measured reflection coefficient, R,^. The comparison was performed 

 by evaluating the mean value of the quantity. 



R T.(R /R ) 



P 



N 



and its standard deviation, 

 R 



otjf) = ( 



N-1 



(128) 



2 1/2 

 E(<R /R > - R /R ) ^^^ 

 ^ m p m p -, 



(129) 



in which N is the number of experiments performed for a given value of 

 the slope. 



The data used for this comparison are presented in Appendix B, 

 and the results are presented in Table 2. 



Table 2. Comparison of measured and predicted reflection coefficients 

 of rough slopes. 



Slope 



ip from equation (126) 



(() from equation (127) 



tan 3 

 s 



<R /R > 

 ra ps 



o(R /R ) 

 ^ m ps-^ 



<R /R > 

 m p 



a(R /R ) 

 ^ m p-^ 



1 on 1.5 



0.92 



0.051 



0.89 



0.041 



1 on 2.0 



1.03 



0.059 



0.99 



0.053 



1 on 2.5 



1.06 



0.084 



1.05 



0.059 



1 on 3.0 



1.01 



0.083 



1.02 



0.064 



As is evident from the comparison in Table 2, the procedure is 

 quite accurate in reproducing the reflection coefficients obtained for 

 tanBg = 1/2.0 and 1/3.0 in spite of the scatter exhibited in Figure 22. 

 The procedure also predicts the reflection coefficients obtained for 

 tangg = 1/2.5 with a comparable degree of accuracy. Thus, for slopes 

 1/3.0 < tanBg < 1/2.0 the procedure is quite accurate in predicting 

 the reflection coefficient of rough slopes. The more elaborate 

 empirical formula (eq. 127) for the slope friction angle, c() , is 

 superior to the simpler formula (eq. 126) as could be expected. Howeverj 

 it is noted that even the simple formula leads to reasonably accurate 

 estimates of R. 



