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The Visible and Infrared Imager/Radiometer Suite

The Visible and Infrared Imager/Radiometer Suite (VIIRS) is a multi-disciplinary instrument that will fly on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) series of spacecraft, including the NPOESS Preparatory Project (NPP). NPOESS is a multi-platform, multi-agency program that consolidates the polar orbiting spacecraft of NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Department of Defense. NPP is the initial spacecraft in this series, and VIIRS is the successor to MODIS for Earth science data product generation.

VIIRS has 22 spectral bands ranging from 412 nm to 12 μm. There are 16 moderate-resolution bands (750m at nadir), 5 image-resolution bands (375m), and one day-night band (DNB). For more information, see the VIIRS Instrument link below.

VIIRS Instrument (NPOESS Website)

NASA’s role is to assess the quality of the NPP data products for use as Climate Data Records (CDRs). The OBPG was been selected by NASA to support the VIIRS Ocean Science Team (VOST), while the ODPS has been designated as the Ocean Product Evaluation and Analysis Tool Element (PEATE) within the NASA Science Data Segment (SDS).

NPOESS Orbiter Artistic Rendition



As an element of the SDS, the Ocean PEATE performs the following tasks in support of the VOST:

  • Acquire VIIRS data products from the Science Data Depository and Distribution Element (SD3E) and the Archive Data Segment (ADS) / Comprehensive Large-Array Stewardship System (CLASS).
  • Support the assessment of the quality of the NPP Ocean Color/Chlorophyll (OCC) and Sea Surface Temperature (SST) Environmental Data Records (EDRs) for accomplishing NASA’s climate research requirements.
  • Provide suggested algorithm improvements to the NPOESS Interface Data Processing Segment (IDPS) via the Project Science Working Group (PSWG).
  • Process selected data subsets in support of Evaluation and Validation activities.

The PEATE will acquire, ingest and archive the VIIRS data products, and perform additional processing as needed for product evaluation, using the existing capabilities of the ODPS. Presentations that were made for the Ocean PEATE at the SDS design reviews and other meetings can be found here.



Supporting the NASA Science Team, the VOST evaluates the NPP Ocean Color EDR data products to determine whether they provide data continuity for NASA climate data records (CDR).  In this sense, the main focii are:

  • Use instrument radiometric testing and characterization data to assess VIIRS performance.
  • Evaluate how instrument performance affect science data quality and quantify the impact.
  • Determine how effective on-orbit calibration capabilities and reprocessing are to produce CDR data products.
  • Determine how effective operations algorithms are in providing CDR data products.

The VOST works with other government (e.g, NOAA, NAVY) and science community stakeholders to determine whether the VIIRS instrument will provide quality data that is sufficient to support other objectives for ocean science research. This included, but is not limited, coastal ecosystems and biogeochemical processes.

Reports - ATBD Reviews - Code Reviews