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

The VIIRS/JPSS1 Albedo Daily L3 Global 500 m SIN Grid Near Real Time (NRT), short-name VJ143IA3N product provides albedo values at 500 m resolution for the bi-hemispherical reflectance white-sky albedos (WSA) and directional hemispherical reflectance black-sky albedos (BSA) at local solar noon. The VNP43IA3N product is produced daily using 16-day VIIRS data (i.e., the current day and the previous 15 days).

The algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VJ143IA1N 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 VNP43IA3N product provides a total of 9 SDS layers including: BSA, WSA, and mandatory quality layers for VIIRS imagery bands I1, I2, and I3.

VIIRS/JPSS1 反照率每日 L3 全球 500 米 SIN 网格近实时（NRT）产品，简称 VJ143IA3N，提供了在本地正午太阳下的双半球反射率白天空反照率（WSA）和方向性半球反射率黑天空反照率（BSA）的 500 米分辨率反照率值。VNP43IA3N 产品每日生成，采用过去 16 天的 VIIRS 数据（即当前日及前 15 日）。该算法采用罗斯厚/李稀疏-互易（RTLSR）半经验核驱动双向反射分布函数（BRDF）模型，利用来自 VJ143IA1N 的三个核权重，重建地表各向异性效应，将方向反射率校正至公共视图几何（VJ143IA4N），同时计算本地正午的集成黑天空反照率（BSA）和白色天空反照率（WSA）（VJ143IA3N）。研究人员可以使用 BRDF 模型参数与简单的多项式相结合，以获得任意太阳照明角度下的黑天空反照率。同样，BSA 和 WSA 科学数据集（SDS）层也可以与简单多项式结合使用，以手动估计瞬时实际反照率（蓝色天空反照率）。有关该方法的详细说明可在算法理论基础文档（ATBD）中找到，链接为 https://www.umb.edu/editor_uploads/images/school_for_the_environment_cs…。VNP43IA3N 产品提供总共 9 个 SDS 层，包括：BSA、WSA 以及 VIIRS 图像波段 I1、I2 和 I3 的强制性质量层。