SUBJECT INDEX 427 



Fog attenuation, 303 



Four-thirds earth (see also Effective earth), 14-15, 20, 51, 57, 59-60, 62, 66-75, 



247, 360 

 Fresnel discontinuity value, 252, 257 

 Frontal zone, influence on refractivity, 176-177, 187-193, 195-224, 323 



G 



Geometric range, 335, 357 



Gradient of refractive index (see Refractive index) 



Gradient of refractivity (see Refractivity) 



regression expressions for, 363-364, 372 

 Graphical method of computing refraction, 80-81, 375, 380-381 

 Ground-based radio ducts (see also Ducting), 42-44, 132-163, 324, 328, 333, 375 



frequency of occurrence, 140-141 



thickness of, 140, 143-145 

 Ground-based superrefractive layers, 250 



H 



//-parameters, 265 

 Hail attenuation, 302-303 

 Half-length, 150-154, 160 

 Hay refractometer, 36-37 

 Height errors, 356-357, 360-373 



definition, 356, 360 



regression equations for, 364-372 

 High angle approximation for computing refraction, 53-54 

 Horizontal homogeniety, assumption of, 49, 52, 163, 322 

 Horizontal inhomogenieties, 52, 322-333, 356 

 Horizontal ray, 329 



I 



ICAO Standard Atmosphere, 9, 11, 312-314 



Initial gradient of refractivity {see Delta-A'^ and Refractivity) 



Intensity factor, 273-274 



Inversions (see Ducting and Elevated layers) 



K 



ii:-unit, 180, 182, 239-240 



L 



Lag times, 29, 38-45 



in electrical thermometers, 26 



of relative humidity sensor in radiosondes, 39, 41-45 



of temperature sensor in radiosondes, 39, 41-45 

 Land breeze, relative to duct formation, 134-135, 323 

 Level of nondivergence, 183 

 Lifting condensation level, 260 



Line widths of atmospheric gaseous absorption (see also Attenuation), 272-275 

 Lithium chloride humidity strip, 26, 28-29, 39, 45 



M 



il/-parameter {see Thermal stability) 



Macroscale fluctuation of refractive index, 173, 223 



Maritime polar air mass, 79, 114, 169, 179, 197 



Maritime tropical air mass, 79, 102, 119, 125-126, 164, 167, 169, 174, 177, 179-181, 



201, 213, 221-222, 319 

 Maximum wavelengths trapped by a duct, 141-143 

 Mesocale fluctuation of refractive index, 173, 185, 223 

 Microscale fluctuation of refractive index, 173 

 Mixing ratio, 260 

 Models 



of atmospheric absorption structure, 283 

 of atmospheres, 9, 11, 16-17, 64, 92-93, 180, 186, 312-314 



of refractivity structure, 13-20, 40-41, 51, 56-80, 92-93, 106, 110, 149, 153-156, 

 164, 166-170, 174, 176-177, 180, 186, 189-195, 197, 213-227, 244-245, 250, 

 261-264, 311-322, 329, 331-332, 357, 360-362, 375-378, 381, 385-389, 

 393-396 



