We are actively developing an airborne system for the remote observation of short wind waves and near-surface currents. The system is comprised of a Freefly Alta X quadrotor and a gimballed payload containing multiple polarimetric cameras. In a single 20-minute flight, we are able to recovery the 2D wave slope field at wavelengths ranging from 3 mm to 30 m. This enables determination of the full directional spectrum of wind waves spanning the upper portion of the equilibrium range well into the capillary regime.
This field observation took place approximately 1 km off the coast of Rye, NH in Summer 2023. Slope fields were dynamically rectified to earth coordinates by 3D rotations corresponding to camera pitch, roll, and yaw. Additional motion correction (leveraging the full-frame oscillation as detected from the observed wave celerity) is currently being developed to mitigate residual motion contamination.