
	Where results make sense

Topic: Spectral reflectance

Related Topics

Colorimetry

Spectrophotometry

IR spectroscopy

Spectroscopy

Laser Induced Breakdown Spectroscopy (LIBS)

Infrared spectroscopy

Fourier transform

In the News (Thu 31 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Spectral signature sampling
		Reflectance is the fraction of incident flux that is reflected by a surface.
		The spectral irradiance may be measured directly by attaching a cosine receptor to the spectroradiometer and pointing the receptor parallel to the surface for which the irradiance is to be measured.
		The spectral reflectance signatures should in the ideal world be independent of the illumination situation, it is however always preferential to measure the spectral reflectance signatures at conditions similar to the situation when the image data are acquired.
	www.dmu.dk /rescoman/Groundobs/Radiometer_acquisition.htm (987 words)

	Spectral reflectance of whitecaps
		Spectral properties of whitecaps are of importance for color ocean remote sensing and aerosol optical thickness probing from satellite-based instruments.
		Several experimental measurements of whitecap spectral reflectance have been performed both in the surf zone and in the open ocean, which indicate that oceanic foam cannot be considered as a gray body (e.g., for satellite remote sensing techniques).
		The model introduced is capable of explaining main features observed, like a sharp decrease of the foam spectral reflectance in the infrared as compared with the visible part of the electromagnetic spectrum and a high correlation of the foam reflectance R and the water absorption coefficient α.
	www.agu.org /pubs/crossref/2004/2003JC002177.shtml (279 words)

	Bibliography
		Spectral field measurements for the determination of reflectance characteristics of vegetated surfaces: Proceedings of an International Symposium on Remote Sensing for Observation and Inventory of Earth Resources and the Endangered Environment, Feiburg, F.R. Germany, 2-8 July 1978.
		Spectral reflectance of carbonate minerals in the visible and near-infrared (0.35 to 2.55 microns): Anhydrous carbonate minerals: Journal of Geophysical Research, 92 (B1): 1428-1440.
		Spectral identification of geological units on the surface of Mars related to the presence of silicates from earth-based near-infrared telescope Charge-Coupled Device Imaging.
	www.pimausa.com /spectralbib.html (3368 words)

	Near Infrared 45 ° /0 ° Reflectance Factor of Pressed Polytetrafluoroethylene (PTFE) Powder
		The wavelength dependence of the reflectance factor of PTFE is presented for the near-infrared spectral region (800 nm to 1600 nm) for the 45 ° /0 ° geometry, as well as in the visible spectral region (380 nm to 800 nm) for comparison with previously published results.
		The reflectance factor of a sample is defined [4] as the ratio of the radiant flux reflected in the direction delimited by a given cone, with the apex at the surface of the sample, to the radiant flux reflected in the same direction by a perfectly reflecting diffuser illuminated in the same manner.
		A UV-enhanced silicon photodiode is used for the spectral region of 380 nm to 1000 nm and a germanium photodiode, thermoelectrically cooled to –20 ° C mounted on a 38 mm integrating sphere coated with PTFE, is used for the spectral region of 900 nm to 1600 nm.
	nvl.nist.gov /pub/nistpubs/jres/104/2/html/nad-k/nad.htm (1774 words)

	sect25
		At the thermal spectral region, energy is primarily absorbed, and the reflected energy is significantly less in magnitude than the emission of a target.
		Due to the variability of spectral signature, one of the current research direction is to investigate the bidirectional properties of various targets.
		The one at the red spectral wavelength region (0.65 µm) is caused by high absorptance of energy by chloraphyll a and b in the leaves.
	www.cnr.berkeley.edu /~gong/textbook/chapter2/html/sect25.htm (447 words)

	ARS \| Publication request: Spectral Reflectance Estimates of Cotton Biomass and Yield (Site not responding. Last check: 2007-10-14)
		Crop reflectance in 16 individual wavelengths was measured with a hand-held radiometer in a cotton irrigation study.
		Reflectance in the near infrared region at 750 and 880 nm made during the 2002 and 2003 growing seasons were highly correlated with plant water status, leaf area, and final lint yield.
		Reflectance measurements were made with a hand-held CROPSCAN radiometer equipped with sensors that measured radiation in 16 wavelengths.
	ars.usda.gov /research/publications/publications.htm?SEQ_NO_115=164201 (501 words)

	EPA - Imaging Spectroscopy
		Reflectance spectroscopy is the study of energy as a function of wavelength that has been reflected from or scattered by a solid, liquid or gas (Clark 1995).
		The reflectance characteristics in the range of.4 - 1.0 µm are typically influenced by the presence of transition metals, such as iron, and are extremely diagnostic for minerals.
		The steep rise in the spectral reflectance curve for vegetation at.8 µm is called the red edge of the chlorophyl band and is one of the fundamental characteristics of vegetation analysis by imaging spectroscopy methods.
	www.epa.gov /nerlesd1/land-sci/epic/rsspectroscopy.htm (2007 words)

	FMARS Mission Data - Reflectance Experiment Report 13 July, 2002
		On July the 12th the experimental equipment designed to measure the spectral reflectance of various sources was unpacked and assembled inside the FMARS lab for the purpose of testing before use during EVA.
		The target reflectance spectrum is then divided by the calibration reflectance spectrum and the results are graphed, giving the fractional reflectance of the target with respect to the illuminating source versus wavelength.
		These spectral features were not seen in the reflectance spectra taken inside and were present in all of the spectra taken outside, an example of which is seen in figure 3 which shows the reflectance of water in the lab and a puddle outside.
	www.marssociety.org /arctic/2002/fmfsr071302.asp (722 words)

	[No title]
		It is not known whether this phenomenon is due to skinÕs relatively complex spectral reflectance characteristics, the subjectsÕ familiarity with the appearance of their own skin, or some other factor.
		The relative spectral complexity of skin may be the factor which makes it easier for people to distinguish between different types of fluorescent lamps when viewing their own skin than when viewing other targets.
		An experiment was conducted to see whether spectral reflectance complexity could predict changes in the color of objects better than the color rendering property of the light source as measured by the color rendering index.
	www.rpi.edu /AFS/home/13/bierma2/public/spectral.rev (941 words)

	USGS Mine Drainage Activities- Archives: Microbes and Spectral Reflectance in Virginia
		Spectral curves A and B show the acid and neutral bacterial flocs, in their native water media.
		Field spectral measurements for wavelengths from 350 to 950 nanometers (nm) are taken of the flocs in shallow water.
		Laboratory spectral reflectance measurements were taken for wavelengths from 400 to 2500 nm using a Beckman 5240 spectrometer.
	mine-drainage.usgs.gov /archive/contrary.html (2248 words)

	1.9 Spectral Reflectance of Land Covers (Site not responding. Last check: 2007-10-14)
		Spectral reflectance is assumed to be different with respect to the type of land cover, as explained in 1.3 and 1.8.
		This is the principle that in many cases allows the identification of land covers with remote sensing by observing the spectral reflectance or spectral radiance from a distance far removed from the surface.
		Figure 1.9.1 shows three curves of spectral reflectance for typical land covers; vegetation, soil and water.
	www.profc.udec.cl /~gabriel/tutoriales/rsnote/cp1/cp1-9.htm (288 words)

	IV. SPECTRAL DATA - INFLUENCING FACTORS - RESEARCH ISSUES
		Spectral data from imaging spectrometers can be evaluated on the basis of: shape of the overall curve, or portions of it; intensity differences at any selected wavelength range; wavelength location of absorption bands; and, depth and shape of absorption bands.
		Although the plants look alike, they are not identical--each has some variance in biomass, structure, openness, etc. These factors alter the characteristics of the energy reflected from the vegetal surfaces, as well as the characteristics of the contributing reflected soil component passing through, or reflected from the canopy.
		Basic to such a procedure is a documented library of field and laboratory spectral reflectance and luminescence measurements, coupled, where possible, to physical and chemical measurements.
	www.tec.army.mil /research/products/desert_guide/TUTORIAL/text/lt4.htm (851 words)

	USU CROP PHYSIOLOGY LABORATORY: RESEARCH: SPECTRAL IMAGING
		Detectors for spectral measurements above 1000 nm are expensive, but they can be used to analyze water stress in plants by measuring reflectance of the major water bands at 1450 nm and 1900 nm.
		Vegetation reflectance indices can be used to identify plant health and separate plant growth from spectral contaminants, such as the soil.
		Leaf transmittance and reflectance were compared with plant canopy reflectance to determine the usefulness of using reflectance to detect nitrogen stress in spring wheat (Triticum aestivum cv.
	www.usu.edu /cpl/research_spectral.htm (1295 words)

	JPL Spectral Library
		The JPL spectral library was originally published in Laboratory Reflectance Spectra of 160 Minerals, 0.4 to 2.5 Micrometers, by C.I. Grove, S.J. Hook, and E.D. Paylor II.
		Hemispherical reflectance measurements in the visible and short-wavelength region of the electromagnetic spectrum (0.4 to 2.5µm) were made by using a Beckman UV5240 spectrophotometer (Price, 1977).
		For reflectance measurements, the size-sorted samples were poured into aluminum sample holders that measured 3.2 cm in diameter and 0.5 cm in depth.
	speclib.jpl.nasa.gov /documents/jpl_desc.htm (2060 words)

	Spectral reflectance and directional properties of structural coloration in bird plumage -- Osorio and Ham 205 (14): ...
		Unlike the iridescent reflection, the direction of non-spectrally selective specular reflection was consistent with the reflective surface being in (or close to) the plane of the feather vane.
		These reflectance curves had narrower peaks than for localised illumination, probably because they were recorded from different locations on the blue coloration band (this feather grades from white through fl and is most saturated at an intermediate location).
		The reflective surface was not tilted relative to the feather
	jeb.biologists.org /cgi/content/full/205/14/2017 (5465 words)

	Remote Sensing: An Overview
		Spectral reflectance is the portion of incident radiation that is reflected by a non-transparent surface.
		Thus, two features that are indistinguishable in one spectral range may be very different in another portion of the spectrum.
		A spectral signature is a unique reflectance value in a specific part of the spectrum.
	www.csc.noaa.gov /products/sccoasts/html/rsdetail.htm (792 words)

	Optical Remote Detection of Ice on Aircraft Surfaces
		The technique is based on the variation of local spectral reflectance with the depth of ice and/or water on a surface of known aircraft material (typically, aluminum).
		The spectrum of white light reflected from each surface point includes absorption dips characteristic of any water or and/or ice present at that point, as distinguished from the relatively flat spectral reflectance of aluminum.
		The spectral image data were corrected for CCD dark current and bias and converted to reflectance units, and regions of interest were chosen for determining the spatially averaged reflectance spectra.
	www.nasatech.com /Briefs/Sept98/NPO19929.html (469 words)

	Total Emittance and Hemispherical Spectral Reflectance
		Near-normal infrared reflectance measurements were performed in accordance with ASTM E408-71 (reapproved 1990), method A. A Gier Dunkle Instruments Infrared Reflectometer Model DB 100 was utilized for the measurements.
		Total reflectance measurements were obtained in the solar spectrum from 2500nm to 300nm at an incident angle of 15 degrees.
		The measurements are properly denoted as being “hemispherical spectral reflectance”.
	www.nationwidecoatings.com /TEST06.htm (593 words)

	EOM Archives (Site not responding. Last check: 2007-10-14)
		ince the early 1980s, proximal sensing-collecting spectral reflectance data close to crop plants- has allowed researchers to detect crop stress long before detection with the human eye was possible.
		Walter Bausch uses Exotech (Gaithersburg, Md.) radiometers to monitor reflectance in the green (520-600nm), red (630-690nm), and near-infrared (760-900nm) portions of the spectrum-similar to the Landsat satellite Thematic Mapper wavebands TM2, TM3, and TM4.
		Bausch began his spectral reflectance research on corn in the late 1980s, centering his research in experimental cornfields near Fort Collins, Colo. It was there that he developed a set of crop coefficients derived solely from reflected canopy radiation data.
	www.eomonline.com /Common/Archives/Dec00/john.htm (1742 words)

	SOC Optical Measurement Services and Databases
		Spectral measurements can be made in wavelength regions from the ultraviolet to long wave infrared and include one or all of the following types of reflectance measurements:
		Directional or hemispheric reflectance : the fraction of the light incident on a sample at a given angle that is reflected back into the hemisphere.
		Spectral Reflectance Data for (52) rocks, (29) soils, (28) vegetation types, (41) construction materials, (38) paints, and (12) fabrics from 0.3 to 25 microns.
	www.surfaceoptics.com /Products/Measurements.htm (325 words)

	Welcome to the ASTER Spectral Library
		Welcome to the ASTER spectral library, a compilation of almost 2000 spectra of natural and man made materials.
		The ASTER spectral library includes data from three other spectral libraries: the Johns Hopkins University (JHU) Spectral Library the Jet Propulsion Laboratory (JPL) Spectral Library, and the United States Geological Survey (USGS - Reston) Spectral Library.
		Reproduced from the ASTER Spectral Library through the courtesy of the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California.
	speclib.jpl.nasa.gov (128 words)

	Langley GACP COVE (Site not responding. Last check: 2007-10-14)
		Measurements of upwelling spectral radiance will be recorded for several months to characterize the reflectance as explicitly in terms of both the local wind AND the large scale sea state; the impact of white caps on reflectance will be included implicitly.
		The exisiting COVE instrumentation is sufficient for all radiation components needed to develop the sea optics parameterization, except for the measurement of spectral upwelling radiances by the Schulz photometer supported through GACP.
		Reflectance will be interpreted using the spectral bi-directional reflectance from a model of ocean optics.
	snowdog.larc.nasa.gov /gacp/cove.html (1021 words)

	Ex #1
		One form of reference data is the ground-based measurement of the reflectance of surface features to determine their spectral response patterns.
		It is used primarily to prepare spectral reflectance curves for various objects.
		Reflectance curves such as these have already been generated for a large number of surfaces.
	www.cas.sc.edu /geog/rslab/551/e01.html (692 words)

	Spectral reflectance of Thalassia testudinum (Hydrocharitaceae) seagrass: low salinity effects -- Thorhaug et al. 93 ...
		Spectral reflectance of Thalassia testudinum (Hydrocharitaceae) seagrass: low salinity effects -- Thorhaug et al.
		Spectral reflectance of Thalassia testudinum (Hydrocharitaceae) seagrass: low salinity effects
		Key Words: chlorophyll • chlorophyll normalized difference index • photochemical reflectance index • salinity • seagrasses • spectral reflectance • Thalassia
	www.amjbot.org /cgi/content/abstract/93/1/110 (300 words)

	Spectral reflectance of Picea rubens (Pinaceae) and Abies balsamea (Pinaceae) needles along an elevational gradient, ...
		Spectral reflectance of Picea rubens (Pinaceae) and Abies balsamea (Pinaceae) needles along an elevational gradient, Mt. Moosilauke, New Hampshire, USA -- Richardson et al.
		The strongest correlation was with the slope of the reflectance
		Carter, G. 1991 Primary and secondary effects of water content on the spectral reflectance of leaves.
	www.amjbot.org /cgi/content/full/88/4/667 (6002 words)

	Multispectral Reflectance of Cotton Related to Plant Growth, Soil Water and Texture, and Site Elevation -- Li et al. 93 ...
		Spectral reflectance at 810 and 1665 nm was correlated
		Spectral reflectance was measured 17 Aug. 1998 and 24 Aug. 1999 (when maximum NDVI values were determined).
		Reflectance data were the monthly mean measured in all plots at 50% evapotranspiration (ET) in August 1999.
	agron.scijournals.org /cgi/content/full/93/6/1327 (5789 words)

	Spectral Reflectance of Crop
		Remotely sensed imagery of a field to be mapped for weeds typically has one-meter resolution, i..e., each pixel records the spectral reflectance of a 1-meter by 1-meter area on the ground.
		The spectral reflectance of the soil relative to the spectral reflectance of the crops and weeds is therefore another variable to be studied when crop and weed canopies are incomplete.
		This project proposes to study the percent reflectance of varying combinations of weeds, crop and soils for various dates in various wavelength regions.
	www.engineering.sdstate.edu /~erc/ORS/spectralcrop.htm (1384 words)

	Retinal Spectral Sensitivity, Fur Coloration, and Urine Reflectance in the Genus Octodon (Rodentia): Implications for ...
		Spectral reflectance of body parts in Octodon and of objects in their habitat.
		Top: spectral reflectance of various types of vegetation (see text for species; broken lines) and of ground components (soil, rock, feces; fine solid lines).
		Spectral contrast was highest in the UV (<400 nm) in moist urine and maximum near 450 nm in dry urine.
	www.iovs.org /cgi/content/full/44/5/2290 (4114 words)

Try your search on: Qwika (all wikis)