On Surface Gravity Wave Spectra Observed in a Moving Frame of Reference

摘要

Spectral analyses of one- or two-dimensional records of sea surface elevation yield one- or two-dimensional encounter spectra that are, in fact, weighted integrals over the two-dimensional surface wave spectrum. These integral relationships are determined by the type of record and the motion of the observer relative to the water on which the waves are running. The author derives the relevant relationships for uniform translation of the observer at arbitrary velocity and for arrays of discrete or linearly distributed sensors. The problem of estimating the wave spectrum, given the encounter spectrum, is considered in detail for the two cases exemplified by a wave gage array in a current and by a side-looking surface-imaging radar.