226 



INDEX 



electrical characteristics of elements, 

 104-105 



electronic amplifiers, 105-106 

 Reflection coefficient, 137-147 



calculation by ray diagrams, 26-28 



correlation with angle-of-arrival, 206 



dependence on thickness of wave- 

 length, 21-22 



fresh water pond, 141 



grass-covered gnnuid, 142 



index of refraction, 22-23 



land at centimeter wavelengths, 147 



phase angle shift, 144 



saturated ground, 140 



S-band transmission, 137-147 



sea and land experiments, 144 



sea water, 141 



specular reflection and scattering, 

 146-147 



tap water, 141 



vegetation, 142, 147 



very dry sandy ground, 139 

 Reflection-transmission method of de- 

 tennining dielectric constant, 180 

 Refractive index and M curves 



correlation with, height of antennas, 

 17-18, 32 



correlation with 117 nic radio trans- 

 mission, 14-18 



deficit, 67 



definitions, 130-133 



diurnal variation, 89-00 



effect of temperature inversion, 29-32 



eflfect on electromagnetic waves, 120 



fluctuations near land or sea, 90-92 



forecasting, 111-112 



in radio wave transmission, 22-23 



isopleths, 72 



M curve, 121-123 



M curve variations and radio signal 

 strengths, 10 



M curve versus wind speed, 42-43 



M fomiula, 132 



meteorological measurements for 

 computation of M, 5 



modified index B, 17 



of ocean ducts, 40-43, 120-123 



psychrometric nomograms, 132 



surface trapping, 122 

 Refractive index and M curves, tables 

 for computing, 73-88 



constants of formula, 77 



formula, 73 



mixing ratio and tempcratiu'e, 74-77, 

 84-88 



pressure versus height, 77 



relative humidity and temperature, 

 74^76, 78-83 



use of tables, 74-75 



vapor pressure and tem]3erature, 74 

 Relative humidity, definition, 132 

 Research recommendations for fore- 

 casting radio performance from 

 meteorological data, 54-55, 117- 

 118 

 Resistors, temperature sensitive, 98 

 Rye towers, meteorological measure- 

 ments, 100 



Sanborn ceramic resistance element, OS 

 San Diego radio wave transmission ex- 

 periments, 19-28, 69-73 

 Saturated gromid, reflection coeffici- 

 ents, 140 

 S-band transmission 



absorijtion, 147 



antennas, 33-34 



dielectric constant of steam, 185-188 



meteorological factoi-s, 50-52 



radar echoes, fluctuations, 191 



radar echoes from snow, 189 



rain attenuation, 148, 165, 180 



random scatterers, 192 



receivers, 5, 34 



reflection coefficients, 137-147 



sea echo, 190 



signal strengths, 9-11 



signal types, 7-9 



transmitters, 4 

 S-band transmission in ocean ducts, 

 33-46 



characteristics of ocean ducts, 39-43 



effect of antenna height, 37-39, 44-45 



effect of antenna location, 37-38 



experimental jirocedure, 33-39 



summary, 43-46 

 Scanning rate, radar, 200 

 Scattering by the atmosi)here 



sec Atmospheric absorjition and scat- 

 tering 

 Scattering cross section of spherical 



water drops, 166 

 Sea echoes, 195-197 



calm sea, 196 



cause, 195, 197 



effect of wavelength, 196 



plumes, 107 



stormy sea, 106 



video frec]uency sijectruni, 193 

 Sea surface, effect on air, 124 

 Sea temperatvn-e in ^^'est Indies, 40, 42 

 Sea water, reflection coefficients, 141 

 Seasonal variations in radio transmis- 

 sion, 9, 50, 53-54 

 Signal threshold power, radar, 108-201 



factors affecting, 109 



measurements, 198 



noise figure, 199 



pulse repetition rate, 201 



radio frequency bandwidth, 109 



sweep speed of scojie, 199-200 



video bandwidth, 199 

 Sling psychrometer, 97 

 Snow attenuation of radio waves, 165 

 Snow detection by radar, 189 

 Soil temperature, diurnal variation, 



29-32 

 Sondes, captive balloon, 101-104 



cable and balloon techni(|ue, 103-104 



radio transmission t\^)e, 101-102 



wired transmission typo, 102-103 

 Sounding equi]Hnent for meteorological 



observations, 5, 34-42, 101-104 

 Specific humidity, definition, 132 

 Specular reflection, 146, 147 

 Speedomax, Leeds and Xorthrui), 104 



Sj)hcrical ])articles, scattering and ab- 

 sorption of radio waves, 150-154 



Spherical raindrops 



attenuation of radio waves, 157-159 

 effect of size on scattering, 166 

 scattering cross sections, 166 

 scattering of microwaves, 165-167 



Standard atmosphere, definition, 130 



Standing wave ratio method of deter- 

 mining dielectric constant, 181 



Steam, dielectric constant, 185-186 



Storm detection by radar, 187-190 

 best frequency, 188 

 correlation of echoes with weather 



conditions, 187-188 

 fraction of rainfall detected, 188 

 procedures, 187 

 range, 189 



S-band echoes from snow, 189 

 weather informaticjn facilities, 187 



Subsidence, definition, 133 



Target speed, effect on radar signal de- 

 tection, 202 

 Temperature 



effect on duct formation, 119-120 



effect on nonstandard ranges, 59-60 



forecasts, 107-109 



gradient as basis for radio perform- 

 ance forecasting. 56, 59-60 



"wet bulb" temperature, 132 

 Temperatiu'e inversions 



characteristics, 89 



effect on one-wav radio tranmission, 

 20-21 



effect on radio wave refraction index, 

 29-32 



meteorological analysis, 92-93 

 Temperatiu-e-sensitive resistors, 98 

 Thermometei's, wet and dry bulbs, 07 

 Trade ^^•ind areas, meteorology 



SVC Ducts in the trade wind regions 

 Transmitters for use in radio transmis- 

 sion experiments, 3-4, 19 

 Trapping of radio wa\-es, 20-26 



ray theory, 20-21 



reflection theory, 21-23 



summary, 23-26 



wave guide theory, 21 



Ultra Short Wave Propagation Panel, 47 



Vapor pressiu'e gradients, 89 

 Vegetation, effect on reflection, 142, 147 

 Video band^vidth, radar, 199 



Washington State College, tempera- 

 ture-sensitive resistors, 08, 101 

 Water, dielectric constant, 156 

 Water vapor 



attenuation coefficient, 177 

 attenuation of radio waves, 185 

 effect on overland radio transmission, 

 53-54 

 Watson effect, radar, 202 

 Wave guide theory of radio wave travel, 



21 

 W'eather, substandard, effect on radar 

 transmission, 13 



