Harvest Platform Frequency-Direction Spectrum 

 Date: 19 Jun 94 at 1702 GMT for 136.53 min with 160 dof 

 H m „ = 1.40 m f = 0.113 Hz T p = 8.87 sec B f = 42.0 deg 

 depths: min = 202.42 m mean = 202.72 m max = 202.97 m 



Figure 3. Autospectral intercomparison and frequency-direction spectral 

 estimate 



where Re[ ] and Im[ ] are the real and imaginary parts, respectively, of the entity 

 contained in square brackets. 



Signals from multiple pairs of gauges having redundant lag (or spatial separa- 

 tion) vectors in a uniform wave field are expected to have identical cross spectra. 

 In the Harvest Platform array there are several such sets of pairs as can be seen in 

 Figure 2. In terms of coherences and phases, one would expect 



r 14 c/-„) = r 23 c/„) = r 56 (f n ) 



4>u(f n ) - ^C/".) = 4> 56 (/ n ) (4) 



Chapter 3 Primary Data Analysis 



