MODIS/Terra+Aqua BRDF/Albedo Quality Daily L3 Global 500 m SIN Grid

The MODIS Near Real Time (NRT) Combined Aqua and Terra Bidirectional Reflectance Distribution Function and Albedo (BRDF/Albedo) Quality, MCD43A2N is a L3 daily 16-day composite global gridded tiled product that provides full set of quality control flags for use in determining the quality of the retrievals at pixel level in the daily L3 BRDF/Albedo suite of products: BRDF/Albedo Model Parameters (MCD43A1N), Albedo (MCD43A3N) and the NBAR (MCD43A4N).

There is a significant change in the science algorithm of the Collection 61 (C61) NRT BRDF/Albedo products and, therefore significant differences/discontinuities between the C6 and C61 products. C61 algorithm changes are intended to minimize the differences between the NRT and Standard BRDF. The C61 NRT BRDF code has been modified to allow for an extra round of magnitude inversion, following a full inversion using the full set of inputs. This extra magnitude inversion will only use the set of 9 days that are overlapping between standard and NRT, with the highest weight being assigned to the last day.

Additional information from MODIS Land Science Team at https://modis-land.gsfc.nasa.gov/brdf.html

MODIS近实时(NRT)结合Aqua和Terra双向反射分布函数及反照率(BRDF/Albedo)质量，MCD43A2N是一种L3每日16天复合全球网格化拼贴产品，它提供了一套完整的质量控制标志，用于确定每日L3 BRDF/Albedo产品系列中像素级别数据提取的质量，包括BRDF/Albedo模型参数(MCD43A1N)、反照率(MCD43A3N)以及NBAR(MCD43A4N)。在集合61(C61)NRT BRDF/Albedo产品的科学算法方面发生了显著变化，因此C6与C61产品之间存在显著的不同/间断。C61算法的变更旨在最小化近实时与标准BRDF之间的差异。C61 NRT BRDF代码经过修改，允许在利用完整输入集进行完全反转之后进行额外的幅度反转。这一额外的幅度反转仅使用标准与NRT之间的9天重叠集，且最后一天的权重最高。更多相关信息可从MODIS陆地科学团队网站https://modis-land.gsfc.nasa.gov/brdf.html获取。