314 



INDEX 



Fog 



effect on refractive index, 77, 216 

 effect on signal strength, 221 

 Forecasting and meteorology 



see Meteorology and forecasting 

 Formula for lobe, radar, 171-174 

 Formula for lobe angle, radar, 152-155 

 Formula for reflection area, 160-162 

 Fresnel formulas for reflection 



coefficient, 32-33 

 Fresnel integrals for diffraction 



phenomena, 125-127 

 Fresnel theory, limitations for 



diffraction problems, 133-134 

 Fresnel zones, 121-123, 158-162 

 Fresnel-Kirchhoff diffraction theory, 



37 

 Frictional turbulence, 212-213 



Gaussian distribution, 259 

 Graphical method for determination of 

 standard coverage charts, 93-94 

 Ground and sea reflection, 28 

 Ground radar, antenna patterns 



earth curvature effect on lobe 

 lengths, 166-167 



factors, 164 



local terrain effects, 164-166 



reflecting screens, 163 



vertical patterns, 162, 164 

 Ground radar, equipment, 106-109 



conclusions, 109 



derivation of formulas, 109 



early warning heightfinding radar, 

 106-109 



gunlaying (antiaircraft) radar, 

 106-107, 109 



surface surveillance radar, 108 



tests, 174-175 

 Ground radar, siting and coverage, 

 113-177 



calculation of vertical coverage, 

 145-174 



calibration and testing, 174-177 



diffraction of radio waves, 120-134 



permanent echoes, 134-145 



radar systems, 113-115 



signal measurements, 175-176 



topography of siting, 115-120 

 Ground radar, test data analysis, 

 176-177 



calibrated receiver method, 177 



maximum free space range, 176-177 



signal-to-noise graph, 176 

 Ground radar, types, 113 

 Ground reflection, 190-193 

 Ground roughness estimation, 36-37 

 Guided propagation, 179-182 



see also Superrefraction 



coverage, 181-182 



critical angle, 181 



definition, 190 



duct, 181-182 



equipment faults, 182 



in nonhomogeneous atmosphere, 



244-246 

 occurrence causes, 185 

 wave picture, 207-208 

 Gunlaying (antiaircraft) radar, 

 106-107, 109 



Hankel functions in propagation 

 equation solution, 237-239 

 Heightfinding radar, early warning, 



106-108 

 Height-gain functions, 255 

 Historical background for nonstandard 



propagation, 42 

 History of Committee on Propagation, 

 5-27 

 chronological record of activities, 



13-24 

 contracts and projects, 11-12 

 critique, 26 



investigating bodies, 10 

 liaison channels, 8 

 objectives, 9-10 

 organization, 6-7 

 origin, 5-8 



research recommendations, 26-27 

 results, 25-26 

 Humidity and temperature in 



meteorological measurements, 

 50 

 Huyghens' principle, wave 

 propagation, 121 



Incipient leakage in surface duct, 

 233-234 

 attenuation constant, 233 

 conclusion, 234 



Freehafer and Furry formula, 233 

 Irish Sea transmission experiment, 

 58-59 



Leaky waveguide theory, 48 

 Lobe angle calculations, 147-158 

 computing methods, 155 

 correction for standard earth 



curvature, 149-152 

 diagrams of medium height sites, 



158 

 flat earth, 147-149 

 formula, 152-155 

 general lobe formula, 171-174 

 lobe lengths, 166-167, 170 

 low site lobes, 155-156 

 reflection area, general formula, 



160-162 

 sea reflection with diffuse land 



reflection, 158-159 

 shoreline diffraction, 158, 162 



Lobes for medium height radar, 170 

 Local terrain effects on antenna 

 pattern, 164-166 



cliff edge diffraction, 166 



land reflection and diffraction, 166 



limited reflecting area, 165 



M curves, 43, 55-57 

 Meteorological factors in radar 

 coverage, 182-184 



air turbulence, 184 



measurements, 184 



occurrence frequency of guided 

 propagation, 184 



over land, 183-184 



over sea, 183 



refraction causes, 182-183 



subsidence, 184 



temperature inversion, 182-184 



trapping, 182-184 

 Meteorological measurements, 50-57 



anemometers, 55-56 



M curves, 55-57 



noncaptive radiosonde, 52-55 



psychrometer, 52-55 



refractive index measurements, 52 



temperature and humidity elements, 

 50 



wired sonde, 51 

 Meteorology and forecasting, 75-81 



atmospheric stratification, 75-76 



coastal and martime conditions, 

 77-78 



conditions over land, 76-77 



dynamic effects, 78-79 



fog, 77 



radar forecasting, 80-81 



radio forecasting, 75 



world survey, 79-80 

 Microwave permanent echoes, 144-145 

 Microwaves, scattering and absorption 



see Scattering and absorption of 

 microwaves 

 Moisture gradients, 210-212 



Nocturnal cooling, 75-77, 212, 215-216 



Nomographic solutions for coverage 



diagrams, 95-105 

 Nonoptical radio transmission path, 



221-222 

 Nonstandard propagation, 42-49 



continuously varying modified index 



curve, 247-248 

 duct characteristics, 46-47 

 historical background, 42 

 in ocean surface duct, 247 

 operational applications. 208-210 

 perturbation theory for exponential 



M curve, 249-255 

 ray tracing, 44-45 

 reflection from elevated layers, 49 



