The Soil Moisture Active and Passive (SMAP) mission aims to gather high-resolution global soil moisture and freeze/thaw state data, which should enable improvements to weather and climate forecasts, flood prediction and drought monitoring, and estimations of net carbon dioxide (CO2) uptake in forested regions. Targeted for launch in 2014, SMAP is one of four missions recommended by the U.S. National Research Council Committee on Earth Science and Applications From Space for launch in the early part of the next decade (Earth Science and Applications From Space: National Imperatives for the Next Decade and Beyond, Natl. Acad. Press, 2007).
The SMAP mission concept utilizes an L-band (1.20–1.41 gigahertz) radar and a radiometer that share a rotating 6-meter mesh reflector antenna to provide high-resolution and high-accuracy global maps of soil moisture and freeze/thaw state every 2–3 days.