Tropospheric and Ionospheric Effects on Global Navigation Satellite Systems

Tropospheric and Ionospheric Effects on Global Navigation Satellite Systems Explore atmospheric effects on radio frequency propagation in the context of Global Navigation Satellite System communication In Tropospheric and Ionospheric Effects on Global Navigation Satellite Systems, a team of distinguished researchers deliver an accessible and authoritative introduction to all scientifically relevant effects caused by the ionosphere and troposphere on GNSS RF signals. The book explores the origin of each type of propagation effect and explains it from a fundamental physical perspective. Each of the major methods used for the measurement, prediction, and mitigation of ionospheric and tropospheric effects on GNSS are discussed in detail. The authors also provide the mechanisms that drive ionization and plasma transport in the ionosphere, propagation phenomena (including scattering, absorption, and scintillations), and the predominant predictive models used to predict ionospheric propagation effects. With an emphasis on global navigation satellite systems, the book discusses the US Standard Atmosphere, a general reference model for characteristics of the unionized atmosphere. It also considers: Thorough introductions to the Global Positioning System and the principles of GNSS positioning Comprehensive explorations of tropospheric propagation and predictive models of the troposphere Practical discussions of the physics of the ionosphere, experimental observation of the ionosphere, and ionospheric propagation In-depth examinations of predictive models of the ionosphere, including group delay models for single-frequency GNSS receivers Ideal for engineers and research scientists with a professional or personal interest in geophysics, RF propagation, and GNSS and GPS applications, Tropospheric and Ionospheric Effects on Global Navigation Satellite Systems will also earn a place in the libraries of undergraduate and graduate students studying RF propagation or GNSS.

Table of Contents:
1. Overview of the Global Positioning System 11 1.1. Introduction 12 1.2. Applications of GNSS 14 1.3. GPS Segments 17 1.3.1. Space Segment 17 1.3.2. Control Segment 21 1.3.3. User Segment 23 1.4. Keplerian Orbits 27 1.5. Satellite Broadcast 33 1.5.1. Carrier Frequencies 33 1.5.2. Digital Modulation 34 1.5.3. Ranging Codes 41 1.5.4. Navigation Message 47 2. Principles of GNSS Positioning 57 2.1. Introduction 58 2.2. Basic GNSS Observables 60 2.2.1. Pseudorange 60 2.2.2. Carrier Phase 62 2.2.3. Doppler Shift 68 2.3. GNSS Error Sources 73 2.3.1. Clock and Ephemeris Errors 74 2.3.2. Relativistic E_ects 76 2.3.3. Carrier Phase Wind-Up 82 2.3.4. Atmospheric E_ects 83 2.3.5. Multipath, Di_raction, and Interference E_ects 83 2.3.6. Hardware-Related Errors 87 2.3.7. Dilution of Precision 89 2.3.8. Additional Error Sources 90 2.4. Point Positioning 91 2.4.1. Positioning Using Pseudorange 92 2.4.2. Accounting for Random Error 97 2.4.3. Dilution of Precision 102 2.5. Data Combinations and Relative Positioning 107 2.5.1. Multi-Frequency Combinations 107 2.5.2. Relative Positioning 113 3. Tropospheric Propagation 121 3.1. Introduction 121 3.2. Tropospheric Group Delay 122 3.3. Tropospheric Refraction 128 3.4. Extinction 132 3.4.1. Beer-Lambert Law 132 3.4.2. Scattering 136 3.4.3. Gaseous Absorption 137 3.4.4. Hydrometeor Attenuation 140 3.5. Tropospheric Scintillations 142 4. Predictive Models of the Troposphere 145 4.1. Introduction 145 4.2. Saastamoinen Model 145 4.3. Hop_eld Model 159 4.4. U.S. Standard Atmosphere 163 4.4.1. Model Assumptions 164 4.4.2. Computational Equations 175 4.4.3. Data Sources and Implementation 178 5. Physics of the Ionosphere 181 5.1. Introduction 182 5.2. Solar-Terrestrial Relations 183 5.2.1. The Sun 183 5.2.2. The Interplanetary Medium 186 5.2.3. Earth's Magnetic Field 188 5.2.4. The Magnetosphere 196 5.2.5. Earth's Atmosphere 200 5.3. Physics of Ionization 203 5.3.1. Neutral Atmosphere 203 5.3.2. Ionization 206 5.3.3. Recombination and Attachment 209 5.3.4. Photochemical Processes in the Ionosphere 210 5.4. Chapman's Theory of Ionospheric Layer Formation 213 5.5. Plasma Transport 222 5.5.1. Di_usion 223 5.5.2. Neutral Winds 226 5.5.3. Electromagnetic Drift 228 5.5.4. Combined E_ects of Neutral Wind and Electromagnetic Drift 231 5.5.5. Continuity Equation 237 6. Experimental Observation of the Ionosphere 239 6.1. Introduction 240 6.2. Ionospheric Measurement Techniques 242 6.2.1. Ionosondes 242 6.2.2. Incoherent Scatter Radar 254 6.2.3. In Situ Measurements 262 6.3. Morphology of the Ionosphere 269 6.4. Variability of the Ionosphere 276 6.4.1. F2 Layer Anomalies 276 6.4.2. Solar Activity 282 6.4.3. Magnetic Variation 286 6.4.4. Ionospheric Irregularities 298 7. Ionospheric Propagation 303 7.1. Introduction 304 7.2. Magnetoionic Propagation 305 7.3. Propagation E_ects of the Background Ionosphere 315 7.3.1. Total Electron Content 317 7.3.2. Ionospheric Refraction 322 7.3.3. Group Delay and Phase Advance 325 7.3.4. Dispersion 334 7.3.5. Faraday Rotation 335 7.3.6. Absorption 338 7.4. Scintillations 341 8. Predictive Models of the Ionosphere 351 8.1. Introduction 352 8.2. Group Delay Models for Single-Frequency GNSS Receivers 353 8.2.1. Klobuchar Model 353 8.2.2. NeQuick 363 8.3. Global Ionospheric Scintillation Model 373 8.3.1. Ray Tracing in the Ionosphere 373 8.3.2. Multiple Phase Screen Method 375 8.4. International Reference Ionosphere 379 8.4.1. Data Sources, Inputs, and Outputs 381 8.4.2. Important Functions 387 8.4.3. Characteristic Heights and Electron Densities 392 8.4.4. Electron Density 400 8.4.5. Electron Temperature 416 8.4.6. Ion Temperature 422 8.4.7. Ion Composition 424 8.4.8. Additional Parameters 427 Appendices 431 A. Review of Electromagnetics Concepts 433 A.1. Electromagnetic Waves 434 A.1.1. Maxwell's Equations and the Wave Equation 434 A.1.2. Plane Wave Solutions 436 A.1.3. Constraints Via Maxwell's Equations 440 A.1.4. Poynting Vector 443 A.2. Phase and Group Velocity 446 A.2.1. Phase Velocity 446 A.2.2. Modulated Signals and Group Velocity 446 A.2.3. Group Index of Refraction 448 A.2.4. Relationship Between Phase and Group Velocities 449 A.3. Polarization 450 A.3.1. Linear Polarization 450 A.3.2. Circular Polarization 452 A.3.3. Elliptical Polarization 455 A.3.4. Jones Vectors and Decomposing Polarizations 457 A.4. Derivation of Rayleigh Scattering 462 B. Electromagnetic Properties of Media 473 B.1. Introduction 474 B.2. Dielectric Polarization 475 B.2.1. Induced Dielectric Polarization 475 B.2.2. Electric Susceptibility 476 B.3. Lossy and Dispersive Media 478 B.3.1. Absorption 478 B.3.2. Dispersion 478 B.3.3. Graphical Analysis 479 B.3.4. Multiple Resonances 482 B.4. Conducting Media 484 B.4.1. Time-Varying Conduction Current 484 B.4.2. Propagation in Conducting Media 485 B.4.3. Combined E_ects of Dispersion and Conduction 488 B.5. Kramers-Kronig Relations 489 B.6. Anisotropic Media 492 B.6.1. Dielectric Tensor Properties 492 B.6.2. Wave Equation in Anisotropic Media 494 B.6.3. Optical Axes 496 B.6.4. Index Ellipsoid 499 B.6.5. Phase and Group Velocity in Anisotropic Media 501 B.6.6. Birefringence and Spatial Walk-o_ in ~k Surfaces 503 B.7. Gyrotropic Media 506 B.7.1. Gyrotropic Susceptibility Tensor 506 B.7.2. Propagation in Gyrotropic Media 509 Bibliography 513

About the Author :
Timothy H. Kindervatter is an Associate Scientist at SciTec, Inc., where he develops scientific instrumentation in support of U.S. government defense contracts. His experience also includes a study on the effects of atmospheric aerosols and molecular species on UV scattering. Fernando L. Teixeira, PhD, is Professor of Electrical Engineering at Ohio State University. He is a Fellow of the IEEE and has served as Principal Investigator on projects sponsored by the Department of Defense, the Department of Energy, the National Science Foundation, and NASA.