A Dynamic L-system based Architectural Maize Model for 3D Radiative Transfer Simulation

We integrate the time series simulation capability of the maize model within Extended L-system (ELSYS) using the growth equations from a 4D maize and a leaf breakpoint model. These models simulate maize growth from emergence to male anthesis, accounting for 3D architecture during the vegetative season. We employ two methods to achieve time series simulation in ELSYS: directly use the growth equations in the 4D maize and leaf breakpoint models, and name ELSYS coupling 4D maize (ELSYS 4Dmaize ). Alternatively, replace the stem radius-leaf order function with a stem radius-height function and employ linear interpolation to transform the leaf width-length ratio from a constant value to a function that varies with leaf order, thereby simulating a 4D maize structure, and name the Dynamic L-system based Architectural maize (DLAmaize) model. The DLAmaize model is applied to maize canopy reflectance simulations using the Discrete Anisotropic Radiative Transfer model (DART) and radiosity-graphics combined method (RGM), along with a comparison with the 1D Scattering by Arbitrarily Inclined Leaves (SAIL) model. Simulated reflectance of maize canopy from ELSYS 4Dmaize and DLAmaize differs significantly in the hotspot direction (the absolute value of the relative difference can be up to 67.4%). In addition, comparisons among radiative transfer models show that DART model and RGM yield close results. The SAIL model yields significant differences (e.g., 41.16% overestimate of nadir reflectance) owing to its assumption of the homogeneous canopy. DLAmaize enhances remote sensing of dynamic 4D vegetation canopies modeling and holds promise for remote sensing applications.