Download or read book Global Positioning System GPS Receiver Design for Multipaths Mitigation written by El-Sayed Abdel-Salam Gadallah and published by . This book was released on 1998-08-01 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multipath effects are a source of error degrading the accuracy of DGPS signal processing. The statistical models of multipath are determined by user location and, in addition are time varying. There is no unified statistical model for the multipath signal. Therefore the solution of the multipath problem using statistical models is difficult. This research introduces a new estimator that can detect the presence of multipath, can determine the unknown number of multipath components and can estimate multipath parameters in the GPS receiver (time delay and attenuation coefficients). Furthermore the multipath signal parameters are estimated at any instant of observation. The new estimator is based on maximum likelihood estimation applied to multiple observations of a linear model (regression form) of the received signal. In addition, the estimator is based on a recursive deployment of the multipath time delay. An improvement is achieved to the accuracy of multipath estimates at a low signal- to-noise level by applying Kalman filtering as a cascaded estimator. Kalman filtering application can be considered as an important tool for separating the direct path signal from multipath in noise. This dissertation also includes the design of new modified tracking loops endowed with the mentioned estimator: a modified Phase Lock Loop (PLL) for carrier tracking and a modified Delay Locked- Loop (DLL) in the code tracking. The modified loops can properly track the received direct signal in the presence of multipaths where the standard tracking loops are disabled. Simulations of the standard and the modified loops are presented. Tracking and performance in noise are investigated and a future work is suggested.

Download or read book Global Positioning System GPS Receiver Design for Multipaths Mitigation written by El-Sayed Abdel-Salam Gadallah (LTC, Egypt.) and published by . This book was released on 1998 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multipath Effects in GPS Receivers written by Steven Miller and published by Morgan & Claypool Publishers. This book was released on 2015-12-01 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous vehicles use global navigation satellite systems (GNSS) to provide a position within a few centimeters of truth. Centimeter positioning requires accurate measurement of each satellite's direct path propagation time. Multipath corrupts the propagation time estimate by creating a time-varying bias. A GNSS receiver model is developed and the effects of multipath are investigated. MATLABtm code is provided to enable readers to run simple GNSS receiver simulations. More specifically, GNSS signal models are presented and multipath mitigation techniques are described for various multipath conditions. Appendices are included in the booklet to derive some of the basics on early minus late code synchronization methods. Details on the numerically controlled oscillator and its properties are also given in the appendix.

Download or read book Multipath Effects in GPS Receivers written by Steven Miller and published by Springer Nature. This book was released on 2022-05-31 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autonomous vehicles use global navigation satellite systems (GNSS) to provide a position within a few centimeters of truth. Centimeter positioning requires accurate measurement of each satellite's direct path propagation time. Multipath corrupts the propagation time estimate by creating a time-varying bias. A GNSS receiver model is developed and the effects of multipath are investigated. MATLABtm code is provided to enable readers to run simple GNSS receiver simulations. More specifically, GNSS signal models are presented and multipath mitigation techniques are described for various multipath conditions. Appendices are included in the booklet to derive some of the basics on early minus late code synchronization methods. Details on the numerically controlled oscillator and its properties are also given in the appendix.

Download or read book A GPS Code Tracking Receiver Design for Multipath Mitigation Using Maximum Likelihood Estimation written by Fred Baier and published by . This book was released on 1997-12-01 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NAVSTAR Global Positioning System (GPS) is currently used in many applications requiring precise positioning data. Improving the precise positioning information requires the removal of errors that perturb the received signals. The errors introduced by multiple propagation channels, termed multipath, are not easily removed. These channels are caused by reflective surfaces near the receiver. As such, multipath is uncorrelated between receivers and, thus, cannot be removed through differencing techniques. This thesis investigates a GPS code tracking loop design which uses maximum likelihood (ML) estimation to determine amplitude and phase information of the multipath signal which are used to adjust code tracking to account for multipath effects. Analysis of the operations that govern this design for the case of a single reflection shows that it has no steady state tracking error. Results of simulations indicate that the code tracking loop, in conjunction with the MLE, mitigate the effects of multipath and improves code tracking performance over the narrow correlator NCDLL for most scenarios analyzed. Overall results of simulations indicate that the implementation of the maximum likelihood estimator (MLE) in conjunction with the code tracking loop has the potential to enhance code tracking performance over that offered by the narrow correlator NCDLL in a GPS environment.

Download or read book Global Positioning Systems Inertial Navigation and Integration written by Mohinder S. Grewal and published by John Wiley & Sons. This book was released on 2007-03-05 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: An updated guide to GNSS and INS, and solutions to real-world GPS/INS problems with Kalman filtering Written by recognized authorities in the field, this second edition of a landmark work provides engineers, computer scientists, and others with a working familiarity with the theory and contemporary applications of Global Navigation Satellite Systems (GNSS), Inertial Navigational Systems (INS), and Kalman filters. Throughout, the focus is on solving real-world problems, with an emphasis on the effective use of state-of-the-art integration techniques for those systems, especially the application of Kalman filtering. To that end, the authors explore the various subtleties, common failures, and inherent limitations of the theory as it applies to real-world situations, and provide numerous detailed application examples and practice problems, including GNSS-aided INS, modeling of gyros and accelerometers, and SBAS and GBAS. Drawing upon their many years of experience with GNSS, INS, and the Kalman filter, the authors present numerous design and implementation techniques not found in other professional references. This Second Edition has been updated to include: GNSS signal integrity with SBAS Mitigation of multipath, including results Ionospheric delay estimation with Kalman filters New MATLAB programs for satellite position determination using almanac and ephemeris data and ionospheric delay calculations from single and dual frequency data New algorithms for GEO with L1 /L5 frequencies and clock steering Implementation of mechanization equations in numerically stable algorithms To enhance comprehension of the subjects covered, the authors have included software in MATLAB, demonstrating the working of the GNSS, INS, and filter algorithms. In addition to showing the Kalman filter in action, the software also demonstrates various practical aspects of finite word length arithmetic and the need for alternative algorithms to preserve result accuracy.

Download or read book Fundamentals of GPS Receivers written by Dan Doberstein and published by Springer Science & Business Media. This book was released on 2011-10-22 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of GPS receivers covers GPS receivers' theory and practice. The book begins with the basics of GPS receivers and moves onward to more advanced material. The book examines three types of GPS receiver implementations: first is the custom design by the author; second is an industry standard design, now part of the open source network; the third relates to the receiver designed by JPL /NASA. Each receiver is unique allowing the reader to see how each design solves the same problems. Chapters discuss carrier phase measurements and GPS time and frequency measurements. The overall text is measurement oriented as opposed to processing the measurements. With a focus on the fundamentals of measurements the reader will be building their intuition for the physical phenomenon at work.

Download or read book Analysis and Simulation of a New Code Tracking Loop for GPS Multipath Mitigation written by Mark C. Laxton and published by . This book was released on 1996-12-01 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis proposes a new direct sequence spread spectrum (DS/SS) code phase tracking loop which mitigates the effects of multipath interference on code phase tracking error; such errors can translate to significant range measurement errors in DS/SS ranging systems such as Global Positioning System (GPS). The new code tracking loop, called the modified RAKE delay lock loop (MRDLL), uses maximum likelihood (ML) signal parameter estimation to determine the amplitude, carrier phase, and relative propagation delay of both a direct path and a reflected signal; a multiple correlator code phase tracking loop then exploits these ML signal estimates to remove the tracking error introduced by the reflection. A preliminary analysis showed that the MRDLL's linear tracking region varied with the reflected signal parameters; therefore, an adaptive loop controller (ALC) was introduced to allow the loop designer to fix dynamic specifications such as loop natural frequency. Analysis and computer simulations demonstrated that, when multipath was present, the MRDLL exhibited a significantly lower steady-state code phase tracking error than that of the standard noncoherent delay lock loop (NCDLL), which is typically used in GPS receivers. In an ideal multipath-free environment, the NCDLL is still the best choice for code phase tracking. This GPS receiver design technology will benefit the entire aviation community by eliminating or reducing the dominant source of error in differential GPS-based instrument landing systems, resulting in improved ILS safety, reliability, and integrity. In relative GPS applications, such as precision guided munitions, lethality is improved via elimination of multipath contribution to targeting error. In all GPS applications, the (no longer dominant) error contribution of multipath can be eliminated, yielding enhanced pog(,h-H1

Download or read book A Software Defined GPS and Galileo Receiver written by Kai Borre and published by Springer Science & Business Media. This book was released on 2007-08-03 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explore the use of new technologies in the area of satellite navigation receivers. In order to construct a reconfigurable receiver with a wide range of applications, the authors discuss receiver architecture based on software-defined radio techniques. The presentation unfolds in a user-friendly style and goes from the basics to cutting-edge research. The book is aimed at applied mathematicians, electrical engineers, geodesists, and graduate students. It may be used as a textbook in various GPS technology and signal processing courses, or as a self-study reference for anyone working with satellite navigation receivers.

Download or read book Multifunctional Operation and Application of GPS written by Rustam B. Rustamov and published by BoD – Books on Demand. This book was released on 2018-05-30 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today, Global Positioning System (GPS) has taken a significant place in human life with wide-scale applications. It is a multi-use, space-based radio-navigation system, embracing defense and security, civil, commercial, and scientific research needs. Taking into account the importance of the system, it has been suggested to present current advances of GPS with attention focused on vital aspects of technology. This book provides a general description of GPS, GNSS, and GLONASS with reference to the improvement of characteristics of the segments, including software applications and the equipment itself containing GPS. The book also provides information on application areas. Equally, a number of common shortcomings and errors are described, and elimination and mnimization of such consequences are demonstrated.

Download or read book GPS and GNSS Technology in Geosciences written by George P. Petropoulos and published by Elsevier. This book was released on 2021-02-18 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: GPS and GNSS Technology in Geosciences offers an interdisciplinary approach to applying advances in GPS/GNSS technology for geoscience research and practice. As GPS/GNSS signals can be used to provide useful information about the Earth’s surface characteristics and land surface composition, GPS equipment and services for commercial purposes continues to grow, thus resulting in new expectations and demands. This book provides case studies for a deeper understanding of the operation and principles of widely applied approaches and the benefits of the technology in everyday research and activities. Presents processing, methods and techniques of GPS/GNSS implementation that are utilized in in-situ data collection in design and systems analysis Offers an all-inclusive, critical overview of the state-of-the-art in different algorithms and techniques in GPS/GNSS Addresses both theoretical and applied research contributions on the use of this technology in a variety of geoscience disciplines

Download or read book Fundamentals of Global Positioning System Receivers written by James Bao-Yen Tsui and published by John Wiley & Sons. This book was released on 2005-01-03 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: All the expert guidance you need to understand, build, and operate GPS receivers The Second Edition of this acclaimed publication enables readers to understand and apply the complex operation principles of global positioning system (GPS) receivers. Although GPS receivers are widely used in everyday life to aid in positioning and navigation, this is the only text that is devoted to complete coverage of their operation principles. The author, one of the foremost authorities in the GPS field, presents the material from a software receiver viewpoint, an approach that helps readers better understand operation and that reflects the forecasted integration of GPS receivers into such everyday devices as cellular telephones. Concentrating on civilian C/A code, the book provides the tools and information needed to understand and exploit all aspects of receiver technology as well as relevant navigation schemes: Overview of GPS basics and the constellation of satellites that comprise the GPS system Detailed examination of GPS signal structure, acquisition, and tracking Step-by-step presentation of the mathematical formulas for calculating a user's position Demonstration of the use of computer programs to run key equations Instructions for developing hardware to collect digitized data for a software GPS receiver Complete chapter demonstrating a GPS receiver following a signal flow to determine a user's position The Second Edition of this highly acclaimed text has been greatly expanded, including three new chapters: Acquisition of weak signals Tracking of weak signals GPS receiver related subjects Following the author's expert guidance and easy-to-follow style, engineers and scientists learn all that is needed to understand, build, and operate GPS receivers. The book's logical flow from basic concepts to applications makes it an excellent textbook for upper-level undergraduate and graduate students in electrical engineering, wireless communications, and computer science.

Download or read book Position Navigation and Timing Technologies in the 21st Century written by Y. Jade Morton and published by John Wiley & Sons. This book was released on 2021-01-13 with total page 1170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the latest developments in PNT technologies, including integrated satellite navigation, sensor systems, and civil applications Featuring sixty-four chapters that are divided into six parts, this two-volume work provides comprehensive coverage of the state-of-the-art in satellite-based position, navigation, and timing (PNT) technologies and civilian applications. It also examines alternative navigation technologies based on other signals-of-opportunity and sensors and offers a comprehensive treatment on integrated PNT systems for consumer and commercial applications. Volume 1 of Position, Navigation, and Timing Technologies in the 21st Century: Integrated Satellite Navigation, Sensor Systems, and Civil Applications contains three parts and focuses on the satellite navigation systems, technologies, and engineering and scientific applications. It starts with a historical perspective of GPS development and other related PNT development. Current global and regional navigation satellite systems (GNSS and RNSS), their inter-operability, signal quality monitoring, satellite orbit and time synchronization, and ground- and satellite-based augmentation systems are examined. Recent progresses in satellite navigation receiver technologies and challenges for operations in multipath-rich urban environment, in handling spoofing and interference, and in ensuring PNT integrity are addressed. A section on satellite navigation for engineering and scientific applications finishes off the volume. Volume 2 of Position, Navigation, and Timing Technologies in the 21st Century: Integrated Satellite Navigation, Sensor Systems, and Civil Applications consists of three parts and addresses PNT using alternative signals and sensors and integrated PNT technologies for consumer and commercial applications. It looks at PNT using various radio signals-of-opportunity, atomic clock, optical, laser, magnetic field, celestial, MEMS and inertial sensors, as well as the concept of navigation from Low-Earth Orbiting (LEO) satellites. GNSS-INS integration, neuroscience of navigation, and animal navigation are also covered. The volume finishes off with a collection of work on contemporary PNT applications such as survey and mobile mapping, precision agriculture, wearable systems, automated driving, train control, commercial unmanned aircraft systems, aviation, and navigation in the unique Arctic environment. In addition, this text: Serves as a complete reference and handbook for professionals and students interested in the broad range of PNT subjects Includes chapters that focus on the latest developments in GNSS and other navigation sensors, techniques, and applications Illustrates interconnecting relationships between various types of technologies in order to assure more protected, tough, and accurate PNT Position, Navigation, and Timing Technologies in the 21st Century: Integrated Satellite Navigation, Sensor Systems, and Civil Applications will appeal to all industry professionals, researchers, and academics involved with the science, engineering, and applications of position, navigation, and timing technologies. pnt21book.com

Download or read book Global Navigation Satellite Systems Inertial Navigation and Integration written by Mohinder S. Grewal and published by John Wiley & Sons. This book was released on 2013-01-23 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: An updated guide to GNSS, and INS, and solutions to real-world GNSS/INS problems with Kalman filtering Written by recognized authorities in the field, this third edition of a landmark work provides engineers, computer scientists, and others with a working familiarity of the theory and contemporary applications of Global Navigation Satellite Systems (GNSS), Inertial Navigational Systems, and Kalman filters. Throughout, the focus is on solving real-world problems, with an emphasis on the effective use of state-of-the-art integration techniques for those systems, especially the application of Kalman filtering. To that end, the authors explore the various subtleties, common failures, and inherent limitations of the theory as it applies to real-world situations, and provide numerous detailed application examples and practice problems, including GNSS-aided INS (tightly and loosely coupled), modeling of gyros and accelerometers, and SBAS and GBAS. Drawing upon their many years of experience with GNSS, INS, and the Kalman filter, the authors present numerous design and implementation techniques not found in other professional references. The Third Edition includes: Updates on the upgrades in existing GNSS and other systems currently under development Expanded coverage of basic principles of antenna design and practical antenna design solutions Expanded coverage of basic principles of receiver design and an update of the foundations for code and carrier acquisition and tracking within a GNSS receiver Expanded coverage of inertial navigation, its history, its technology, and the mathematical models and methods used in its implementation Derivations of dynamic models for the propagation of inertial navigation errors, including the effects of drifting sensor compensation parameters Greatly expanded coverage of GNSS/INS integration, including derivation of a unified GNSS/INS integration model, its MATLAB® implementations, and performance evaluation under simulated dynamic conditions The companion website includes updated background material; additional MATLAB scripts for simulating GNSS-only and integrated GNSS/INS navigation; satellite position determination; calculation of ionosphere delays; and dilution of precision.

Download or read book Cepstral Processing for GPS Multipath Detection and Mitigation written by Charles D. Ormsby and published by . This book was released on 1997-12-01 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a novel approach to code phase multipath mitigation for Global Positioning System (GPS) receivers. It uses the power and complex cepstra for multipath detection and mitigation prior to code phase tracking by a standard non-coherent delay lock loop. Cepstral theory is presented to demonstrate how multipath reflection delays can be detected through the use of the power cepstrum. Filtering can then be performed on the complex cepstrum to remove multipath effects in the cepstral domain. Finally, an inverse complex cepstrum is calculated yielding a theoretically multipath free direct path estimate in the time domain. Simulations are presented to verify the applicability of cepstral techniques to the problem of GPS multipath mitigation. Results show that, under noiseless conditions, cepstral processing prior to code tracking by a standard non-coherent delay lock loop leads to lower code tracking biases than direct tracking of the composite multipath signal by a narrow correlator receiver. Finally, this work shows that cepstral processing is highly sensitive to additive white Gaussian noise effects, leading to the conclusion that methods of limiting noise effects must be developed before this technique will be applicable in actual GPS receivers.

Download or read book A GPS Code Tracking Receiver Design for Multipath Mitigation Using Maxiumum Likelihood Estimation written by Fred Paul Baier and published by . This book was released on 1997 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Global Positioning Systems Inertial Navigation and Integration written by Mohinder S. Grewal and published by John Wiley & Sons. This book was released on 2004-04-05 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: The only comprehensive guide to Kalman filtering and its applications to real-world GPS/INS problems Written by recognized authorities in the field, this book provides engineers, computer scientists, and others with a working familiarity with the theory and contemporary applications of Global Positioning Systems (GPS), Inertial Navigational Systems, and Kalman filters. Throughout, the focus is on solving real-world problems, with an emphasis on the effective use of state-of-the-art integration techniques for those systems, especially the application of Kalman filtering. To that end, the authors explore the various subtleties, common failures, and inherent limitations of the theory as it applies to real-world situations, and provide numerous detailed application examples and practice problems, including GPS-aided INS, modeling of gyros and accelerometers, and WAAS and LAAS. Drawing upon their many years of experience with GPS, INS, and the Kalman filter, the authors present numerous design and implementation techniques not found in other professional references, including original techniques for: * Representing the problem in a mathematical model * Analyzing the performance of the GPS sensor as a function of model parameters * Implementing the mechanization equations in numerically stable algorithms * Assessing computation requirements * Testing the validity of results * Monitoring GPS, INS, and Kalman filter performance in operation In order to enhance comprehension of the subjects covered, the authors have included software in MATLAB, demonstrating the workings of the GPS, INS, and filter algorithms. In addition to showing the Kalman filter in action, the software also demonstrates various practical aspects of finite word length arithmetic and the need for alternative algorithms to preserve result accuracy.