Recent Advances in Profile Soil Moisture Retrieval

Remote sensing provides a capability to make frequent and spatially distributed measurements of surface soil moisture, whilst recent advances in affordable Time Domain Reflectometry probes allow continuous monitoring of profile soil moisture at specific points. We believe that reliable estimation of the spatial and temporal variation of profile soil moisture on a routine basis will require a combination of calibration and evaluation of an unsaturated soil moisture model using point measurements, and model updating using remote sensing observations to account for spatial inhomogeneities. This study investigates which of two commonly used assimilation techniques is most efficient for the retrieval of soil moisture and temperature profiles, over what depth soil moisture observations are required, and the effect of update interval on profile retrieval. These questions are addressed through a desktop study using synthetic data