NASA SOIL MOISTURE ACTIVE PASSIVE MISSION STATUS AND SCIENCE PERFORMANCE

The Soil Moisture Active Passive (SMAP) observatory was launched January 31, 2015, and its L-band radiometer and radar instruments became operational during April 2015. The SMAP radiometer has been operating flawlessly, however the radar transmitter ceased operation on July 7. This paper provides a summary of the calibration and validation of the SMAP instruments and the current quality assessment of its soil moisture and freeze/thaw products. Since the loss of the radar, the SMAP project has been conducting two parallel activities to enhance the resolution of its soil moisture products. The first explores the Backus Gilbert optimum interpolation and de-convolution techniques based on the oversampling characteristics of the SMAP radiometer. The second investigates the disaggregation of the SMAP radiometer data using the European Space Agency's Sentinel-1 C-band synthetic aperture radar (SAR) data to obtain soil moisture products at about 1 to 3 km resolution. In addition, SMAP's L-band data have been found useful for many applications, including vegetation opacity, ocean surface salinity and hurricane ocean surface wind mapping. Highlights of these new applications will be provided.