Community Satellite Processing Package

NOAA Clouds from AVHRR Extended (CLAVR-x) Retrieval Software Package in Support of VIIRS, MODIS and AHVRR Version 3.0

16 September 2019

New release of the US National Oceanic and Atmospheric Administration (NOAA) software for transforming direct broadcast NOAA-20 and Suomi-NPP VIIRS Sensor Data Records (SDRs), NOAA-18, NOAA-19, Metop-A, Metop-B and Metop-C AVHRR, and Aqua and Terra MODIS Level-1B (L1B) files into Level 2 cloud products. CLAVR-x is NOAA's operational cloud processing system for the AVHRR, and in 2015 was updated to run the NOAA Enterprise Algorithms. The CLAVR-x group is led by NOAA NESDIS Center for Satellite Applications and Research (STAR) scientist, Dr. Andrew Heidinger.

CLAVR-x software produces single Field-of-View (FOV) cloud retrievals in HDF4 format from input AVHRR, MODIS, and VIIRS Imager calibrated/geolocated data files.

What is New in CSPP CLAVR-x Version 3.0?

  • Added support for NOAA-20 VIIRS instrument.
  • Added support for Metop-C AVHRR instrument.
  • Output product list can now be easily customized.
  • VIIRS CLAVR-x output is now always unaggregated.
  • VIIRS input SDR de-aggregation option (-x) added.
  • Added new dynamic snow basemap ancillary data requirement.
  • Dynamic ancillary site now supports https protocol:

A few key CLAVR-x output parameters are listed below:

  • cloud mask,
  • cloud type (13 categories),
  • cloud height,
  • cloud top pressure,
  • cloud top temperature,
  • cloud emissivity,
  • cloud optical depth,
  • cloud effective radius,
  • cloud phase,
  • rain rate (experimental),
  • VIIRS lunar reflectances,
  • VIIRS nighttime cloud optical depth,
  • VIIRS nighttime cloud effective radius,
  • product quality flags.
Please see the documentation provided in the package to find out more about the products and a description of the retrieval algorithms. CLAVR-x source code is included with this release.

CLAVR-x Version 3.0 System Requirements
  • Intel or AMD CPU with 64-bit instruction support,
  • 2 GB RAM
  • CentOS 6 64-bit Linux (or other compatible 64-bit Linux distribution),
  • 50 GB of disk space,
  • Internet connection (for downloading ancillary data).