lightning damage, but protective measures have been taken to minimize such 
occurrences. A more complete description of the gages’ operational charac— 
teristics is given by Grogg (1986). 
Buo age 
31. One Datawell Laboratory for Instrumentation (Haarlem, The Nether-— 
lands) Waverider buoy gage (Gage 630) measures the vertical acceleration pro— 
duced by the passage of a wave. The acceleration signal is double—integrated 
to produce a displacement signal transmitted by radio to an onshore receiver. 
The manufacturer stated that wave amplitudes are correct to within 3 percent 
of their actual value for wave frequencies between 0.065 and 0.500 Hz 
(corresponding to 15- to 2—sec wave periods). The manufacturer also specified 
that the error gradually increased to 10 percent for wave periods in excess of 
20 sec. The results in this report were not corrected for the manufacturer's 
specified amplitude errors. However, the buoy was calibrated semiannually to 
ensure that it was within the manufacturer’s specification. 
Pressure gage 
32. One Senso—Metrics, Incorporated (Simi Valley, CA), pressure trans— 
duction gage (Gage 111) installed near the ocean bottom measures the pressure 
changes produced by the passage of waves creating an output signal that is 
linear and proportional to pressure when operated within its design limits. 
Predeployment and postdeployment precision calibrations are performed at the 
FRF using a static deadweight tester. The sensor's range is 0 to 25 psi 
(equivalent to 0- to 17-m seawater) above atmospheric pressure with a manufac— 
turer-stated accuracy of +0.25 percent. Copper scouring pads are installed at 
the sensor’s diaphragm to reduce biological fouling, and the system is 
periodically cleaned by divers. 
Digital Data Analysis and Summarization 
33. The data were collected, analyzed, and stored on magnetic tape 
using the FRF’s VAX computer. Data sets were normally collected every 6 hr. 
During storms, the collection was at 3-hr intervals. For each gage, a data 
set consisted of four contiguous records of 4,096 points recorded at 0.5 Hz 
(approximately 34 min long), for a total of 2 hr and 16 min. Analysis was 
performed on individual 34-min records. 
34. The analysis program computes the first moment (mean) and the 
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