A Decade of Global Water Cycle Monitoring: NASA Soil Moisture Active Passive Mission

Introduction The NASA Soil Moisture Active Passive (SMAP) mission, launched in 2015, has over 10 years of global L-band radiometry observations. The low frequency [1.4 GHz frequency or 21 cm (8 in) wavelength] measurements provide information on the state of land surfaces in all weather conditions – regardless of solar illumination. A principal objective of […]

Published by NASA on 08/18/2025