The Advanced Radiometric Ray Tracer: Ararat for Plant Canopy Reflectance Simulation
نویسنده
چکیده
A Monte Carlo ray tracing system, known as 'the Advanced RAdiometric RAy Tracer' (ARARAT) has been developed as a tool for simulating radiance as measured by remote sensing instruments. The system takes 3-D geometric models of vegetation and/or surfac~ topographic data (Digital Elevation ModelDEM) with associated radiometric attributes, and renders a scene for given illumination conditions for a given set of sensor characteristics. ARARAT has been designed primarily for use with plant geometric data generated with the UCL Botanical Plant Modelling System to provide a simulation system capable of realistically simulating directional radiance and reflectance to allow investigations of the dependence of the signal received at a remote sensing instrument on the complex radiometric and geometric properties of plant canopies. The design philosophy and implementation of ARARAT are discussed in this paper, with reference to Monte Carlo methods of estimating the integral of the radiance rendering equation. Results of simulated maize (Zea mais) canopy reflectance are presented for the simple rendering case of singly-scattered directional radiance, and compared with values measured in the field.
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