{"action":"created","issue":{"url":"https://api.github.com/repos/proj4-bot/proj.4/issues/15","labels_url":"https://api.github.com/repos/proj4-bot/proj.4/issues/15/labels{/name}","comments_url":"https://api.github.com/repos/proj4-bot/proj.4/issues/15/comments","events_url":"https://api.github.com/repos/proj4-bot/proj.4/issues/15/events","html_url":"https://github.com/proj4-bot/proj.4/issues/15","id":79309863,"number":15,"title":"utm/GRS80 to tmerc/intl conversion poor now, was good in 4.4.9","user":{"login":"proj4-bot","id":12542084,"avatar_url":"https://avatars.githubusercontent.com/u/12542084?v=3","gravatar_id":"","url":"https://api.github.com/users/proj4-bot","html_url":"https://github.com/proj4-bot","followers_url":"https://api.github.com/users/proj4-bot/followers","following_url":"https://api.github.com/users/proj4-bot/following{/other_user}","gists_url":"https://api.github.com/users/proj4-bot/gists{/gist_id}","starred_url":"https://api.github.com/users/proj4-bot/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/proj4-bot/subscriptions","organizations_url":"https://api.github.com/users/proj4-bot/orgs","repos_url":"https://api.github.com/users/proj4-bot/repos","events_url":"https://api.github.com/users/proj4-bot/events{/privacy}","received_events_url":"https://api.github.com/users/proj4-bot/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/proj4-bot/proj.4/labels/bug","name":"bug","color":"fc2929"},{"url":"https://api.github.com/repos/proj4-bot/proj.4/labels/C:%20Core","name":"C: Core","color":"0000aa"},{"url":"https://api.github.com/repos/proj4-bot/proj.4/labels/P:%20critical","name":"P: critical","color":"ffffb8"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/proj4-bot/proj.4/milestones/6","html_url":"https://github.com/proj4-bot/proj.4/milestones/4.6.1","labels_url":"https://api.github.com/repos/proj4-bot/proj.4/milestones/6/labels","id":1124798,"number":6,"title":"4.6.1","description":"None","creator":{"login":"proj4-bot","id":12542084,"avatar_url":"https://avatars.githubusercontent.com/u/12542084?v=3","gravatar_id":"","url":"https://api.github.com/users/proj4-bot","html_url":"https://github.com/proj4-bot","followers_url":"https://api.github.com/users/proj4-bot/followers","following_url":"https://api.github.com/users/proj4-bot/following{/other_user}","gists_url":"https://api.github.com/users/proj4-bot/gists{/gist_id}","starred_url":"https://api.github.com/users/proj4-bot/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/proj4-bot/subscriptions","organizations_url":"https://api.github.com/users/proj4-bot/orgs","repos_url":"https://api.github.com/users/proj4-bot/repos","events_url":"https://api.github.com/users/proj4-bot/events{/privacy}","received_events_url":"https://api.github.com/users/proj4-bot/received_events","type":"User","site_admin":false},"open_issues":1,"closed_issues":0,"state":"closed","created_at":"2015-05-22T06:06:08Z","updated_at":"2015-05-22T06:09:54Z","due_on":"2008-08-01T04:00:00Z","closed_at":"2015-05-22T06:06:08Z"},"comments":4,"created_at":"2015-05-22T06:09:54Z","updated_at":"2015-05-22T06:10:02Z","closed_at":null,"body":"**Reported by janne on 17 Sep 2008 10:31 UTC**\nThe +towgs84 parameters in the epsg file of version 4.6.1 are incorrect. These are not the TOWGS84 parameters of the current or even the prior versions of the real EPSG database. Additionally the parameters in the Proj4's epsg file are the same.\r\n\r\nList of CRSs having wrong parameters:\r\nEPSG:2391\r\nEPSG:2392\r\nEPSG:2393\r\nEPSG:2394\r\nEPSG:3385\r\nEPSG:3386\n\nMigrated-From: https://trac.osgeo.org/proj/ticket/15"},"comment":{"url":"https://api.github.com/repos/proj4-bot/proj.4/issues/comments/104532370","html_url":"https://github.com/proj4-bot/proj.4/issues/15#issuecomment-104532370","issue_url":"https://api.github.com/repos/proj4-bot/proj.4/issues/15","id":104532370,"user":{"login":"proj4-bot","id":12542084,"avatar_url":"https://avatars.githubusercontent.com/u/12542084?v=3","gravatar_id":"","url":"https://api.github.com/users/proj4-bot","html_url":"https://github.com/proj4-bot","followers_url":"https://api.github.com/users/proj4-bot/followers","following_url":"https://api.github.com/users/proj4-bot/following{/other_user}","gists_url":"https://api.github.com/users/proj4-bot/gists{/gist_id}","starred_url":"https://api.github.com/users/proj4-bot/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/proj4-bot/subscriptions","organizations_url":"https://api.github.com/users/proj4-bot/orgs","repos_url":"https://api.github.com/users/proj4-bot/repos","events_url":"https://api.github.com/users/proj4-bot/events{/privacy}","received_events_url":"https://api.github.com/users/proj4-bot/received_events","type":"User","site_admin":false},"created_at":"2015-05-22T06:10:02Z","updated_at":"2015-05-22T06:10:02Z","body":"**Comment by warmerdam on 29 Oct 2008 16:14 UTC**\nCopying Ari's example in a more readable format:\r\n```\r\n [ogr](ajolma@vesi-110)$ cs2cs -?\r\n Rel. 4.4.9, 29 Oct 2004\r\n [ogr](ajolma@vesi-110)$ cs2cs +proj=utm +zone=35 +ellps=GRS80 +units=m\r\n +no_defs +to +proj=tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=3500000 +y_0=0\r\n +ellps=intl +towgs84=-90.7,-106.1,-119.2,4.09,0.218,-1.05,1.37 +units=m\r\n +no_defs\r\n 353250 6690840\r\n 3353360.61      6693649.65 -24.80\r\n [ogr](ajolma@vesi-110)$ cs2cs -?\r\n Rel. 4.6.1, 21 August 2008\r\n [ogr](ajolma@vesi-110)$ cs2cs +proj=utm +zone=35 +ellps=GRS80 +units=m\r\n +no_defs +to +proj=tmerc +lat_0=0 +lon_0=27 +k=1 +x_0=3500000 +y_0=0\r\n +ellps=intl +towgs84=-90.7,-106.1,-119.2,4.09,0.218,-1.05,1.37 +units=m\r\n +no_defs\r\n 353250 6690840\r\n 3353183.92      6693674.70 0.00\r\n```\r\n\r\nNote that the behavior of PROJ.4 changes in 4.6.0 so that no attempt is made to do a datum or ellipsoid transformation if the source and destination coordinate system do not both have datum shift info available.  So in the above case 4.4.9 would convert from GRS80 to geocentric, then apply the towgs84 for the second coordinate system (in reverse) and back to intl coordinates.  In 4.6.0 no change is applied between the datum/ellipsoids.\r\n\r\nIf you want the old behavior you need to attach a +towgs84=0,0,0 to the coordinate systems with only an ellipsoid and no other datum shift info.\r\n\r\nPlease close unless you can confirm there is some other issue in play here."}}