{"id":48499,"date":"2022-10-26T18:09:14","date_gmt":"2022-10-26T18:09:14","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=48499"},"modified":"2022-10-31T17:02:11","modified_gmt":"2022-10-31T17:02:11","slug":"band-7-on-himawari-9-vs-band-7-on-himawari-8","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/48499","title":{"rendered":"Band 7 on Himawari-9 vs. Band 7 on Himawari-8"},"content":{"rendered":"\n
\"\"<\/a>
Himawari-8 Visible Imagery (Band 3, 0.64 \u00b5m) along with Himawari-8 and Himawari-9 Day Convection RGB imagery, 0200 UTC on 26 October 2022, near Guam (click to enlarge)<\/figcaption><\/figure>\n\n\n\n

Himawari-9 is slated to become operational (replacing Himawari-8, which has been operational at 140.7o <\/sup>E Longitude since 2015!) on 13 December 2022 (Link<\/a>). One change that users might observe arises from the slightly shorter central wavelength in the shortwave infrared band (Band 7). On Himawari-8, the central wavelength is 3.885 \u00b5m; on Himawari-9, the central wavelength is closer to 3.829 \u00b5m (see this link from JMA<\/a>, or this one<\/a>). The effect of the shorter wavelength on Himawari-9 is more noticeable during the daytime, when solar reflectance will lead to warmer observed brightness temperatures, especially over highly reflective convective updrafts (This presentation<\/a> — see slide 19 — given at the CIRA RGB Workshop<\/a> in October 2022, suggests daytime differences of up to 5 C.), and especially when compared to longwave infrared imagery as a brightness temperature difference.<\/p>\n\n\n\n

The toggle above compares Himawari-8 visible imagery and Day Convection RGB<\/a> imagery from Himawari-8 and -9 at 0200 UTC on 26 October 2022. in a region near Guam, without much intense convection. Subtle differences in the yellow shading over some convection are apparent (here’s a toggle<\/a> just between Himawari-8 and -9 Day Convection RGB over Guam). It’s very hard to discern a difference in regions of no convection.<\/p>\n\n\n\n

For strong convection, however, as shown below for a case over the south-central Equatorial Pacific, differences in yellow coloring over very strong convection are noteable; users might need to adjust the range of the RGB to draw out details in cloud tops, where, for Himawari-9 imagery, contrast is lost. (Here’s<\/a> a toggle, over the strong convection, between Day Convection RGBs from Himawari-8<\/a> and Himawari-9<\/a>).<\/p>\n\n\n\n

\"\"
Himawari-8 Visible Imagery (Band 3, 0.64 \u00b5m) along with Himawari-8 and Himawari-9 Day Convection RGB imagery, 0200 UTC on 26 October 2022, over the Equatorial Pacific (click to enlarge)<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

Spectral Response Functions for the infrared channels are available from Himawari-8 (here<\/a>) and Himawari-9 (here<\/a>). You will note that most infrared channels have similar functions; the outlier is band 7, shown below (and in this animated gif<\/a>).<\/p>\n\n\n\n\t\n\t\t\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/polyline>\n\t\t\t<\/svg>\n\t\t<\/span>\n\t<\/span>\n<\/div>\n\n\n\n\n\n

\n\n\n\n

Thanks to JMA<\/a> for providing simultaneous image files for the different bands on Himawari-8 and Himawari-9!<\/p>\n","protected":false},"excerpt":{"rendered":"

Himawari-9 is slated to become operational (replacing Himawari-8, which has been operational at 140.7o E Longitude since 2015!) on 13 December 2022 (Link). One change that users might observe arises from the slightly shorter central wavelength in the shortwave infrared band (Band 7). On Himawari-8, the central wavelength is 3.885 \u00b5m; on Himawari-9, the central […]<\/p>\n","protected":false},"author":19,"featured_media":48505,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[62,73,45],"tags":[],"class_list":["post-48499","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-himawari-8","category-himawari-9","category-redgreenblue-rgb-images"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/48499","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=48499"}],"version-history":[{"count":6,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/48499\/revisions"}],"predecessor-version":[{"id":48564,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/48499\/revisions\/48564"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/48505"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=48499"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=48499"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=48499"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}