Development of a High Resolution BRDF/Albedo Product by Fusing Airborne CASI Reflectance with MODIS Daily Reflectance in the Oasis Area of the Heihe River Basin, China

Abstract

A land-cover-based linear BRDF (bi-directional reflectance distribution function) unmixing (LLBU) algorithm based on the kernel-driven model is proposed to combine the compact airborne spectrographic imager (CASI) reflectance with the moderate resolution imaging spectroradiometer (MODIS) daily reflectance product to derive the BRDF/albedo of the two sensors simultaneously in the foci experimental area (FEA) of the Heihe Watershed Allied Telemetry Experimental Research (HiWATER), which was carried out in the Heihe River basin, China. For each land cover type, an archetypal BRDF, which characterizes the shape of its anisotropic reflectance, is extracted by linearly unmixing from the MODIS reflectance with the assistance of a high-resolution classification map. The isotropic coefficients accounting for the differences within a class are derived from the CASI reflectance. The BRDF is finally determined by the archetypal BRDF and the corresponding isotropic coefficients. Direct comparisons of the cropland archetypal BRDF and CASI OPEN ACCESSRemote Sens. 2015, 7 6785 albedo with in situ measurements show good agreement. An indirect validation which compares retrieved BRDF/albedo with that of the MCD43A1 standard product issued by NASA and aggregated CASI albedo also suggests reasonable reliability. LLBU has potential to retrieve the high spatial resolution BRDF/albedo product for airborne and spaceborne sensors which have inadequate angular samplings. In addition, it can shorten the timescale for coarse spatial resolution product like MODIS.

Retrieval of High Temporal Resolution Aerosol Optical Depth Using the GOCI Remote Sensing Data

“…MODIS BRDF/albedo, a land level 3 standard data product, was also used in this study. MODIS BRDF products have the characteristics of high time resolution, high spatial resolution, full spectrum coverage, and global imaging [22][23][24]. The core data set of the product is MCD43A1, which implements the RossThick-LiSparseR semi-empirical BRDF model (RTLSR), and provides information on MODIS 1-7 bands and the other three bands.…”

Assessment of NPP VIIRS Albedo Over Heterogeneous Crop Land in Northern China

“…Remote sensing provides a unique method for obtaining albedos at regional and global scales. Efforts have been devoted to establish the methodologies to retrieve albedos from satellite remote sensing data, and significant progress has been achieved over the past few decades, including narrow‐to‐broadband conversions (Liang, Strahler, & Walthall, ), bidirectional reflectance distribution function (BRDF) angular modeling (Lucht et al, ; Schaaf et al, ; Wanner et al, ; You et al, ), direct‐estimation algorithms based on linear regression models (Cui, Mitomi, & Takamura, ; He et al, ; Qu et al, ), and joint optimal algorithms to estimate albedos from geostationary satellite data (Govaerts et al, ). Albedo products have been generated using the above algorithms, including albedos derived from the advanced very high resolution radiometer (AVHRR) (Saunders, ), Moderate Resolution Imaging Spectroradiometer (MODIS) (Gao et al, ), Polarization and Directionality of Earth Reflectances (Bicheron & Leroy, ), Meteosat Second Generation (Govaerts et al, ; Leeuwen & Roujean, ), and Medium‐Resolution Imaging Spectrometer (Muller, ).…”

Validation of Regional-Scale Remote Sensing Products in China: From Site to Network

“…The retrieved CASI albedo with 5 m resolution showed promising high accuracy, with an RMSE of 0.013 compared against in situ measurements. In addition, good performance was observed when the CASI albedo was upscaled to a 500 m pixel scale, with an RMSE of 0.019 compared with MODIS products [165].…”