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.