426 SUBJECT INDEX 



Correlation of field strength with meteorological parameters, 105, 174, 229, 233-266 



Crain refractometer, 31-33 



Cross-over height, 248-249, 263-264 



CRPL Reference Atmosphere {see Exponential atmosphere model for refractivity) 



CRPL Standard A^-profile Sample, 335, 338-353, 355-356 



Curvature of radio ray, 13, 42, 56, 264, 360-361 



D 



Deam refractometer, 36-37 



Delta-A'^ (A N) {see also Refractivity, vertical gradient), 15-16, 61, 63-66, 73-76, 



106, 129-131, 139, 229-230, 342, 363, 365, 371, 373, 389, 394-396 



as a field strength predictor, 234-238, 240, 243-244, 246, 264-266 



usage for 24-hour horizontal changes, 201-204, 209-211 

 Departures-from-normal method of computing refraction, 77-79, 167-168, 181, 190- 



191, 375, 378-379, 381, 392-393 

 Dielectric constant of air {see also Refractive index), 2-8, 12 

 Dispersion, 5, 8 



Diurnal index (diurnal ratio), 129-130 

 Diurnal range 



of field strength, 105, 235-236 



of A^o, 111-121, 129-130, 204 

 Divergence 



centers of, 182, 240-241 



influencing atmospheric refractivity, 182-185, 240 

 Drop size distribution, 292, 294-297 

 Dropsonde, 36 

 Dry term 



of atmospheric absorption, 283 



of the Smith- Weintraub equation, 30, 91, 93-94, 136, 174-175, 311-322 

 scale heights of (see Scale height) 

 surface values of, 93-94, 311-312, 320 

 Ducting, 42-45, 52, 89, 132-163, 241-246, 248, 324, 328, 331-333, 376 



E 



Effective earth, 13-15, 51, 56-62, 64-65, 106, 189, 195, 250, 264, 359-362 



curvature, 13, 56-57, 62, 106, 195, 361 



method of calculating refraction, 56-59 



radius, 13-15, 51, 56-57, 59-62, 64-65, 106, 189, 195, 250, 264, 359-362 

 Elevated layer, 241, 244-258, 324-329, 331 



reflection coefficient of, 252-257 

 Elevation angle (see also Refraction) 



approximation for, 82-83 



definition, 49-50 



errors, 49-50, 178, 333-335, 340-342, 344-345, 348-350, 356, 404, 420-422 

 prediction of, 174, 334, 340-342, 344-345, 348-350, 356, 404, 420-422 

 Epoch chart, 221-227 

 Equation of continuity, 183 

 Equivalent gradient, 236-239, 243, 246, 264-266 



as a field strength predictor, 236-239, 243, 246, 265 



method of calculation, 264 

 Exponential atmosphere models 



for absorption, 283 



for refractivity, 15-20, 56, 61, 63-80, 92-93, 106, 110, 149, 153-156, 164, 166- 

 167, 174, 176-177, 186, 189-190, 192-194, 244-245, 261-263, 311-322, 

 329-332, 357, 362, 375-378, 385-389, 393-396 



in radiosonde correction process, 40-41 



method of computing refraction, 375-377, 385-388 

 Eta {t)) parameter, 238-239 



F 



Fading (see also Field Strength), 146-163, 223 



caused by ducting, 146-163 



definitions, 147 



due to rainfall attenuation, 298-302 

 Field strength 



prediction from radio meteorological parameters, 89, 105-106, 109, 174, 177-180, 

 229-236, 238-251, 253-258, 263-266 



