The NASA SMAP satellite took off for space on January 31, 2015 to study our planet's soil moisture and freeze/thaw state. Once in space, the satellite had to go through a prescribed series of steps to ensure that the spacecraft was functioning and all its instruments and components on-board were working properly. This took several months.
In mid-April 2015, NASA starting receiving its first soil moisture measurements from SMAP's combined high resolution radar and its high accuracy radiometer. The combination of this data produced a data resolution of approximately 8km. Unfortunately, SMAP's radar ceased operation on July 7, due to an on-board anomaly, resulting in SMAP getting all its data from the single radiometer. This meant that the resolution of the soil moisture data would be compromised, but high accuracy data remains to this day from SMAP.
The SMAP team is working closely with a European satellite called SENTINAL, that uses an on-board radar, and flies close to the SMAP satellite when it orbits the Earth. SMAP is hoping to use the SENTINAL radar data to bring back the high resolution soil moisture data.
Since April, NASA has gotten approximately 416GB of SMAP radiometer data that equated to about 13.3 million soil moisture measurements from the satellite.
Check out more SMAP information HERE!