Leather. Determination of surface reflectance

2015 ◽  
Keyword(s):  
Surface Reflectance

scholarly journals Retrieval of spectral aerosol optical thickness over land using ocean color sensors MERIS and SeaWiFS

2010 ◽  
Vol 3 (3) ◽  
pp. 2107-2164 ◽  
Author(s):  
W. von Hoyningen-Huene ◽  
J. Yoon ◽  
M. Vountas ◽  
L. G. Istomina ◽  
G. Rohen ◽  
...  
Keyword(s):  
Optical Thickness ◽  
Vegetation Index ◽  
Single Scattering ◽  
Aerosol Optical Thickness ◽  
Visible Range ◽  
Surface Reflectance ◽  
Spectral Determination ◽  
Aerosol Retrieval ◽  
Phase Functions

Abstract. For the determination of aerosol optical thickness (AOT) Bremen AErosol Retrieval (BAER) has been developed. Method and main influences on the aerosol retrieval are described together with validation and results. The retrieval separates the spectral aerosol reflectance from surface and Rayleigh path reflectance for the shortwave range of the measured spectrum of top-of-atmosphere reflectance less than 0.670 μm. The advantage of MERIS (Medium Resolution Imaging Spectrometer on ENVISAT) and SeaWiFS (Sea viewing Wide Fiels Sensor on OrbView-2) observations are the existence of several spectral channels in the blue and visible range enabling the spectral determination of AOT in 7 (or 6) channels (0.412–0.670 μm) and additionally channels in the NIR, which can be used to characterize the surface properties. A dynamical spectral surface reflectance model for different surface types is used to obtain the spectral surface reflectance for this separation. Normalized differential vegetation index (NDVI), taken from the satellite observations, is the model input. Further surface BRDF is considered by the Raman-Pinty-Verstraete (RPV) model. Spectral AOT is obtained from aerosol reflectance using look-up-tables, obtained from radiative transfer calculations with given aerosol phase functions and single scattering albedos either from aerosol models, given by OPAC or from experimental campaigns. Validations of the obtained AOT retrieval results with AERONET data over Europe gave a preference for experimental phase functions derived from almucantar measurements. Finally long-term observations of SeaWiFS have been investigated for trends in AOT.

scholarly journals Retrieval of spectral aerosol optical thickness over land using ocean color sensors MERIS and SeaWiFS

2011 ◽  
Vol 4 (2) ◽  
pp. 151-171 ◽  
Author(s):  
W. von Hoyningen-Huene ◽  
J. Yoon ◽  
M. Vountas ◽  
L. G. Istomina ◽  
G. Rohen ◽  
...  
Keyword(s):  
Optical Thickness ◽  
European Space Agency ◽  
Aerosol Optical Thickness ◽  
Visible Range ◽  
Wide Field ◽  
Surface Reflectance ◽  
Spectral Determination ◽  
Aerosol Retrieval ◽  
Phase Functions

Abstract. For the determination of aerosol optical thickness (AOT) Bremen AErosol Retrieval (BAER) has been developed. Method and main features on the aerosol retrieval are described together with validation and results. The retrieval separates the spectral aerosol reflectance from surface and Rayleigh path reflectance for the shortwave range of the measured spectrum of top-of-atmosphere reflectance for wavelength less than 0.670 μm. The advantage of MERIS (Medium Resolution Imaging Spectrometer on the Environmental Satellite – ENVISAT – of the European Space Agency – ESA) and SeaWiFS (Sea viewing Wide Field Sensor on OrbView-2 spacecraft) observations is the availability of several spectral channels in the blue and visible range enabling the spectral determination of AOT in 7 (or 6) channels (0.412–0.670 μm) and additionally channels in the NIR, which can be used to characterize the surface properties. A dynamical spectral surface reflectance model for different surface types is used to obtain the spectral surface reflectance for this separation. The normalized differential vegetation index (NDVI), taken from the satellite observations, is the model input. Further surface bi-directional reflectance distribution function (BRDF) is considered by the Raman-Pinty-Verstraete (RPV) model. Spectral AOT is obtained from aerosol reflectance using look-up-tables, obtained from radiative transfer calculations with given aerosol phase functions and single scattering albedos either from aerosol models, given by model package "optical properties of aerosol components" (OPAC) or from experimental campaigns. Validations of the obtained AOT retrieval results with data of Aerosol Robotic Network (AERONET) over Europe gave a preference for experimental phase functions derived from almucantar measurements. Finally long-term observations of SeaWiFS have been investigated for 11 year trends in AOT. Western European regions have negative trends with decreasing AOT with time. For the investigated Asian region increasing AOT have been found.

scholarly journals Usability of water surface reflectance for the determination of riverine dissolved methane during extreme flooding in northeastern Siberia

Polar Science ◽  
2019 ◽  
Vol 21 ◽  
pp. 186-194 ◽  
Author(s):  
Tomoki Morozumi ◽  
Ryo Shingubara ◽  
Jun Murase ◽  
Shin Nagai ◽  
Hideki Kobayashi ◽  
...  
Keyword(s):  
Water Surface ◽  
Surface Reflectance ◽  
Dissolved Methane ◽  
Northeastern Siberia ◽  
Extreme Flooding

Determination of Reflectance of Some Decorative Stones

2014 ◽  
Vol 1000 ◽  
pp. 306-309
Author(s):  
Martin Pospíšil
Keyword(s):  
Field Measurements ◽  
Surface Reflectance ◽  
Stone Surface ◽  
Architectural Practice ◽  
Laboratory Conditions ◽  
Constant Height ◽  
Light Reflectance ◽  
Natural Stones

This paper describes a simple methodology for determining the light reflectance of some natural stones used in architectural practice. The methodology is based on the interpolation of the value lying between two etalons for which the reflectance of light was precisely measured under laboratory conditions. For field measurements there were two illumination chambers constructed; in these chambers indirect daylight was transmitted to a stone surface. Reflectance of light from the stone surface was then measured by a luxmeter in a predetermined constant height and the result was interpolated between the values ​​of both etalons. In copending case study 300 measurements on fifteen samples of stones were performed in this manner and resulting coefficient of reflectance of light was then calculated. Resulting coefficient is applicable for the calculation of daylighting of buildings according to the standard CSN 73 0580.

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