VJ143C4: Daily Global Nadir-Adjusted Surface Reflectance

NOAA-20 VIIRS data corrects for view-angle effects to model surface reflectance as if viewed from directly overhead at local solar noon. The product provides daily, global coverage at a 0.05-degree resolution using a 16-day moving window of observations. It includes Nadir BRDF-Adjusted Reflectance for 10 spectral bands plus five ancillary layers for quality, uncertainty, and snow cover.

Use Cases

• Climate model initialization and validation based on daily, global surface reflectance data.
• Monitoring land surface anisotropy and albedo changes using the RossThick/Li-Sparse-Reciprocal BRDF model.
• Assessing snow cover dynamics and data quality via the included snow cover percentage and quality assurance layers.

Strengths

• Provides global daily coverage at a consistent 0.05-degree (approx. 5.6 km) Climate Modeling Grid resolution.
• Includes 15 science variables: NBAR for 10 VIIRS bands plus ancillary data for uncertainty, quality, and snow cover.
• Uses a sophisticated, kernel-driven BRDF model (RTLSR) to normalize reflectance to a nadir view, reducing angular artifacts.

Limitations

• Metadata completeness is low: column names, row counts, and exact file sizes are not provided by any source.
• The data is derived from a 16-day moving window, meaning daily values are not from a single instantaneous observation.
• Users must assess provided quality flags before use, as underlying pixel quality and inversion status vary.

Provenance

Source

LPCLOUD (NASA Land Processes Distributed Active Archive Center)

Collection Method

Derived from the 30 arc-second VJ143D Version 2 product suite using the VJ143 algorithm.

Freshness

Last updated 2026-04-09 according to nasa_earthdata and datagov.

Geography

Global