{"id":16719,"date":"2014-09-29T16:47:03","date_gmt":"2014-09-29T16:47:03","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=16719"},"modified":"2014-09-29T18:13:09","modified_gmt":"2014-09-29T18:13:09","slug":"co-registration-issues-on-goes-13","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/16719","title":{"rendered":"Co-registration Issues on GOES-13"},"content":{"rendered":"

Previous posts on this blog<\/a> (and elsewhere<\/a>) have detailed the co-registration misalignment that exists between the 3.9 \u00b5m and 10.7 \u00b5m channels on the GOES-13 Imager. Because of this diurnally-varying co-registration error, a 3.9 \u00b5m pixel may be offset to the right or left of a 10.7 \u00b5m pixel; if this occurs near a pronounced temperature gradient (such as along a lakeshore), a false brightness temperature difference signal can ensue.<\/p>\n

\"Brightness<\/a>

Brightness Temperature Difference (10.7 \u00b5m – 3.9 \u00b5m), 1825 and 1830 UTC, 26 September 2014<\/strong> (click to enlarge)<\/p><\/div>\n

Consider, for example, the toggle above from 26 September 2014. A strong brightness temperature difference exists at 1825 UTC along the shorelines of Lakes Michigan, Huron and Erie; it is gone five minutes later, at 1830 UTC. There is no discernible change in the visible image over the same 5-minute interval (Link<\/a>).<\/p>\n

\"GOES-13<\/a>

GOES-13 Imagery (0.63\u00b5m , top, 10.7\u00b5m , middle and 3.9\u00b5m micron, bottom) at 1825 and 1830 UTC, 26 September 2014<\/strong> (click to enlarge)<\/p><\/div>\n

NESDIS operations alters the GVAR signal just before 1830 UTC (when the 3.9 \u00b5m imagery is shifted one pixel to the West) and at 0630 UTC (when the 3.9 \u00b5m imagery is shifted one pixel to the East) to mitigate the effects of the diurnally-varying co-registrations differences between the 3.9 \u00b5m and 10.7 \u00b5m channels. The imagery above shows the visible and two infrared (10.7 \u00b5m and 3.9 \u00b5m) channels at 1825 and 1830 UTC (GOES-13 was in Rapid Scan Operations mode at this time). The 3.9 \u00b5m imagery shows a one-pixel westward shift that is especially evident if you look at the unchanging navigation along the eastern shore of Lake Michigan. (1825 UTC imagery: Visible<\/a>, 3.9\u00b5m<\/a> and 10.7\u00b5m<\/a>; 1830 UTC imagery: Visible<\/a>, 3.9\u00b5m<\/a> and 10.7\u00b5m<\/a>) A similar link between 1815 and 1830 UTC on 25 September<\/a> shows the same shift in the shortwave IR. A toggle<\/a> between 0615<\/a> and 0630<\/a> UTC on 29 September shows the eastward shift in the 3.9 \u00b5m imagery that occurs then.<\/p>\n

NOAA\/NESDIS continues to monitor this co-registration issue.<\/p>\n","protected":false},"excerpt":{"rendered":"

Previous posts on this blog (and elsewhere) have detailed the co-registration misalignment that exists between the 3.9 \u00b5m and 10.7 \u00b5m channels on the GOES-13 Imager. Because of this diurnally-varying co-registration error, a 3.9 \u00b5m pixel may be offset to the right or left of a 10.7 \u00b5m pixel; if this occurs near a pronounced […]<\/p>\n","protected":false},"author":19,"featured_media":16741,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[50,11],"tags":[],"class_list":["post-16719","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-calibration","category-goes-13"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/16719","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=16719"}],"version-history":[{"count":27,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/16719\/revisions"}],"predecessor-version":[{"id":16748,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/16719\/revisions\/16748"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/16741"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=16719"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=16719"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=16719"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}