VIIRS/JPSS1 BRDF/Albedo Model Parameters Daily L3 Global 500 m SIN Grid NRT

The VIIRS/JPSS1 BRDF/Albedo Model Parameters Daily L3 Global 500 m SIN Grid Near Real Time (NRT), short-name VJ143IA1N product provides BRDF/Albedo model parameters at 500 meter (m) resolution. The VJ143IA1N product is produced daily using 16-day VIIRS data (i.e., the current day and the previous 15 days).

The VJ143 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VNP43IA1N to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VJ143IA4N), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VJ143IA3N). Researchers can use the BRDF model parameters with a simple polynomial, to obtain black-sky albedo at any solar illumination angle. Likewise, both the BSA and WSA Science Dataset (SDS) layers can be used with a simple polynomial, to manually estimate instantaneous actual albedo (blue-sky albedo). Additional details regarding the methodology are available in the Algorithm Theoretical Basis Document (ATBD) at https://www.umb.edu/editor_uploads/images/school_for_the_environment_cs….

The VJ143IA1N data product provides a total of six SDS layers including: mandatory quality bands and three multi-dimensional model parameter bands representing fiso, fvol, and fgeo of the VIIRS imagery bands: I1, I2, and I3. Each data product file is provided in HDF-EOS5 format.

该VIIRS/JPSS1反照率/反照率模型参数每日L3全球500米SIN网格近实时（NRT）产品，简称VJ143IA1N，提供了500米分辨率下的反照率/反照率模型参数。VJ143IA1N产品通过利用16天的VIIRS数据（即当前日及前15日）每日生成。VJ143算法采用基于罗斯厚/李稀疏-互易（RTLSR）半经验核驱动的BRDF模型，从VNP43IA1N中提取三个核权重，以重建地表各向异性效应，并校正方向反射率至共同视角几何（VJ143IA4N），同时计算当地时间正午的集成黑天空反照率（BSA）和白色天空反照率（WSA）（VJ143IA3N）。研究人员可以利用BRDF模型参数，通过简单的多项式运算，获取任何太阳光照角度下的黑天空反照率。同样，BSA和WSA科学数据集（SDS）层也可以通过简单的多项式运算，手动估算瞬时实际反照率（蓝天空反照率）。有关方法的详细信息，可在算法理论依据文档（ATBD）中查阅，文档链接为https://www.umb.edu/editor_uploads/images/school_for_the_environment_cs…。VJ143IA1N数据产品包含总计六个SDS层，包括强制质量波段和三个多维模型参数波段，分别代表VIIRS影像波段I1、I2和I3的fiso、fvol和fgeo：每个数据产品文件均以HDF-EOS5格式提供。