NOAA Office of Satellite and Product Operations

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UHR Winds Algorithm

For Ultra High Resolution (UHR) wind retrieval the ASCAT SZF measurements are processed using the AVE algorithm (the first iteration of the SIR algorithm) from single passes, separately for each beam. The geometry information is retained. Then, the standard KNMI wind retrieval algorithm is applied at each pixel of the set of multi-azimuth images to estimate the wind speed and direction and each 4.45 km wind vector cell (pixel). The UHR winds are noisier than conventional 25 km winds, but have higher spatial resolution. Near the coastline, the estimated winds can be contaminated by proximity to land, causing the retrieved wind speeds to appear excessively high. Note that UHR winds are not currently rain flagged. Rain generally causes the wind speed to appear higher than it should but it can also cause the wind speed to appear reduced.