Multi-scale validation strategy for satellite albedo products and its uncertainty analysis

• Published in: Science China. Earth sciences 2015-04, Vol.58 (4), p.573-588
• Main Authors: Peng, JingJing, Liu, Qiang, Wen, JianGuang, Liu, QinHuo, Tang, Yong, Wang, LiZhao, Dou, BaoCheng, You, DongQin, Sun, ChangKui, Zhao, XiaoJie, Feng, YouBin, Shi, Jian
• Format: Article
• Language: English
• Subjects: Albedo; Atmospheric sciences; Calibration; China; Climate change; Earth and Environmental Science; Earth Sciences; Energy balance; In situ measurement; Land; Remote sensing; Research Paper; Satellites; Uncertainty; 不确定性分析; 中分辨率成像光谱仪; 产品; 卫星星座; 反照率; 多尺度; 验证过程; 高分辨率卫星
• ISSN: 1674-7313; 1869-1897
• DOI: 10.1007/s11430-014-4997-y

Coarse-resolution satellite albedo products are important for climate change and energy balance research because of their capability to characterize the spatiotemporal patterns of land surface parameters at both the regional and global scales. The accuracy of coarse-resolution products is usually assessed via comparison with in situ measurements. The key issue in the comparison of remote sensing observations with in situ measurements is scaling and uncertainty. This paper presents a strategy for validating 1-km-resolution remote sensing albedo products using field measurements and high-resolution re- mote sensing observations. Field measurements were collected to calibrate the high-resolution （30 m） albedo products derived from HJ-1a/b images. Then, the calibrated high-resolution albedo maps were resampled （i.e., upscaled） to assess the accuracy of the coarse-resolution albedo products. The samples of field measurements and high-resolution pixels are based on an uncertainty analysis. Two types of coarse-resolution albedo datasets, from global land surface satellite （GLASS） and moderate-resolution imaging spectroradiometer （MODIS）, are validated over the middle reaches of the Heihe River in Chi- na. The results indicate that the upscaled HJ （Huan Jing means environment in Chinese and this refers to a satellite constel- lation designed for environment and disaster monitoring by China） albedo, which was calibrated using field measurements, can provide accurate reference values for validating coarse-resolution satellite albedo products. However, the uncertainties in the upscaled HJ albedo should be estimated, and pixels with large uncertainties should be excluded from the validation process.