Estimating Infragravity Wave Properties from Pressure-Current Meter Array Observations

A new method for estimating infragravity wave properties from a two-dimensional horizontal array of pressure and current meters is developed. At each frequency the mix of progressive and standing (in the cross-shore direction) waves is determined by a least squares fit to the observed cross-spectral matrix. The method yields estimates of edge wave shoreline amplitudes and of the propagation directions and cross-shore structure of progressive waves. Observations from an array spanning depths between 1–5 m are used to illustrate the method, and preliminary results suggest that progressive and standing (both trapped and leaky) waves both contribute substantially to the infragravity wave field.