Download or read book Efficient Time of Arrival Calculation for Acoustic Source Localization Using Wireless Sensor Networks written by Prashanth G. Reddy and published by . This book was released on 2011 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic source localization is a very useful tool in surveillance and tracking applications. Potential exists for ubiquitous presence of acoustic source localization systems. However, due to several significant challenges they are currently limited in their applications. Wireless Sensor Networks (WSN) offer a feasible solution that can allow for large, ever present acoustic localization systems. Some fundamental challenges remain. This thesis presents some ideas for helping solve the challenging problems faced by networked acoustic localization systems. We make use of a low-power WSN designed specifically for distributed acoustic source localization. Our ideas are based on three important observations. First, sounds emanating from a source will be free of reflections at the beginning of the sound. We make use of this observation by selectively processing only the initial parts of a sound to be localized. Second, the significant features of a sound are more robust to various interference sources. We perform key feature recognition such as the locations of significant zero crossings and local peaks. Third, these features which are compressed descriptors, can also be used for distributed pattern matching. For this we perform basic pattern analysis by comparing sampled signals from various nodes in order to determine better Time Of Arrivals (TOA). Our implementation tests these ideas in a predictable test environment. A complete system for general sounds is left for future work.
Download or read book Sound Source Localization written by Richard R. Fay and published by Springer Science & Business Media. This book was released on 2006-05-20 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Springer Handbook of Auditory Research presents a series of compreh- sive and synthetic reviews of the fundamental topics in modern auditory - search. The volumes are aimed at all individuals with interests in hearing research including advanced graduate students, postdoctoral researchers, and clinical investigators. The volumes are intended to introduce new investigators to important aspects of hearing science and to help established investigators to better understand the fundamental theories and data in ?elds of hearing that they may not normally follow closely. Each volume presents a particular topic comprehensively, and each serves as a synthetic overview and guide to the literature. As such, the chapters present neither exhaustive data reviews nor original research that has not yet appeared in peer-reviewed journals. The volumes focus on topics that have developed a solid data and conceptual foundation rather than on those for which a literature is only beginning to develop. New research areas will be covered on a timely basis in the series as they begin to mature.
Download or read book Localization Algorithms and Strategies for Wireless Sensor Networks Monitoring and Surveillance Techniques for Target Tracking written by Mao, Guoqiang and published by IGI Global. This book was released on 2009-05-31 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless localization techniques are an area that has attracted interest from both industry and academia, with self-localization capability providing a highly desirable characteristic of wireless sensor networks. Localization Algorithms and Strategies for Wireless Sensor Networks encompasses the significant and fast growing area of wireless localization techniques. This book provides comprehensive and up-to-date coverage of topics and fundamental theories underpinning measurement techniques and localization algorithms. A useful compilation for academicians, researchers, and practitioners, this Premier Reference Source contains relevant references and the latest studies emerging out of the wireless sensor network field.
Download or read book Localization and Tracking in Wireless Networks written by Enyang Xu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Given the increasing number of location-based applications in wireless networks, efficient solution to the problem of source localization and tracking has become more and more important. In this dissertation, we present our works on improving source localization and tracking in wireless networks. First we investigate localization algorithms for the time difference of arrival (TDOA) measurement model. Taking into account the colored measurement noise, we adopt a minmax principle to develop semidefinite relaxation algorithms that can be reliably solved using semidefinite programming with low complexity. The reduction of algorithm complexity is achieved through a simple but effective method for reference node selection among participating measurement nodes such that only a subset of selective time-differences of signal arrival are exploited. Our estimation methods are less sensitive to the source locations and can be used either as the final location estimate or as the initial point for traditional search algorithms. We also consider the more practical time of arrival (TOA) measurement model, in which the source start transmission time is unknown. We present two new methods that utilize semidefinite programming relaxation for direct source localization. We further address the issue of robust estimation given measurement errors and inaccuracy in the locations of receiving sensors. Our results demonstrate some potential advantages of source localization based on the direct TOA data over time-difference preprocessing. Next, we investigate the emitter source tracking problem in which a mobile tracking sensor and multiple anchored sensors cooperate to track and estimate a mobile source node locations. We propose a min-max approximation approach to estimate the location for tracking which can be efficiently solved via semidefinite programming relaxation, and apply a cubic function for mobile sensor navigation. We jointly estimate the location of the mobile sensor and the target to improve the tracking accuracy. To further improve the system performance, we propose a weighted tracking algorithm by using the measurement information more efficiently. Our results demonstrate that the proposed algorithm provides good tracking performance and can quickly direct the mobile sensor to follow the mobile target. Lastly, we consider the multi source localization problem. With nknown source node index of each received signal, we need to identify the source of each received signal as well as estimate the locations. The combinational nature of the receive signal mixing and ordering makes the problem very complicated. We propose two algorithms based on semidefinite relaxation, and provide corresponding refinement method for each algorithm. In addition, we consider the localization problem given ambiguous anchor node measurement. We propose to identify the ambiguous anchor nodes based on the estimated noise amplitude. After identifying the ambiguous anchor nodes, we can remove the incorrect TOA measurements and obtain more accurate location estimation. In summary, the works presented in this dissertation provide several effective approaches to localization and tracking in wireless networks under different measurement models. The proposed algorithms improve the performance with relatively low complexity. As the demands for location based service rise, our methods will have applications in real systems.
Download or read book Handbook of Position Location written by Reza Zekavat and published by John Wiley & Sons. This book was released on 2019-03-06 with total page 1376 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of position location technology — from fundamental theory to advanced practical applications Positioning systems and location technologies have become significant components of modern life, used in a multitude of areas such as law enforcement and security, road safety and navigation, personnel and object tracking, and many more. Position location systems have greatly reduced societal vulnerabilities and enhanced the quality of life for billions of people around the globe — yet limited resources are available to researchers and students in this important field. The Handbook of Position Location: Theory, Practice, and Advances fills this gap, providing a comprehensive overview of both fundamental and cutting-edge techniques and introducing practical methods of advanced localization and positioning. Now in its second edition, this handbook offers broad and in-depth coverage of essential topics including Time of Arrival (TOA) and Direction of Arrival (DOA) based positioning, Received Signal Strength (RSS) based positioning, network localization, and others. Topics such as GPS, autonomous vehicle applications, and visible light localization are examined, while major revisions to chapters such as body area network positioning and digital signal processing for GNSS receivers reflect current and emerging advances in the field. This new edition: Presents new and revised chapters on topics including localization error evaluation, Kalman filtering, positioning in inhomogeneous media, and Global Positioning (GPS) in harsh environments Offers MATLAB examples to demonstrate fundamental algorithms for positioning and provides online access to all MATLAB code Allows practicing engineers and graduate students to keep pace with contemporary research and new technologies Contains numerous application-based examples including the application of localization to drone navigation, capsule endoscopy localization, and satellite navigation and localization Reviews unique applications of position location systems, including GNSS and RFID-based localization systems The Handbook of Position Location: Theory, Practice, and Advances is valuable resource for practicing engineers and researchers seeking to keep pace with current developments in the field, graduate students in need of clear and accurate course material, and university instructors teaching the fundamentals of wireless localization.
Download or read book Efficient Localization Methods for a Point Source and Rigid Body written by Shanjie Chen (Computer engineer) and published by . This book was released on 2015 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Localization has been a very important and fundamental research topic in GPS, radar, sonar, and especially in mobile communications and sensor networks over the past few years. Localization of a signal source is often accomplished by using a number of sensors that measure the radiated signal from the source, here we consider the range based measurements, including time of arrival (TOA) and time difference of arrival (TDOA). In such study, the object is far away or only the position information is needed, and we refer this as point source localization. For some applications, e.g., robotics, spacecraft, and gaming, orientation information in addition to position is also needed. Although an inertial measurement unit (IMU) can perform such task once the initial state is available, it suffers from long-term performance deviation and requires accurate calibration using additional devices. Here we consider joint position and orientation estimation using the distance or AOA measurements between the fixed sensors on the object and the anchors at fixed locations, and it is called rigid body localization. Our research has two manifolds: First, for the point source localization, the original squared range least squares (SR-LS) admits global and computationally efficient solution using generalized trust region subproblems (GTRS) technique but with non-optimal accuracy, therefore we add proper range weighting (SR-WLS) into it and investigate the resulting performances of mean squared error (MSE) and bias. Its asymptotic efficiency is proven theoretically and validated by simulations. The effects of range weighting on the localization performance under different sensor number, noise correlation, and localization geometry are examined. We also conduct similar range weighting for squared range difference least squares (SRD-LS and SRD-WLS) under TDOA measurements. In addition, the weighting technique is extended to the scenario where the sensor positions are not exactly known. The resultant cost function has the same structure as that without sensor position errors, thereby existing algebraic or exact solutions to the squared measurements can still be used without requiring new optimization method. Second, for the rigid body localization, under distance measurements, the existing method cancels the quadratic term of the sensor position in the squared distance measurement equations, which may cause serious degradation. Our proposed estimators are non-iterative and have two steps: preliminary and refinement. The preliminary step provides a coarse estimate and the refinement step improves the first step estimate to yield an accurate solution. When the rigid body is stationary, we are able to locate the rigid body with accuracy higher than the solutions of comparable complexity found in the literature. When the rigid body is moving, we introduce additional Doppler shift measurements and develop an estimator that contains the additional unknowns of angular and translational velocities. Simulations show that the proposed estimators, in both stationary and moving cases, can approach the Cramer-Rao lower bound (CRLB) performance under Gaussian noise over the small error region. Under AOA measurements, we solve the 3D scenario that is seldom considered before, through estimating its distances to landmarks and contrasting the landmark positions in object local frame and the global frame. Furthermore, we extend it to the scenario where there is more than one AOA sensor on-board, which either increases the robustness and accuracy or decreases the minimum requirement on number of landmarks. And the methods for 2D and 3D are designed respectively. The simulations confirm the effectiveness of proposed methods.
Download or read book Velocity Free Localization Methodology for Acoustic and Microseismic Sources written by Longjun Dong and published by Springer Nature. This book was released on 2023-02-03 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, we proposed velocity-free localization methods for acoustic and microseismic sources. This method does not require predetermination of wave velocity, which is a dynamically adjusted free real-time parameter. These methods solve the problem of large localization error caused by the difference between measured wave velocity and actual wave velocity in the source area and greatly improve the positioning accuracy. They are suitable for complex structures where the wave velocity changes dynamically in time and space, such as mines, bridges, buildings, pavements, loaded mechanical structures, dams, geothermal mining, oil extraction, and other engineering fields. This book includes progress in the development of localization methods, factors affecting the accuracy of source localization, analytical methods without the pre-measured wave velocity, velocity-free numerical methods for localizing acoustic sources, combined optimal velocity-free localization methods, velocity-free source localization considering complex paths of spatial structures, and theories as well as some cases of engineering applications of these methods.
Download or read book Underwater Acoustic Sensor Networks written by Yang Xiao and published by CRC Press. This book was released on 2010-05-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed review of underwater channel characteristics, Underwater Acoustic Sensor Networks investigates the fundamental aspects of underwater communication. Prominent researchers from around the world consider contemporary challenges in the development of underwater acoustic sensor networks (UW-ASNs) and introduce a cross-layer approach for effec
Download or read book Interior Point Methods for Linear Optimization written by Cornelis Roos and published by Springer Science & Business Media. This book was released on 2006-02-08 with total page 501 pages. Available in PDF, EPUB and Kindle. Book excerpt: The era of interior point methods (IPMs) was initiated by N. Karmarkar’s 1984 paper, which triggered turbulent research and reshaped almost all areas of optimization theory and computational practice. This book offers comprehensive coverage of IPMs. It details the main results of more than a decade of IPM research. Numerous exercises are provided to aid in understanding the material.
Download or read book Information Processing in Sensor Networks written by Feng Zhao and published by Springer Science & Business Media. This book was released on 2003-04-10 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the Second International Workshop on Information Processing in Sensor Networks, IPSN 2003, held in Palo Alto, CA, USA, in April 2003. The 23 revised full papers and 21 revised poster papers presented were carefully reviewed and selected from 73 submissions. Among the topics addressed are wireless sensor networks, query processing, decentralized sensor platforms, distributed databases, distributed group management, sensor network design, collaborative signal processing, adhoc sensor networks, distributed algorithms, distributed sensor network control, sensor network resource management, data service middleware, random sensor networks, mobile agents, target tracking, sensor network protocols, large scale sensor networks, and multicast.
Download or read book Advances in Sound Localization written by Pawel Strumillo and published by BoD – Books on Demand. This book was released on 2011-04-11 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sound source localization is an important research field that has attracted researchers' efforts from many technical and biomedical sciences. Sound source localization (SSL) is defined as the determination of the direction from a receiver, but also includes the distance from it. Because of the wave nature of sound propagation, phenomena such as refraction, diffraction, diffusion, reflection, reverberation and interference occur. The wide spectrum of sound frequencies that range from infrasounds through acoustic sounds to ultrasounds, also introduces difficulties, as different spectrum components have different penetration properties through the medium. Consequently, SSL is a complex computation problem and development of robust sound localization techniques calls for different approaches, including multisensor schemes, null-steering beamforming and time-difference arrival techniques. The book offers a rich source of valuable material on advances on SSL techniques and their applications that should appeal to researches representing diverse engineering and scientific disciplines.
Download or read book Synchronous data acquisition with wireless sensor networks written by Funck, Jürgen Helmut and published by Universitätsverlag der TU Berlin. This book was released on 2018-07-19 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wireless sensor networks (WSN) are predicted to play a key role in future technological developments like the internet of things. Already they are beginning to be used in many applications not only in the scientific and industrial domains. One of the biggest challenges, when using WSN, is to fuse and evaluate data from different sensor nodes. Synchronizing the data acquisition of the nodes is a key enabling factor for this. So far research has been focused on synchronizing the clocks of the nodes, largely neglecting the implications for the actual measurement results. This thesis investigates the relation between synchronization accuracy and quality of measurement results. Two different classes of time synchronous data acquisition are investigated: event detection and waveform sampling. A model is developed that describes a WSN as a generic multi-channel data acquisition system, thus enabling direct comparison to other existing systems. With the help of this model it is shown, that synchronization accuracy should best be expressed as uncertainty of the acquired timing information. This way, not only the contribution of the synchronization to the overall measurement uncertainty can be assessed, but also the synchronization accuracy required for an application can be estimated. The insights from the uncertainty analysis are used to develop two distinct approaches to synchronous data acquisition: a proactive and a reactive one. It is shown that the reactive approach can also be used to efficiently implement synchronous angular sampling, i.e. data acquisition synchronous to the rotation of a machine's shaft. Furthermore, testing methods are suggested, that evaluate the synchronized data acquisition of an existing WSN as a whole. These methods can be applied to other data acquisition systems without changes, thus enabling direct comparisons. The practical realization of a WSN is described, on which the developed data acquisition methods have been implemented. All implementations were thoroughly tested in experiments, using the suggested testing methods. This way it was revealed, that a system's interrupt handling procedures may have a strong influence on the data acquisition. Furthermore, it was shown that the effective use of fixed-point arithmetic enables synchronous angular sampling in real-time during a streaming measurement. Finally, two application examples are used to illustrate the utility of the implemented data acquisition: the acoustic localization of two sensor nodes on a straight line and a simple order tracking at an induction motor test bench. Diese Dissertation untersucht die Zusammenhänge zwischen Synchronisationsgenauigkeit und Qualität der Messergebnisse. Zwei Klassen von zeitsynchroner Datenerfassung werden dabei betrachtet: die Detektion von Ereignissen und die Aufnahme von Kurvenformen. Es wird ein Modell entwickelt, welches ein WSN als ein allgemeines mehrkanaliges Datenerfassungssystem beschreibt. Dies ermöglicht den direkten Vergleich zwischen WSN und anderen Messsystemen. Weiter wird mit Hilfe des Modells gezeigt, dass die Synchronisationsgenauigkeit vorzugsweise als Unsicherheit der Zeitinformation angegeben werden sollte. Hierdurch kann nicht nur der Beitrag der Synchronisation zur gesamten Messunsicherheit bestimmt sondern auch die von einer Anwendung tatsächlich benötigte Synchronisationsgenauigkeit abgeschätzt werden. Ausgehend von den durch die Unsicherheitsbetrachtung gewonnenen Erkenntnissen werden ein proaktiver und ein reaktiver Ansatz zur synchronen Datenaufnahme entwickelt. Mit dem reaktiven Ansatz können Messdaten auch effizient drehwinkelsynchron, d. h. synchron zur Drehbewegung einer Maschinenwelle, aufgenommen werden. Es werden Testverfahren vorgeschlagen, mit denen sich die Synchronizität der Datenerfassung für ein WSN als Ganzes überprüfen lässt. Diese Verfahren lassen sich unverändert auf andere Messsysteme anwenden und ermöglichen somit direkte Vergleiche. Es wird die praktische Umsetzung eines WSN beschrieben, auf dem die entwickelten Methoden zur Datenerfassung implementiert wurden. Alle Implementierungen wurden mit den vorgeschlagenen Testverfahren untersucht. Hierdurch konnte gezeigt werden, dass die Interrupt-Bearbeitung der Sensorknoten entscheidenden Einfluss auf die Messdatenerfassung hat. Weiter konnte durch den Einsatz von Fixed-Punkt-Arithmetik die drehwinkelsynchrone Datenerfassung in Echtzeit realisiert werden. Schließlich wird die Nützlichkeit der implementierten Datenerfassung an zwei Anwendungen gezeigt: der akustischen Ortung zweier Sensorknoten sowie einer einfachen Ordnungsanalyse.
Download or read book Mobile Entity Localization and Tracking in GPS less Environnments written by Richard Fuller and published by Springer Science & Business Media. This book was released on 2009-09-11 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the second International Workshop on Mobile Entity Localization and Tracking in GPS-less Environnments, MELT, held in Orlando, Florida, USA, in September 2009 in conjunction with the 11th International Conference on Ubiquitous Computing (Ubicomp 2009). MELT is a forum for the state-of-the-art technologies in mobile localization and tracking and novel applications of location-based services. The research contributions in these proceedings cover significant aspects of localization and tracking of mobile devices that include techniques suitable for smart phones and mobile sensor networks in both outdoor and indoor environments using diverse sensors and radio signals. Novel theoretical methods, algorithmic design and analysis, application development, and experimental studies are presented in 14 papers that were reviewed carefully by the program committee. In addition, three invited papers, with topics on location determination using RF systems, Cramer-Rao-Bound analysis for indoor localization and approaches targeting mobile sensor networks, are also included in the proceedings.
Download or read book Nature Inspired Computing for Wireless Sensor Networks written by Debashis De and published by Springer Nature. This book was released on 2020-02-01 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents nature inspired computing applications for the wireless sensor network (WSN). Although the use of WSN is increasing rapidly, it has a number of limitations in the context of battery issue, distraction, low communication speed, and security. This means there is a need for innovative intelligent algorithms to address these issues.The book is divided into three sections and also includes an introductory chapter providing an overview of WSN and its various applications and algorithms as well as the associated challenges. Section 1 describes bio-inspired optimization algorithms, such as genetic algorithms (GA), artificial neural networks (ANN) and artificial immune systems (AIS) in the contexts of fault analysis and diagnosis, and traffic management. Section 2 highlights swarm optimization techniques, such as African buffalo optimization (ABO), particle swarm optimization (PSO), and modified swarm intelligence technique for solving the problems of routing, network parameters optimization, and energy estimation. Lastly, Section 3 explores multi-objective optimization techniques using GA, PSO, ANN, teaching–learning-based optimization (TLBO), and combinations of the algorithms presented. As such, the book provides efficient and optimal solutions for WSN problems based on nature-inspired algorithms.
Download or read book Source Localization Via Time Difference of Arrival written by Ciprian Romeo Comsa and published by . This book was released on 2012 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate localization of a signal source, based on the signals collected by a number of receiving sensors deployed in the source surrounding area is a problem of interest in various fields. This dissertation aims at exploring different techniques to improve the localization accuracy of non-cooperative sources, i.e., sources for which the specific transmitted symbols and the time of the transmitted signal are unknown to the receiving sensors. With the localization of non-cooperative sources, time difference of arrival (TDOA) of the signals received at pairs of sensors is typically employed. A two-stage localization method in multipath environments is proposed. During the first stage, TDOA of the signals received at pairs of sensors is estimated. In the second stage, the actual location is computed from the TDOA estimates. This later stage is referred to as hyperbolic localization and it generally involves a non-convex optimization. For the first stage, a TDOA estimation method that exploits the sparsity of multipath channels is proposed. This is formulated as an l1-regularization problem, where the l1-norm is used as channel sparsity constraint. For the second stage, three methods are proposed to offer high accuracy at different computational costs. The first method takes a semi-definite relaxation (SDR) approach to relax the hyperbolic localization to a convex optimization. The second method follows a linearized formulation of the problem and seeks a biased estimate of improved accuracy. A third method is proposed to exploit the source sparsity. With this, the hyperbolic localization is formulated as an an l1-regularization problem, where the l1-norm is used as source sparsity constraint. The proposed methods compare favorably to other existing methods, each of them having its own advantages. The SDR method has the advantage of simplicity and low computational cost. The second method may perform better than the SDR approach in some situations, but at the price of higher computational cost. The l1-regularization may outperform the first two methods, but is sensitive to the choice of a regularization parameter. The proposed two-stage localization approach is shown to deliver higher accuracy and robustness to noise, compared to existing TDOA localization methods. A single-stage source localization method is explored. The approach is coherent in the sense that, in addition to the TDOA information, it utilizes the relative carrier phases of the received signals among pairs of sensors. A location estimator is constructed based on a maximum likelihood metric. The potential of accuracy improvement by the coherent approach is shown through the Cramer Rao lower bound (CRB). However, the technique has to contend with high peak sidelobes in the localization metric, especially at low signal-to-noise ratio (SNR). Employing a small antenna array at each sensor is shown to lower the sidelobes level in the localization metric. Finally, the performance of time delay and amplitude estimation from samples of the received signal taken at rates lower than the conventional Nyquist rate is evaluated. To this end, a CRB is developed and its variation with system parameters is analyzed. It is shown that while with noiseless low rate sampling there is no estimation accuracy loss compared to Nyquist sampling, in the presence of additive noise the performance degrades significantly. However, increasing the low sampling rate by a small factor leads to significant performance improvement, especially for time delay estimation.
Download or read book Classical and Modern Direction of Arrival Estimation written by T. Engin Tuncer and published by Academic Press. This book was released on 2009-07-10 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: Classical and Modern Direction of Arrival Estimation contains both theory and practice of direction finding by the leading researchers in the field. This unique blend of techniques used in commercial DF systems and state-of-the art super-resolution methods is a valuable source of information for both practicing engineers and researchers. Key topics covered are: - Classical methods of direction finding - Practical DF methods used in commercial systems - Calibration in antenna arrays - Array mapping, fast algorithms and wideband processing - Spatial time-frequency distributions for DOA estimation - DOA estimation in threshold region - Higher order statistics for DOA estimation - Localization in sensor networks and direct position estimation - Brings together in one book classical and modern DOA techniques, showing the connections between them - Contains contributions from the leading people in the field - Gives a concise and easy- to- read introduction to the classical techniques - Evaluates the strengths and weaknesses of key super-resolution techniques - Includes applications to sensor networks
