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Biospheric Sciences
Operational

Soil Moisture Active-Passive Mission (SMAP)

The Soil Moisture Active Passive (SMAP) mission is an orbiting observatory that measures the amount of water in the surface soil everywhere on Earth. It was launched in January 2015 and started operation in April 2015. The SMAP radiometer has been operating flawlessly. The radar instrument, ceasing operation in early 2015 due to failure of radar power supply, collected close to 3 months of science data. The prime mission phase of three years was completed in 2018, and since then SMAP has been in extended operation phase.

Launch Date
January 31, 2015
Class
Flight Project
Websites
Key Staffs

The Soil Moisture Active Passive (SMAP) mission is an orbiting observatory that measures the amount of water in the surface soil everywhere on Earth. It was launched in January 2015 and started operation in April 2015. The SMAP radiometer has been operating flawlessly. The radar instrument, ceasing operation in early 2015 due to failure of radar power supply, collected close to 3 months of science data. The prime mission phase of three years was completed in 2018, and since then SMAP has been in extended operation phase.

Related Publications

2026. "Soil Carbon Assimilation Effectively Constrains Carbon‐Cycle Model Forecasting.", Journal of Geophysical Research: Biogeosciences, 131 (7): e2026JG009935 [10.1029/2026jg009935] [Journal Article/Letter]

2026. "Regulation of Transpiration and Whole‐Tree Crown Conductance in Tropical Forests.", Plant, Cell & Environment, pce.70719 [10.1111/pce.70719] [Journal Article/Letter]

2026. "Streamflow Calibration in Ungauged Basins Using SWOT Discharge and SMAP Surface Soil Moisture Products.", Water Resources Research, 62 (7): e2025WR041875 [10.1029/2025wr041875] [Journal Article/Letter]

2026. "A Global, Daily Carbon Budget for Terrestrial Ecosystems Constrained by Satellite Observations of Soil Moisture: The SMAP Level 4 Carbon Product at Ten Years.", Journal of Geophysical Research: Biogeosciences, 131 (6): e2025JG009588 [10.1029/2025jg009588] [Journal Article/Letter]

2026. "TEC Signature in Soil Moisture Active/Passive (SMAP) L-Band Microwave Radiometer Measurements.", IEEE Transactions on Geoscience and Remote Sensing, 64 1-7 [10.1109/tgrs.2026.3672714] [Journal Article/Letter]