Polar2Grid Version 3.0 Release

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kathys
Posts: 484
Joined: Tue Jun 22, 2010 4:51 pm

Polar2Grid Version 3.0 Release

Post by kathys »

Dear Colleagues,

The University of Wisconsin Space Science and Engineering Center (SSEC) is pleased to announce a new release of the Community Satellite Processing Package (CSPP) Polar2Grid software Version 3.0. Polar2Grid is open source software for reprojecting and gridding of polar orbiter satellite data
including VIIRS, MODIS and AVHRR imager instruments into a variety of output formats including:

• GeoTIFF files,
• Advanced Weather Interactive Processing System (AWIPS) gridded files. AWIPS is the visualization and analysis tool used operationally by the US National Weather Service (NWS),
• Keyhole Markup language Zipped (KMZ) files,
• HDF5 files, and
• Binary files.

Polar2Grid is designed to make it easy to create high quality images from Polar Orbiter data and science products. Development is led by David Hoese with funding support from the NOAA/NASA Joint Polar Satellite System (JPSS) program.

What is new in Version 3.0:

Polar2Grid Version 3.0 is a major update. There are many changes including the basic polar2grid.sh execution. These changes were implemented in order to bring the code base in line with Pytroll Satpy. 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.

Highlighted changes:
• New basic implementation “polar2grid.sh -r reader -w writer”
• Reader and writer name changes and replacements. For instance the GeoTIFF writer is now “geotiff” replacing “gtiff”
• NOAA20 output file names standardized to “noaa20” prefix
• Add support for NOAA21 VIIRS
• An Alpha Band is now included by default for all GeoTIFFs. Use "--fill-value 0" to create files without the Alpha band
• Users can now specify the number of worker threads to use with the "--num-workers “ option
• Rescaling “.ini” files are no longer supported, and have been replaced with “.yaml” format files

The documentation included with this release contains extensive examples of the new Version 3.0 implementations, including example executions in every reader section, 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 encounter in transitioning to V3.0. Please use the `Contact Us` form from our CSPP website to submit your inquiry.

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:
polar2grid.sh -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: https://github.com/ssec/polar2grid.

Improved Performance

Polar2Grid Version 3.0 now uses Xarry and Dask python libraries which can enable efficient parallel computations on single machines or distributed clusters. This results in better performance especially when processing large data sets. For example, to create a full suite of VIIRS SDR band GeoTIFF images plus true and false color images from a 10 granule overpass on a modern computer took Polar2Grid Version 2.3 12m45s using one CPU. The same data set was processed by Polar2Grid Version 3.0 in 4m32s using the default 4 worker threads.

The following is a list of Satellite Instruments and Science Data Products supported by Polar2Grid Version 3.0:

• NOAA-21, NOAA-20, S-NPP VIIRS
• Aqua, Terra MODIS
• NOAA-18,-19, MetOP-A,-B,-C AVHRR
• GCOM-W1 AMSR2
• 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)

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)

Source code, binaries, execution scripts and documentation are available for download at the CSPP website:

https://cimss.ssec.wisc.edu/cspp/polar2grid_v3.0.shtml

The online documentation is now available at: https://www.ssec.wisc.edu/software/polar2grid/

Sincerely,

Kathy Strabala and David Hoese
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