A BASIC ATLAS OF RADIO-WAVE PROPAGATION

SHIGEKAZU SHIBUYA Yokohama, Japan

Translated by

HARUO ISHIZUKA Japan

A WILEY-INTERSCIENCE PUBLICATION JOHN WILEY & SONS

New York • Chichester • Brisbane • Toronto • Singapore

CONTENTS

INTRODUCTION HOW TO USE A BASIC ATLAS OF RADIO-WAVE PROPAGATION

CHAPTER 0 BASIC CONCEPTS 3

0.1 Abbreviations and Important Values 3 A. Specific Symbols 3 B. Numerical Multiplier Prefix 3 C. Common Measuring Units 4 D. Common Constants for Propagation Design 4

0.2 Electromagnetic Waves 5 A. Classification of Electromagnetic Waves 5 B. Electromagnetic Field in Free Space 6 C. Electromagnetic Waves within an Enclosed Space 7

0.3 Wave Front and Directivity 8 A. Wave Front 8 B. Directivity 9 C. Requisites for Approximation by Plane Wave 11

0.4 Polarization 12 A. Types of Polarization 12 B. Linearly Polarized Wave 12 C. Elliptically and Circularly Polarized Waves 14 D. Definition of Right-Hand and Left-Hand Rotation 14

xi

XÜ CONTENTS

E. Nature of Polarization and Its Application 15 F. Polarization Rotation by Reflection 17

0.5 Reference Antenna 19 A. Antenna Directivity and Radiation Characterisics 19 B. Reference Antenna 19

0.6 Radio-Wave Intensity 21 A. Electric Field Strength 21 B. Flux Density 21 C. Isotropie Input Power 22 D. Relationship between Various Methods of Expression 22 E. Received Voltage and Receiving Input Power 23 F. Field Intensity Conversion Graph 24

0.7 Propagation Loss 24 A. Free-Space Propagation Loss T0 24 B. Propagation Loss T 24 C. Additional Propagation Loss T 25

0.8 Radio Transmission Loss 25 A. Transmission Units 25 B. Transmission Loss 26

0.9 Refraction of Radio Waves in Troposphere 27 A. Troposphere 27 B. Expression of Atmospheric Refractivity 28 C. M Curves and Definition of K 29 D. K and Path Profile Chart 30 E. Variation and Definable Range oi K 31

0.10 Ground Reflection 33 A. Ground and Ground Reflection 33 B. Effective Reflection Coefflcient pe 34 C. Propagation Echo Ratio pe 36

0.11 Various Types of Propagation 36 A. Physical Classification of Propagation Waves 36 B. Propagation Path Types and Applicable Frequency Bands 38 C. Propagation Path Types in VHF to SHF Bands 40

Chart Index 41

CHAPTER 1 FREE-SPACE PROPAGATION PATH 89

1.1 Conditions for Free-Space Propagation Path 89

1.2 Basic Parameters of Free Space 90 A. Free-Space Flux Density 90

CONTENTS xiü

B. Free-Space Basic Input Power 90 C. Free-Space Propagation Loss 91 D. Free-Space Electric Field Strength 91

1.3 Free-Space Transmission by Actual Antennas 92 A. Antenna Gain versus Transmission Loss 92 B. Effective Antenna Aperture Area versus Transmission Loss 92 C. Transmission Loss between Unit-Area Antennas 93

1.4 Voltage Received by a Linear Antenna (Induced Voltage and Open-Circuit Voltage at the Feeding Point) 94

1.5 Aperture Area and Gain of an Antenna 94

1.6 Correction to Field Strength and Flux Density by Radiated Power 95

1.7 Summary of Basic Formulas for Radio-Wave Field Strength and Transmission Loss 96

1.8 Nomograph for Simplified Calculations 97

Examples 97

Chart Index 101

CHARTER 2 REFLECTIONINTERFERENCE PROPAGATION PATH 159

2.1 Types of Interference Propagation Paths 159 A. Factors Causing Variation in the Mean Received Signal Level 159 B. Comparison of Effects 160 C. Types of Propagation Paths with Interference Caused by

Ground-Reflected Waves 161 D. Classification and Treatment of the Reflected-Wave

Interference Path 163

2.2 Basic Equations of Interference Propagation 163

2.3 Smooth Fiat Ground 164 A. Equations of Propagation 164 B. Equations of Propagation with a Small Grazing Angle ^

( Ä = -l,ArbitraryS) 165 C. Case of R = - 1 , 8 < 1 rad 166 D. Effect of Ground Wave in Low Antenna Region (Over-Sea-water

Propagation, Vertical Polarization, in or below VHF Band) 166 E. Flat-Ground Reflection Coefncient 166

2.4 Smooth Spherical Ground 167 A. Equation of Propagation 167 B. Small Grazing Angle \p 168

xiv CONTENTS

C. Small 4> and 8 < 1 rad 168 D. Line-of-Sight Distance over Spherical-ground dt 168 E. Equivalent Antenna Heights h{ and h'2 169 F. Method to Determine the Reflection Point 169

2.5 Rough Ground 171 A. Equation of Propagation 171 B. Criteria for Mirror Reflection 171 C. Size of Effective Reflection Area 172 D. Effective Reflection Coefficient of Ordinary Ground 173 E. Effect of Shielding Ridge 173

2.6 Interference Pattern 174 A. Classification of Interference Patterns 174 B. Path-Length Difference 175 C. Path-Length Difference between Maximum and

Minimum Points 175 D. Range of Variation of Interference Pattern 176

E. Half-Pitch in Height Pattern 177

2.7 Effect of Antenna Directivity 178

2.8 Vertical Angle 178

Examples 179

Chart Index 187

CHAPTER 3 DIFFRACTION PROPAGATION PATH 239

3.1 Basic Types of Diffraction Propagation Paths 239 A. Smooth-Spherical-Ground Diffraction Model 239 B. Rough-Spherical-Ground Diffraction Model 240 C. Thick-Ridge Diffraction Model 240 D. Knife-Edge Diffraction Model 241 E. Multiridge Diffraction Model 241

3.2 Single-Ridge Diffraction Loss Calculation Method 242 A. Parameters for Approximate Solution of

Single-Ridge Knife-Edge 242 B. Diffraction Loss Z of Single Ridge (Approximated by

a Knife-Edge) 242 C. Nomograph for Direct Estimation of Diffraction Loss Due to a

Single Ridge 243

3.3 Calculation of Diffraction Loss Caused by Multiple Ridges 243

CONTENTS XV

3.4 Effects Caused by a Nearby Ridge and a Reflected Wave 244 A. Additional Loss Js Caused by Nearby Ridge 244 B. Additional JR Loss Due to Reflected-Wave Interference 245

3.5 Fresnel Zone 246 A. First Fresnel Zone Radius r0 for Transmission between Points

Separated by an Extremely Long Distance 246

B. First Fresnel Zone Radius rx 247

3.6 >?th Fresnel Zone Radius 247

3.7 Calculation Chart for a MultiRidge (i < 5) 248

3.8 Diffraction Loss over Smooth Spherical Ground 249 A. Propagation Loss 249 B. Estimation of Additional Loss Ap over

Smooth Spherical Ground 249 C. Application of Graphs 249 D. Notes on Application Method 250

Examples 250

Chart Index 257

CHAPTER 4

TROPOSCATTER PROPAGATION PATH 291

4.1 Approach to Troposcatter Propagation Path 291

4.2 Method of Predicting the Median Transmission Loss T(50) 292 A. Prediction Formula 292 B. Angular Distance (Scatter Angle) 292 C. F2(@D) 294 D. V(de) 294

4.3 Long-Term Variability of Hourly Median Transmission Loss T(q) 294 A. g(f) 295 B. Y0(q) 295

4.4 Simplified Method of Estimating Transmission Loss (Alternative Method) 295 A. 99% Value of Transmission Loss for the Worst Month

in a Year 295 B. 1% Value of Transmission Loss in a Year 296 C. Frequency Correction Coefficient 296 D. Standard Deviation 296

4.5 Transmission Loss 296

xvi CONTENTS

4.6 Method Using Vertical Distribution of Atmospheric Refractivity 297

4.7 Remarks on the Application of the Calculation Charts 298

Examples 299

Chart Index 305

CHAPTER5

ABSORPTION PROPAGATION PATH 327

5.1 Absorption Attenuation in the Troposphere 327

5.2 Composition of the Atmosphere 328

5.3 Causes and Characteristics of Atmospheric Attenuation 328 A. Oxygen 328 B. Water Vapor 329 C. Rain 329 D. Snow, Hail, and Hailstones 330 E. Clouds and Fog 330 F. Smoke, Sandstorms, etc. 330

5.4 Estimation of Attenuation 330 A. Attenuation Caused by Oxygen and Water Vapor 331 B. Attenuation Caused by Clouds and Fog 332 C. Attenuation Due to Rainfall 332 D. System Time Reliability and Statistical Value of

Rainfall Intensity 332

5.5 Design Charts for 8- to 15-GHz Bands 333

5.6 World Rainfall 334

5.7 Countermeasures in Radio System Design Against Outage Due to Heavy Rain 335 A. Route Diversity 335 B. Auxiliary System Using Lower Frequency Band 335

C. Lower Frequency Auxiliary System with Antenna Sharing 335

5.8 Absorption Attenuation in Millimeter Waves 335

Examples 336

Chart Index 341

CHAPTER6

PASSIVE-RELAY PROPAGATION PATH 369

6.1 Passive-Relay System 369

6.2 Passive-Relay Additional Loss 370

CONTENTS xvii

6.3 Passive Section as Free-Space Propagation Path 372

6.4 Near-Field-Type Passive Relay (Beam Feeding) 373

6.5 Method of Definition of Far-Field and Near-Field Types 374

6.6 Equivalent Propagation Loss of Radio Path with Totally Free-Space Main and Passive Relay Sections 374 A. General Equation 375 B. Double-Stage Passive Relay 375 C. Single-Stage Passive Relay (Including Double-Stage Passive

Relays Whose Reflectors Are Located Close to Each Other) 375 6.7 Application of Reflectors of Various Types According to Transfer-

Supplementry Angle 376

6.8 Geometrical Parameters of a Double Passive Plane Reflector System 377 A. Relationship between the Angle of Incidence <#> and the

Transfer-Supplementary Angle 0 377 B. Horizontal Width W of Reflector 377 C. Spacing between Two Reflectors 378 D. Geometrical Analysis of Double-Plane Reflector System 379

6.9 Loss of Double-Reflector System 379 A. Effective Area Be and Bidirectional Gain GREF 380 B. Plane-Area Efficiency TJ 380

C. Additional Loss XR between Two Plane Reflectors 380

6.10 Two-Antenna Method 381

Examples 381

Chart Index 387

CHAPTER7

NOISE AND SIGNAL-TO-NOISE RATIO 427

7.1 Classification of Noise 427

7.2 Terminal Environmental Noise and Intersystem Noise 428 A. Terminal Environmental Noise 428 B. Noise Produced within a System 428

7.3 External Noise 430 A. Natural Noise 430 B. Man-Made Noise 431

7.4 Thermal Noise 433 A. Propagation Design and Thermal Noise 433 B. Available Power and Thermal Noise Source 433

xviii CONTENTS

C. Thermal Noise Power at an Ambient Temperture 434 D. Peak Factor of Thermal Noise 435

7.5 Noise Temperature 435 A. Definition of Noise Temperature 435 B. Overall System Equivalent Noise Temperature 435

C. Influence of Feeder System on Noise Temperature 436 D. Antenna Equivalent Noise Temperature Ta All

7.6 Noise Figure NF 437 A. Definition 437

B. Noise Figure of Cascaded Four-Terminal Networks 438 C. Feeder System Loss and Noise Figure 438

7.7 External Noise Figure EN 439 A. External Noise Figure (Isotropie Antenna) 439 B. External Noise Figure (Ordinary Antenna) 440

7.8 System Overall Noise Figure (Operating Noise Figure) F 440

7.9 Threshold Input Level (Lowest Input Level for Required S/N Ratio) 441 A. S/N Ratio Improvement Factor 441 B. Threshold Input 442

7.10 Graph for Estimation of S/N Ratio 444 A. S/N Ratio for Ordinary FM System 444 B. S/N Ratio for FM Television Transmission System 444 C. S/N Ratio for Arbitrary Channel of Single-Sideband System 445 D. Graph for Quick Estimation of S/N Ratio in Single-Sideband

FM System (According to CCIR Recommendation) 445

E. Graphs of Receiver Input versus S/N Ratio for Quick Estimation (Single-Sideband FM System) 446

F. White Noise Generated in a Radio Relay System 446

Examples 447

Chart Index 457

CHAPTER 8 FADING ESTIMATION AND SYSTEM EVALUATION 551

8.1 Estimation Limit and Approach to Engineering Design 551 A. Fading and Radio Meteorology 551 B. Estimation of Fading 552

C. Procedures to Accomplish a Radio Relay System 553

CONTENTS xix

3.2 Basic Classification of Fading 553 A. Basic Causes and Classification of Fading 553 B. Atmospheric Fading 554 C. Ground-Based Fading 558 D. Man-Made Fading (Type U or V) 559 E. Composite Fading (Types G, K, and T) 561

8.3 Fading on Actual Radio Paths 564 A. Free-Space Radio Path 564 B. Interference Radio Path 564 C. Ridge Diffraction Grazing Radio Path 565 D. Mountain Diffraction Radio Path 565 E. Mountain Diffraction Interference Radio Path 565 F. Tropospheric Scatter Propagation Path 565 G. Spherical-Ground Diffraction Radio Path 566

3.4 Statistical Treatment of Fading 566 A. Variables 567 B. Sampling Time Interval 567 C. Statistical Period 567 D. Reliability and Fade Probability 568 E. Estimated Loss Due to Fading 569

5.5 System Standard Composition and AUowable Noise 570 A. AUowable Noise 570 B. Criteria for Allowable-Noise Power Applied to a Specific

Country or Region 571 C. Crieria for AUowable Noise Power of Systems for International

Connection 571 D. Prevention of Mutual Interference between Satellite

Communication System and Terrestrial Radio System 572 E. Graphs to Determine the AUowable Noise 573 F. AUowable Noise Power of Line-of-Sight FDM Relay System 573 G. AUowable Propagation Noise 575

3.6 Propagation Design 576 A. Route Engineering 576 B. Propagation Design for Radio Hop Locations 577 C. Assessment of Design Propagation Noise Power 580 D. Modification of Designed Value 581 E. Station Site Selection Survey and Measurement 581 F. Radio Propagation Test 583 G. Additional Correction and Reevaluation of Propagation Design 584

XX CONTENTS

8.7 Estimation of Fading 585 A. Numerical Expression of Fading 585 B. Basic Philosophy of Fading Estimation 585 C. Radio Meteorological Coefficient 587 D. Coefficient of Surrounding Terrain Conditions 588 E. Path Profile Coefficient 589 F. Frequency-Distance Coefficient 590 G. Fading Parameter 591 H. Comparison with Conventional Estimating Methods 592 I. Alternative Approximation 595 J. Approximate Fading Estimation Applicable to Preliminary

Design Stage 596

8.8 Estimation of Total Noise in Radio Relay System 597 A. Mean Propagation Noise (Allowable Value NA, Designed

Value NAX) 597 B. 20% Propagation Noise (Allowable Value NB, Designed Value

NBX) 599 C. Fade Probability and Outage Factor for a Specified Noise

Power Level 600

Examples 601

Chart Index 643

CHARTER 9

ASTRONOMY AND GEOGRAPHY 695

9.1 Astronomical and Geographical Survey and Radio Engineering 695

9.2 Tolerable Error and Calculation Method 696 A. Tolerable Error (in a Simplifed Survey) 696 B. Features of Calculation 697

9.3 Determination of Various Survey Parameters 697 A. Position of a Point 697 B. Distance 698 C. Elevation above Mean Sea Level and Difference in Elevation 698 D. Vertical Angle (Elevation) 698 E. Direction toward an Adjacent Station 698 F. Bearing Angle 698 G. Determination of True North (Bearing Angle of Meridian from

the North) 699

9.4 Geographical Measurements 699 A. Constants on the Earth 699 B. Map 699

CONTENTS xx i

C. Great-Circle Distance 700 D. Geographie Azimuth 700 E. Measurement of Distance 701 F. Measurement of Level 701

9.5 Astronomical Measurements 702 A. Definition 702 B. Time and Angles Relating to Celestial Bodies 702 C. Relationship between Local Sidereal Time and Standard Time 702 D. Computation of Hour Angle (General Case) 704 E. Hour Angle and Declination of the Sun 704 F. Surveying of Astronomical Azimuth 705 G. Atmospheric Refraction and Dip of Horizon 706 H. Comparison of Surveying Methods of Astronomical Longitude

and Latitude 706

9.6 Bright Fixed Star and Its Application 707 A. Brightness, Apparent Radius and Symbols of Celestial Bodies 707 B. Major Fixed Stars and Their Positions 708 C. Positions of Major Fixed Stars and Their Application 708 D. Star Finding Chart 709 E. Simplified Chart of Fixed Stars in the Sky 711

9.7 Time-Angle Conversion Table 711

9.8 Radio Stars and Applications 712 A. Kinds of Radio-Wave Sources 712 B. Application of Radio Stars 713

Chart Index 715

INDEX 771