Polar2Grid—Reprojecting Satellite Data Made Easy

Polar-orbiting multi-band meteorological sensors such as those on the Aqua, Terra, and Suomi NPP satellites pose substantial challenges for taking imagery the last mile to forecast offices, scientific analysis environments, and the general public. To make high quality imagery, satellite instrument observation artifacts, such as the MODIS and VIIRS "bow-tie" overlap regions, must be handled gracefully. To do this quickly and easily, the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin has created an open-source modular application, Polar2Grid. This bundled solution automates tools for converting various satellite products like those from MODIS and VIIRS into a variety of output formats, including GeoTIFFs, AWIPS compatible NetCDF files, and NinJo forecasting workstation compatible TIFF images. In addition to traditional visible and infrared imagery, Polar2Grid includes multiple perceptual enhancements for the VIIRS Day-Night Band (DNB), as well as providing the capability to create sharpened atmospherically-corrected true color and false color imagery. Polar2Grid performs conversions and projections in seconds on large swaths of data. Polar2Grid is currently providing VIIRS imagery over the Continental United States, as well as Alaska, Hawaii, and Puerto Rico, from various Direct-Broadcast antennas to operational forecasters at the NOAA National Weather Service (NWS) offices in their AWIPS terminals, within minutes of an overpass of the Suomi NPP satellite. Recently the Polar2Grid team has added new products like ACSPO sea surface temperatures, new features like a native-resolution SCMI file format for AWIPS clients, and new partnerships with the open source PyTroll group. Five years after Polar2Grid development started, the Polar2Grid team is getting ready to release version 2.2 of the software; supporting more sensors, generating more products, and providing all of its features in an easy to use command line interface.