{"action":"created","issue":{"url":"https://api.github.com/repos/sunpy/sunpy/issues/1281","labels_url":"https://api.github.com/repos/sunpy/sunpy/issues/1281/labels{/name}","comments_url":"https://api.github.com/repos/sunpy/sunpy/issues/1281/comments","events_url":"https://api.github.com/repos/sunpy/sunpy/issues/1281/events","html_url":"https://github.com/sunpy/sunpy/pull/1281","id":56253986,"number":1281,"title":"Solar rotation as seen from Earth - calculation and application to mapcube de-rotation.","user":{"login":"wafels","id":983575,"avatar_url":"https://avatars.githubusercontent.com/u/983575?v=3","gravatar_id":"","url":"https://api.github.com/users/wafels","html_url":"https://github.com/wafels","followers_url":"https://api.github.com/users/wafels/followers","following_url":"https://api.github.com/users/wafels/following{/other_user}","gists_url":"https://api.github.com/users/wafels/gists{/gist_id}","starred_url":"https://api.github.com/users/wafels/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wafels/subscriptions","organizations_url":"https://api.github.com/users/wafels/orgs","repos_url":"https://api.github.com/users/wafels/repos","events_url":"https://api.github.com/users/wafels/events{/privacy}","received_events_url":"https://api.github.com/users/wafels/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/sunpy/sunpy/labels/[Review]","name":"[Review]","color":"fad8c7"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":14,"created_at":"2015-02-02T15:58:15Z","updated_at":"2015-02-06T07:25:25Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/sunpy/sunpy/pulls/1281","html_url":"https://github.com/sunpy/sunpy/pull/1281","diff_url":"https://github.com/sunpy/sunpy/pull/1281.diff","patch_url":"https://github.com/sunpy/sunpy/pull/1281.patch"},"body":"This PR implements the \"rot_xy.pro\" function of SSWIDL, under the name \"rot_hpc\"  This function takes the position on the Sun as seen from Earth at a given time, and calculates where that point moves to (as seen from Earth) given a second time, under the assumption that the point moves according to solar differential rotation.\r\n\r\nThis function is used to implement solar de-rotation of mapcubes.  The implementation given here shifts layers in mapcubes according to how far the *center* of each layer moves according to rot_hpc.  Sub-pixel shifts are implemented.  Differential rotation according to the latitude of each image pixel is *not* accounted for in this implementation.  This is equivalent to assuming that the mapcubes contain images of \"small\" (limited spatial extent) patches of the Sun, for \"short\" periods of time.  This is often a very good approximation to use, and is commonly used.  Further, it is relatively simple to implement and is less computationally expensive that differentially rotating every pixel in a mapcube.\r\n"},"comment":{"url":"https://api.github.com/repos/sunpy/sunpy/issues/comments/73196446","html_url":"https://github.com/sunpy/sunpy/pull/1281#issuecomment-73196446","issue_url":"https://api.github.com/repos/sunpy/sunpy/issues/1281","id":73196446,"user":{"login":"landscape-bot","id":10010231,"avatar_url":"https://avatars.githubusercontent.com/u/10010231?v=3","gravatar_id":"","url":"https://api.github.com/users/landscape-bot","html_url":"https://github.com/landscape-bot","followers_url":"https://api.github.com/users/landscape-bot/followers","following_url":"https://api.github.com/users/landscape-bot/following{/other_user}","gists_url":"https://api.github.com/users/landscape-bot/gists{/gist_id}","starred_url":"https://api.github.com/users/landscape-bot/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/landscape-bot/subscriptions","organizations_url":"https://api.github.com/users/landscape-bot/orgs","repos_url":"https://api.github.com/users/landscape-bot/repos","events_url":"https://api.github.com/users/landscape-bot/events{/privacy}","received_events_url":"https://api.github.com/users/landscape-bot/received_events","type":"User","site_admin":false},"created_at":"2015-02-06T07:25:25Z","updated_at":"2015-02-06T07:25:25Z","body":"[![Code Health](https://landscape.io/badge/106294/landscape.svg?style=flat)](https://landscape.io/diff/91668)\nRepository health increased by 0.04% when pulling **[feca334](https://github.com/wafels/sunpy/commit/feca3341b77c8a24f90519e85740aa3bff725b45) on wafels:newdiffrot1** into **[94e1380](https://github.com/sunpy/sunpy/commit/94e1380e91ba8a06b6dea554f7796f13e97a4876) on sunpy:master**.\n\n * [6 new problems were found](https://landscape.io/diff/91668) (including 0 errors and 2 code smells).\n * [1 problem was fixed](https://landscape.io/diff/91668/fixed) (including 0 errors and 0 code smells)."}}