidos métodos para a extração de segmentos de retas longos da primeira imagem. Em seguida é localizada uma imagem do modelo no conjunto desses segmentos com base em uma árvore de interpretação. De posse desse reconhecimento, é feito um reajuste nos segmentos que compõem a visualização do modelo, sendo obtidos pontos de interesse que são repassados a um procedimento capaz de encontrar a câmera responsável pela visualização do modelo. Para a segunda imagem da seqüência em diante, apenas uma parte do algoritmo é utilizada, levando em consideração a coerência entre quadros, a fim de aumentar o desempenho e tornar possível o processamento em tempo real. Entre diversas aplicações que podem ser empregadas para comprovar o desempenho e a validade do algoritmo proposto, está uma que captura imagens através de uma câmera para demonstrar o funcionamento do algoritmo on line. A utilização de captura de imagens permite testar o algoritmo em inúmeros casos, incluindo modelos e ambientes diferentes.
In the television casting of sports events, it has become very common to insert synthetic elements to the images in real time, such as adds, marks on the field, etc. Usually, this insertion is made using special cameras, previously calibrated and provided with features that record their movements and parameter changes. With such information, inserting new objects to the scene with the adequate projection is a simple task. In the present work, we will introduce an algorithm to retrieve, in real time and using no additional information, the position and parameters of the camera in a sequence of images containing the visualization of previously-known models. For such, the method explores the existence in these images of straight-line segments that compose the visualization of the model whose positions are known in the three-dimensional world. In the case of a soccer match, for example, the respective model is composed by the set of field lines determined by the rules that define their geometry and dimensions. Firstly, methods are developed to extract long straight- line segments from the first image. Then an image of the model is located in the set formed by such segments based on an interpretation tree. With such information, the segments that compose the visualization of the model are readjusted, resulting in the obtainment of interest points which are then passed to a proceeding able to locate the camera responsible for the model`s visualization. For the second image on, only a part of the algorithm is used, taking into account the coherence between the frames, with the purpose of improving performance to allow real-time processing. Among several applications that can be employed to evaluate the performance and quality of the proposed method, there is one that captures images with a camera to show the on-line functioning of the algorithm. By using image capture, we can test the algorithm in a great variety of instances, including different models and environments.
16
Masko, David. "Calibration in Eye Tracking Using Transfer Learning." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210815.
Full textAbstract:
This thesis empirically studies transfer learning as a calibration framework for Convolutional Neural Network (CNN) based appearance-based gaze estimation models. A dataset of approximately 1,900,000 eyestripe images distributed over 1682 subjects is used to train and evaluate several gaze estimation models. Each model is initially trained on the training data resulting in generic gaze models. The models are subsequently calibrated for each test subject, using the subject's calibration data, by applying transfer learning through network fine-tuning on the final layers of the network. Transfer learning is observed to reduce the Euclidean distance error of the generic models within the range of 12-21%, which is in line with current state-of-the-art. The best performing calibrated model shows a mean error of 29.53mm and a median error of 22.77mm. However, calibrating heatmap output-based gaze estimation models decreases the performance over the generic models. It is concluded that transfer learning is a viable calibration framework for improving the performance of CNN-based appearance based gaze estimation models.Detta examensarbete är en empirisk studie på överföringsträning som ramverk för kalibrering av neurala faltningsnätverks (CNN)-baserade bildbaserad blickapproximationsmodeller. En datamängd på omkring 1 900 000 ögonrandsbilder fördelat över 1682 personer används för att träna och bedöma flertalet blickapproximationsmodeller. Varje modell tränas inledningsvis på all träningsdata, vilket resulterar i generiska modeller. Modellerna kalibreras därefter för vardera testperson med testpersonens kalibreringsdata via överföringsträning genom anpassning av de sista lagren av nätverket. Med överföringsträning observeras en minskning av felet mätt som eukilidskt avstånd för de generiska modellerna inom 12-21%, vilket motsvarar de bästa nuvarande modellerna. För den bäst presterande kalibrerade modellen uppmäts medelfelet 29,53mm och medianfelet 22,77mm. Dock leder kalibrering av regionella sannolikhetsbaserade blickapproximationsmodeller till en försämring av prestanda jämfört med de generiska modellerna. Slutsatsen är att överföringsträning är en legitim kalibreringsansats för att förbättra prestanda hos CNN-baserade bildbaserad blickapproximationsmodeller.
17
Graziani, Alberto <1980>. "Troposphere Calibration Techniques for Deep Space Probe Tracking." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3023/1/AGraziani_Tesi_Final.pdf.
Full textAbstract:
Ground-based Earth troposphere calibration systems play an important role in planetary exploration, especially to carry out radio science experiments aimed at the estimation of planetary gravity fields. In these experiments, the main observable is the spacecraft (S/C) range rate, measured from the Doppler shift of an electromagnetic wave transmitted from ground, received by the spacecraft and coherently retransmitted back to ground. If the solar corona and interplanetary plasma noise is already removed from Doppler data, the Earth troposphere remains one of the main error sources in tracking observables.
Current Earth media calibration systems at NASA’s Deep Space Network (DSN) stations are based upon a combination of weather data and multidirectional, dual frequency GPS measurements acquired at each station complex. In order to support Cassini’s cruise radio science experiments, a new generation of media calibration systems were developed, driven by the need to achieve the goal of an end-to-end Allan deviation of the radio link in the order of 3×〖10〗^(-15) at 1000 s integration time.
The future ESA’s Bepi Colombo mission to Mercury carries scientific instrumentation for radio science experiments (a Ka-band transponder and a three-axis accelerometer) which, in combination with the S/C telecommunication system (a X/X/Ka transponder) will provide the most advanced tracking system ever flown on an interplanetary probe. Current error budget for MORE (Mercury Orbiter Radioscience Experiment) allows the residual uncalibrated troposphere to contribute with a value of 8×〖10〗^(-15) to the two-way Allan deviation at 1000 s integration time.
The current standard ESA/ESTRACK calibration system is based on a combination of surface meteorological measurements and mathematical algorithms, capable to reconstruct the Earth troposphere path delay, leaving an uncalibrated component of about 1-2% of the total delay.
In order to satisfy the stringent MORE requirements, the short time-scale variations of the Earth troposphere water vapor content must be calibrated at ESA deep space antennas (DSA) with more precise and stable instruments (microwave radiometers). In parallel to this high performance instruments, ESA ground stations should be upgraded to media calibration systems at least capable to calibrate both troposphere path delay components (dry and wet) at sub-centimetre level, in order to reduce S/C navigation uncertainties. The natural choice is to provide a continuous troposphere calibration by processing GNSS data acquired at each complex by dual frequency receivers already installed for station location purposes.
The work presented here outlines the troposphere calibration technique to support both Deep Space probe navigation and radio science experiments. After an introduction to deep space tracking techniques, observables and error sources, in Chapter 2 the troposphere path delay is widely investigated, reporting the estimation techniques and the state of the art of the ESA and NASA troposphere calibrations. Chapter 3 deals with an analysis of the status and the performances of the NASA Advanced Media Calibration (AMC) system referred to the Cassini data analysis. Chapter 4 describes the current release of a developed GNSS software (S/W) to estimate the troposphere calibration to be used for ESA S/C navigation purposes. During the development phase of the S/W a test campaign has been undertaken in order to evaluate the S/W performances. A description of the campaign and the main results are reported in Chapter 5. Chapter 6 presents a preliminary analysis of microwave radiometers to be used to support radio science experiments. The analysis has been carried out considering radiometric measurements of the ESA/ESTEC instruments installed in Cabauw (NL) and compared with the requirements of MORE. Finally, Chapter 7 summarizes the results obtained and defines some key technical aspects to be evaluated and taken into account for the development phase of future instrumentation.
18
Graziani, Alberto <1980>. "Troposphere Calibration Techniques for Deep Space Probe Tracking." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/3023/.
Full textAbstract:
Ground-based Earth troposphere calibration systems play an important role in planetary exploration, especially to carry out radio science experiments aimed at the estimation of planetary gravity fields. In these experiments, the main observable is the spacecraft (S/C) range rate, measured from the Doppler shift of an electromagnetic wave transmitted from ground, received by the spacecraft and coherently retransmitted back to ground. If the solar corona and interplanetary plasma noise is already removed from Doppler data, the Earth troposphere remains one of the main error sources in tracking observables.
Current Earth media calibration systems at NASA’s Deep Space Network (DSN) stations are based upon a combination of weather data and multidirectional, dual frequency GPS measurements acquired at each station complex. In order to support Cassini’s cruise radio science experiments, a new generation of media calibration systems were developed, driven by the need to achieve the goal of an end-to-end Allan deviation of the radio link in the order of 3×〖10〗^(-15) at 1000 s integration time.
The future ESA’s Bepi Colombo mission to Mercury carries scientific instrumentation for radio science experiments (a Ka-band transponder and a three-axis accelerometer) which, in combination with the S/C telecommunication system (a X/X/Ka transponder) will provide the most advanced tracking system ever flown on an interplanetary probe. Current error budget for MORE (Mercury Orbiter Radioscience Experiment) allows the residual uncalibrated troposphere to contribute with a value of 8×〖10〗^(-15) to the two-way Allan deviation at 1000 s integration time.
The current standard ESA/ESTRACK calibration system is based on a combination of surface meteorological measurements and mathematical algorithms, capable to reconstruct the Earth troposphere path delay, leaving an uncalibrated component of about 1-2% of the total delay.
In order to satisfy the stringent MORE requirements, the short time-scale variations of the Earth troposphere water vapor content must be calibrated at ESA deep space antennas (DSA) with more precise and stable instruments (microwave radiometers). In parallel to this high performance instruments, ESA ground stations should be upgraded to media calibration systems at least capable to calibrate both troposphere path delay components (dry and wet) at sub-centimetre level, in order to reduce S/C navigation uncertainties. The natural choice is to provide a continuous troposphere calibration by processing GNSS data acquired at each complex by dual frequency receivers already installed for station location purposes.
The work presented here outlines the troposphere calibration technique to support both Deep Space probe navigation and radio science experiments. After an introduction to deep space tracking techniques, observables and error sources, in Chapter 2 the troposphere path delay is widely investigated, reporting the estimation techniques and the state of the art of the ESA and NASA troposphere calibrations. Chapter 3 deals with an analysis of the status and the performances of the NASA Advanced Media Calibration (AMC) system referred to the Cassini data analysis. Chapter 4 describes the current release of a developed GNSS software (S/W) to estimate the troposphere calibration to be used for ESA S/C navigation purposes. During the development phase of the S/W a test campaign has been undertaken in order to evaluate the S/W performances. A description of the campaign and the main results are reported in Chapter 5. Chapter 6 presents a preliminary analysis of microwave radiometers to be used to support radio science experiments. The analysis has been carried out considering radiometric measurements of the ESA/ESTEC instruments installed in Cabauw (NL) and compared with the requirements of MORE. Finally, Chapter 7 summarizes the results obtained and defines some key technical aspects to be evaluated and taken into account for the development phase of future instrumentation.
19
Fernandez, Javier Oscar. "The Virginia Tech Calibration System." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/32669.
Full textAbstract:
Phasor measurement unit (PMU) applications on power grid monitoring systems have been implemented since the early ninetyâ s. Large monitoring system network performance relies on the consistent measurements of PMUs across the system. This has become a major challenge for designers since large networks use PMUs from various manufacturers who likely implement different synchrophasor technologies to perform the phasor estimations. The current synchrophasor standard, the IEEE C37.118-2005 Synchrophasor Standard, covers adequately the steady-state characterization of PMUs but does not specify transient condition requirements. The North American Synchrophasor Initiative (NASPI) has developed a guide outlining the several tests required for dynamic characterization of PMUs. The National Institute of Standards and Technology (NIST) developed two PMU testing stands for steady-state conformance with the current standard and for dynamic performance testing. Since May 2010, Virginia Tech has been working closely with the NIST in developing a PMU testing system similar to the NIST designs for commercial testing of PMUs and research purposes, the Virginia Tech Calibration System. This thesis focuses on assessing the system accuracy differences between the designs, and the software interface modifications to adapt the new hardware.Master of Science
20
Hansen, Hedvik Louise. "Human Tracking System." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for teknisk kybernetikk, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26769.
Full textAbstract:
This thesis is motivated by Statoil's wish to localize people operating inside an onshore or offshore production facility. There are especially two benefits of such systems. By monitoring an operator's exposure to noise, vibration and harmful gases, short and long term damages can be avoided. In addition, a localization system would provide employees with a higher degree of safety in case of emergency. The aim of this thesis is to develop a prototype system for localizing people indoors as well as outdoors with use of an inertial measurement unit. As a consequence, challenges such as drift and signal noise, as well as magnetic interference are directed. Since the IMU is subject to drift, investigations on different sensor configurations must be conducted. Collected sensor data from the hip-mounted IMU are used for step detection, step length estimation and heading determination. By combining the results from these three approaches, a positioning estimate for the human operator is calculated using dead reckoning. Dead reckoning is a positioning method for determining an objects location based on a former position, velocity and direction.Experiments indicated satisfying performance by both the implemented step detection algorithm and the step length estimation model. However, the heading determination is subject to magnetic interferences when the sensor is applied in an industrial area. In an indoors environment are position error 2-4 meters after 22 meters walking. Performance in an outdoors environment are significantly better, with a position error of 10 meter after 400 meters. Integrating the suggested solution with another positioning system will increase system performance indoors and thus fulfill the aim of this thesis.
21
Mossop, Ben. "Telescope tracking system." Thesis, Mossop, Ben (2013) Telescope tracking system. Other thesis, Murdoch University, 2013. https://researchrepository.murdoch.edu.au/id/eprint/17874/.
Full textAbstract:
This report covers the design methodologies and principles used to develop an automated telescope tracking system. The 1980’s Murdoch University owned telescope was the hardware used in this project and the challenges experienced were primarily due to mechanical failures or part specification.
With utilising open-sourced equipment came great benefit as many design ideas were easily implemented due to a large following of these devices. In fact much of the code required to have this project operational already exists on the internet and is freely available to download.
Overall, the project outcomes were not fully achieved but the project is deemed partially successful given the large amount of research and development future students can learn from.
22
Najafi, Mohammad. "New methods for calibration and tool tracking in ultrasound-guided interventions." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/51776.
Full textAbstract:
Ultrasound is a safe, portable, inexpensive and real-time modality that can produce 2D and 3D images. It is a valuable intra-operative imaging modality to guide surgeons aiming to achieve higher accuracy of the intervention and improve patient outcomes. In all the clinical applications that use tracked ultrasound, one main challenge is to precisely locate the ultrasound image pixels with respect to a tracking sensor on the transducer. This process is called spatial calibration and the objective is to determine the spatial transformation between the ultrasound image coordinates and a coordinate system defined by the tracking sensor on the transducer housing. Another issue in ultrasound guided interventions is that tracking surgical tools (for example an epidural needle) usually requires expensive, large optical trackers or low accuracy magnetic trackers and there is a need for a low-cost, easy-to-use and accurate solution. In this thesis, for the first problem I have proposed two novel complementary methods for ultrasound calibration that provide ease of use and high accuracy. These methods are based on my differential technique which enables high measurement accuracy. I developed a closed-form formulation that makes it possible to achieve high accuracy with using a low number of images. For the second problem, I developed a method to track surgical tools (epidural needles in particular) using a single camera mounted on the ultrasound transducer to facilitate ultrasound guided interventions. The first proposed ultrasound calibration method achieved an accuracy of 0.09 ± 0.39 mm. The second method with a much simpler phantom yet achieved similar accuracy compared to the N-wire method. The proposed needle tracking method showed high accuracy of 0.94 ± 0.46 mm.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
23
Mostek, Nick. "Calibration system design and determination of filter calibration requirements for SNAP." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3278455.
Full textAbstract:
Thesis (Ph. D.)--Indiana University, Dept. of Astonomy, 2007.Source: Dissertation Abstracts International, Volume: 68-10, Section: B, page: 6711. Adviser: Stuart Mufson. Title from dissertation home page (viewed May 20, 2008).
24
Peng, Tao. "Reflectivity Measurement System Development and Calibration." The University of Waikato, 2007. http://hdl.handle.net/10289/2301.
Full textAbstract:
Accurate assessment of road luminance provided by overhead streetlights helps to optimize the visibility of objects on the road and therefore promotes driver safety, while minimizing energy consumption. To calculate road luminance, the road surface reflectivity has to be known. Odyssey Energy Limited has developed a prototype system that has the potential to determine the road reflectivity properties at high speed. In this thesis, an investigation into the prototype system has been conducted and further enhancement and redesign has been done. A portable on-site road surface reflectivity measurement system that complies with the Commission Internationale de I' Eclairage (CIE) standard was developed. The road test of this new system has been carried out on a series of Hamilton city roads. It proved that the new system is capable of measuring the road surface reflectivity and classifying the road into its appropriate R class according to the CIE standards specified in street lighting design criteria. Later the OEL prototype system was calibrated against the new system to find out the correlation between the two systems.
25
Pieralli, Francesca <1979>. "LBT AO system: tests and calibration." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2390/1/pieralli_francesca_tesi.pdf.
Full textAbstract:
An Adaptive Optic (AO) system is a fundamental requirement of 8m-class telescopes. We know that in order to obtain the maximum possible resolution allowed by these telescopes we need to correct the atmospheric turbulence.
Thanks to adaptive optic systems we are able to use all the effective potential of these instruments, drawing all the information from the universe sources as best as possible.
In an AO system there are two main components: the wavefront sensor (WFS) that is able to measure the aberrations on the incoming wavefront in the telescope, and the deformable mirror (DM) that is able to assume a shape opposite to the one measured by the sensor. The two subsystem are connected by the reconstructor (REC).
In order to do this, the REC requires a “common language" between these two main AO components. It means that it needs a mapping between the sensor-space and the mirror-space, called an interaction matrix (IM). Therefore, in order to operate correctly, an AO system has a main requirement: the measure of an IM in order to obtain a calibration of the whole AO system.
The IM measurement is a 'mile stone' for an AO system and must be done regardless of the telescope size or class.
Usually, this calibration step is done adding to the telescope system an auxiliary artificial source of light (i.e a fiber) that illuminates both the deformable mirror and the sensor, permitting the calibration of the AO system. For large telescope (more than 8m, like Extremely Large Telescopes, ELTs) the fiber based IM measurement requires challenging optical setups that in some cases are also impractical to build. In these cases, new techniques to measure the IM are needed.
In this PhD work we want to check the possibility of a different method of calibration that can be applied directly on sky, at the telescope, without any auxiliary source. Such a technique can be used to calibrate AO system on a telescope of any size.
We want to test the new calibration technique, called “sinusoidal modulation technique”, on the Large Binocular Telescope (LBT) AO system, which is already a complete AO system with the two main components: a secondary deformable mirror with by 672 actuators, and a pyramid wavefront sensor.
My first phase of PhD work was helping to implement the WFS board (containing the pyramid sensor and all the auxiliary optical components) working both optical alignments and tests of some optical components. Thanks to the “solar tower” facility of the Astrophysical Observatory of Arcetri (Firenze), we have been able to reproduce an environment very similar to the telescope one, testing the main LBT AO components: the pyramid sensor and the secondary deformable mirror. Thanks to this the second phase of my PhD thesis: the measure of IM applying the sinusoidal modulation technique. At first we have measured the IM using a fiber auxiliary source to calibrate the system, without any kind of disturbance injected. After that, we have tried to use this calibration technique in order to measure the IM directly “on sky”, so adding an atmospheric disturbance to the AO system.
The results obtained in this PhD work measuring the IM directly in the Arcetri solar tower system are crucial for the future development: the possibility of the acquisition of IM directly on sky means that we are able to calibrate an AO system also for extremely large telescope class where classic IM measurements technique are problematic and, sometimes, impossible.
Finally we have not to forget the reason why we need this: the main aim is to observe the universe. Thanks to these new big class of telescopes and only using their full capabilities, we will be able to increase our knowledge of the universe objects observed, because we will be able to resolve more detailed characteristics, discovering, analyzing and understanding the behavior of the universe components.
26
Pieralli, Francesca <1979>. "LBT AO system: tests and calibration." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2390/.
Full textAbstract:
An Adaptive Optic (AO) system is a fundamental requirement of 8m-class telescopes. We know that in order to obtain the maximum possible resolution allowed by these telescopes we need to correct the atmospheric turbulence.
Thanks to adaptive optic systems we are able to use all the effective potential of these instruments, drawing all the information from the universe sources as best as possible.
In an AO system there are two main components: the wavefront sensor (WFS) that is able to measure the aberrations on the incoming wavefront in the telescope, and the deformable mirror (DM) that is able to assume a shape opposite to the one measured by the sensor. The two subsystem are connected by the reconstructor (REC).
In order to do this, the REC requires a “common language" between these two main AO components. It means that it needs a mapping between the sensor-space and the mirror-space, called an interaction matrix (IM). Therefore, in order to operate correctly, an AO system has a main requirement: the measure of an IM in order to obtain a calibration of the whole AO system.
The IM measurement is a 'mile stone' for an AO system and must be done regardless of the telescope size or class.
Usually, this calibration step is done adding to the telescope system an auxiliary artificial source of light (i.e a fiber) that illuminates both the deformable mirror and the sensor, permitting the calibration of the AO system. For large telescope (more than 8m, like Extremely Large Telescopes, ELTs) the fiber based IM measurement requires challenging optical setups that in some cases are also impractical to build. In these cases, new techniques to measure the IM are needed.
In this PhD work we want to check the possibility of a different method of calibration that can be applied directly on sky, at the telescope, without any auxiliary source. Such a technique can be used to calibrate AO system on a telescope of any size.
We want to test the new calibration technique, called “sinusoidal modulation technique”, on the Large Binocular Telescope (LBT) AO system, which is already a complete AO system with the two main components: a secondary deformable mirror with by 672 actuators, and a pyramid wavefront sensor.
My first phase of PhD work was helping to implement the WFS board (containing the pyramid sensor and all the auxiliary optical components) working both optical alignments and tests of some optical components. Thanks to the “solar tower” facility of the Astrophysical Observatory of Arcetri (Firenze), we have been able to reproduce an environment very similar to the telescope one, testing the main LBT AO components: the pyramid sensor and the secondary deformable mirror. Thanks to this the second phase of my PhD thesis: the measure of IM applying the sinusoidal modulation technique. At first we have measured the IM using a fiber auxiliary source to calibrate the system, without any kind of disturbance injected. After that, we have tried to use this calibration technique in order to measure the IM directly “on sky”, so adding an atmospheric disturbance to the AO system.
The results obtained in this PhD work measuring the IM directly in the Arcetri solar tower system are crucial for the future development: the possibility of the acquisition of IM directly on sky means that we are able to calibrate an AO system also for extremely large telescope class where classic IM measurements technique are problematic and, sometimes, impossible.
Finally we have not to forget the reason why we need this: the main aim is to observe the universe. Thanks to these new big class of telescopes and only using their full capabilities, we will be able to increase our knowledge of the universe objects observed, because we will be able to resolve more detailed characteristics, discovering, analyzing and understanding the behavior of the universe components.
27
Gembarski, Joseph A. "Use of multiple tracking data in the calibration of short baseline arrays." Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/23806.
Full text
28
Woschitz, Helmut [Verfasser]. "System Calibration of Digital Levels: Calibration Facility, Procedures and Results / Helmut Woschitz." Aachen : Shaker, 2003. http://d-nb.info/1170544592/34.
Full text
29
Quillinan, Cormac. "Application packaging tracking system." [Denver, Colo.] : Regis University, 2007. http://165.236.235.140/lib/CQuillinan2007.pdf.
Full text
30
Chin, Yue Hann. "Radar tracking system development." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30368.
Full textAbstract:
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (leaf 65).
The Airborne Seeker Test Bed (ASTB) is an airborne sensor testing platform operated by the Tactical Defense Systems group at MIT Lincoln Laboratory. The Instrumentation Head (IH) is a primary sensor on the ASTB. It is a passive X-band radar receiver located on the nose of the plane. The IH serves as a truth sensor for other RF systems on the test bed and is controlled by an onboard tracking system, the Seeker Computer. The Seeker Computer processes IH data in real-time to track targets in Doppler, angle, and range. From these tracks it then produces angle-error feedback signals that command the IH gimbals, keeping targets centered along the antenna boresight. Over three years, a new Seeker Computer was built to replace an old system constrained by obsolete hardware. The redevelopment project was a team effort and this thesis presents a systems-level analysis of the design process, the new Seeker Computer system, and the related team and individual contributions to software and digital signal processing research that took place during development.
by Yue Hann Chin.
M.Eng.
31
Jackson, Joshua D. "Optical vehicular tracking system." Birmingham, Ala. : University of Alabama at Birmingham, 2009. https://www.mhsl.uab.edu/dt/2009p/jackson.pdf.
Full textAbstract:
Thesis (Ph. D.)--University of Alabama at Birmingham, 2009.Additional advisors: Thomas C. Jannett, David Pan, Gregg L. Vaughn, Percy F. Wang. Description based on contents viewed June 2, 2009; title from PDF t.p. Includes bibliographical references (p. 69-72).
32
Sidenmark, Ludwig. "Immersive Eye Tracking Calibration in Virtual Reality Using Interactions with In-game Objects." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209431.
Full textAbstract:
This thesis aims to investigate an eye tracking calibration method in virtual reality where users’ visual attention from eye-hand coordination is used when interacting with in-game items. This could potentially allow eye tracking calibration without interrupting the virtual experience, in comparison with traditional eye tracking calibration which is cumbersome, disruptive, and requires the user’s full attention. A user study was conducted with 15 participants in which they were tasked to complete three different interactions. The interactions tested were a knob, a slider and a liftable cube. Where in the virtual environment the participants were looking during the interactions was recorded and processed to enable comparison. The processed data was analysed to find factors that influenced the calibration method. Additionally, the results was analysed to find at what point during the interactions that has the most consistent eye tracking fixations on the interacted item, and therefore most potential for eye tracking calibration. The results showed that when the participant is interacting with the item and the interacted item is stationary, we received a fixation for around 60% of all trials at any time. When the interacted item was moving the results indicated a lower percentage. To increase this number, the gaze data should be filtered instead of using raw gaze data in order to avoid flickering from the eye tracker. Regarding factors that influence the calibration method, the choice of interaction has a big impact on the method’s success where interactions in which the interacted item is stationary has more potential. Additionally, interactions that take longer time and requires precision in order to complete the interaction positively influences the potential of the calibration method. The surrounding virtual environment also has an influence, as a more distracting environment can negatively impact the calibration method.Denna avhandling ämnar att att undersöka en kalibreringsmetod för ögonspårning i virtuell verklighet där användarnas visuella uppmärksamhet från ögon och hand koordination används när man interagerar med objekt i den virtuella verkligheten. Detta kan möjliggöra kalibrering av ögonspårning utan att avbryta den virtuella upplevelsen, i jämförelse med traditionell kalibrering som är besvärlig, störande och kräver användarens fulla uppmärksamhet. En användarstudie genomfördes med 15 deltagare där de hade till uppgift att slutföra tre olika interaktioner. De testade interaktionerna var en knopp, en slider och en lyftbar kub. Deltagarnas blick spelades in under interaktionerna och analyserades för att möjliggöra jämförelse. Den bearbetade data analyserades för att hitta faktorer som påverkar kalibreringsmetoden. Dessutom analyserades resultaten för att hitta vid vilken tidpunkt under interaktionerna som hade de mest konsekventa ögonfixeringarna på objektet de interagerade med och därmed störst potential för kalibrering av ögonspårning. Resultaten visade att när deltagaren interagerar med objektet och det interaktiva objektet är stillastående, fick vi en fixering för omkring 60% av alla försök under godtycklig tidpunkt. När det interaktiva objektet rörde sig, visade resultaten en lägre procentandel. För att öka antalet, ska blickdatan filtreras i stället för att använda rå blickdata för att undvika att flicker från ögonspåraren. När det gäller faktorer som påverkar kalibreringsmetoden har valet av interaktion stor inverkan på metodens framgång, där interaktioner där det interaktiva objektet är stationärt har större potential. Dessutom påverkar interaktioner som tar längre tid och kräver precision för att slutföra interaktionen kalibreringsmetodens potential positivt. Den omgivande virtuella miljön har också inflytande, eftersom en mer distraherande miljö kan negativt påverka kalibreringsmetoden.
33
Gonzalez, Garcia Gerardo. "Optimised calibration, registration and tracking for image enhanced surgical navigation in ENT operations." Thesis, University of East Anglia, 2011. https://ueaeprints.uea.ac.uk/24512/.
Full text
34
Mirpour, Sasha. "A Comparison of 3D Camera Tracking Software." Thesis, University of Gävle, Department of Mathematics, Natural and Computer Sciences, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-779.
Full textAbstract:
In the past decade computer generated images have become widely used in the visual effects industry. One of the main reasons is being able to seamlessly blend three dimensional (3D) animation with live-action footage. In this study, different 3D camera tracking software (also referred to as matchmoving) is compared focusing on workflow, user-friendly system, and quality of production.
35
Seierstad, Johanne. "Design system for primary calibration of flow." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for energi- og prosessteknikk, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-23595.
Full textAbstract:
Whilst growing demand for energy in Nepal and neighbouring- countries, investments in hydro- power projects appears continuously, both by local and multinational companies. As a consequence of this, Turbine Testing Lab was founded in 2011 at Kathmandu University in Nepal. The laboratory is rapidly developing, and is currently implementing a Francis turbine test rig. A long- term goal for the laboratory, is to execute model tests according to IEC 60193, which is the standard used in model tests of hydraulic runners.When determining the hydraulic efficiency of a runner, a central parameter is the discharge measurement. According to IEC, any secondary device used to measure the discharge shall be calibrated in sitù against one of the following primary methods: the weighing method, volumetric method or the moving- screen method.The aim of this work has been to develop and design a primary method for calibration of the flowmeter at TTL. Based on an evaluation of the mentioned primary methods, as well as economy, accuracy and correspondence with technical staff, a volumetric method is chosen as calibration principle. The principle of the method is based on collecting water into a tank with a known geometry, and by execution of level- and time measurements calculating the discharge.The calibration rig consists of a flowmeter, inlet nozzle, deflector mechanism, emergency weir, calibration tank, level measurement, time measurement, drainage system, emergency weir, and an upgraded pipe run at the measuring section of the flowmeter.It is developed a LabView program, for logging and processing the voltage output from the flowmeter. The other measurements executed is registered manually in a separate calibration sheet for data processing. An evaluation of the accuracy in the calibration method is conducted, which may be used to determine the total uncertainty when the calibration facility is installed. Provided design and installation according to ISO 8316, the accuracy in discharge measurement with the volumetric method lies within $\pm$ 0,1- 0,2 \%. The major uncertainty contribution in the method lies in the determination of the volume collected, and the corresponding tank calibration.It is proposed to reduce the diameter of the flowmeter from original size of 400 mm to 250 mm. Reduction in diameter and upgraded pipe run will increase accuracy of the flow measurement, a result of improved flow pattern at the measuring section. When the primary calibration rig is installed at TTL, this will be a large step towards an IEC- approved laboratory in Nepal, which open doors against an international market.
36
Needham, Richard Lee. "Calibration of strapdown system accelerometer dynamic errors." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/47358.
Full text
37
Kapelan, Zoran. "Calibration of water distribution system hydraulic models." Thesis, University of Exeter, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370011.
Full textAbstract:
A number of mathematical models are used nowadays to describe behaviour of the reallife water distribution system (WDS). It is a well known fact that, to have any meaningful use, any WDS mathematical model must be calibrated first. Here, calibration is defined as process in which a number of WDS model parameters are adjusted until the model mimics behaviour of the real WDS as closely as possible. In this thesis, WDS mathematical models that are used to model water quantity aspect only are analysed. Three hydraulic models considered here are: (1) steady-state flow model, (2) quasi-steady flow (extended period simulation) model and (3) unsteady flow model. The calibration problem analysed here is formulated as a constrained optimisation problem of weighted least square type with the objective defined in a way that enables effective incorporation of prior information on calibration parameters. WDS calibration problem is then analysed in detail, including special issues of identifiability, uniqueness and stability of the problem solution. A list of diagnostic and other statistics and analysis is presented to improve existing calibration approaches by providing partial insight into the calibration process. Calibration of WDS hydraulic models is further improved by the development of new hybrid optimisation method. Being closely related to calibration, the problem of sampling design for calibration of WDS hydraulic models is also addressed here. First, sampling design is formulated as a constrained two-objective optimisation problem. Then, two novel models are developed to solve it. The first model is based on standard, single-objective Genetic Algorithms (SOGA). The second model is based on multi-objective Genetic Algorithms (MOGA). Finally, all novel methodologies presented here are verified successfully on multiple case studies that involve both artificial and real-life WDS. At the end, relevant conclusions are drawn and suggestions for further research work are made.
38
Aldoumani, Anoor. "Calibration enhancement of non-linear VNA system." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/100407/.
Full textAbstract:
Communication systems are generally found wherever data is to be transmitted from point-to-point or from a point to many points. It is impossible to imagine modern life without communication systems such as radio, telephone, TV, Satellite and etc. The transmission of information from one place to another requires an operation or other alteration to be sent through an electrical signal; the same principle applies for the receiving terminal. Modern life requires that efficient wireless communication systems for long range transmission be built, therefore, base-stations must use high power transistors almost exclusively. Furthermore, modern cellular communication systems also need to transmit across long distances, hence, to achieve this aim successfully, a radio frequency (RF) power amplifier is employed. That is considered to be a key element of any wireless communication system. Efficient communication systems must have minimum spectral re-growth, interference and employ linear. Signal amplification is one of the core circuit functions in modern microwave and RF systems. The Power Amplifier (PA) is a key element in the construction of all wireless communication systems. The PA uses the most current because it is the last stage in the transmission chain. In modern PA design, the RFPA designer must have accurate S-parameter data for the DUT, thereby allowing the creation of an accurate system model and to reduce the re-design and rework effort. The ultimate aim of the research work presented in this thesis is to achieve improvement in the accuracy of a waveform measurement system by increasing the accuracy of the small-signal calibration used. This involved removing the phase reference from the NVNA during calibration and operation, which in turn removes the bandwidth and frequency limitations that the phase reference imposes, as well as reducing the complexity of the overall system. Essential contributions to this research work concentrated in two areas; firstly, developments that allow for Enhanced Vector Calibration of Load-pull measurement systems, especially near the edge of the Smith Chart, and secondly, the operation and Anoor Aldoumani Abstract IV calibration of a VNA-based large-signal RF I-V waveform measurement system without using a harmonic phase reference standard. The first research area described in this thesis involved investigating the prospect of improving vector measurement accuracy, especially near the edge of the Smith Chart, by using load pull technology. Increased measurement error near the edge of the Smith chart was observed during calibration. To help correct this, the realisation of novel optimization that increases the accuracy of all the raw data which was collected during calibration process and therefore increases the accuracy of calibration at reflection coefficients close to unity. This research work focuses on taking advantage of the load-pull capability during calibration, this reduces the effect of measurement errors on the raw data when measuring the calibration standards before being applied in traditional LRL/TRL calibration algorithms. Leading to time proved measurement accuracy and eliminates the requirement to use complex optimisation algorithms post calibration. The second concept developed simplifies the NVNA architecture and removes the complexities and bandwidth limitations introduced when employing a harmonic phase reference generator. A key capability of the Rohde and Schwarz ZVA-67 VNA is that it incorporates internal signal and local oscillator sources and employs direct digital synthesis was exploited to advantage allows the Vector Network Analyzer to be operated as a NVNA without the need for a harmonic phase reference generator. This is due to such a Vector Network Analyzer based NVNA configuration provided a system with both coherent receivers and sources. This feature combined with a modified calibration procedure, means that during calibration only the internal signal sources and an external phase meter are required during measurement. All the internal signal sources and receiver port are available to measure, also now since no phase reference required, bandwidth and functionality issues and avoided.
39
Carrillo, Agirre Amaia. "Time Tracking System with GWT." Thesis, Linnaeus University, School of Computer Science, Physics and Mathematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-7105.
Full textAbstract:
Applied Research in System Analysis (ARiSA) AB, is a company whose main objective is to market the VizzAnalyzer™ software quality tool and related services, experiences, and research results.
In the beginning, recording the time spent on different activities and projects for project control, cost calculation, and customer billing manually and individually was sufficient and effective. With the number of projects and people involved at a time increasing the existing mechanisms were not sufficient anymore and needed to be replaced to support an efficient recording of time and report generation.
To solve this situation, a prototype of a web-based time tracking system was implemented. The task for this thesis was to build on the existing prototype implementation, to improve and complete it. In detail, to extend the functionalities of the web application adding user, project and activity management, and report creation.
The solution supports an efficient time tracking for employees and it makes the report generation easier.
This thesis describes the requirements for the project and the resulting implementation.
40
Zou, Hanzheng. "Build an Inventory Tracking System." Thesis, Växjö University, School of Mathematics and Systems Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1580.
Full textAbstract:
This thesis paper introduces you about the process of how to build an inventory tracking system in a local Swedish company. The related project is to support the thesis paper, and is also for the company’ using. The software product of this project is an application that works for managing various types’ instruments in the company of SWECO-Vaxjo. It will play an important role in the further management work of the company.
In this thesis paper, the candidate techniques and theories for implementing this system are discussed. And in the end a good solution for this problem will be presented in the paper.
41
Brengesjö, Carl, and Martine Selin. "Tracking System : Suaineadh satellite experiment." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-52906.
Full textAbstract:
The purpose of this bachelor thesis is to present a tracking system for the Suaineadh satellite experiment. The experiment is a part of the REXUS (Rocket EXperiments for University Students) program and the objective is to deploy a foldable web in space. The assignment of this thesis is to develop a tracking system to find the parts from the Suaineadh experiment that will land on Earth. It is important to find the parts and recover all the data that the experiment performed during the travel in space. The implementation of this thesis investigates two different ways to track and find the experiment. The first way is to locate the experiment module by a Global Positioning System (GPS) and send the coordinates to a satellite modem, controlled by a programmed microprocessor. The other way is by using a radio beacon that sends a speciffic radio frequency. The results of this thesis presents a prototype for the tracking system with a GPS and the satellite modem and code example for the microprocessor. It also presents a working radio freqency beacon system on a Printed Circuit Board. The thesis had some unexpected incidents and had to change some directives. This rendered the work to take longer time then estimated. Despite the difficulties resulted this thesis in a working system to track the experiment.
42
Wessler, Mike. "A modular visual tracking system." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11459.
Full text
43
HART, MICHAEL JAMES. "ADVANCED TELEMETRY TRACKING SERVO SYSTEM." International Foundation for Telemetering, 1991. http://hdl.handle.net/10150/612158.
Full textAbstract:
International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, NevadaThe primary objective of the Advanced Telemetry Tracking System Integration and Development program at WSMR was the development and evaluation of an advanced, almost totally digital servo tracking and control system. This was satisfied by replacing the aging analog servo tracking and control system in one of WSMR’s seven Transportable Telemetry Acquisition Systems (TTAS) with a Digital Control Unit (DCU), an Antenna Control Unit (ACU), and other related equipment, and then evaluating the performance of the resultant digital tracking system, referred to as the Advanced TTAS (TTAS-A). The ACU is the primary interface between the operator and the DCU. Through the ACU, the TTAS-A operator has independent control over each pedestal axis (elevation and azimuth) involving the selection of tracking mode and servo bandwidth. The DCU reports various servo system status and warning conditions back to the operator through the ACU. In this paper, a discussion of the TTAS-A servo system, with emphasis upon hardware external to the DCU, is presented. This includes the operation of servo position and rate loops, system status and warning conditions, and a description of the operator-to-system interface via the ACU display and control functions.
44
Kenington, P. B. "Tracking receiver design for the electronic 'beam squint' tracking system." Thesis, University of Bristol, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235772.
Full text
45
Larsson, Joakim. "Using gaze aware regions in eye tracking calibration for users with low-attention span." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216672.
Full textAbstract:
Eye trackers have enabled users to interact with computers for a long time. Yet, there are still many challenges left to be solved to make the interaction easy for users with development disabilities. Especially, when it comes to setup eye tracking where calibration of the eye tracker is important to get accurate estimation of where users are looking. This paper presents a study in which three modified versions of a calibration interface for eye trackers has been designed and evaluated by nine participants with development disabilities. These calibration interfaces used regions that were aware of when a user gazed at them, gaze-aware regions, and varied in the speed of which a stimulus moved during the calibration and how quickly the regions around the stimulus grew. Data was collected for each interface about interaction with the gaze-aware regions, time to complete a calibration, how many calibration points that were completed and gaze offset from the stimulus. No statistically significance was found between the modified interfaces for its efficiency, effectiveness and accuracy. However, a stimulus moving quicker and a gaze-aware region growing faster indicated a more effective and efficient calibration method without loss in accuracy. Also, if only screen engagement is involved using smooth-pursuit calibration could improve the calibration process.Ögonstyrning har under en längre tid möjliggjort interaktion för användare. Dock är det fortfarande många utmaningar för att göra interaktionen lätt för användare med intellektuella funktionsnedsättningar. Framförallt när det kommer till inställningar för ögonstyrning, där kalibrering har visat sig vara viktigt för att ge en noggrann uppskattning vart användarna fokuserar. Denna rapport presenterar en studie där tre modifierade versioner av ett kalibreringsgränsnitt för ögonstyrning har blivit designat och utvärderat av nio deltagare med låg fokuseringsförmåga. Dessa gränssnitt använde regioner som var medvetna när en användare tittade inom dom, så kallade blickmedvetna regioner, och varierade i vilken hastighet ett stimuli rörde sig och hur snabbt regionerna runt ett stimuli växte. Data samlades in för varje gränssnitt om interaktionen med de blickmedvetna regionerna, tiden för att genomföra kalibreringen, antal avklarade kalibreringspunkter och avståndet mellan användarnas blick och stimuli. Ingen statistisk signifikans hittades mellan de modifierade gränssnitten mellan tidseffektivitet, effektivitet och noggrannhet. Däremot indikerades en mer tidseffektiv och effektiv kalibreringsmetod, utan minskad noggrannhet, genom användningen av ett stimuli som rör sig snabbare med blickmedvetna regioner som växer. Dessutom skulle kalibreringsprocessen kunna förbättras om enbart engagemang med skärmen används genom smooth-pursuit kalibrering
46
Taba, Isabella Bahareh. "Improving eye-gaze tracking accuracy through personalized calibration of a user's aspherical corneal model." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/40247.
Full textAbstract:
The eyes present us with a window through which we view the world and gather information. Eye-gaze tracking systems are the means by which a
user's point of gaze (POG) can be measured and recorded. Despite the active research in gaze tracking systems and major advances in this field,
calibration remains one of the primary challenges in the development of eye tracking systems. In order to facilitate gaze measurement and tracking,
eye-gaze trackers utilize simplifications in modeling the human eye. These simplifications include using a spherical corneal model and using population averages for eye parameters in place of individual measurements, but use of these simplifications in modeling contribute to system errors and impose inaccuracies on the process of point of gaze estimation.
This research introduces a new one-time per-user calibration method for gaze estimation systems. The purpose of the calibration method developed in this thesis is to calculate and estimate different individual eye parameters based on an aspherical corneal model. Replacing average measurements with
individual measurements promises to improve the accuracy and reliability of the system. The approach presented in this thesis involves estimating eye parameters by statistical modeling through least squares curve fitting.
Compared to a current approach referred to here as the Hennessey's calibration method, this approach offers significant advantages, including improved, individual calibration. Through analysis and comparison of this new calibration method with the Hennessey calibration method, the research data presented in this thesis shows an improvement in gaze estimation accuracy of approximately 27%. Research has shown that the average accuracy for the Hennessey calibration method is about 1:5 cm on an LCD screen at a distance of 60 cm, while the new system, as tested on eight different subjects, achieved an average accuracy of 1:1 cm. A statistical analysis (T-test) of the comparative accuracy of the new calibration method versus the Hennessey calibration method has demonstrated that the new system represents a statistically significant improvement.
47
Mayer, Joseph Raymond Rene. "Further development, modelling and calibration of a laser tracking instrument for 3D dynamic measurement." Thesis, University of Surrey, 1988. http://epubs.surrey.ac.uk/843985/.
Full textAbstract:
The emergence of robots as essential components in the development of flexible manufacturing systems has created a demand for measurement techniques capable of measuring their performance. Typically it is required to measure the position of the robot end effector at speeds of up to 5 m/sec in a 1 metre sided cube and with a precision better than 0.1 mm. An instrument has been developed that uses a laser tracking technique and the principle of triangulation to determine the x,y and z co-ordinates of an optical target. It consists of two identical sub-systems, a retroreflective cat's eye target and a supervisory microcomputer. Each sub-system aims a low power laser beam at the target and detects the retroreflected beam for feedback to the mirror actuators controlling the beam direction. The instrument has been modelled, calibrated and evaluated. The effect on the target coordinate calculation of various system errors has been studied and a variety of measurement tools and methods are presented to calibrate the instrument both at component and sub-system level and also as a final system. The design of the cat's eye target is reviewed and a method of manufacture presented. Preliminary results and design details of a new optical sub-system with up-graded characteristics are also included. Tests show that the present instrument has a measurement accuracy of 0.03%, a repeatability of 0.01% (all for 1 standard deviation) for a measurement space of approximately one metre cube. The beam steering scanners have a bandwidth in excess of 74 Hz and the tracking velocity is approximately 3 m/s.
48
Jansson, Sebastian. "On Vergence Calibration of a Stereo Camera System." Thesis, Linköpings universitet, Institutionen för systemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-84770.
Full textAbstract:
Modern cars can be bought with camera systems that watch the road ahead. They can be used for many purposes, one use is to alert the driver when other cars are in the path of collision. If the warning system is to be reliable, the input data must be correct. One input can be the depth image from a stereo camera system; one reason for the depth image to be wrong is if the vergence angle between the cameras are erroneously calibrated. Even if the calibration is accurate from production there's a risk that the vergence changes due to temperature variations when the car is started. This thesis proposes one solution for short-time live calibration of a stereo camera system; where the speedometer data available on the CAN-bus is used as reference. The motion of the car is estimated using visual odometry, which will be affected by any errors in the calibration. The vergence angle is then altered virtually until the estimated speed is equal to the reference speed. The method is analyzed for noise and tested on real data. It is shown that detection of calibration errors down to 0.01 degrees is possible under certain circumstances using the proposed method.
49
Ramírez, Eduardo Díaz. "A MORE EFFICIENT TRACKING SYSTEM FOR THE SANTIAGO SATELLITE TRACKING STATION." International Foundation for Telemetering, 2007. http://hdl.handle.net/10150/604559.
Full textAbstract:
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, NevadaA digital antenna control system has been designed and installed on a pedestal that was formerly used to drive a VHF array and that has now been replaced with an 11 meter S-Band parabolic reflector. In this Paper, the former analog tracking system will be described, showing all the drawbacks that made it unusable for S-Band. Subsequently, the development and implementation of the digital S-Band tracking system, using Labview, C++ & digital control theory will be discussed. Finally, there will be a comparison between the digital and analog system, too.
50
Lord, Martin Edmund. "An improved, adaptive calibration system for weather radar." Thesis, Lancaster University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286979.
Full text