(Woods Hole Oceanographic Institution, 1963-06)
Stevens, Raymond G.
A mathematical model, consistent with certain physical features of ocean waves may be constructed by superposition of long crested sinusoidal gravity waves. Such a model, as proposed by Pierson (1955) and Longuet-Higgins (1957), depends upon the random superposition of the component waves, so that the interpretation of ocean wave measurements must be regarded as a statistical problem.
Barber (1958) has suggested that measurement of sea surface elevation as a function of time at several points along a line array may be used to deduce the distribution of energy with regard to frequency and direction of the component gravity waves. In fact, by preserving the time relationship among the signals from several detectors in a line array , the array need not be physically rotated to examine component gravity waves coming from various directions.
After developing the physical basis and mathematical notation for a stochastic model of ocean waves the limitations and potential errors in the measurement and calculation of directional spectra from finite and discrete data are discussed.
Finally, some directional spectra calculated from measurements of wind generated waves in Buzzards Bay, Massachusetts are presented without attempting interpretation.
