866 



BELL SYSTEM TECHNICAL JOURNAL 



taken with a 24-inch triangular reflector for several values of a. A wave- 

 length of 1.25 centimeters was used in obtaining both sets of curves. Later, 

 similar measurements were made at a wavelength of 3.2 centimeters. It 

 was found that the loss of signal is a function of the Imear error of the aper- 

 ture in wavelengths rather than the angular error in degrees. Thus a given 

 angular error in a 9f-inch reflector at a wavelength of 1.25 centimeters will 

 produce the same loss in signal as the same angular error in a 24-inch reflector 

 operating at a wavelength of 3.2 centimeters. 



89 90 91 



ANGLE, a, IN DEGREES 



ANGLE, 4) =0 DEGREES 



WAVELENGTH, A = 

 1.25 CENTIMETERS 



-50 -40 -30 -20 -10 10 20 30 40 50 



ANGLE, e, IN DEGREES 



Fig. 15 — Effect of an error in all three comer angles upon the performance of a trihedral. 



Spheres and Cylinders 

 Formulas for the effective areas of spheres and cylinders which have 

 dimensions large in comparison with a wavelength have been supplied by 

 J. F. Carlson and S. A. Goudsmit of the Radiation Laboratory.^ The 

 effective area of a sphere of radius R is given by 



where X is the wavelength. 



For a cylinder of radius R and height L, both large with respect to a wave 

 length, the effective area for rays perpendicular to the axis of the cylinder is 



/^ 



2 

 'Unpul)lishcd Report 



(4) 



A = L 



/'- 



(5) 



