A Study of Sea Surface Wind Vector Estimation From Near-Nadiral Cross-Track-Scanned Backscatter Data

The possibility of recovering sea surface wind vectors from near-nadiral cross-track Ku- or Ka-band backscatter measurements using a measuring geometry similar to that of the Airborne Precipitation Radar 2 is discussed. The cross-track scanning geometry includes diversity in both elevation and azimuth angles, allowing the possibility of both wind speed and direction retrieval to within a 180 ^° direction ambiguity. A simulation study of wind vector retrieval accuracy is performed based on the use of the “cutoff-invariant two-scale model” of sea surface backscatter returns. The results show that a maximum likelihood retrieval approach utilizing data from the cross-track scan can provide reasonable wind vector retrieval accuracy.