SMAP Level 4 Carbon (L4_C) project
SMAP is one of four first-tier missions recommended by the National Research Council's Committee on Earth Science and Applications from Space (Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, Space Studies Board, National Academies Press, 2007). SMAP data have both high science value and high applications value. The accuracy, resolution, and global coverage of SMAP soil moisture and freeze/thaw measurements are invaluable across many science and applications disciplines including hydrology, climate, carbon cycle, and the meteorological, environmental and ecology applications communities.
Future water resources are a critical societal impact of climate change, and scientific understanding of how such change may affect water supply and food production is crucial for policy makers. Current climate models uncertainties result in disagreement on whether there will be more or less water regionally compared to today; SMAP data will enable climate models to be brought into agreement on future trends in water resource availability. For these reasons, the Committees Water Resources Panel gave SMAP the highest mission priority within its field of interest.
The SMAP instrument includes a radiometer and a synthetic aperture radar operating at L-band (1.20-1.41 GHz). The instrument is designed to make coincident measurements of surface emission and backscatter, with the ability to sense the soil conditions through moderate vegetation cover. The instrument measurements will be analyzed to yield estimates of soil moisture and freeze/thaw state. The antenna scan has a swath width of 1000 km providing global coverage within 3 days at the equator and 2 days at boreal latitudes (>45 degrees N).