{"action":"created","issue":{"url":"https://api.github.com/repos/sunpy/sunpy/issues/1615","labels_url":"https://api.github.com/repos/sunpy/sunpy/issues/1615/labels{/name}","comments_url":"https://api.github.com/repos/sunpy/sunpy/issues/1615/comments","events_url":"https://api.github.com/repos/sunpy/sunpy/issues/1615/events","html_url":"https://github.com/sunpy/sunpy/issues/1615","id":118052722,"number":1615,"title":"Alignment of Halpha & HMI composite maps","user":{"login":"slyardley","id":5773943,"avatar_url":"https://avatars.githubusercontent.com/u/5773943?v=3","gravatar_id":"","url":"https://api.github.com/users/slyardley","html_url":"https://github.com/slyardley","followers_url":"https://api.github.com/users/slyardley/followers","following_url":"https://api.github.com/users/slyardley/following{/other_user}","gists_url":"https://api.github.com/users/slyardley/gists{/gist_id}","starred_url":"https://api.github.com/users/slyardley/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/slyardley/subscriptions","organizations_url":"https://api.github.com/users/slyardley/orgs","repos_url":"https://api.github.com/users/slyardley/repos","events_url":"https://api.github.com/users/slyardley/events{/privacy}","received_events_url":"https://api.github.com/users/slyardley/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2015-11-20T14:32:13Z","updated_at":"2015-11-20T15:28:09Z","closed_at":null,"body":"I am trying to create a composite map consisting of submaps of H-alpha and HMI data. The H-alpha data seems to be offset in both the x and y direction by ~100\", compared with HMI.\r\n\r\nHalpha fits: \r\nftp://ftp.kso.ac.at/Ha4M/2011/20110605/processed/kanz_halph_fi_20110605_065522.fts\r\n(password for Halpha available here: http://cesar.kso.ac.at/main/ftp.php)\r\n\r\nHMI fits: \r\nhttp://jsoc.stanford.edu/SUM72/D761559934/S00000/\r\n(hmi.M_720s.20110605_070000_TAI.1.magnetogram.fits)\r\n\r\n```python\r\nhmap = sunpy.map.Map('kanz_halph_fi_20110605_065522.fts').rotate()\r\nhmap.meta['waveunit'] = 'AA' #changing ANG to proper units\r\nhmap.meta['CTYPE1'] = 'HPLN-TAN'\r\nhmap.meta['CTYPE2'] = 'HPLT-TAN'\r\nsmap = hmap.submap(u.Quantity([-100, 500], u.arcsec),\r\n                   u.Quantity([-600, -250], u.arcsec))\r\nhmimap = sunpy.map.Map('hmi.M_720s.20110605_070000_TAI.1.magnetogram.fits').rotate()\r\nshmimap = hmimap.submap(u.Quantity([-100, 500], u.arcsec),\r\n                   u.Quantity([-600, -250], u.arcsec))\r\n\r\ncomp_map = sunpy.map.Map(smap,shmimap, composite=True)\r\ncomp_map.set_alpha(1, 0.75)\r\ncomp_map.set_colors(1,'winter')\r\ncomp_map.set_levels(1, [-300,-500,300,500])\r\nfig = plt.figure(figsize=(12,8))\r\ncomp_map.plot()\r\nplt.title('2011-06-05 06:55:22')\r\n\r\n```\r\n![comp_plot](https://cloud.githubusercontent.com/assets/5773943/11302049/e31dd534-8f92-11e5-819f-30ac8e586830.png)\r\n"},"comment":{"url":"https://api.github.com/repos/sunpy/sunpy/issues/comments/158432088","html_url":"https://github.com/sunpy/sunpy/issues/1615#issuecomment-158432088","issue_url":"https://api.github.com/repos/sunpy/sunpy/issues/1615","id":158432088,"user":{"login":"slyardley","id":5773943,"avatar_url":"https://avatars.githubusercontent.com/u/5773943?v=3","gravatar_id":"","url":"https://api.github.com/users/slyardley","html_url":"https://github.com/slyardley","followers_url":"https://api.github.com/users/slyardley/followers","following_url":"https://api.github.com/users/slyardley/following{/other_user}","gists_url":"https://api.github.com/users/slyardley/gists{/gist_id}","starred_url":"https://api.github.com/users/slyardley/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/slyardley/subscriptions","organizations_url":"https://api.github.com/users/slyardley/orgs","repos_url":"https://api.github.com/users/slyardley/repos","events_url":"https://api.github.com/users/slyardley/events{/privacy}","received_events_url":"https://api.github.com/users/slyardley/received_events","type":"User","site_admin":false},"created_at":"2015-11-20T15:28:09Z","updated_at":"2015-11-20T15:28:09Z","body":"I couldn't see anything in the headers (unless I missed it). Also I have made the same plot before in IDL with no alignment issues?"}}