E. J. Skudrzyk 225 
0.01 
0.0! 0.1 I 10 
kK/L -R 
Fig. 12.15. Scattering as a function of patch size. 
slab. For a computation of the fluctuations of the transmitted signal, at least 
the squares have to be retained in the exponent of the Rayleigh integral. 
In computing the amplitude of the transmitted signal, the receiver may be 
assumed to lie on the € axis ata distance L from the sound source. If the squares 
are retained in the exponent in the Rayleigh integral, the following expression 
is obtained for the mean-square scattered pressure after a laborious computa- 
tion [58, 12]: 
SP =F = 1) (60) 
The magnitudes /, and I, are given by 
hy = K2<a"> I ie sin 22P- R(t) dndéd€, dé. (61) 
a Hee ples v 2 tf 192 
For a parallel incident beam of sound, and for a Gaussian correlation function 
2a2seq eR? = SPs KA ty? + el /n? (62) 
I, = V7 <a?>k? RL 
and 
las psa > kOR® tan7! = (63) 
