The assessment of the spatial distribution of soil water content could improve the effectiveness of agro-hydrological
models. Although it is possible to retrieve the spatial distribution of the soil water content using thermal inertia, the main
limit is its applicability to bare soils only. Recently, a variation of the thermal inertia approach has been setup also on
vegetated soils characterized by low fractional cover. In particular, the methodology proposes to attenuate the solar
radiation at the top of the canopy to the one reaching the soil trough an extinction factor.
In situ data were acquired in June 2011 and July 2012 over two fields of maize and sunflowers; both were at their early
growing stages. An airborneplatform provided images in the visible/near infrared and thermal infrared, both in day and
Results of the 2011 experiment demonstrated that the vegetation cover correction is required even with low fractional
cover; indeed, not applying this correction would results in strong overestimation. The 2012 experiment
(REFLEX) further validates the model on an independent dataset, thus, confirming the reliability of the methodology.
Furthermore, a spatial resolution analysis highlighted that retrievals at low spatial resolution best compares with in
situsoil water content than those obtained at high-resolution. Finally, the availability of a thermal image acquired
after irrigating demonstrated the unreliability of the method when soil water content significantly changes between the
two thermal acquisitions.