Two models for rapidly calculating bidirectional reflectance of complex vegetation scenes: Photon spread (PS) model and statistical photon spread (SPS) model

Discrete Anisotropic Radiative Transfer (DART 5) for Modeling Airborne and Satellite Spectroradiometer and LIDAR Acquisitions of Natural and Urban Landscapes

“…and instrument specifications (spatial and spectral resolutions, sensor viewing directions, platform altitude, etc.). DART forward simulations of vegetation reflectance were successfully verified by real measurements [32] and also cross-compared against a number of independently designed 3D reflectance models (e.g., FLIGHT [26], Sprint [33], Raytran [27]) in the context of the RAdiation transfer Model Intercomparison (RAMI) experiment [34][35][36][37][38]. To date, DART has been successfully employed in various scientific applications, including development of inversion techniques for airborne and satellite reflectance images [39,40], design of satellite sensors (e.g., NASA DESDynl, CNES Pleiades, CNES LIDAR mission project [41]), impact studies of canopy structure on satellite image texture [42] and reflectance [32], modeling of 3D distribution of photosynthesis and primary production rates in vegetation canopies [43], investigation of influence of Norway spruce forest structure and woody elements on canopy reflectance [44], design of a new chlorophyll estimating vegetation index for a conifer forest canopy [45], and studies of tropical forest texture [46][47][48], among others.…”

Coupled soil–leaf-canopy and atmosphere radiative transfer modeling to simulate hyperspectral multi-angular surface reflectance and TOA radiance data

“…The bi-directional reflectance, or rather the bi-directional reflectance distribution function BRDF (Nicodemus, 1970), of vegetation canopies is the fundamental physical object property which eventually determines the remotely sensed radiance signal, along with other factors such as the local solar and sky irradiances, and the atmospheric conditions. Modeling the top-of-canopy BRDF has evolved in several directions (Goel, 1988;Pinty et al, 2004), making use of various numerical solution techniques like ray tracing (Chelle, 1997), Monte Carlo (North, 1996;Thompson & Goel, 1998) and radiosity (Gerstl & Borel, 1992), or analytical solutions like four-stream (Verhoef, 1985), N + 2 stream (Verhoef, 2002) and discrete ordinates (Knyazikhin et al, 1992), for 1-D as well as 3-D canopy architectures (Gastellu-Etchegory et al, 1996;Kuusk & Nilson, 2000). In hybrid models analytical and numerical techniques are combined (Gobron et al, 1997), or geometric optics (GO) approaches are combined with radiative transfer (RT) approaches (so-called GORT models, Li et al, 1995).…”

Simulation of Multitemporal and Hyperspectral Vegetation Canopy Bidirectional Reflectance Using Detailed Virtual 3-D Canopy Models

“…Since the third phase of RAMI (RAMI-3, Widlowski et al 2007) the drat model belongs to a series of "credible" 3D Monte-Carlo ray tracing models. The others are DART (Gastellu-Etchegorry et al 1996, FLIGHT (North 1996), Rayspread (Widlowski et al 2006), raytran (Govaerts and Verstraete 1998), and Sprint3 (Thompson and Goel 1998), (Widlowski et al 2007).…”