FluorMODgui: A Graphic User Interface for the Spectral Simulation of Leaf and Canopy Fluorescence Effects

Abstract

This paper reports on the status of the FluorMODgui, a Graphic User Interface (GUI) software package developed within the frame of the FluorMOD project "Development of a Vegetation Fluorescence Canopy Model". The study was launched in 2002 by the European Space Agency to advance the science of vegetation fluorescence simulation through the development and integration of leaf and canopy fluorescence models based on physical methods. The FluorMODgui enables simulation of leaf and canopy reflectance with the effects of chlorophyll fluorescence, running the leaf and canopy models (dubbed FluorMODleaf and FluorSAIL) independently, as well as through a coupling scheme. Inputs for the FluoMODleaf layer are N (number of leaf layers, as in PROSPECT), Cab (chlorophyll a+b content), Cw (water equivalent thickness), Cm (dry matter content), Fi (fluorescence quantum efficiency), T (temperature), S (species type), and Sto (stoichiometry). Inputs for the FluorSAIL canopy layer are: a MODTRAN4 6-parameter spectra, a soil reflectance spectra, leaf reflectance & transmittance spectra, a excitation-fluorescence response matrix (back & forward), 2 PAR-dependent coefficients for the fluorescence response to light level, solar zenith angle, viewing zenith & relative azimuth angles, canopy LAI and LIDF parameters, and a hot spot parameter. Outputs for the linked leaf-canopy fluorescence model are the leaf spectral reflectance, transmittance, and canopy reflectance with and without the fluorescence signal. Current software developments also accommodate multiple runs to simulate diurnal effects under different viewing geometries.