where 



« = 1 « = 1 



fei 



are the observed amplitudes of the cosine and sine components. The amplitude 

 and phase spectra are given by 



A(w, z) 



(\l A„W„fe;|l[s B,W„fefp fo,^^^^ 



,2) = 



elsewhere 



arctan ^^^"^ 

 not defined elsewhere 



(33) 



for CO = 



where A(a),z) is the amplitude density and should not be confused with A^ 

 A schematic of the amplitude A{co,z) is given in figure 3. 



»- PERIOD 



I A„W Jz) 



A. A SPECTRUM AT AN 

 ARBITRARY LEVEL z. 



B. VERTICAL DISTRI- 

 BUTION OF THE 

 AMPLITUDE 



Figure 3. Schematic diagram of an observed amplitude distribution A W (z) at an anchor 

 station (eqn. 32) • 



16 



