Download or read book An Investigation of Multipath Effects on the GPS System During Auto Rendezvous and Capture written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed use of a Cargo Transport Vehicle (CTV) to carry hardware to the Space Station Freedom (SSF) during the construction phase of the SSF project requires remote maneuvering of the CTV. The CTV is not a manned vehicle. Obtaining the relative positions of the CTV and SSF for remote auto-rendezvous and capture (AR&C) scenarios will rely heavily on the Global Positioning System (GPS). The GPS system is expected to guide the CTV up to a distance of 100 to 300 meters from the SSF. At some point within this range, an optical docking system will take over the remote guidance for capture. During any remote guidance by GPS it is possible that significant multipath signals may be caused by large objects in the vicinity of the module being remotely guided. This could alter the position obtained by the GPS system from the actual position. Due to the nature of the GPS signals, it has been estimated that if the difference in distance between the Line of Sight (LOS) path and the multipath is greater than 300 meters, the GPS system is capable of discriminating between the direct signal and the reflected (or multipath) signal. However, if the path difference is less than 300 meters, one must be concerned. This report details the work accomplished by the Electromagnetic Simulations Laboratory at Marquette University over the period December 1993 to May 1995. This work is an investigation of the strength and phase of a multipath signal arriving at the CTV relative to the direct or line of sight (LOS) signal. The signal originates at a GPS satellite in half geo-stationary orbit and takes two paths to the CTV: (1) the direct or LOS path from the GPS satellite to the CTV; and (2) a scattered path from the GPS satellite to the SSF module and then to the CTV. The scattering from a cylinder has been computed using the physical optics approximation for the current. No other approximations or assumptions have been made including no assumptions regarding the far field or Fresnel fi...

Download or read book An Assessment of the Technology of Automated Rendezvous and Capture in Space written by M. E. Polites and published by . This book was released on 1998 with total page 64 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 An Experimental Investigation of the Effects of GPS Satellite Multipath written by Ruth Elizabeth Neilan and published by . This book was released on 1986 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1969 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cooperative Localization and Navigation written by Chao Gao and published by CRC Press. This book was released on 2019-08-21 with total page 731 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book captures the latest results and techniques for cooperative localization and navigation drawn from a broad array of disciplines. It provides the reader with a generic and comprehensive view of modeling, strategies, and state estimation methodologies in that fields. It discusses the most recent research and novel advances in that direction, exploring the design of algorithms and architectures, benefits, and challenging aspects, as well as a potential broad array of disciplines, including wireless communication, indoor localization, robotics, emergency rescue, motion analysis, etc.

Download or read book Space Shuttle Missions Summary NASA TM 2011 216142 written by Robert D. Legler and published by www.Militarybookshop.CompanyUK. This book was released on 2011-09-01 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full color publication. This document has been produced and updated over a 21-year period. It is intended to be a handy reference document, basically one page per flight, and care has been exercised to make it as error-free as possible. This document is basically "as flown" data and has been compiled from many sources including flight logs, flight rules, flight anomaly logs, mod flight descent summary, post flight analysis of mps propellants, FDRD, FRD, SODB, and the MER shuttle flight data and inflight anomaly list. Orbit distance traveled is taken from the PAO mission statistics.

Download or read book Aeronautical Engineering written by and published by . This book was released on 1993 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).

Download or read book NASA Space Technology Roadmaps and Priorities written by National Research Council and published by National Academies Press. This book was released on 2012-06-07 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: NASA's Office of the Chief Technologist (OCT) has begun to rebuild the advanced space technology program in the agency with plans laid out in 14 draft technology roadmaps. It has been years since NASA has had a vigorous, broad-based program in advanced space technology development and its technology base has been largely depleted. However, success in executing future NASA space missions will depend on advanced technology developments that should already be underway. Reaching out to involve the external technical community, the National Research Council (NRC) considered the 14 draft technology roadmaps prepared by OCT and ranked the top technical challenges and highest priority technologies that NASA should emphasize in the next 5 years. This report provides specific guidance and recommendations on how the effectiveness of the technology development program managed by OCT can be enhanced in the face of scarce resources.

Download or read book The U S Air Force in Space 1945 to the Twenty First Century Proceedings written by Air Force Historical Foundation. Symposium and published by Department of the Air Force. This book was released on 1998-09-02 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains papers presented at the Air Force Historical Foundation Symposium, held at Andrews Air Force Base, Maryland, on September 21-22, 1995. Topics addressed are: Pt. 1, The Formative Years, 1945-1961; Pt. 2, Mission Development and Exploitation Since 1961; and Pt. 3, Military Space Today and Tomorrow. Includes notes, abbreviations & acronyms, an index, and photographs.

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 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 Introduction to Embedded Systems Second Edition written by Edward Ashford Lee and published by MIT Press. This book was released on 2017-01-06 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the engineering principles of embedded systems, with a focus on modeling, design, and analysis of cyber-physical systems. The most visible use of computers and software is processing information for human consumption. The vast majority of computers in use, however, are much less visible. They run the engine, brakes, seatbelts, airbag, and audio system in your car. They digitally encode your voice and construct a radio signal to send it from your cell phone to a base station. They command robots on a factory floor, power generation in a power plant, processes in a chemical plant, and traffic lights in a city. These less visible computers are called embedded systems, and the software they run is called embedded software. The principal challenges in designing and analyzing embedded systems stem from their interaction with physical processes. This book takes a cyber-physical approach to embedded systems, introducing the engineering concepts underlying embedded systems as a technology and as a subject of study. The focus is on modeling, design, and analysis of cyber-physical systems, which integrate computation, networking, and physical processes. The second edition offers two new chapters, several new exercises, and other improvements. The book can be used as a textbook at the advanced undergraduate or introductory graduate level and as a professional reference for practicing engineers and computer scientists. Readers should have some familiarity with machine structures, computer programming, basic discrete mathematics and algorithms, and signals and systems.

Download or read book Introduction to Radar Systems written by Merrill I. Skolnik and published by . This book was released on 1988 with total page 581 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Smaller Satellites Bigger Business written by Michael J Rycroft and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Y. Fujimori, Symposium Programme Committee Chair, and Faculty Member, International Space University e-mail: [email protected] M.Rycroft, Faculty Member, International Space University e-mail: [email protected] N. Crosby, International Space University e-mail: [email protected] For the sixth annual ISU Symposium the theme was "Smaller Satellites: Bigger Business? Concepts, Applications and Markets for Micro/Nanosatellites in a New Information World". Thus, the Symposium addressed the crucial question: are small satellites the saviour of space programmes around the world It did this from the unique perspective of the International Space today? University - the interdisciplinary, international and intercultural perspective. This Symposium brought together a variety of people working on small satellites - engineers, scientists, planners, providers, operators, policy makers and business executives, together with representatives from regulatory bodies, from national and international organizations, and from the finance sector, and also entrepreneurs. Discussion and debate were encouraged, based on the papers presented and those published here.