{"id":50988,"date":"2023-03-08T21:48:40","date_gmt":"2023-03-08T21:48:40","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=50988"},"modified":"2023-03-08T22:10:04","modified_gmt":"2023-03-08T22:10:04","slug":"polar2grid-version-3-0-has-been-released","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/50988","title":{"rendered":"Polar2Grid version 3.0 has been released"},"content":{"rendered":"\n
\"\"<\/a>
VIIRS True-Color imagery over the Great Lakes, 7 March 2023, from Suomi NPP (1734 UTC), NOAA-20 (1821 UTC) and NOAA-21 (1846 UTC). (Click to enlarge)<\/figcaption><\/figure>\n\n\n\n

Note: NOAA-21 data used in this blog post are preliminary and non-operational. Imagery was created using Polar2Grid v3.0.<\/p>\n\n\n\n

The CIMSS Community Satellite Processing Package (CSPP)<\/a> team has released Polar2Grid version 3.0<\/a>, a software package that can be used (among many other things!) to create high-quality imagery from JPSS Sensor Data Record (SDR) files as might be produced at a Direct Broadcast site (or ordered\/downloaded from NOAA CLASS). Polar2Grid v3.0 represents a significant change from Polar2Grid v2.3, and some of those changes are documented here. The latest Polar2Grid also has significantly faster processing. The three true-color images above were created using Suomi NPP, NOAA-20 and NOAA-21 VIIRS imagery. (Note that NOAA-21 data are still preliminary and non-operational, although Beta maturity has been reached<\/a>. They are included here to show that Polar2Grid can produce NOAA-21 imagery every bit as stunning as imagery from Suomi NPP and NOAA-20!). An especial advantage of 3 Polar Orbiters is obvious in the imagery above: the capability to animate high-resolution JPSS data.<\/p>\n\n\n\n

Polar2Grid linux-based software can be downloaded from this website<\/a> in the form of a gzipped tar file (Documentation on Polar2Grid is also available<\/a>.) After expanding the downloaded file, and setting an environment file, i.e., export POLAR2GRID_HOME = \/directory\/where\/software\/sits<\/code>, the various packages within $POLAR2GRID_HOME\/bin can be run. To create the imagery above, I first created a map on which to reproject the data. This required the use of the p2g_grid_helper.sh<\/code> scripts that creates the required navigation information in a format Polar2Grid recognizes. I wanted to create something that covered the Great Lakes because all 3 JPSS satellites — Suomi-NPP, NOAA-20 and NOAA-21 — scanned the entire Great Lakes in one swath on a relatively clear day. How will the three scenes compare? After some trial and error, I used this command<\/p>\n\n\n\n

.\/p2g_grid_helper.sh GreatLakes -84.0 45.0 500.0 -500.0 2880 1920 > GreatLakes.yaml<\/code><\/p>\n\n\n\n

that created a grid (called ‘GreatLakes’) centered at 84o<\/sup>W, 45o<\/sup>N, with 500 m resolution in the N-S and E-W directions, with a grid size of 2880×1920. The information created was redirected into the file ‘GreatLakes.yaml’; Polar2Grid software by default now expects grid configuration files created by the p2g_grid_helper shell script to reside in files with a suffix of ‘yaml’.<\/p>\n\n\n\n

To acquire data for Polar2Grid to process, I accessed the CIMSS real-time system<\/a> holding files created from the Direct Broadcast site. Data are separated out by satellite, and by day\/time. Multiple granules are within each day\/time file, especially now that CIMSS is producing expanded files by using data from other Direct Broadcast sites<\/a>! Suomi NPP data for this case, for example, are at this link<\/a> from 1734 UTC on 7 March; data from NOAA-20 are from 1821 UTC; data from NOAA-21 are from 1846 UTC. I could also have requested data from NOAA CLASS by selecting ‘JPSS VIIRS Sensor Data Record Operational (VIIRS_SDR) — although this site only distributes Operational<\/span><\/strong> data: NOAA-21 data are not available (yet). Usually when I access JPSS data from NOAA CLASS, I first view the orbits (from this website<\/a>) for the day in question (7 March in this instance) for NPP<\/a>, NOAA-20<\/a> and (eventually) NOAA-21<\/a>, so I can access specific times that cover the region of interest.<\/p>\n\n\n\n

Once the data were on the machine that holds the Polar2Grid software, it was straightforward to create imagery, using these commands for Suomi-NPP, NOAA-20 and NOAA-21 data, respectively; all the data were in the same directory:<\/p>\n\n\n\n

.\/polar2grid.sh -r viirs_sdr -w geotiff -g GreatLakes --grid-configs GreatLakes.yaml -p true_color -f ..\/..\/daydata\/*npp*.h5<\/code>
.\/polar2grid.sh -r viirs_sdr -w geotiff -g GreatLakes --grid-configs GreatLakes.yaml -p true_color -f ..\/..\/daydata\/*j01*.h5<\/code>
.\/polar2grid.sh -r viirs_sdr -w geotiff -g GreatLakes --grid-configs GreatLakes.yaml -p true_color -f ..\/..\/daydata\/*j02*.h5<\/code><\/p>\n\n\n\n

Polar2Grid’s viirs_sdr reader (the -r flag) is being used, as is the geotiff writer (the -w flag). This syntax is different from earlier versions of Polar2Grid, but more in line with that in Geo2Grid. The data are being regridded (the -g flag) to a ‘GreatLakes’ grid, and grid configurations are stored within the ‘GreatLakes.yaml’ file. The product (-p flag) being created is ‘true_color’ and the data files (the -f flag) are found in the relative directory specified. If a user is unsure of what products can be created given the data in the data directory, the –list-products-all instruction can be used in place of -p to find that out.<\/p>\n\n\n\n

The three commands above create (spectacular!!) True-Color imagery from Suomi-NPP<\/a>, NOAA-20<\/a> and NOAA-21<\/a>, seen in the animation above. Polar2Grid can also be used to add maps to the imagery, but this blogger thought those weren’t necessary.<\/p>\n","protected":false},"excerpt":{"rendered":"

Note: NOAA-21 data used in this blog post are preliminary and non-operational. Imagery was created using Polar2Grid v3.0. The CIMSS Community Satellite Processing Package (CSPP) team has released Polar2Grid version 3.0, a software package that can be used (among many other things!) to create high-quality imagery from JPSS Sensor Data Record (SDR) files as might […]<\/p>\n","protected":false},"author":19,"featured_media":50991,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[78,131,109,49],"tags":[],"class_list":["post-50988","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-noaa-20","category-noaa-21","category-software","category-suomi_npp"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/50988","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=50988"}],"version-history":[{"count":5,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/50988\/revisions"}],"predecessor-version":[{"id":50998,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/50988\/revisions\/50998"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/50991"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=50988"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=50988"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=50988"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}