VNP09A1: VIIRS 8-Day Land Surface Reflectance at 1km

VIIRS/NPP Surface Reflectance 8-Day L3 Global 1km SIN Grid V001 provides atmospherically corrected land surface reflectance for nine spectral bands. This Version 1 product was officially decommissioned on April 8th, 2025, with users directed to newer Version 2 data for improved calibration. Each 1-kilometer pixel represents the best cloud-free, low-angle observation selected from an 8-day period, alongside quality assurance and angular data layers.

Use Cases

• Monitoring vegetation health based on atmospherically corrected surface reflectance bands.
• Assessing aerosol loading and its impact using the reflectance state quality assurance layers.
• Modeling surface bidirectional reflectance distribution function (BRDF) using the included sensor and solar zenith angles.
• Generating composite land surface maps by selecting the best-quality pixel from an 8-day observation period.

Strengths

• Data is atmospherically corrected for gases and aerosols, providing a cleaner land surface signal.
• Pixel selection optimizes for high coverage, low sensor angle, and absence of clouds within an 8-day window.
• Product is available on multiple authoritative platforms (NASA Earthdata, Data.gov), indicating its foundational role.

Limitations

• This is a deprecated Version 1 product with known issues, such as incorrect 'High Aerosol' flagging over bright surfaces.
• Key metadata like row count, column names, and exact file size is unavailable across all sources.
• The last update date conflicts between sources (2026-04 09 vs. 2024-06-16), creating uncertainty about the provenance record.

Provenance

Source

NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, VIIRS sensor.

Collection Method

Derived through resampling native 750m Level 2G data to a nominal 1km Sinusoidal (SIN) grid.

Time Range

Coverage period is not specified, but the product provides 8-day temporal composites.

Freshness

Last updated: 2026-04-09 21:12:20.214057 (per two sources, though a third lists 2024-06-16).

Geography

Global coverage.