KA-band Radar Onboard GPM Satellite Surface Wind Speed Algorithm

The data of Dual Frequency Precipitation Radar onboard Global Precipitation Measurement satellite is used to retrieve near surface wind speed. The radar operates in scanning mode. At nadir correlation of normalized cross section and wind speed is high, but at particular incidence angles tends to zero. To solve this problem, the following methodology is used. First normalised radar cross section at nadir is obtained for all the wide radar swath, second, wind speed is retrieved from this data. The algorithm was inspired by radar altimeter wind speed algorithm, but here we suggest a simpler parametrization. The wind speed model was built using National Data Buoy Center data on wind speed. Verification using ASCAT scatterometer data showed good results.