Adapting the sir algorithm to ASCAT

Scatterometers have been launched primarily to measure ocean winds. The value of scatterometer data is increased by application of the SIR (Scatterometer Image Reconstruction) algorithm. The SIR algorithm enhances the effective resolution of the scatterometer data to support its use for other studies. SIR has been used successfully on several scatterometers, including QuikSCAT. In this paper, we describe how the SIR algorithm is adapted to ASCAT data. Using SZF data from ASCAT leads to the best resolution enhancement. SIR requires an estimate of the spatial extent for each measurement. We detail our method to estimate an approximate spatial response function for each ASCAT measurement. Finally, SIR parameters are tuned for use with ASCAT.