appears to be less than six seconds, with more energy evident in the incident spectrum.
To calculate a transfer rate for the hourly incident waves, the transferred record within
15 minutes of the top of the hour was selected.
A transfer coefficient spectrum, (xf) can be calculated by dividing the transferred
energy at each frequency by the corresponding incident energy, eqn.2.
Etf
xf =
(2)
Eif
per frequency.
Figure 6 shows the corresponding hourly xf spectrums for figure 5. For most fre-
quencies during this time period, the transferred energy is less than 100%. However,
there is substantial increase in energy in the 6.5 second range, about 500%.
For more information, contact: James P. McKinney or Margaret A. Sabol, CEERD-
HC-SO
References
[1] P. D. Welch, "The Use of Fast Fourier Transform for the Estimation of Power
Spectrum: A Method Based on Time Averaging Over Short, Modified Peri-
odogams," IEEE Transactions on Audio and Electroacoustics, June 1967.
3
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