Sequential Downscaling of the SMOS Soil Moisture at 100 M Resolution Via a Variable Intermediate Spatial Resolution

The disaggregation based on physical and theoretical scale change (DISPATCH) algorithm was developed to improve the spatial resolution of Soil Moisture and Ocean Salinity (SMOS) soil moisture (SM) using 1 km resolution Moderate resolution Imaging Spectroradiometer (MODIS) data. The main objective of this paper is firstly, to adapt the DISPATCH algorithm to the 100 m resolution Landsat data and secondly, to determine an optimal intermediate spatial resolution (ISR) between the original (40 km) SMOS resolution and the targeted 100 m resolution. It is found that the ISR (set to 1 km, 3 km and 5 km) impacts the accuracy in the sequentially downscaled 100 m resolution SM depending on both the SM heterogeneity present within the spatial extent considered, and the gap between the low to high resolution ratio.