{"action":"created","issue":{"url":"https://api.github.com/repos/PX4/Firmware/issues/1777","labels_url":"https://api.github.com/repos/PX4/Firmware/issues/1777/labels{/name}","comments_url":"https://api.github.com/repos/PX4/Firmware/issues/1777/comments","events_url":"https://api.github.com/repos/PX4/Firmware/issues/1777/events","html_url":"https://github.com/PX4/Firmware/issues/1777","id":57305199,"number":1777,"title":"PosHold handles GPS regain poorly","user":{"login":"Zefz","id":1359524,"avatar_url":"https://avatars.githubusercontent.com/u/1359524?v=3","gravatar_id":"","url":"https://api.github.com/users/Zefz","html_url":"https://github.com/Zefz","followers_url":"https://api.github.com/users/Zefz/followers","following_url":"https://api.github.com/users/Zefz/following{/other_user}","gists_url":"https://api.github.com/users/Zefz/gists{/gist_id}","starred_url":"https://api.github.com/users/Zefz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Zefz/subscriptions","organizations_url":"https://api.github.com/users/Zefz/orgs","repos_url":"https://api.github.com/users/Zefz/repos","events_url":"https://api.github.com/users/Zefz/events{/privacy}","received_events_url":"https://api.github.com/users/Zefz/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-02-11T11:38:14Z","updated_at":"2015-02-11T14:36:33Z","closed_at":null,"body":"This bug occurred using MultiCopter and the ```ekf_att_pos_estimator``` algorithm.\r\n\r\nThis is easily reproducible by the following steps:\r\n1. Set vehicle in PosHold mode and verify that the mode works as it should\r\n2. Disable the GPS while hovering in PosHold\r\n3. After a period of time, the Commander will trigger AltHold because the position fix times out\r\n4. As expected the position begins to drift and now we *enable* the GPS again.\r\n5. The drone makes some wild acrobatics and you'll have to switch back to Manual/AltHold to make it recover. "},"comment":{"url":"https://api.github.com/repos/PX4/Firmware/issues/comments/73890469","html_url":"https://github.com/PX4/Firmware/issues/1777#issuecomment-73890469","issue_url":"https://api.github.com/repos/PX4/Firmware/issues/1777","id":73890469,"user":{"login":"Zefz","id":1359524,"avatar_url":"https://avatars.githubusercontent.com/u/1359524?v=3","gravatar_id":"","url":"https://api.github.com/users/Zefz","html_url":"https://github.com/Zefz","followers_url":"https://api.github.com/users/Zefz/followers","following_url":"https://api.github.com/users/Zefz/following{/other_user}","gists_url":"https://api.github.com/users/Zefz/gists{/gist_id}","starred_url":"https://api.github.com/users/Zefz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Zefz/subscriptions","organizations_url":"https://api.github.com/users/Zefz/orgs","repos_url":"https://api.github.com/users/Zefz/repos","events_url":"https://api.github.com/users/Zefz/events{/privacy}","received_events_url":"https://api.github.com/users/Zefz/received_events","type":"User","site_admin":false},"created_at":"2015-02-11T14:36:33Z","updated_at":"2015-02-11T14:36:33Z","body":"Example where the problem occurs. Notice how position jumps once GPS is re-enabled (notice the EKF position diverges):\r\n![flightlog](https://cloud.githubusercontent.com/assets/1359524/6148650/a6db19b4-b203-11e4-851e-d13d33bce453.png)\r\n\r\nLogfile:\r\nhttps://drive.google.com/file/d/0B7HSl0pSS6x3TDVLdzFXZFI1SHc/view?usp=sharing"}}