{"id":360,"date":"2010-09-02T16:14:17","date_gmt":"2010-09-02T16:14:17","guid":{"rendered":"http:\/\/bcmeteors.net\/wp\/2010\/09\/02\/sentinel-camera-calibration\/"},"modified":"2010-09-02T16:14:17","modified_gmt":"2010-09-02T16:14:17","slug":"sentinel-camera-calibration","status":"publish","type":"post","link":"https:\/\/bcmeteors.net\/?p=360","title":{"rendered":"Sentinel Camera Calibration"},"content":{"rendered":"<p>In December of 2008, after a series of back of the envelope type discussions on how to calibrate a Sentinel camera, Ken formalized the discussions in a pdf. To see Ken&#8217;s method<a href=\"https:\/\/bcmeteors.net\/wp\/wp-content\/uploads\/2010\/09\/camera_calibration.pdf\"> Click here for Ken&#8217;s original paper<\/a><a href=\"home\/bcmeteor\/public_html\/images\/pdf\"> <\/a>on how we can calibrate the Sentinel camera.<\/p>\n<p>As a footnote I (Jeff) did a work through with my camera system. After the spreadsheet was made and a small Python program run Ken took my results and plotted it to see how his model stood up. Here are those results.<\/p>\n<p>\u00a0<\/p>\n<p>Hi Jeff,<\/p>\n<p>I could not resist having a quick look. Your data is lovely. I simply plotted<\/p>\n<p>R = sqrt((x-x<sub>0<\/sub>)<sup>2<\/sup>+(y-y<sub>0<\/sub>)<sup>2<\/sup>)<\/p>\n<p>against zenith angle.<\/p>\n<p>In the first plot I assumed the camera zenith was (371,240), and in the second I optimized it, and got (370,231). This of course would be the camera zenith not the centre of the frame.<\/p>\n<p>HOWEVER: Look at the nice clean plot and good correlation. I think you can use the camera zenith method and ignore trying to find the centre of the frame; they are obviously very close because the plot, including the very slight nonlinearity due to the fisheye effect, integrates so cleanly.<\/p>\n<p>The very slight fisheye effect can be approximated more than adequately by a 2nd-order polynomial, as Martin Connors said it would.<\/p>\n<p>I would say, for your system, you should be able to simply calculate R and use the equation to get the zenith angle, and then do a rotation to find the azimuth error&#8230;. job done.<\/p>\n<p>Regards,<\/p>\n<p>Ken<\/p>\n<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In December of 2008, after a series of back of the envelope type discussions on how to calibrate a Sentinel camera, Ken formalized the discussions in a pdf. To see Ken&#8217;s method Click here for Ken&#8217;s original paper on how we can calibrate the Sentinel camera. As a footnote I (Jeff) did a work through &hellip; <a href=\"https:\/\/bcmeteors.net\/?p=360\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Sentinel Camera Calibration&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":358,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[42],"tags":[],"class_list":["post-360","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-video-methods"],"_links":{"self":[{"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/posts\/360","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=360"}],"version-history":[{"count":0,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/posts\/360\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=\/wp\/v2\/media\/358"}],"wp:attachment":[{"href":"https:\/\/bcmeteors.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=360"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=360"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bcmeteors.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=360"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}