-1000 



t 



3.0 

 i 2.0 - 



U '0 



UJ 



z 0.0- 







96 

 ^l3 



I- o 



. a 



■s. 



-1-0 -| — I — I — I — I — I — I — I — I — I — I — I — I — I — I — I — I r 



20 40 . 60 80 100 120 140 160 180 



AZIMUTH (degrees) 



Figure E-1 Artificially generated surface composed of two identical 

 orthogonal trends, both with spectral slope b= -1.5, and 

 spectral intercept a= 1.0. Viewpoint is^from^ the 

 southwest. Below, the variation of parameters a and b are 

 shown versus azimuth. 



204 



