Visible Infrared Imaging Radiometer Suite (VIIRS) Climate Raw Data Record (C-RDR)

False-color image created from the raw band 5, 4, and 2 (used as blue, green, and red, respectively) 375 m resolution pixels extracted from the VIIRS C-RDR file with a start time of 18:24:51 GMT, January 28, 2014.

NCDC's Visible Infrared Imaging Radiometer Suite (VIIRS) Climate Raw Data Record (C-RDR) is an intermediary product between the Raw Data Record (RDR) product and the many Sensor Data Record (SDR) products for the VIIRS instrument. The VIIRS instrument is a key element of the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite, which was launched in October 2011. VIIRS collects data in 22 spectral channels, from visible to longwave infrared, at two different spatial resolutions: 375 m and 750 m at nadir.

The VIIRS C-RDR contains all the raw measurements from the VIIRS RDR collected into time series variables. This simplifies access to the data for reprocessing using alternative calibration and geolocation methods. The VIIRS C-RDR also provides the coefficients and tables used by the NESDIS Interface Data Processing Segment (IDPS) to convert the raw measurements to science units and calibrate them. These data are all written to files using the Network Common Data Form 4 (netCDF-4) format, which is platform-independent, binary, hierarchical, and self-describing. Each variable within a VIIRS C-RDR file is annotated with a description of the measurement, information about the source, and specifications of valid limits and fill values.

Each VIIRS C-RDR file also contains file-level metadata conforming to the Climate and Forecast (CF) metadata conventions, the Attribute Convention for Dataset Discovery (ACDD), and the Joint Polar Satellite System (JPSS) standards for Suomi NPP data products. Metadata elements, such as granule IDs, which are found in Suomi NPP data product files, are also present in C-RDR files as an aid to understanding the provenance and processing history of the VIIRS C-RDR files.

A number of existing software applications (IDL, MATLAB, etc.) can easily read the variables contained within VIIRS C-RDR files. Users can also easily access the file contents in their own applications by employing netCDF libraries that are available for FORTRAN, C, C++, Java, or Python.

Data Access

• Climate Raw Data Record Products
  Access the VIIRS C-RDR dataset by searching and submitting an order based on observation time.
• CrdrExplorer Application
  A self-contained Java application (jar file) that demonstrates access to the VIIRS C-RDR.

Documentation

• VIIRS C-RDR Product Specification
  Detailed description of the contents of the VIIRS Climate Raw Data Record.

Additional Information

• VIIRS Climate Raw Data Record from Suomi NPP, Version 1
  More information on the VIIRS C-RDR including points of contact, coverage, and dataset identifiers.
• The VIIRS Climate Raw Data Record: An Easy-to-use Raw Data Set (Level 1b) for the Suomi-NPP Visible Infrared Imaging Radiometer Suite
  Learn more about the VIIRS C-RDR through this recorded presentation.
• Efficient Access to Raw Measurements and Processing Coefficients for NPOESS Preparatory Project and Joint Polar Satellite Systems Sensor Data
  This poster describes the motivation and methodology behind the VIIRS C-RDR.
• Joint Polar Satellite System
  Learn more about the Joint Polar Satellite System in general, as well as the Suomi National Polar-orbiting Partnership mission.
• Visible Infrared Imaging Radiometer Suite
  Learn more about the VIIRS instrument and how it contributes to ocean, land, and cloud science from our partners at NASA.