224 



INDEX 



height of cUict base, 94-95 



intensity of ducts, 95 



leeward vs windward conditions, 38, 



42 

 near the western coasts of continents, 



95-96 

 refractive index, 40-43 

 surface ducts, 40, 95-96 

 thickness of ducts, 95 

 vapor pressure difference, 95 

 wind speed, 41-43, 95 



Echoes and targets, 191-204 



effect of receiver parameters on signal 



threshold power, 197-202 

 fluctuations of radar echoes, 191-195 

 frequency dependence of sea echoes, 



195-197 

 radar scattering over cross-section 

 area, 202-204 

 Electrical constants, 138-144 

 dry sandy ground, 139 

 tor 9 cm waves, 143 

 saturated gi'ound, 140 

 sea water, 141 

 Electromagnetic waves, absoi-ption and 

 scattering by dielectric spheres, 

 150-154 



Fading in line-of-sight, 58-59 

 Fog 



attenuation of radio waves, 160 

 effect on radio transmission, 58 

 effect on S-band transmission, 50 

 Forecasting radio performance from 

 meteorological data 

 see Meteorology for forecasting radio 

 performance 

 Formulas 



angle-of-arrival, 207-208 

 atmosplieric absorption and scatter- 

 ing, 150-174 

 dielectric constants, 181-185 

 diffusion eqiiation, G3-05 

 electrical constants, 139 

 frequency dependence of sea eclio, 



196-197 

 gravitational waves, 92 

 humidity, relative and specific, 132 

 probability tliat given signal from 

 given target \\'\\\ he of given in- 

 tensity, 192 

 reflection of electromagnetic waves, 



139 

 refractive index, 73-78, 89 

 refractive index, modified, 132, 138 

 signal power dependence on receiver 



parameters, 197-198 

 temperature gradient, 59 

 Fresnel formulas for reflection of elec- 

 tromagnetic waves, 139 

 Friez Cycloray recorder, 104 

 Front, definition, 132 



Gas absorption of radio waves, 148-151, 



171 

 Grass-covered ground 

 dielectric constant, 143 



reflection coefficients, 142 

 Gravitational waves, 92-93 

 Gregory humidiometer, 98 

 Ground clutter, radar, 193-195 

 Groundsurfaces, effect on reflection, 146 



Hoyle's hypothesis, temperature lapse 



rate, 29 

 HRK (high sited K-band) receiver, 12 

 Humidiometer, 98 

 Humidity, effect on nonstandard pro]ia- 



gation, 120 

 Humidity measurements, equipment, 



97-98 

 Humidity terms (definition), 132 



Ice, dielectric constants, 184 

 Index of refraction 



.see Refractive index and M curves 

 Irish Sea transmission measurements, 

 47-52 



K-band transmission 



attenuation measurement apparatus, 

 178 



dielectric constant of steam, 185-186 



HRK receiver, 12 



rain absorption, 160-161 



raindrop attenuation, 148, 158, 164, 

 177-180 



receivers, 5 



sea echo, 196 



water vapor absorption, 175-177 

 Kite sondes, captive, 104-106 



Leeds and Northrup Speedomax, 104 

 Line-of-sight fading, 58-59 

 Liquid water, chelectric constant, 180- 

 184 



AI (modified refractive intlex) ciu'ves 



see Refractive index and M ciu'ves 

 Massachusetts Bay radio wave trans- 

 mission exjieriments, 3-18 

 Maximum range, radar transmission, 12 

 Meteorology 



air flowing over water, 66-67 



diffusion, low-level, 65-66 



diffusion equation, 63 



equilibrium, 67-69 



gravitational waves and temperature 

 inversions, 92-93 



refractive index, diurnal variation, 

 89-90 



refractive index, fluctuations near 

 land or sea, 90-92 



refractive index deficit, 67 



inversion surface, 71-73 



inversions, high, 69-71 



temperature and moisture distribu- 

 tion, 107-109 



warm air modification by a cold 

 water smiace, 63-65 

 Meteorology, measm-ing equipment, 

 97-l56 



anemometers, 99-100 



automatic recording of soundings, 

 104-106 



bulbs, wet and dry, 97-98 



captive balloon sondes and kites, 101- 

 104 



circuit design for resistor elements, 

 98-99 



measurements on board planes and 

 dirigibles, 101 



psychrographs, 7 



semipermanent installations, 100-101 



sling psychrometer, 97 



soundings, synthetic, 14 



tables for computing the modified in- 

 dex of refraction, 73-88 



temperature and humidity resistance 

 elements, 98 

 Meteorologj' for forecasting radio per- 

 formance, 47-60. 107-133 



computed chmatological information 

 on surface ducts, 126-128 



correlation between theories and ob- 

 servations, 54-56 



definition of terms, 130-133 



diurnal signal variations, 50, 53-54 



effect of fogs and fronts, 50 



effect of water vapor, 53-54 



overland propagation measurements, 

 52-58 



oversea propagation measurements, 

 47-52 



radar propagation, 109-118 



relationship between meteorological 

 elements and radar performance, 

 123-126 



seasonal signal variations, 50, 53-54 



soundings as guide to signal varia- 

 tions, 54 



temperature gradient as forecasting 

 basis, 56, 59-60 

 Meteorology of ocean ducts, 33-46 



leeward vs wndward measurements, 

 38, 42 



mean soundings, 41-43 



procedure, 33-39 



refractive index, 40-43 



sea temperatures, 42 



summary, 43 



wind sjjeeds, 41-43 

 Microwave transmission 



see Centimeter wave propagation; 

 Radio wave transmission 

 Mixing ratio, definition, 132 

 ML-24A psychrometer, 115, 117 

 MI^313/AM psychrometer, 116 

 Moisture distribution forecasts, 107-109 



National Physical Laboratory, Great 



Britain 

 centimeter wave propagation, 47-60 

 reflection coefficient measurements, 



147 

 Navy Radio and Sound Laboratory, 



balloon sonde, 102 

 Neoprene balloons for meteorological 



observations, 103 

 Noise figure, radar receiver, 199 



Ocean ducts, radio transmission in, 

 33-46 



