Radio Techniques for Probing the Terrestrial Ionosphere

ISBN-13: 9783642762598 / Angielski / Miękka / 2011 / 293 str.

Robert D. Hunsucker

Opis

In the years since the pioneering efforts of Sir Edward Appleton, M. A. F. Barnett, G. Breit, and M. A. Thve, many radio techniques have been employed to investigate the terrestrial ionosphere. The purposes of this book are to exam ine the basic physical interaction process of radio waves with the ionosphere, scrutinize each of the radio techniques currently in use, and describe the elements of each technique, as well as assess their capabilities and limitations. I have included some of the history of each technique, since we often tend to forget the efforts of the "pioneers." The interaction of radio waves with the terrestrial ionosphere has been described in considerable detail in several "classic" treatments, e.g., Ratcliffe (1959), Al'pert (1963), Budden (1961) and Davies (1965), Rishbeth and e.g., Flock (1979), Davies Garriott (1969), and in other more recent books, (1990), Hargreaves (1979), and Budden (1985). A few of the radio techniques have been described by Hargreaves (1979) and a book by Giraud and Petit (1978) has also included discussion of several of the techniques. The "WITS" handbook No. 2 (1989) also contains description of several radio techniques."

Spis treści

I Introduction.- 1 Terrestrial Atmospheric Structure and Properties of Electromagnetic Waves.- 1.1 The Radio Spectrum.- 1.2 Structure and Composition of the Terrestrial Ionosphere.- 1.3 Electrical Noise and Radio Frequency Interference.- 1.3.1 Thermal Noise in a Resistor.- 1.3.2 The Noise Factor, Figure, and Temperature of a Radio Receiver.- 1.4 Properties of Electromagnetic Waves and Their Interaction with Matter.- 1.4.1 Maxwell’s Equations and the Wave Equation.- 1.4.2 Some Characteristics of Propagating Plane Waves.- 1.4.3 Properties of the Propagation Constant and Vector.- 1.4.4 Polarization of an Electromagnetic Wave in Free Space.- 1.4.5 The Radar Equation.- 2 Radio Propagation in a Plasma.- 2.1 Radio Wave Propagation in an Unmagnetized Plasma.- 2.1.1 Vertical and Oblique Propagation.- 2.1.2 The Virtual Height Concept.- 2.1.3 Vertical and Oblique Propagation.- 2.2 Radio Propagation in a Magnetized Plasma.- 2.2.1 Dispersion and Polarization.- 2.2.2 Absorption of Radio Waves in the Ionosphere.- 2.3 Ionospheric Scattering of Radio Waves.- 2.3.1 Coherent Scatter from Ionospheric Irregularities.- 2.3.2 Incoherent Scatter from the Ionosphere.- II Earth-Based Radio Techniques.- 3 Vertical Sounders — the Ionosonde.- 3.1 History of Development and Basic Principles of Operation.- 3.2 Standard Ionosondes.- 3.3 Advanced Ionospheric Sounders.- 3.4 Capabilities of Ionosondes.- 3.5 Limitations.- 4 Oblique Backscatter Sounders.- 4.1 HF Pulsed Groundscatter Systems.- 4.1.1 The Development of Backscatter Sounding as a Remote Sensor of the Ionosphere.- 4.1.2 Basic Ionospheric Groundscatter Theory.- 4.1.3 Various Techniques Employed in Groundscatter Sounding.- 4.2 Characteristics of a Typical Scanned Groundscatter System with Variable Frequency.- 4.2.1 The ITS/ESSA OBS System (1960’s Technology).- 4.3 Direct Ionospheric Backscatter.- 4.3.1 History of Development of the Technique.- 4.3.2 Direct Backscatter from the E-Region.- 4.3.3 Backscatter from the F-Region.- 4.4 Capabilities and Limitations of OBS Systems.- 4.4.1 HF Groundscatter OBS Capabilities.- 4.4.2 Direct HF Backscatter OBS Systems.- 4.4.3 Auroral Radar Systems.- 5 Incoherent Scatter Radar (ISR) Systems.- 5.1 Introduction.- 5.2 Basic ISR System Considerations.- 5.3 Currently Operational ISR Systems.- 5.3.1 Descriptions of Individual Operational ISR’s.- 5.3.2 How to Obtain Data and Information from Currently Operational ISR’s.- 5.4 Capabilities and Limitations.- 6 Ionospheric Modification by High Power Radio Waves.- 6.1 Ionospheric Cross Modulation Techniques — Some Representative Results.- 6.1.1 Modulated Disturbing Wave, Unmodulated Wanted Wave at Oblique Incidence, and Gyro Interaction.- 6.1.2 Self-Interaction and Gyro Self-Interaction.- 6.1.3 Pulse Modulated Disturbing and Wanted Waves — Vertical Propagation.- 6.1.4 Pulse Modulated Disturbing Wave — Cosmic Noise Wanted Wave, Using Vertical Propagation.- 6.1.5 Outline of Cross Modulation Theory.- 6.2 Ionospheric Heating Using High Power HF/CW Transmitters.- 6.2.1 Basic Theory of Ionospheric Heating.- 6.2.2 Descriptions of Facilities and Some Results from Ionospheric Heating Investigations at Mid-Latitudes.- 6.2.3 The Low-Latitude HF Heating Facility at the National Aeronomy and Ionosphere Center (NAIC), Arecibo, Puerto Rico.- 6.2.4 HF Heating Facilities at High Latitudes.- 6.3 Capabilities and Limitations of Radio-Wave Interaction and HF Heating Experiments.- 6.3.1 Capabilities.- 6.3.2 Limitations.- 7 Methods of Measuring Ionospheric Absorption and Other D-Region Parameters.- 7.1 A1 — The Pulse Reflection Method.- 7.1.1 Vertical Incidence.- 7.1.2 A1 Technique — Oblique Incidence.- 7.2 A2 — The Cosmic Noise Technique.- 7.3 Oblique Field Strength Measurements (the A3 Method).- 7.3.1 The A3a Method — Oblique Incidence Field Strength Observation on Frequencies Above 2 MHz.- 7.3.2 Method A3b — Oblique Incidence Field Strength Observation on Frequencies in and Below the MF Broadcasting Band.- 7.4 Partial Reflection Experiments (PRE).- 7.4.1 Theory.- 7.4.2 Experimental Technique.- 7.5 Other Techniques.- 7.6 Capabilities and Limitations.- III Satellite, Rocket, and Other Techniques.- 8 Earth Satellite Radio Studies of the Ionosphere.- 8.1 Satellite Radio Experiments.- 8.1.1 A Short History of Radio Beacon Experiments (RBE).- 8.1.2 Methods of Determining Electron Content.- 8.1.3 Global Variation of TEC.- 8.1.4 RBE Studies of Ionospheric Scintillation.- 8.2 Satellite Topside Sounders.- 8.2.1 Sweep Frequency Topside Sounders.- 8.3 Capabilities and Limitations of Satellite Radio Techniques.- 9 Other Radio Techniques.- 9.1 Ionospheric in Situ Measurements.- 9.2 HF Spaced-Receiver and Doppler Systems.- 9.3 Whistlers and Controlled Stimulation of VLF Emissions.- 9.3.1 Whistlers and Other Natural VLF Radiation.- 9.3.2 Controlled Stimulation of VLF Emissions.- 9.4 VLF and HF High Resolution Sounders.- 9.5 Ionospheric Imaging by Radio.- 9.6 Backscatter from Meteoric Ionization.- 10 Epilog.- 10.1 “Where We Have Been and Where We Are Now”.- 10.2 Specific Techniques and Their Applications.- 10.3 Complementarity.- 10.4 Concluding Remarks.- 10.4.1 The Present Status of Radio Instrumentation.- 10.4.2 Possible Future Trends.- 10.4.3 Excelsior!.- A.1 List of Principal Symbols, Constants, and Conversion Factors.- A.1.1 Principal Symbols.- A.1.2 Selected Physical Constants.- A.1.3 Some Selected Conversion Factors.- A.2 Acronyms.- A.3 A Radio Frequency Spectrum Chart Showing the ITU Nomenclature and Principal Uses.- A.4 Annotated Bibliography.- A.5 Selected Global Maps and Other Information on Electrical Noise.- A.6 Some Representative Values of Ground Electrical Characteristics.- A.7 Fresnel Zone Antenna Siting Fundamentals.- A.7.1 Introduction.- A.7.2 HF Antenna Siting Example.- A.7.3 The Fresnel Zone in Three Dimensions.- References.