@Article{EpiphanioHuet:1994:SoLiRe,
               author = "Epiphanio, Jos{\'e} Carlos Neves and Huete, A. R",
                title = "Soil and litter reflectance contrast effects on vegetation indices 
                         and their relationship to FAPAR",
              journal = "EOS Transactions",
                 year = "1994",
               volume = "75",
               number = "44",
                pages = "206",
             keywords = "Vegetation indices (VIs).",
             abstract = "Vegetation indices (VIs)derived from remote sensing data are 
                         related to important vegetation parameters, e.g. fAPAR and LAI. 
                         These parameters are regular inputs to models of primary 
                         productivity. Generally, VIs use relationships between near 
                         infrared (NIR)and red reflectances and may utilize the blue band 
                         for atmospheric correction. Soil brightness influences on canopy 
                         reflectance and VIs have been well shown. Soil color effects as 
                         well as canopy backgrounds with litter present, however, have been 
                         less well studied. These backgrounds not only affect brightness, 
                         but also significantly alter the contrast ratio of NIR and red 
                         reflectances. The effects of background NIR/red reflectance 
                         contrast due to presence of litter and soil on different VI's were 
                         studied using the Myneni canopy radiative transfer model. Several 
                         ground cover percentages and two clump LAI's were simulated. The 
                         background NIR/red reflectance ratio was varied from 0.9 to 1.5, 
                         and the red reflectance was allowed to vary from 0.1 to 0.35, thus 
                         covering a large range of background reflectances. It is shown 
                         that the NIR/red contrast of backgrounds affect the VIs, and that 
                         VIs which reduce background brightness effects also reduce 
                         background NIR/red contrast effects, mainly for low vegetation 
                         amounts. fAPAR was computed and the effects of background NIR/red 
                         reflectance ratio on the relationships between VIs and fAPAR are 
                         discussed.",
                 issn = "2324-9250",
                label = "7044",
             language = "en",
           targetfile = "INPE 6566.pdf",
        urlaccessdate = "26 abr. 2024"
}