WindSat, a satellite-based multi-frequency polarimetric microwave radiometer developed by the Naval Research Laboratory for the U.S. Navy and the NPOESS Integrated Program Office (IPO), has collected more than four years of fully-polarimetric microwave measurements from space since its launch in 2003. The primary WindSat mission was to demonstrate the capability retrieve the ocean surface wind vector from a space-based microwave radiometer. The WindSat data is now being used to produce near-real-time products for the ocean surface wind vector, sea surface temperature (SST) and atmospheric columnar water vapor and cloud liquid water over the ocean at the U.S. Navy's Fleet Numerical Meteorological and Oceanographic Center (FNMOC). Several groups have worked on assimilating WindSat data products into numerical weather models with positive results.

While WindSat was designed to demonstrate the capability of polarimetric microwave radiometry to measure the ocean surface wind vector from space, it also provides many forms risk reduction for the NPOESS Microwave Imager Sounder (MIS). WindSat design and performance provide key information for specifying the MIS sensor. WindSat data serve as MIS proxy data for developing MIS algorithms and applications. Lastly, lessons learned from the WindSat development and operations serve to reduce the development risk of the MIS. This poster will describe the WindSat products and provide examples of WindSat risk reduction for MIS.