Open AccessAn improved derivation of the top‐of‐atmosphere albedo from POLDER/ADEOS‐2: Narrowband albedos
Author(s) -
Buriez JeanClaude,
Parol Frédéric,
Cornet Céline,
DoutriauxBoucher Marie
Publication year - 2005
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2004jd005243
Subject(s) - narrowband , albedo (alchemy) , environmental science , remote sensing , shortwave , satellite , atmosphere (unit) , shortwave radiation , sky , polarization (electrochemistry) , bidirectional reflectance distribution function , water vapor , broadband , meteorology , radiation , radiative transfer , geology , reflectivity , geography , optics , physics , art , astronomy , performance art , art history , chemistry
The Polarization and Directionality of Earth Reflectances (POLDER) instrument was routinely functioning aboard the second Advanced Earth Observing Satellite (ADEOS‐2) from April to October 2003. A series of algorithms dedicated to Earth radiation budget, water vapor, and clouds are applied to the POLDER data. This paper presents the derivation scheme of the narrowband albedos at the top of the atmosphere from POLDER measurements at 443, 670, and 865 nm. These narrowband albedos are used to estimate the broadband shortwave albedo at the top of atmosphere in a companion paper. Here we focus on the 670 nm (over land)/865 nm (over ocean) albedo. Although our derivation is based on the plane‐parallel hypothesis, and thanks to the multidirectional capability of POLDER, results appear reliable for both cloudy and clear‐sky scenes. A quality index is introduced from the comparison between the angular variability of the retrieved “directional” albedo values and that of the measured reflectances. This quality index is “good” in 80% of the cases. Moreover, the retrieved albedo values are found to be statistically little dependent on the viewing direction.