Evaluation of MODIS albedo product (MCD43A) over grassland, agriculture and forest surface types during dormant and snow-covered periods
Evaluation of MODIS albedo product (MCD43A) over grassland, agriculture and forest surface types during dormant and snow-covered periods
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DOI：
10.1016/j.rse.2013.08.025
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发表时间：
2014
影响因子：
13.5
通讯作者：
Zhuosen Wang;C. Schaaf;A. Strahler;M. Chopping;M. Roman;Y. Shuai;C. Woodcock;D. Hollinger;D. Fitzja
中科院分区：
文献类型：
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作者：
Zhuosen Wang;C. Schaaf;A. Strahler;M. Chopping;M. Roman;Y. Shuai;C. Woodcock;D. Hollinger;D. Fitzja
这项研究评估了中分辨率成像光谱仪（MODIS）BRDF/BRDO 8天标准产品和产品从每日直播BRDF/BRDO算法，并表明，这些产品同意与地面BRDO测量在更困难的时期，植被休眠和积雪。耕地、草地、落叶林和针叶林都被考虑在内。使用综合验证策略，休眠和积雪覆盖的情况下的表面异质性的代表性进行分析，以决定是否可以直接比较地面测量和500米卫星观测，或是否需要更精细的空间分辨率机载或星载数据，以缩放结果在每个位置。大地卫星增强型专题制图仪（ETM +）数据被用于生成每个地点的更精细比例尺的卫星图像，以便将地面数据与卫星数据充分联系起来。在一般情况下，结果表明，根均方误差（RMSE）小于0.030以上的农业/草地在休眠期和小于0.050在积雪覆盖期间的MCD 43 A的产品的空间代表性的网站。对于森林，RMSE在休眠期小于0.020，在积雪期小于0.025。然而，每天的检索策略是必要的，以捕捉短暂的雪事件或快速变化的情况，如春季雪融化。
This study assesses the Moderate-resolution Imaging Spectroradiometer (MODIS) BRDF/albedo 8 day standard product and products from the daily Direct Broadcast BRDF/albedo algorithm, and shows that these products agree well with ground-based albedo measurements during the more difficult periods of vegetation dormancy and snow cover. Cropland, grassland, deciduous and coniferous forests are considered. Using an integrated validation strategy, analyses of the representativeness of the surface heterogeneity under both dormant and snow-covered situations are performed to decide whether direct comparisons between ground measurements and 500-m satellite observations can be made or whether finer spatial resolution airborne or spaceborne data are required to scale the results at each location. Landsat Enhanced Thematic Mapper Plus (ETM +) data are used to generate finer scale representations of albedo at each location to fully link ground data with satellite data. In general, results indicate the root mean square errors (RMSEs) are less than 0.030 over spatially representative sites of agriculture/grassland during the dormant periods and less than 0.050 during the snow-covered periods for MCD43A albedo products. For forest, the RMSEs are less than 0.020 during the dormant period and 0.025 during the snow-covered periods. However, a daily retrieval strategy is necessary to capture ephemeral snow events or rapidly changing situations such as the spring snow melt.