Remote Sensing of Soil Moisture

Olivier Merlin, Jeffrey Walker and Yann Kerr

Power Point Presentation

Soil moisture is a key variable of the terrestrial biosphere, controlling the partitioning of available incoming energy into latent and sensible heat flux and the partitioning of rainfall into runoff and infiltration. Soil moisture measurement over large areas (national or global) and with a repeat time consistent with hydrological processes (~1 day) is possible only through the use of L-band microwave radiometers. The Soil Moisture and Ocean Salinity (SMOS) mission (, to be launched in 2008, is the first soil moisture-dedicated satellite based on L-band radiometry. In preparation for SMOS, the National Airborne Field Experiments (NAFE were conducted in the Goulburn River catchment during November 2005 and in the Murrumbidgee River catchment during November 2006. These two month-long NAFE data sets are being used to test soil moisture retrieval algorithms from the paddock scale to the satellite scale, and develop downscaling and assimilation techniques of remote sensing observations. This talk will discuss how these developments can be used to improve predictions of the hydrologic impacts of climate change.