Water Surface Wind Roughness from Ka-band

While many studies have been conducted regarding wind- and rain-driven Ka-band scattering on the ocean and sea surfaces, few have identified the impacts of Ka-band scattering on inland water bodies…
Wind impacts scattering on water surfaces by driving surface roughness. Rivers and lakes are subject to wind-driven capillary waves, larger wind-waves, and seiches, which cause surface roughness on varying wavelength scales depending on water body size and shape, atmospheric pressure, wind rate, direction, and timing.

We find that the significantly higher spatial resolution of AirSWOT data affords the assessment of scattering from water bodies much smaller than conventional altimetry (1 km2 vs 25 km2). Very small water bodies (<0.0625km2) have up to 5dB lower scattering than larger water bodies (>1km2). AirSWOT backscatter and coherence increase with increasing wind speeds, with ideal values for producing InSAR elevations when winds are greater than 3 m/s. Scattering from smaller water bodies increases with increasing wind speed at a similar rate as larger water bodies, and smaller water bodies maintain a consistently lower amount of scattering.

%d bloggers like this: