Community Satellite Processing Package

  CSPP Polar2Grid Reprojection Software Version 3.0 Release

21 February 2023

The CSPP Polar2Grid Software was created to enable Polar Orbiter Satellite Imager users (VIIRS, AVHRR and MODIS), including the US National Weather Service (NWS), the capability to easily create high quality reprojected imagery. NOAA JPSS has funded this effort to create an open-source, modular application system. This bundled solution automates tools for converting satellite data including Suomi-NPP VIIRS into a variety of output formats, including GeoTIFFs, AWIPS compatible NetCDF, binary and HDF5.

In addition to traditional visible and infrared imagery, the software provides the capability to create sharpened true color, sharpened false color, and user-defined Red/Green/Blue (RGB) images.

What is new in Version 3.0:

Polar2Grid Version 3.0 is a major update that includes changes to the basic execution. These changes were implemented in order to bring the code base in line with the Pytroll Satpy library, instead of having to duplicate the effort. This will make adding Satpy functionality to Polar2Grid much easier in the future. Polar2Grid also now uses the Xarry and Dask python libraries which result in improved performance for most applications.
  • New Implementation “ -r reader -w writer"
  • Reader name changes and replacements
  • Writer name changes
  • NOAA20 output file names standardized to “noaa20” prefix
  • NOAA21 VIIRS SDR supported
  • Alpha Band now included as default for GeoTIFFS. Use --fill-value 0 to reproduce previous versions
  • Specify number of CPU’s to use using option "--num-workers "
  • "--list-products" and "--list-product-all" now available
  • Scaling “.ini” files no longer supported. Replaced with “.yaml”
The documentation contains extensive examples of the new implementation, including example executions following every reader description, updated examples in the Examples section, and the addition of an Appendix that includes a longer list of changes and direct comparisons of Polar2Grid V2.3 to V3.0 executions. We are happy to help with any questions or problems that you may have. Please use the `Contact Us` link at the bottom of any CSPP website page.

Features of Polar2Grid
  • Execution is performed through simple bash shell scripts, wrapping python underlying modules. For example, to create GeoTIFF files of NOAA20 VIIRS I-Bands 1 and 5 using the default Platte Carrée (Google Earth) projection, you can execute a command like this: -r viirs_sdr -w geotiff -p i01 i05 -f /viirs/sdr/SVI{01,05}*.h5 /viirs/geo/GITCO*.h5
  • True color and False color reprojections can be created using a single command.
  • If more than one contiguous granule is provided as input, an aggregated output image file will be created.
  • Users can define their own grids. A grid definition helper script is included with the package.
  • Proj4 grid definitions can be used.
  • The Polar2Grid open source software code repository is also available through github at:
System Requirements

  • Intel or AMD CPU with 64-bit instruction support (2+ cores - 2.4GHz)
  • 16 GB RAM (minimum)
  • CentOS 7.9 64-bit Linux; the software has been tested successfully on Rocky Linux 8.5
  • 5 GB disk space (minimum)
The following is a list of Satellite Instruments and Science Data Products supported:
  • Aqua, Terra MODIS
  • NOAA18, NOAA19, MetOP-A,-B,-C AVHRR
  • FY3-D MERSI-2
  • CSPP CLAVR-x Cloud Retrievals
  • CSPP MIRS Microwave Retrievals
  • CSPP ACSPO Sea Surface Temperature Retrievals
  • CSPP VIIRS Active Fire Retrievals
  • CSPP NUCAPS Atmospheric Profile Retrievals (CrIS/ATMS)

Software, execution scripts and documentation are included with the release. The software uses standard CSPP or IDPS Sensor Data Records (SDRs) as input, and allows the user a selection of projections or grids to use for the remapping. The default GeoTIFF projection is the WGS 84/Platte Carrée coordinate system.

Software, execution scripts and documentation are included with the release.