Overview
VIIRS Global Area Coverage (VGAC) is a comprehensive satellite climate data record that provides calibrated, quality-controlled observations from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard multiple polar-orbiting satellites. VGAC serves as a critical component of NOAA’s satellite climate data portfolio, designed to support long-term climate monitoring and research applications.
As a modern satellite data record, VGAC builds on decades of polar-orbiting satellite observations to create a consistent, well-calibrated dataset suitable for climate studies. The product leverages cloud-based processing architectures to ensure efficient, scalable data production and distribution.
Data Access
NCEI Archive
Operational and archived data at NCEI are available with a 3-5 week latency. Some of the data are available by HTTPS download
For the entire archive period of record, users would need to contact NCEI directly: ncei.orders@noaa.gov
Operational updates
The archived data were routinely produced and made by NOAA STAR in coordination with the University of Maryland until January 2026. Their latency issporadic (performing updates every 2-4 weeks). Their anonymous FTP server provides access to historic data:
ftp://snpp.umd.edu/VGAC/
Since January 2026, the operational and archived data are produced by and available from NCICS (in cooperation with NCEI). The data are available generally with a 3 hour latency at their anonymous FTP server:
ftp://filsrv.cicsnc.org/vgac/data/
Presentations and papers
Data Description
VGAC integrates observations from multiple VIIRS instruments on operational polar-orbiting satellites, including:
- Suomi NPP (NOAA-20): Provides continuous global coverage with advanced radiometric capabilities
- JPSS Series: JPSS-1, JPSS-2, and future missions ensuring long-term data continuity
- Global Coverage: Near-global observations with polar-orbiting satellite swaths
The dataset undergoes rigorous calibration and quality control procedures to ensure consistency across different satellite platforms and instrument generations. Data processing implements:
- Inter-satellite calibration for seamless multi-platform integration
- Robust quality assurance procedures for operational data validation
- Modern cloud-based processing infrastructure for efficient data handling
- Integration with NOAA data distribution systems for broad accessibility
Applications
VGAC supports a wide range of scientific and operational applications:
- Climate Record Development: Long-term, consistent observations for climate trend analysis and monitoring
- Environmental Monitoring: Tracking changes in Earth’s atmosphere, land surface, and oceans
- Research Support: Providing validated satellite data for academic and scientific research
- International Coordination: Supporting collaborative efforts with international partners including EUMETSAT
- Data Continuity: Ensuring seamless transition between satellite generations for uninterrupted climate records
The standardized calibration and global coverage make VGAC particularly valuable for studies requiring consistent observations over extended time periods.
Technical Details
VGAC employs modern data processing approaches optimized for climate data record production:
- Processing Architecture: Python-based algorithms deployed in cloud environments (AWS)
- Scalability: Designed for routine operational processing with parallel processing capabilities
- Quality Control: Comprehensive validation frameworks ensuring data integrity
- Data Stewardship: Follows NOAA Climate Data Record standards and best practices
- Integration: Compatible with existing NOAA Open Data Dissemination (NODD) systems
The technical implementation emphasizes practical solutions that bridge research innovation with operational requirements, ensuring sustainable long-term production of this critical climate dataset.