Sea state from single optical images: A methodology to derive wind-generated ocean waves from cameras, drones and satellites

Rafael Almar; Erwin W. J. Bergsma; Patrico A. Catalan; Rodrigo Cienfuegos; Leandro Suarez; Felipe Lucero; Alexandre Nicolae Lerma; Franck Desmazes; Eleonora Perugini; Margaret L. Palmsten; Chris Chickadel

doi:10.3390/rs13040679

USGS · 70236572

Sea state from single optical images: A methodology to derive wind-generated ocean waves from cameras, drones and satellites

Rafael Almar·Erwin W. J. Bergsma·Patrico A. Catalan·Rodrigo Cienfuegos·Leandro Suarez·Felipe Lucero·Alexandre Nicolae Lerma·Franck Desmazes·Eleonora Perugini·Margaret L. Palmsten·Chris Chickadel

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Abstract

Sea state is a key variable in ocean and coastal dynamics. The sea state is either sparsely measured by wave buoys and satellites or modelled over large scales. Only a few attempts have been devoted to sea state measurements covering a large domain; in particular its estimation from optical images. With optical technologies becoming omnipresent, optical images offer incomparable spatial resolution from diverse sensors such as shore-based cameras, airborne drones (unmanned aerial vehicles/UAVs), or satellites. Here, we present a standalone methodology to derive the water surface elevation anomaly induced by wind-generated ocean waves from optical imagery. The methodology was tested on drone and satellite images and compared against ground truth. The results show a clear dependence on the relative azimuth view angle in relation to the wave crest. A simple correction is proposed to overcome this bias. Overall, the presented methodology offers a practical way of estimating ocean waves for a wide range of applications.

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Rafael Almar, Erwin W. J. Bergsma, Patrico A. Catalan, Rodrigo Cienfuegos, Leandro Suarez, Felipe Lucero, Alexandre Nicolae Lerma, Franck Desmazes, Eleonora Perugini, Margaret L. Palmsten, Chris Chickadel. 2021-02-13. Sea state from single optical images: A methodology to derive wind-generated ocean waves from cameras, drones and satellites. https://doi.org/10.3390/rs13040679

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