{"action":"created","issue":{"url":"https://api.github.com/repos/terraref/reference-data/issues/32","repository_url":"https://api.github.com/repos/terraref/reference-data","labels_url":"https://api.github.com/repos/terraref/reference-data/issues/32/labels{/name}","comments_url":"https://api.github.com/repos/terraref/reference-data/issues/32/comments","events_url":"https://api.github.com/repos/terraref/reference-data/issues/32/events","html_url":"https://github.com/terraref/reference-data/issues/32","id":156848021,"number":32,"title":"Converting lemnatec scanner metadata to absolute geographic positions","user":{"login":"dlebauer","id":464871,"avatar_url":"https://avatars.githubusercontent.com/u/464871?v=3","gravatar_id":"","url":"https://api.github.com/users/dlebauer","html_url":"https://github.com/dlebauer","followers_url":"https://api.github.com/users/dlebauer/followers","following_url":"https://api.github.com/users/dlebauer/following{/other_user}","gists_url":"https://api.github.com/users/dlebauer/gists{/gist_id}","starred_url":"https://api.github.com/users/dlebauer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/dlebauer/subscriptions","organizations_url":"https://api.github.com/users/dlebauer/orgs","repos_url":"https://api.github.com/users/dlebauer/repos","events_url":"https://api.github.com/users/dlebauer/events{/privacy}","received_events_url":"https://api.github.com/users/dlebauer/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/terraref/reference-data/labels/sensor-data","name":"sensor-data","color":"c2e0c6"}],"state":"open","locked":false,"assignee":{"login":"caicai89-","id":9286213,"avatar_url":"https://avatars.githubusercontent.com/u/9286213?v=3","gravatar_id":"","url":"https://api.github.com/users/caicai89-","html_url":"https://github.com/caicai89-","followers_url":"https://api.github.com/users/caicai89-/followers","following_url":"https://api.github.com/users/caicai89-/following{/other_user}","gists_url":"https://api.github.com/users/caicai89-/gists{/gist_id}","starred_url":"https://api.github.com/users/caicai89-/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/caicai89-/subscriptions","organizations_url":"https://api.github.com/users/caicai89-/orgs","repos_url":"https://api.github.com/users/caicai89-/repos","events_url":"https://api.github.com/users/caicai89-/events{/privacy}","received_events_url":"https://api.github.com/users/caicai89-/received_events","type":"User","site_admin":false},"milestone":null,"comments":6,"created_at":"2016-05-25T20:54:31Z","updated_at":"2016-05-25T23:52:53Z","closed_at":null,"body":"_From @solmazhajmohammadi on March 18, 2016 20:31_\n\n@czender, At the moment there is no accurate GPS at the gantry box. It is planned to add geographical coordinates to metadata, based on the fixed point on the ground and a RTK GPS location.\r\nHere are locations from each corner of the field that @rjstrand sent from his phone:\r\n\r\nSE Corner 33° 04.470' N / -111° 58.485' W\r\nSW Corner. 33° 04.474' N / -111° 58.505' W\r\nNW Corner. 33° 04.592' N / -111° 58.505' W\r\nNE Corner. 33° 04.591' N / -111° 58.487' W\r\n  \r\nI have used linear scaling formula to transfer the coordinates, it should be enough for the current GPS location. \r\n\r\nTo determine the location of each pixel within the image, Extrinsic and Intrinsic calibration matrices are needed.\r\n3 coordinate systems exist: \r\n- Field coordinate frame (Xf , Yf , Zf)\r\n- Camera coordinate (Xc , Yc , Zc)\r\n- Image coordinate (Xp , Yp)\r\n\r\n1 ) Extrinsic calibration matrix: \r\nThe extrinsic calibration parameters specify the transformation from the field to the camera coordinates, and it is represented as,\r\n[Xc  Yc  Zc]'= Ro  [Xf  Yf  Zf]'+ to\r\nSince there is no rotation (Ro), MEX is only translating vector to. to is transition vector from the control point (0,0,0) to camera position [Xc Yc Zc]. Considering that gantry is moving with constant speed in x direction, and metadata information shows the starting time and start position of a scan.  \r\nto = [+xg+Vx*(t)   +yg   +zg]'  \r\n\r\nWhere (xg ,yg ,zg ) is the camera position in gantry box. For Hyperspectral camera (xg, yg ,zg ) is (1.9 , 0.855 , 0.635). Vx is velocity in x direction. t represents time difference. ()' is transpose operation.\r\n\r\n2 ) Intrinsic calibration matrix: \r\nNotes:\r\n\r\n- The geometric distortions that exist between the 272 bands are considered to be small. \r\n- No rectification is done. \r\n- No distortion and lens model is considered.\r\n- Mirror angle change is not considered. \r\n\r\nThe intrinsic calibration parameters specify the transformation from the camera coordinate to the pixel coordinates.\r\nCoordinate transformation between camera plane and image plane:\r\n[Xp Yp f]'= **A** [ **I  0** ] [Xc  Yc  Zc]'\r\nSimple orientation matrix is:\r\n ![stereocalibrate1](https://cloud.githubusercontent.com/assets/17046539/13890132/e71ffdf0-ed17-11e5-9dad-ccf39e0459bd.png)\r\nαx = αy =α and it's focal length divided by pixel pitch. u0 and v0 denote the principal point (ideally center of image) \r\nFor SWIR camera focal length is 24 mm, and pixel pitch is equal to 25 um. I dont know how much is γ. I have contacted the Headwall group and hopefully soon, they will provide me with more information on calibration of the camera. So, I will update your response soon. \r\n\r\n\r\n\r\n\n\n_Copied from original issue: terraref/documentation#9_"},"comment":{"url":"https://api.github.com/repos/terraref/reference-data/issues/comments/221741345","html_url":"https://github.com/terraref/reference-data/issues/32#issuecomment-221741345","issue_url":"https://api.github.com/repos/terraref/reference-data/issues/32","id":221741345,"user":{"login":"dlebauer","id":464871,"avatar_url":"https://avatars.githubusercontent.com/u/464871?v=3","gravatar_id":"","url":"https://api.github.com/users/dlebauer","html_url":"https://github.com/dlebauer","followers_url":"https://api.github.com/users/dlebauer/followers","following_url":"https://api.github.com/users/dlebauer/following{/other_user}","gists_url":"https://api.github.com/users/dlebauer/gists{/gist_id}","starred_url":"https://api.github.com/users/dlebauer/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/dlebauer/subscriptions","organizations_url":"https://api.github.com/users/dlebauer/orgs","repos_url":"https://api.github.com/users/dlebauer/repos","events_url":"https://api.github.com/users/dlebauer/events{/privacy}","received_events_url":"https://api.github.com/users/dlebauer/received_events","type":"User","site_admin":false},"created_at":"2016-05-25T23:52:53Z","updated_at":"2016-05-25T23:52:53Z","body":"I meant @SolmazHajmohammadi"}}
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