Maps of global soil moisture were created using data from the radiometer instrument on NASA's Soil Moisture Active Passive (SMAP) observatory. Each image is a composite of three days of SMAP radiometer data, centered on April 15, 18 and 22, 2015.
Retrieved soil moisture based on both simulated “active” radar and “passive” radiometer data over three spacecraft swaths. The SMAP Testbed facility hosted the simulations, retrievals, and the presentation tools that yielded this output.