Validation of Regularized Retrieval Algorithm for Clear-Sky Land Surface Albedo with Multi-Angular POLDER Data

Abstract

Abstract:

Based on discrepancy principle and regularization techniques, a regularizing inversion method is employed for the retrieval of clear-sky land surface bidirectional reflectance distribution function (BRDF), directional-hemispherical reflectance (DHR) and bi-hemispherical reflectance (BHR). The fraction of diffuse skylight is computed by using the 6S radiative transfer code. Therefore, by interpolating between DHR and BHR, the actual instantaneous spectral albedos can be computed. Accordingly, the calculation of shortwave (0.25~2.5μm) albedos can be implemented by the conversion of narrowband spectral albedos to broadband albedos. Validation of the presented algorithm is implemented with the POLDER-3/PARASOL BRDF data sets. Comparison of results retrieved by the presented algorithm with that by MODIS AMBRALS algorithm indicates that the accuracy of regularizing retrieval algorithm is equivalent to that of the MODIS algorithm.

Key words: discrepancy principle, regularization, albedo, retrieval

CLC Number:

TP79
P407.8

CUI Sheng-Cheng, YANG Shi-Zhi, ZHAO Qiang, WANG Jia-Cheng, WANG Zhen, WANG Yan-Mei. Validation of Regularized Retrieval Algorithm for Clear-Sky Land Surface Albedo with Multi-Angular POLDER Data[J]. Journal of Atmospheric and Environmental Optics, 2011, 6(3): 215-223.

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