Global Positioning System

Transcription

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2 B. Hofmann-Wellenhof, H. Lichtenegger, and 1. Collins Global Positioning System Theory and Practice Second edition Springer-Verlag Wien New York

3 Prof. Dr. Bernhard Hofmann-Wellenhof Dr. Herbert Lichtenegger Abteilung fur Landesvermessung und Landinformation, Technische Universitat Graz Graz, Austria Dr. James Collins GPS Services, Inc. Rockville, Maryland, U.S.A. This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks and 1993 Springcr-Verlag Wien Printed on acid-free paper Cover illustration courtesy of Rockwell International With 35 Figures ISBN ISBN (ebook) DOI /

4 We dedicate this book to Benjamin William Remondi

5 Foreword This book is dedicated to Dr. Benjamin William Remondi for many reasons. The project of writing a Global Positioning System (GPS) book was conceived in April 1988 at a GPS meeting in Darmstadt. Dr. Remondi discussed with me the need for an additional GPS textbook and suggested a possible joint effort. In 1989, I was willing to commit myself to such a project. Unfortunately, the timing was less than ideal for Dr. Remondi. Therefore, I decided to start the project with other coauthors. Dr. Remondi agreed and indicated his willingness to be a reviewer. I selected Dr. Herbert Lichtenegger, my colleague from the University of Technology at Graz, Austria, and Dr. James Collins from the United States. In my opinion, the knowledge of the three authors should cover the wide spectrum of GPS. Dr. Lichtenegger is a geodesist with broad experience in both theory and practice. He has specialized his research to geodetic astronomy including orbital theory and geodynamical phenomena. Since 1986, Dr. Lichtenegger's main interest is dedicated to GPS. Dr. Collins retired from the U.S. National Geodetic Survey in 1980, where he was the Deputy Director. For the past ten years, he has been deeply involved in using GPS technology with an emphasis on surveying. Dr. Collins was the founder and president of Geo/Hydro Inc. My own background is theoretically oriented. My first chief, Prof. Dr. Peter Meissl, was an excellent theoretician; and my former chief, Prof. DDDr. Helmut Moritz, fortunately, still is. It is appropriate here to say a word of thanks to Prof. DDDr. Helmut Moritz, whom I consider my mentor in science. He is - as is probably widely known - one of the world's leading geodesists and is currently president of the International Union for Geodesy and Geophysics (IUGG). In the fall of 1984, he told me I should go to the U.S.A. to learn about GPS. I certainly agreed, although I did not even know what GPS meant. On the same day, Helmut Moritz called Admiral Dr. John Bossler, at that time the Director ofthe National Geodetic Survey, and my first stay in the U.S. was arranged. Thank you, Helmut! I still remember the flight where I started to read the first articles on GPS. I found it interesting but I did not understand very much. Benjamin W. Remondi deserves the credit for providing my GPS instruction. He was a very patient and excellent teacher. I benefited enormously, and I certainly accepted his offer to return to the U.S.A. several times. Aside from the scientific aspect, our families have also become friends. The selection of topics is certainly different from the original book conceived by Dr. Remondi. The primary selection criteria of the topics were:

6 Vlll relevancy, tutorial content, and the interest and expertise of the authors. The book is intended to be a text on GPS, recognizing the tremendous need for textual materials for professionals, teachers, and for students. The authors believe that it was not necessary to dwell on the latest technical advances. Instead, concepts and techniques are emphasized. The book can be employed as a classroom text at the senior or graduate levels, depending on the level of specialization desired. It can be read, selectively, by professional surveyors, navigators, and many others who need to position with GPS. May 1992 B. Hofmann-Wellenhof

7 Preface The contents of the book are partitioned into 13 chapters, a section of references, and a very detailed index which should immediately help in finding certain topics of interest. The first chapter is a historical review. It shows the origins of surveying and how global surveying techniques have been developed. In addition, a short history on the Global Positioning System (GPS) is given. The second chapter is an overview of GPS. The system is explained by means of its three segments: the space segment, the control segment, and the user segment. The third chapter deals with the reference systems, such as coordinate and time systems. The inertial and the terrestrial reference frames are explained in the section on coordinate systems, and the transformation between them is shown. The definition of different times is given in the section on time systems, together with appropriate conversion formulas. The fourth chapter is dedicated to satellite orbits. This chapter specifically describes GPS orbits and covers the determination of the Keplerian and the perturbed orbit, as well as the dissemination of the orbital data. The fifth chapter covers the satellite signal. It shows the fundamentals of the signal structure with its various components and the principles of the signal processing. The sixth chapter deals with the observables. The data acquisition comprises code and phase pseudoranges and Doppler data. The chapter also contains the data combinations, both the phase combinations and the phase/code range combinations. Influences affecting the observables are described. Examples are: the atmospheric and relativistic effects, multipath, and the impact of the antenna phase center. The seventh chapter is dedicated to surveying with GPS. This chapter defines the terminology used and describes the planning of a GPS survey, surveying procedures, and in situ data processing. The eighth chapter covers mathematical models for positioning. Models for observed data are investigated. Therefore, models for point positioning and relative positioning, based on various data sets, are derived. The ninth chapter comprises the data processing and deals with the sophisticated cycle slip detection and repair technique. This chapter also includes the resolving of phase ambiguities. The method of least squares adjustment is assumed to be known to the reader and, therefore, only a brief review is included. Consequently, no details are given apart from the

8 x linearization of the mathematical models, which are the input for the adjustment procedure. The tenth chapter links the GPS results to terrestrial data. The necessary transformations are given where the dimension of the space and the transformations are considered. The eleventh chapter treats software modules. The intent of this chapter is not to give a detailed description of existing software and how it works. This chapter should help the reader decide which software would best suit his purposes. The very short sections of this chapter try to cover the variety of features which could be relevant to the software. The twelfth chapter describes some applications of GPS. Global, regional, and local uses are mentioned, as well as the installation of control networks. The compatibility of GPS with other systems, such as Inertial Navigation Systems (INS) and the Global Navigation Satellite System (GLONASS), the Russian equivalent to GPS, is shown. The thirteenth chapter deals with the future of GPS. Both critical aspects, such as selective availability and anti-spoofing, are discussed, along with positive aspects such as the combination of GPS with GLONASS and the International Maritime Satellite Communication Organization (IN MARSAT). Also, some possible improvements in the hardware and software technology are suggested. The hyphenation is based on Webster's Dictionary. Therefore, some deviations may appear for the reader accustomed to another hyphenation system. For example, the word "measurement", following Webster's Dictionary, is hyphenated mea-sure-mentj whereas, following The American Heritage Dictionary, the hyphenation is meas-ure-ment. The Webster's hyphenation system also contains hyphenations which are sometimes unusual for words with a foreign language origin. An example is the word "parameter". Following Webster's Dictionary, the hyphenation is pa-ram-e-ter. The word has a Greek origin, and one would expect the hyphenation pa-ra-me-ter. Symbols representing a vector or a matrix are underlined. The inner product of two vectors is indicated by a dot ".". The outer product, cross product, or vector product is indicated by the symbol "x". The norm of a vector, i.e., its length, is indicated by two double-bars "II". Many persons deserve credit and thanks. Dr. Benjamin W. Remondi of the National Geodetic Survey at Rockville, Maryland, was a reviewer of the book. He has critically read and corrected the full volume. His many suggestions and improvements, critical remarks and proposals are gratefully acknowledged. A second technical proofreading was performed by Dipl.-Ing. Gerhard Kienast from the section of Surveying and Landinformation of the University

9 Xl of Technology at Graz. He has helped us with constructive critique and valuable suggestions. Nadine Collins kindly read and edited the book in its final form, improving the flow and grammar of the text. The index of the book was produced using a computer program written by Dr. Walter Klostius from the section of Surveying and Landinformation of the University of Technology at Graz. Also, his program helped in the detection of spelling errors. The book is compiled based on the text system LATEX. Some of the figures included were also developed with LATEX. The remaining figures are drawn by using Autocad The section of Physical Geodesy of the Institute of Theoretical Geodesy of the University of Technology at Graz deserves the thanks for these figures. Dr. Norbert Kiihtreiber has drawn one of these figures, and the others were carefully developed by Dr. Konrad Rautz. This shows that theoreticians are also well-suited for practical tasks. We are also grateful to the Springer Publishing Company for their advice and cooperation. Finally, the inclusion by name of a commercial company or product does not constitute an endorsement by the authors. In principle, such inclusions were avoided whenever possible. Only those names which played a fundamental role in receiver and processing development are included for historical purposes. May 1992 B. Hofmann-Wellenhof H. Lichtenegger J. Collins

10 Preface to the second edition The first edition was released in May Since then, the first and second printing have been completely sold. There was not sufficient time to prepare a revised version for the second edition. Therefore, only a few misspellings and errors were corrected and other minor improvements performed. However, the authors would appreciate your comments for consideration in the case of a fully revised and updated version. March 1993 B. Hofmann-Wellenhof H. Lichtenegger J. Collins

11 Contents Abbreviations xix 1. Introduction The origins of surveying Development of global surveying techniques Optical global triangulation Electromagnetic global trilateration History of the Global Positioning System Navigating with GPS Surveying with GPS Overview of GPS Basic concept Space segment Constellation Satellites... " Denial of accuracy and access Control segment Master control station Monitor stations Ground control stations User segment User categories Receiver types Reference systems Introduction Coordinate systems Definitions Transformations Time systems Definitions Conversions Calendar Satellite orbits Introduction Orbit description... "... 37

12 XlV Keplerian motion Perturbed motion Disturbing accelerations Orbit determination Keplerian orbit Perturbed orbit Orbit dissemination Tracking networks Ephemerides Satellite signal Signal structure Physical fundamentals Components of the signal Signal processing General remarks Receiver Observables Data acquisition Code pseudoranges Phase pseudoranges Doppler data Biases and noise Data combinations Linear phase combinations Phase and code pseudorange combinations Atmospheric effects Phase and group velocity Ionospheric refraction Tropospheric refraction Relativistic effects Special relativity General relativity Relevant relativistic effects for GPS Multipath Antenna phase center offset and variation Surveying with GPS Introduction Terminology definitions Observation technique

13 7.1.3 Field equipment Planning a GPS survey General remarks Presurvey planning Field reconnaissance Monumentation Organizational design Surveying procedure Preobservation Observation Postobservation Ties to control monuments In situ data processing Data transfer Data processing Trouble shooting and quality control Datum transformations Computation of plane coordinates Survey report Mathematical models for positioning Point positioning Point positioning with code ranges Point positioning with carrier phases Point positioning with Doppler data Relative positioning Phase differences Correlations of the phase combinations Static relative positioning Kinematic relative positioning Mixed-mode relative positioning Data processing Data preprocessing Data handling Cycle slip detection and repair Ambiguity resolution Adjustment, filtering, and smoothing Least squares adjustment Kalman filtering Smoothing Adjustment of mathematical GPS models xv

14 XVI Linearization Linear model for point positioning with code ranges Linear model for point positioning with carrier phases Linear model for relative positioning Network adjustment Single baseline solution Multipoint solution Single baseline versus multipoint solution Dilution of Precision Transformation of GPS results Introduction Coordinate transformations Cartesian coordinates and ellipsoidal coordinates Ellipsoidal coordinates and plane coordinates Height transformation Similarity transformations Three-dimensional transformation Two-dimensional transformation One-dimensional transformation Combining GPS and terrestrial data Data transformation Adjustment Fiducial point concept Software modules Introduction Planning Satellite visibility Satellite geometry Simulations ~ Receiver!. 4 preprogramming Data transfer Downloading data Decoding data Checking transferred data File handling Baseline definition Data processing Generating RINEX formatted data Ephemerides Code data processing

15 xvii Phase data processing Data analysis Covariance matrices Modeling the atmosphere Parameter estimation Quality control Statistical data Loop closures Residuals Repaired cycle slips Network adjustment Helmert transformation Hybrid data combination Data base management Storage and retrieval of data Archiving survey results Interface to national control points Interface to GIS software Utilities File editing Time conversions Optimization of survey design Transformation of coordinates Documentation of results Flexibility Checklist for software modules Applications of GPS General uses of GPS Global uses Regional uses Local uses Installation of control networks Passive control networks Active control networks Interoperability of GPS GPS and Inertial Navigation Systems GPS and GLONASS GPS and other sensors GPS and terrestrial survey Future of GPS 281

16 xviii 13.1 New application aspects Impact of limited accuracy and access Selective availability Anti-spoofing Improved constellation Next generation satellites GLONASS satellites INMARSAT satellites ,4 Hardware improvements ,4.1 Receiver cost ,4.2 Receiver capability Software improvements Conclusion References 289 Subject index 313

17 Abbreviations AC ACS AFB AGREF AOC A-S AVL BC BDT CIA CAD CEP CIGNET CIO CIS CSOC CTS DC DD DEC DGPS DMA DoD DOP ECEF FAA FGCC FM GDOP GIS GLONASS GOTEX GPS GPST GRS HDOP Alternating Current Active Control System Air Force Base Austrian GPS Reference (network) Auxiliary Output Chip Anti-Spoofing Automatic Vehicle Location Ballistic Camera Barycentric Dynamic Time Coarse Acquisition Computer Aided Design Celestial Ephemeris Pole Cooperative International GPS Network Conventional International Origin Conventional Inertial System Consolidated Space Operations Center Conventional Terrestrial System Direct Current Dou ble-difference Digital Equipment Corporation Differential GPS Defense Mapping Agency Department of Defense Dilution of Precision Earth-Centered-Earth-Fixed Federal Aviation Administration Federal Geodetic Control Committee Frequency Modulated Geometric Dilution of Precision Geographic Information System Global Navigation Satellite System Global Orbit Tracking Experiment Global Positioning System GPS Time Geodetic Reference System Horizontal Dilution of Precision

18 xx HIRAN HOW lag IAT IBM IERS IGS INMARSAT INS ISU IUGG JD JPL JPO LAN MCS MIT MITES MJD MMIC NAD NASA NAVSTAR NGS NNSS NSWC OCS OEM OTF P PC PDOP PDP PPS PRN RAIM RF RINEX SA SD SERIES High Range Navigation Hand Over Word International Association of Geodesy International Atomic Time International Business Machines (corporation) International Earth Rotation Service International GPS Geodynamics Service International Maritime Satellite (organization) Inertial Navigation System International System of Units International Union for Geodesy and Geophysics Julian Date Jet Propulsion Laboratory J oint Program Office Local Area Network Master Control Station Massachusetts Institute of Technology Miniature Interferometer Terminals for Earth Survey Modified Julian Date Monolithic Microwave Integrated Circuit North American Datum National Aeronautics and Space Administration Navigation System with Time and Ranging National Geodetic Survey Navy Navigational Satellite System Naval Surface Warfare Center Operational Control System Original Equipment Manufacturer On-the-Fly Precision Personal Computer Position Dilution of Precision Program able Data Processor Precise Positioning Service Pseudorandom Noise Receiver Autonomous Integrity Monitoring Radio Frequency Receiver Independent Exchange (format) Selective Availability Single-Difference Satellite Emission Range Inferred Earth Surveying

19 XXI SLR SPOT SPS SV TD TDOP TDT TEC TLM TM TOPEX TRANSIT UERE USGS UT UTC UTM VDOP VHSIC VLBI WGS Satellite Laser Ranging Satellite Probatoire d'observation de la Terre Standard Positioning Service Space Vehicle Tri ple-difference Time Dilution of Precision Terrestrial Dynamic Time Total Electron Content Telemetry Trade Mark (Ocean) Topography Experiment Time Ranging and Sequential User Equivalent Range Error U.S. Geological Survey Universal Time Universal Time Coordinated Universal Transverse Mercator (projection) Vertical Dilution of Precision Very High Speed Integrated Circuit Very Long Baseline Interferometry World Geodetic System