Artmo’s Global Sensitivity Analysis (gsa) Toolbox to Quantify Driving Variables of Leaf and Canopy Radiative Transfer Models

This contribution introduces ARTMO’s new global sensitivity analysis (GSA) toolbox. With the GSA toolbox the majority of ARTMO’s available radiative transfer models (RTMs) can be used for global sensitivity analysis with little user interaction. For a selected RTM output, the global sensitivity analysis identifies most influential and non-influential input variables according to Sobol’ first-order and total-order indices. The toolbox can process RTM spectral outputs for any kind of optical sensor setting within the spectral range of 400-2400 nm. Multiple model outputs can be automatically analysed within the same execution, which is of interest for more advanced, multi-output RTMs such as SCOPE. To illustrate its functioning, total-order sensitivity indices results for spectral outputs of PROSPECT-4/5 (leaf) and PROSPECT+SAIL (canopy) RTMs were calculated. Wavelength-dependent key driving and non-influential input variables were identified. The toolbox can be beneficial to the broader remote sensing community to gain insight into vegetation-light interactions and RTM input-output functioning.