2.5 percent of the digital values in a record were determined to be bad, the 

 record was rejected as unsuitable for analysis; for a few bad data points, 

 the routine linearly interpolated between the erroneous values. If the rec- 

 ord was determined suitable for analysis, the distribution function of the 

 sea surface elevations and first five moments were computed. The variance 

 (second moment) and skewness (third moment) were checked to determine if full 

 analysis of the data record was warranted. Records with very low variance 

 values and excessively skewed distribution functions were not fully 

 analyzed. 



59. After it had been determined that the record justified full analy- 

 sis, a cosine bell data window was applied to increase the resolution for the 

 energy spectrum of the record (use of the data window is discussed by Harris 

 (1974)). After application of the data window, the program computed the vari- 

 ance spectrum (energy spectrum) using an FFT procedure. 



60. Significant wave height and peak spectral (or significant) period 

 provided a convenient way to characterize the wave conditions contained in the 

 data record and were more conducive to statistical summarization than the more 

 complete, but complex, description provided by the spectrum. 



61. Although significant wave height is defined as the average height 

 of the highest one-third of the waves in a record, experimental results and 

 calculations based on the Rayleigh distribution function show that the sig- 

 nificant height is approximately equal to four times the standard deviation 

 of the wave record (U. S. Army Corps of Engineers, Coastal Engineering Re- 

 search Center (CERC) 1977). The peak spectral wave period (also referred to 

 as the significant or peak period) for each digital record is defined as that 

 period associated with the maximum energy density in the spectrum (Thompson 

 1977). 



62. After 1 month of data had been analyzed, the significant wave height 

 and peak period values were segregated by gage and tabulated for visual edit- 

 ing. The editor checked for such things as unreasonable distribution of the 

 sea surface elevations; clipping of the crest or troughs; inconsistencies be- 

 tween successive observations; large trends in the 17-minute, 4-second data 

 record; and discontinuities in the data. After the data had been edited, 

 monthly summaries of significant height and peak period were generated for 

 inclusion in summary reports. 



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