VNP43IA4: Nadir BRDF-Adjusted Reflectance Daily Global 500m Grid

NASA/NOAA Suomi NPP VIIRS Version 1 data provides daily, 500-meter resolution Nadir BRDF-Adjusted Reflectance (NBAR) estimates, correcting view-angle effects to produce stable surface reflectance. This product, now decommissioned, used 16 days of VIIRS data weighted to the ninth day and applied the RossThick/Li-Sparse-Reciprocal BRDF model to ensure continuity with NASA's MODIS BRDF/Albedo suite. It includes six Science Dataset layers for quality and nadir reflectance across VIIRS imagery bands I1, I2, and I3.

Use Cases

• Land surface change detection based on stable, view-angle corrected nadir reflectance.
• Albedo estimation and modeling using the provided black-sky and white-sky albedo Science Dataset layers.
• Continuity analysis with MODIS BRDF/Albedo products for long-term time series studies.
• Surface anisotropic effect reconstruction using the RTLSR kernel-driven BRDF model parameters.

Strengths

• Provides stable, view-angle corrected reflectance at a consistent 500-meter spatial resolution.
• Designed for continuity with the established NASA MODIS BRDF/Albedo data product suite.
• Uses a sophisticated, documented methodology (RTLSR BRDF model) detailed in an Algorithm Theoretical Basis Document.

Limitations

• The Version 1 product was officially decommissioned on July 31, 2025, limiting its use for current operations.
• Key metadata such as row count, file size, and specific column names are not provided across platforms.
• Platforms show conflicting 'last updated' dates (2026-04-09 vs. 2025-02-08), creating provenance uncertainty.

Provenance

Source

NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS).

Collection Method

Satellite remote sensing data processed daily using a 16-day temporal window and the RTLSR BRDF model.

Time Range

Daily production, but specific start and end dates for the data record are not provided.

Freshness

2026-04 09 20:43:35.759274 (most recent update recorded)

Geography

Global coverage at 500m resolution on the SIN grid.