The location of the peak reflectance was given by the formula: ... , 1999) in which the spectral reflectance is independent of viewing geometry. How colours vary with viewing geometry. Examples of spectral signatures for soils, litter, and vegetation are shown in Figure 11.4.In the case of vegetation, light absorption by leaf pigments dominates the reflectance spectrum in the visible region (400–700 nm). Box 22085, Valencia E-46071, Spain 2Material Science Institute, University of Valencia, P.O. These feathers might combine features of laminar and foam-like structures. Box 22085, Valencia E-46071, Spain Spectral reflectance signatures result from the presence or absence, as well as the position and shape of specific absorption features, of the surface. Sometimes the earth-sun distance correction is included. It was demonstrated that physical properties changed the total reflectance intensity while the spectral characteristics (peak position and peak intensity) remained constant. The kingfisher and Indian roller's coloration (Figs 7, 8) was diffuse but also iridescent. Fig.1 Spectral Reflectance Curve. Last, the two formulas to predict the color difference and spectral reflectance were compared. Takahama and Nayatani (1972) proposed a method in which a number of real reflectance functions are modified by least squares technique to give the same tristimulus values under one illuminant. Solving (5) for reflectance and using (2) gives ρλ =πIλ/ Fλ =πIλ/ Sλcosφ (6) This is a familiar formula seen in textbooks and in the Landsat Science Data Users Handbook. The method consists of changing each given ρ α (λ) function of the initial collection of spectral reflectance functions to a new function ρ α * (λ) that meets the conditions (Equation [5.6]): Soil emissivity and reflectance spectra measurements José A. Sobrino,1,* Cristian Mattar,1 Pablo Pardo,2 Juan C. Jiménez-Muñoz,1 Simon J. Hook,3 Alice Baldridge,3 and Rafael Ibañez2 1Global Change Unit, Image Processing Laboratory, University of Valencia, P.O. Then, particle swarm algorithm was used to optimize two algorithm models, the obtained reflectance curve was fit, and the color differences were calculated according to the human eye-based CIEDE2000 color difference evaluation standard formula. This curve will visualize the formula of NDVI, NDBI, NDWI.