Accuracy

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Accuracy

Author	Message
Misc.	Misc. posted 1/8/2017 10:59:40 AM Topic Details Share Topic
Group: Forum Members Posts: 4, Visits: 10	I'd be interested to understand how the accuracy displayed on SkyDemon can differ from the GPS source? ‌Flying with a WIFI only iPad mini and a Bad Elf Pro Plus the Bad Elf track shows an accurate track, whilst the SkyDemon log is less accurate. The tracks do appear to converge after take off? ‌ ‌EG Bad Elf shows tracking runway; SD shows track outside the airfield. ‌ ‌ ‌ ‌ Edited 1/8/2017 10:59:40 AM by Misc.
	Reply Like 65
Tim Dawson	Tim Dawson posted 1/9/2017 10:41:43 AM Post Details Share Post
Group: Forum Members Posts: 7.8K, Visits: 8.4K	I cannot think of any reason why the two would be different. SkyDemon does no "processing" of your position whatsoever to change it; we simply take whatever the GPS (via iOS location services) gives us. There is no good reason why the GPS unit itself should log different data than it is passing to iOS.
	Reply Like 74
Misc.	Misc. posted 1/9/2017 7:22:54 PM Post Details Share Post
Group: Forum Members Posts: 4, Visits: 10	+x Tim Dawson - 1/9/2017 10:41:43 AM I cannot think of any reason why the two would be different. SkyDemon does no "processing" of your position whatsoever to change it; we simply take whatever the GPS (via iOS location services) gives us. There is no good reason why the GPS unit itself should log different data than it is passing to iOS. Tim, I have been thinking it through. From previous correspondence I understand SD only starts recording at a certain speed. In other words SD does not take what is offered until a predetermined SD parameter is met? Is it possible SD registered position on connecting to the Bad Elf and did not update during a very slow taxy, (it was slower than usual following another aircraft) therefore SD beginning the take off roll from outside the hangar, which roughly corresponds to the SD track. As you'll see from the tracks they do converge on climb out. ‌ ‌
	Reply Like 70
Tim Dawson	Tim Dawson posted 1/10/2017 10:40:16 AM Post Details Share Post
Group: Forum Members Posts: 7.8K, Visits: 8.4K	SkyDemon starts recording a flight log when you take off, by default. You can start recording earlier, manually, by selecting the option in the main menu when navigating.
	Reply Like 80
nkt2000	nkt2000 posted 1/26/2017 2:12:01 PM Post Details Share Post
Group: Forum Members Posts: 23, Visits: 128	Could it be anything to do with the geodesic datum being different between the Bad Elf and the maps used in SD?
	Reply Like 68
Tim Dawson	Tim Dawson posted 1/27/2017 10:36:12 AM Post Details Share Post
Group: Forum Members Posts: 7.8K, Visits: 8.4K	No, the location received via iOS and Android location services will be the same as used in our maps.
	Reply Like 68
macht_rebel	macht_rebel posted 1/27/2017 12:47:42 PM Post Details Share Post
Group: Forum Members Posts: 18, Visits: 37	Could it be that the iPad uses the Wi-Fi signal in addition to the GPS for positioning reasons?
	Reply Like 53
Tim Dawson	Tim Dawson posted 1/30/2017 11:12:55 AM Post Details Share Post
Group: Forum Members Posts: 7.8K, Visits: 8.4K	SkyDemon won't use a position derived from a WiFi signal. It will only accept a GPS position.
	Reply Like 66
Tim Dawson	Tim Dawson posted 2/2/2017 10:29:21 AM Post Details Share Post
Group: Forum Members Posts: 7.8K, Visits: 8.4K	No. Assisted GPS means the operating system can use a rough location (usually obtained via wifi) to speed up the time to get a proper GPS fix.
	Reply Like 74