Canopy reflectance modeling of row aquatic vegetation: AVRM and AVMC

Abstract

Row aquatic vegetation is characterized by distinctive features as inundated habitats and individuals arranged in rows. However, current radiative transfer models have not yet taken into account both the water background and the row structure. To address this problem, we developed a hybrid radiative transfer and geometric optical model (Aquatic Vegetation Row Model, AVRM) for row vegetation and taken rice at early growth stages as a typical example. We verified the model through field experiment and an independently developed Monte Carlo simulation model (Aquatic Vegetation Row Monte Carlo model, AVMC), and found that they could better simulate the canopy reflectance characteristics of rice before canopy closure than existing models: PROSAIL model for uniform terrestrial vegetation, AVRT model for uniform aquatic vegetation, and Kimes model for row terrestrial vegetation, respectively. The effects of row structure, leaf area index, and water background on the bidirectional reflectance spectra of rice canopies were investigated. Our models could be used as virtual laboratory to simulate the reflectance characteristics of rice at early growth stages, which may benefit rice condition monitoring and growth management.