Estimation of Soil Moisture Content of bare soils from their spectral optical properties in the 0.4 - 12 µm spectral domain

The purpose of this paper is the capacity of spectral reflectance, in the full optical domain 0.4 – 12.0 m, to retrieve the Soil Moisture Content (SMC) of bare soils. Indeed, the knowledge of surface soil moisture is a key point for many applications like trafficability after flood, ground – atmosphere exchanges and plant good health. Hyperspectral image acquisitions (narrow spectral bands and high spectral resolution) provide the most detailed information. Thus, the opportunity of using such measurements to retrieve the soil moisture of bare soils is exploited. Using the opportunity accessing to the spectral reflectance of bare soil as a function of several SMC on the entire optical domain, this paper aims to compare the SMC estimation as a function of existing SMC formulations and of the spectral domain. To this end, an end to end simulator is used to simulate the incident signal, acquired by an optical sensor over a given homogeneous landscape characterised by its spectral optical properties, followed by a retrieval method to estimate the on ground spectral reflectance and then its corresponding SMC. The results are compared to SMC methods directly applied on spectra measured in laboratory [5].