VIIRS/NPP BRDF/Albedo Model Parameters Daily L3 Global 1km SIN Grid NRT

The VIIRS/NPP BRDF/Albedo Model Parameters Daily L3 Global 1 km SIN Grid Near Real Time (NRT), short-name VNP43MA1N product provides BRDF/Albedo model parameters at 1 km resolution. The VNP43MA1N product is produced daily using 16-day VIIRS data (i.e., the current day and the previous 15 days).

The VNP43 algorithm uses the RossThick/Li-Sparse-Reciprocal (RTLSR) semi-empirical kernel-driven BRDF model, with the three kernel weights from VNP43MA1N to reconstruct surface anisotropic effects, correcting the directional reflectance to a common view geometry (VNP43MA4N), while also computing integrated black-sky albedo (BSA) at local solar noon and white-sky albedo (WSA) (VNP43MA3N). 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 VNP43MA1N data product provides a total of 24 SDS layers including: mandatory quality bands and three multi-dimensional model parameter bands representing fiso, fvol, and fgeo for VIIRS moderate resolution bands: M1-M5, M7-M8, and M10-M11.

VIIRS/NPP BRDF/Albedo 模型参数每日 L3 全球 1 公里 SIN 格网近实时（NRT）产品，简称 VNP43MA1N，提供 1 公里分辨率的 BRDF/Albedo 模型参数。VNP43MA1N 产品基于 16 天的 VIIRS 数据（即当前日及前 15 天）每日生成。VNP43 算法采用 RossThick/Li-Sparse-Reciprocal（RTLSR）半经验核驱动 BRDF 模型，通过从 VNP43MA1N 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统一观测几何（VNP43MA4N），同时计算当地时间正午的集成黑天反照率（BSA）及白天反照率（WSA）（VNP43MA3N）。研究者可利用 BRDF 模型参数与简单的多项式相结合，获取任意太阳光照角度下的黑天反照率。同样，BSA 和 WSA 科学数据集（SDS）层也可通过简单多项式进行使用，以手动估算瞬时实际反照率（蓝天反照率）。有关方法的详细信息可在算法理论依据文档（ATBD）中找到，文档链接为 https://www.umb.edu/editor_uploads/images/school_for_the_environment_cs…。VNP43MA1N 数据产品共提供 24 个 SDS 层，包括强制质量带和代表 VIIRS 中等分辨率波段 M1-M5、M7-M8 以及 M10-M11 的 fiso、fvol 和 fgeo 三个多维度模型参数带。