38. The program computes the first five moments of the distribution of 
sea surface elevations. It then edits the digital data file, checking for 
data points out of the O- to 5-V range and "jumps" and "spikes". A jump is 
defined as a data value in excess of 2.5 standard deviations from the previous 
data value, while a spike is a data value 5 standard deviations or more from 
the mean. If less than 5 jumps or spikes in a row are found, the program lin- 
early interpolates between acceptable data and replaces the erroneous data 
values. If more than 5 jumps or spikes in a row or a total of 100 bad data 
points for the file are found, the program stops interpolation and further 
editing, analyzes the data, and prints a flag indicating there is a problem 
with the file. If the variance is less than 0.001 me, the record is not anal- 
yzed. After editing, the first five moments of the distribution of sea sur- 
face elevations are again computed. A cosine bell data window was applied to 
increase the resolution for the energy spectrum of the file; use of the data 
window is discussed by Harris (1974). After application of the data window, 
the program computed the variance spectrum (energy spectrum) using the FFT 
procedure. After the data files were analyzed, the results were eliminated 
for files that were flagged as bad or appeared inconsistent with simultaneous 
observations from nearby gage sites. Frequently, the spectrum and/or distri- 
bution function of sea surface elevations were examined to determine if the 
data were acceptable. After the analysis results were edited, monthly sum- 
maries of wave heights and periods were generated for inclusion in summary 
reports. 
39. Unless otherwise specified, "wave height" means the energy based 
parameter H, defined as four times the standard deviation of the sea 
surface elevations. 
40. The wave period T is defined as the period associated with the 
maximum energy in the cHeeattien This is resolved by partitioning the spectrum 
into frequency bands of equal width and finding the band with the maximum 
energy density. The period reported is the reciprocal of the center frequency 
(e.g., Tp = 1/frequency), of the spectral band. Since the spectral bands are 
of equal frequency width, namely 0.010742 Hz (e.g., 11/1,024 sec), the 
analysis provides uniform resolution in frequency. However, the resolution in 
period is not uniform, since the period intervals become larger for lower 
frequencies. Due to the convention of reporting the period at the center of 
the interval, only a discrete set of period values is possible (Table 1). 
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