GLOSSARY 



A. 



Ao. 



A,. 

 Ap. 

 A. 



b. 

 B. 

 c. 



C,C{v). 

 d. 



do. 

 di^di. 



dT,dR. 



dh. 



D. 



E. 



E„. 



E,. 

 /. 



fe- 

 rn, 

 u 



Fn. 



Fs. 

 Fs'- 



.9- 



O,. 



1) Radius of the earth 



2) Radius of scattering plate, sphere, or cyhiider 

 Gain factor = A^Ap 



Gahi factor for doublet antennas in free space, 

 adjusted for maximum transfer of power = 

 3\/8ird 



Plane-earth factor 



Path-gain factor 



Gain-factor curve parameter 



di — & 

 ~ di + d. 

 Bandwidth 



1) Velocity of light in free space 



hi — h2 



hi + hi 

 Real part of Fresnel's integral 



Distance from center of transmitting antenna to a 

 point in space measured along the surface of the 

 earth 



Free-space distance for field of strength E 



Normahzed free-space distance 



dr 



Distance from transmitter, receiver to reflecting 

 point measured along the earth's surface 



Distance from transmitter, receiver to the radio 

 horizon measured along the earth's surface 



Line of siglit distance measured along the earth's 

 surface = dr + d^ 



Maximum radar range 



1) Divergence factor for spherical earth 



2) Aperture of reflector 



1) Water- vapor pressure 



2) Coefficient for height-gain function 

 Electric-field strength 



Maximum free-space field strength of a doublet 

 transmitter at distance d 



Radiation field strength at one meter from trans- 

 mitter 



1) Frequency 



2) Focal length of paraboloid reflector 

 Cutoff frequency of a wave guide 

 Height-gain function 



Height-gain function for the w*'' mode 



Fraction of maximum radiation field strength in the 



direction of direct, reflected rays 

 Noise figure 



Shadow factor for the first mode 

 Sum of shadow factors for all modes 



1) Receiver gain 



2) Exponential factor of height-gain function for 



elevated antennas 

 Correction to y(2) 

 Transmitting antenna gain 

 Receiving antenna gain 



Gr. Radar gain of a target 



h. Height above ground 



hiih-!. Height of transmitter, receiver above ground 



hi, hi'. Height of transmitter, receiver above tangent plane 



at point of reflection 

 h,.. Critical height distinguishing high and low antennas 



located in diffraction region = SOX^''^ 

 /jo- Virtual height of obstructing screen 



H. 1) Magnetic field strength 



2) Height of a reflecting or diffracting obstruction 

 Hl- Height-gain function for low antennas 



HA. Hour angle of the sun 



I. RMS current 



li. Input current to antenna or circuit 



i. ^^ 



h. 1) Boltzmann's constant 



2) Factor multiplying earth's radius to account for 

 atmospheric refraction 

 K. 1) Amplitude of generalized reflection coefficient 



2) Echo constant of a target 



I. I) Length of a doublet 



2) Height coefficient to include effect of earth's 

 constants and wavelength 

 L. 1) Effective length of a doublet 



2) Characteristic length or scattering coefficient of 



a target 



3) Radar length of a target 



m. 1) Ratio of radius of curvature of a ray to the radius 



of the earth = p 'a 



d' 



2) TO = 



4:ka{hi + hi) 

 M. Modified index of refraction 



n. 1) Index of refraction 



2) Number of elements in an antenna array 

 7i',n" Lobe numbers 



N. Lobe variable for imi:)erfect reflection 



NF. Noise figure 



p. 1) Total pressure of the atmosphere 



2) Dimensionless parameter = di/dr 

 p'. Distance coefficient to include earth constants 



P. Power 



Pi. Power output of a transmitting doublet 



Po. Power delivered by a receiving doublet to a matched 



load 

 Pmin. Minimum power detectable by a receiver 

 Pn. Noise power 



Pr. Power received by load circuit of receiving antenna 



P,. Scattered power 



q. Dimensionless parameter = d^/d 



Q. Parameter determining phase of beam reflected by 



the earth 



60 aX 



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