Soil RTM

The proposed new WP8- RTM4carbon aims to develop a transferable radiative transfer model (RTM) using laboratory spectroscopy information from soil samples collected in the different countries covered by the SensRes projects to support the mapping of soil properties in areas with no in situ samples. RTMs describe the transfer and interaction of electromagnetic radiation with the soil surface based on physical laws. One of the most well-known soil RTMs is the SOILSPECT model (Jacquemoud et al., 1992), which was derived from Hapke's model (Hapke, 1981) and represents the optical properties (i.e. bidirectional reflectance factor; BRDF) of soils from 450 nm to 2500 nm. Alternative RTMs, such as BSM (Verhoef et al., 2018) and MARMIT (Bablet et al., 2018), have in common that the focus is on the simulation of moisture content effects mainly. The spectral effects of soil organic matter, Fe/Al oxides and other soil physico-chemical variables are missing, and hence it remains to be investigated whether the single scattering albedo (wλ) of soils can be calibrated within the existing SOILSPECT model as a function of SOC and other optically relevant soil constituents. If successful, this would be a major step forward regarding the analysis of multi- and hyperspectral sensor data acquired on board aircraft, drones and satellite platforms.