Evaluation of Atmospheric Effects on Land-Surface Directional Reflectance With the Coupled RAPID and VLIDORT Models

• Published in: IEEE geoscience and remote sensing letters Vol. 14; no. 6; pp. 916 - 920
• Main Authors: Huaguo Huang, Wenhan Qin, Spurr, Robert J. D., Qinhuo Liu
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.06.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aerosol optical depth; Aerosols; Agriculture; Atmospheric correction; Atmospheric effects; Atmospheric modeling; Atmospheric models; Bidirectional reflectance; Bidirectional reflectance distribution function (BRDF) shape; Boundary conditions; Corrections; Distribution functions; Earth; Earth surface; Evaluation; Hot spots; land atmosphere; Land surface; Lookup tables; Mathematical analysis; Model testing; MODIS; Radiative transfer; radiative transfer (RT); Radiosity; radiosity applicable to porous individual object (RAPID); Reflectance; Remote sensing; Scattering; Solid modeling; Three dimensional models; vector linearized discrete ordinate RT (VLIDORT)
• ISSN: 1545-598X; 1558-0571
• DOI: 10.1109/LGRS.2017.2687702

In order to assess atmospheric effects on the directional reflectance of land surface, we have developed a new approach coupling the 3-D radiosity-based land-surface model [radiosity applicable to porous individual objects (RAPID)] with the atmospheric radiative transfer (RT) model [vector linearized discrete ordinate RT (VLIDORT)]. RAPID is used to generate a lookup table of bidirectional reflectance distribution function (BRDF) elements required by VLIDORT for the surface boundary condition. To test the RAPID-VLIDORT model, we used five natural 3-D scenes along with five aerosol optical depths (AODs). Results for top-of-atmosphere radiances show semiempirical analytical BRDF models are insufficiently accurate to represent bidirectional reflectance factors (BRFs) in hotspot regions and over wide angular variations. The large impact of AOD on BRF hotspot also underlines the importance of precise atmospheric corrections for multiangular remote sensing of the earth's surface.