Each chemical variety of a pigment or dye has its own specific spectrophotometric fingerprint. Figure 18 shows the spectral reflectance of a maple leaf, as measured by the U.S. Geological Survey (USGS) in the laboratory. In the spectral reflectance curves shown in Figs 5 and 6, the reflectance increases with increasing wavelength. The spectral reflectance curve is a measure of how much energy it will reflect at a different wavelength. •Water (in soil, vegetation or water bodies) absorbs radiation at near-IR wavelengths and beyond (strong absorption bands at about 1.4, 1.9 and 2.7 μm) •Reflectance from a water body can stem from an interaction with: –the water’s surface (specular reflection), –with material suspended in the water, or … Vegetation has a unique spectral signature, but different types of vegetation differ in their reflectance. Plants that are stressed or diseased can also be identified by their distinct spectral signatures. Reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is possible to establish three invariant group. This energy is measured as a function of wavelength and is called spectral reflectance. This invariant is defined by 15 parameters that simulate modulation of spectral curve. Spectral reflectance of Water. When white light falls upon an opaque object, the object interacts with that light. There are many different ways that the spectral reflectance pattern of an object or surface can be recorded. Spectral Reflectance Curve The reflectance characteristics of earth surface feature may be quantified by measuring the portion of incident energy (Irradiance) that is reflected (Radiance). Both of these surface enhancement technologies are commonly used for military and industrial grade applications requiring reflectivity in the near through far IR range. Additives may affect colorant dispersion and appearance properties. Reflectance curves are like fingerprints. ColorXpress* Services colorists use this knowledge and SABIC’s proprietary FormTool artificial intelligence software to select colorants and develop the color formulations for each color match. The characteristic spectral reflectance curve Fig1.8 for water shows thatfrom about 0.5µm , a reduction in reflectance with increasing wavelength, so that in the near infrared range, the reflectance of deep, clear water is virtually a zero (Mather, 1987). The following factors or items may cause differences in color and appearance between the standard and color match: Dissimilar polymers or colorants introduce Refractive Index differences. Laboratory and field spectrometers typically collect hundreds of data points, m… This curve can be than described by some graphical invariant. Differences in surfaces between standard and color match. Generalised Spectral Reflectance Envelopes for Deciduous (Broad-leaved) and Coniferous (Needle-bearing leaves) Trees Spectral reflectance curve for each type overlap in most of the visible portion However, in NIR they are quite different and distinguishable Oblique normal color aerial photograph showing portion of Univ. This is shape or modulation of the spectral reflectance curve. Spectral Reflectivity Curves Details Inrad Optics offers a wide range of in-house coating and plating options, including in-house electrolytic gold plating and evaporative gold coatings. However, the reflectance is maximum at the blue end of the spectrum and decreases as wavelength … White objects produce a reflectance curve which is essentially flat at nearly 100 percent (reflecting all wavelengths), and black objects produce a curve which is essentially flat at nearly 0 percent (absorbing all wavelengths).