428 SUBJECT INDEX 



Modified effective earth's radius method of computing refraction, 59-65 

 Modified index of refraction (M-unit), 14-15, 17-20, 193, 195, 324 



N 



A'^-unit (see Refractivity) 



NACA Standard Atmosphere, 16-17, 92-93, 186 



Nocturnal duct formation (see also Ground-based radio ducts), 133, 135 



Nonpolar gases, dielectric constant of, 2-3 



O 



Optical depth, 304 

 Outage time, 298-301 

 Oxygen 



absorption properties of (see Attenuation by gases) 



refractivity at STP, 9 



P 



Permeability of air, 3-4 



Pi-factors (turbulence parameters), 262-266 



Polar air mass (see Continental polar air mass) 



Polar front (see also Frontal zone), 195-197, 213 



Polar wave, 193, 195-197, 213 



Polar gases, dielectric constant of, 2-3 



Potential refractive modulus (<p-unit), 17, 19-20, 166, 193 



Pound oscillator (see Deam refractometer) 



Precipitation rate, 292 



Profile (gradient) classification (see also Air masses and Refractivity), 248-250 



Profiles of refractive index (see Refractive index, vertical profile of) 



Profiles of refractivity (see Refractivity, vertical profile of) 



Psychrometric equation, 12, 24 



R 



Radar 



applications involving (see also Rain attenuation), 49, 51, 56, 59, 61, 77, 340, 357 



anomalous propagation in (see Ducting) 

 Radiation, relative to duct formation, 133 

 Radiative transfer equation, 304 

 Radio 



duct (see Ducting) 



holes (see Ducting) 



horizon 



equation for, 59 



in ducting, 146-148, 152, 155, 157 



refractive index (see Refractive index) 

 Radiosonde (RAOB), 10-11, 26-30, 36, 38-43, 53-55, 59, 61, 70-72, 74-75, 79, 110- 



111, 135, 138-140, 144, 179, 181, 194, 205, 211, 213, 243, 246, 247-249, 251, 253, 



255, 258, 264, 280, 283, 326, 363, 375 



sensors in, 26-27, 29-30, 39-45 

 Rain attenuation, 292-297 

 Range 



errors (radio), 12, 174, 335-342, 345, 350-353, 356 

 definitions, 335-336 

 prediction of, 341, 345, 350-353 

 total, 335-337 



of a radio ray, 51, 335-336, 357-361 

 Ray tracing (see also Refraction), 52, 132, 135-136, 148, 322-323 



limitations of, 52, 132 

 Rayleigh-Jeans law, 304-305 

 Reflection coefficient (of an elevated layer), 185, 252-257 



models of, 252-257 

 Refraction (angular) of a radio ray, 14-15, 19-20, 49-87, 163-170, 178-181, 190, 192, 



236, 266, 311, 319-323, 326-337, 339, 341-350, 357, 375-396 



definition, 49 



derivation in terms of refractive index, 87 



