{"action":"created","issue":{"url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/1817","labels_url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/1817/labels{/name}","comments_url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/1817/comments","events_url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/1817/events","html_url":"https://github.com/mavlink/qgroundcontrol/pull/1817","id":104152567,"number":1817,"title":"WIP: reduce sensor noise variances","user":{"login":"kd0aij","id":2300221,"avatar_url":"https://avatars.githubusercontent.com/u/2300221?v=3","gravatar_id":"","url":"https://api.github.com/users/kd0aij","html_url":"https://github.com/kd0aij","followers_url":"https://api.github.com/users/kd0aij/followers","following_url":"https://api.github.com/users/kd0aij/following{/other_user}","gists_url":"https://api.github.com/users/kd0aij/gists{/gist_id}","starred_url":"https://api.github.com/users/kd0aij/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kd0aij/subscriptions","organizations_url":"https://api.github.com/users/kd0aij/orgs","repos_url":"https://api.github.com/users/kd0aij/repos","events_url":"https://api.github.com/users/kd0aij/events{/privacy}","received_events_url":"https://api.github.com/users/kd0aij/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":7,"created_at":"2015-08-31T23:21:16Z","updated_at":"2015-09-08T17:19:52Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/mavlink/qgroundcontrol/pulls/1817","html_url":"https://github.com/mavlink/qgroundcontrol/pull/1817","diff_url":"https://github.com/mavlink/qgroundcontrol/pull/1817.diff","patch_url":"https://github.com/mavlink/qgroundcontrol/pull/1817.patch"},"body":"This PR changes the default sensor noise variances to values measured when stationary. \r\n\r\nI was unable to follow the code past UAS::qt_static_metacall... Is that intentional obfuscation? :)"},"comment":{"url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/comments/138639063","html_url":"https://github.com/mavlink/qgroundcontrol/pull/1817#issuecomment-138639063","issue_url":"https://api.github.com/repos/mavlink/qgroundcontrol/issues/1817","id":138639063,"user":{"login":"scott-eddy","id":5719830,"avatar_url":"https://avatars.githubusercontent.com/u/5719830?v=3","gravatar_id":"","url":"https://api.github.com/users/scott-eddy","html_url":"https://github.com/scott-eddy","followers_url":"https://api.github.com/users/scott-eddy/followers","following_url":"https://api.github.com/users/scott-eddy/following{/other_user}","gists_url":"https://api.github.com/users/scott-eddy/gists{/gist_id}","starred_url":"https://api.github.com/users/scott-eddy/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/scott-eddy/subscriptions","organizations_url":"https://api.github.com/users/scott-eddy/orgs","repos_url":"https://api.github.com/users/scott-eddy/repos","events_url":"https://api.github.com/users/scott-eddy/events{/privacy}","received_events_url":"https://api.github.com/users/scott-eddy/received_events","type":"User","site_admin":false},"created_at":"2015-09-08T17:19:52Z","updated_at":"2015-09-08T17:19:52Z","body":"This conversation is moving in circles and points to the fact that we need to have these values user adjustable.  \r\n\r\nI am of the same mindset of Lorenz in that we need something that we can quickly and easily test new firmware on that approximates system noise to some degree (instead of giving you perfect state estimates).  Once your firmware has passed that initial testing you take actual flight data which is when your real analysis can occur.  \r\n\r\nThe sensor noise that you will see in flight comes from a host of sources and no matter how  \"properly set-up\" people's aircraft are there will always be variation in noise between airframes.  Indeed the flight environment itself will lead to different noise levels from log to log on the same airframe.   \r\n\r\nA final note, additive Gaussian white noise is a convenient noise model as the Bayesian estimation routines being employed here all make this assumption about noise.  By adding GWN we know that the estimation techniques should still operate fine.\r\n\r\nWith all this in mind I think that my summary above still stands with a high priority on the UI widget for setting the noise.  @kd0aij if you disagree can you answer the following:\r\n1) What is a better model for noise than additive gaussian white noise, and why?\r\n2) How do you suggest getting and analysing data to validate that the final noise values \"accurately reflect vibration levels\" on an aircraft? \r\n3) If adding the noise to the simulator outputs is not the correct way to go about injecting noise into the system how do you suggest it be done?"}}