The Soil Moisture Active Passive (SMAP) "Disaggregated Brightness Temperature 9 km (L3, Active/Passive, V Polarization)” layers display brightness temperatures (TBs) in Kelvin (K) posted on a 9 km EASE-Grid 2.0 for the vertical (V) polarization from the SMAP radiometer. The TBs are adjusted for the presence of water bodies and disaggregated from the 36 km EASE-Grid 2.0 cells into 9 km grid cells. At the L-band frequency used by SMAP, the TB of the land surface is proportional to its emissivity multiplied by its physical temperature.

The SMAP spacecraft carries two instruments, a radar (active) and a radiometer (passive), that together make global measurements of land surface soil moisture and freeze/thaw state. It is useful for monitoring and predicting natural hazards such as floods and droughts, understanding the linkages between Earth’s water, energy and carbon cycles, and reducing uncertainties in predicting weather and climate.

References: SMAP L3 Radar/Radiometer Global Daily 9 km EASE-Grid Soil Moisture

Data field: tb_v_disaggregated