Understanding GPS: Principles and Applications Second Edition

Transcription

1 Understanding GPS: Principles and Applications Second Edition Elliott Kaplan and Christopher Hegarty ISBN Approx. 680 pages Navtech Part #1024 This thoroughly updated second edition of an Artech House bestseller brings together a team of leading experts who provide you with a current and comprehensive treatment of the Global Positioning System (GPS). The book covers all the latest advances in technology, applications, and systems. The second edition includes new chapters that explore the integration of GPS with vehicles and cellular telephones, new classes of satellite broadcast signals, the emerging GALILEO system, and new developments in the GPS marketplace. This single-source reference provides both a quick overview of GPS essentials and an indepth treatment of advanced topics. The book guides you in developing new applications and shows you how to evaluate their performance. It explains all the differential GPS services available to let you decide which is best for particular applications. You learn how to build GPS receivers and integrate them into navigational and communications equipment. Moreover, this unique volume helps you determine how technology is affecting the marketplace and where best to invest your company s resources. Author Bio Elliott Kaplan is a principal engineer at the MITRE Corporation, Bedford, Massachusetts. He is the New England Section Officer of the Institute of Navigation.. He earned his M.S. in electrical engineering from Northeastern University. Christopher Hegarty is a senior principal engineer at the MITRE Corporation, Bedford, MA. He received a D.Sc. in electrical engineering from The George Washington University and currently serves as editor of the Institute of Navigation s quarterly journal, NAVIGATION, and as a member of RTCA, Inc. s Program Management Committee.

2 Contents Preface Acknowledgments xv xvii CHAPTER 1 Introduction Introduction Condensed GPS Program History GPS Overview PPS SPS GPS Modernization Program GALILEO Satellite System Russian GLONASS System Chinese BeiDou System Augmentations Markets and Applications Land Aviation Space Guidance Maritime Organization of the Book 14 References 19 CHAPTER 2 Fundamentals of Satellite Navigation Concept of Ranging Using TOA Measurements Two-Dimensional Position Determination Principle of Position Determination Via Satellite-Generated Ranging Signals Reference Coordinate Systems Earth-Centered Inertial Coordinate System Earth-Centered Earth-Fixed Coordinate System World Geodetic System Height Coordinates and the Geoid Fundamentals of Satellite Orbits Orbital Mechanics Constellation Design Position Determination Using PRN Codes Determining Satellite-to-User Range Calculation of User Position 54 vii

3 viii Contents 2.5 Obtaining User Velocity Time and GPS UTC Generation GPS System Time Receiver Computation of UTC (USNO) 62 References 63 CHAPTER 3 GPS System Segments Overview of the GPS System Space Segment Overview Control Segment (CS) Overview User Segment Overview Space Segment Description GPS Satellite Constellation Description Constellation Design Guidelines Space Segment Phased Development Control Segment Current Configuration CS Planned Upgrades User Segment GPS Set Characteristics GPS Receiver Selection 109 References 110 CHAPTER 4 GPS Satellite Signal Characteristics Overview Modulations for Satellite Navigation Modulation Types Multiplexing Techniques Signal Models and Characteristics Legacy GPS Signals Frequencies and Modulation Format Power Levels Autocorrelation Functions and Power Spectral Densities Cross-Correlation Functions and CDMA Performance Navigation Message Format Modernized GPS Signals L2 Civil Signal L M Code L1 Civil Signal Summary 150 References 150

4 Contents ix CHAPTER 5 Satellite Signal Acquisition, Tracking, and Data Demodulation Overview GPS Receiver Code and Carrier Tracking Predetection Integration Baseband Signal Processing Digital Frequency Synthesis Carrier Aiding of Code Loop External Aiding Carrier Tracking Loops Phase Lock Loops Costas Loops Frequency Lock Loops Code Tracking Loops Loop Filters Measurement Errors and Tracking Thresholds PLL Tracking Loop Measurement Errors FLL Tracking Loop Measurement Errors C/A and P(Y) Code Tracking Loop Measurement Errors Modernized GPS M Code Tracking Loop Measurement Errors Formation of Pseudorange, Delta Pseudorange, and Integrated Doppler Pseudorange Delta Pseudorange Integrated Doppler Signal Acquisition Tong Search Detector M of N Search Detector Direct Acquisition of GPS Military Signals Sequence of Initial Receiver Operations Data Demodulation Special Baseband Functions Signal-to-Noise Power Ratio Meter Phase Lock Detector with Optimistic and Pessimistic Decisions False Frequency Lock and False Phase Lock Detector Use of Digital Processing Considerations for Indoor Applications Codeless and Semicodeless Processing 239 References 240 CHAPTER 6 Interference, Multipath, and Scintillation Overview Radio Frequency Interference Types and Sources of RF Interference Effects of RF Interference on Receiver Performance Interference Mitigation Multipath 279

5 x Contents Multipath Characteristics and Models Effects of Multipath on Receiver Performance Multipath Mitigation Ionospheric Scintillation 295 References 297 CHAPTER 7 Performance of Stand-Alone GPS Introduction Measurement Errors Satellite Clock Error Ephemeris Error Relativistic Effects Atmospheric Effects Receiver Noise and Resolution Multipath and Shadowing Effects Hardware Bias Errors Pseudorange Error Budgets PVT Estimation Concepts Satellite Geometry and Dilution of Precision in GPS Accuracy Metrics Weighted Least Squares (WLS) Additional State Variables Kalman Filtering GPS Availability Predicted GPS Availability Using the Nominal 24-Satellite GPS Constellation Effects of Satellite Outages on GPS Availability GPS Integrity Discussion of Criticality Sources of Integrity Anomalies Integrity Enhancement Techniques Continuity Measured Performance 361 References 375 CHAPTER 8 Differential GPS Introduction Spatial and Time Correlation Characteristics of GPS Errors Satellite Clock Errors Ephemeris Errors Tropospheric Errors Ionospheric Errors Receiver Noise and Multipath Code-Based Techniques Local-Area DGPS 391

6 Contents xi Regional-Area DGPS Wide-Area DGPS Carrier-Based Techniques Precise Baseline Determination in Real Time Static Application Airborne Application Attitude Determination Message Formats Version Version Examples Code Based Carrier Based 450 References 454 CHAPTER 9 Integration of GPS with Other Sensors and Network Assistance Overview GPS/Inertial Integration GPS Receiver Performance Issues Inertial Sensor Performance Issues The Kalman Filter GPSI Integration Methods Reliability and Integrity Integration with CRPA Sensor Integration in Land Vehicle Systems Introduction Review of Available Sensor Technology Sensor Integration Principles Network Assistance Historical Perspective of Assisted GPS Requirements of the FCC Mandate Total Uncertainty Search Space GPS Receiver Integration in Cellular Phones Assistance Data from Handsets Types of Network Assistance 543 References 554 CHAPTER 10 GALILEO GALILEO Program Objectives GALILEO Services and Performance Open Service (OS) Commercial Service (CS) Safety of Life (SOL) Service Public Regulated Service (PRS) Support to Search and Rescue (SAR) Service 563

7 xii Contents 10.3 GALILEO Frequency Plan and Signal Design Frequencies and Signals Modulation Schemes SAR Signal Plan Interoperability Between GPS and GALILEO Signal in Space Geodetic Coordinate Reference Frame Time Reference Frame System Architecture Space Segment Ground Segment GALILEO SAR Architecture GALILEO Development Plan 592 References 594 CHAPTER 11 Other Satellite Navigation Systems The Russian GLONASS System Introduction Program Overview Organizational Structure Constellation and Orbit Spacecraft Description Ground Support User Equipment Reference Systems GLONASS Signal Characteristics System Accuracy Future GLONASS Development Other GLONASS Information Sources The Chinese BeiDou Satellite Navigation System Introduction Program History Organization Structure Constellation and Orbit Spacecraft RDSS Service Infrastructure RDSS Navigation Services RDSS Navigation Signals System Coverage and Accuracy Future Developments The Japanese QZSS Program Introduction Program Overview Organizational Structure Constellation and Orbit Spacecraft Development 627

8 Contents xiii Ground Support User Equipment Reference Systems Navigation Services and Signals System Coverage and Accuracy Future Development 629 Acknowledgments 630 References 630 CHAPTER 12 GNSS Markets and Applications GNSS: A Complex Market Based on Enabling Technologies Market Scope, Segmentation, and Value Unique Aspects of GNSS Market Market Limitations, Competitive Systems, and Policy Civil Navigation Applications of GNSS Marine Navigation Air Navigation Land Navigation GNSS in Surveying, Mapping, and Geographical Information Systems Surveying Mapping GIS Recreational Markets for GNSS-Based Products GNSS Time Transfer Differential Applications and Services Precision Approach Aircraft Landing Systems Other Differential Systems Attitude Determination Systems GNSS and Telematics and LBS Creative Uses for GNSS Government and Military Applications Military User Equipment Aviation, Shipboard, and Land Autonomous Receivers Smart Weapons Space Applications Other Government Applications User Equipment Needs for Specific Markets Financial Projections for the GNSS Industry 660 References 661 APPENDIX A Least Squares and Weighted Least Squares Estimates 663 Reference 664 APPENDIX B Stability Measures for Frequency Sources 665 B.1 Introduction 665

9 xiv Contents B.2 Frequency Standard Stability 665 B.3 Measures of Stability 667 B.3.1 Allan Variance 667 B.3.2 Hadamard Variance 667 References 668 APPENDIX C Free-Space Propagation Loss 669 C.1 Introduction 669 C.2 Free-Space Propagation Loss 669 C.3 Conversion Between PSDs and PFDs 673 References 673 About the Authors 675 Index 683