GPS Location Inaccurate

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GPS Location Inaccurate

Postby cbyte » Tue Mar 03, 2009 7:53 am

Surprised no one else is having this issue... Or are you?

We have a small application which updates the users location on an interval and sends the co-ordinates (lat/long) to our server. We have the G1 phone and find that quite often the location given is wrong... not just 100 meters wrong, sometimes 1000meters wrong!! It can be very inaccurate. Sometimes I notice when i launch google maps and it first gets a GPS read it says i am 500meters way, then i watch 'my location' update every couple of seconds and I move closer and closer to my true location...

Any tips on how we can make sure we get a more accurate location before we send it over to our server? Can we for example wait for it to get a GPS fix, then wait about 15 seconds and then only read co-ordinates (so that it has had time to calibrate) or any other ideas.

tnx
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Postby atxe » Tue Mar 03, 2009 11:02 am

Can it be related with losing information when you're casting variables?
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Postby torpor » Tue Mar 03, 2009 12:48 pm

GPS Location services can be wildly inaccurate at times - it really depends a lot on environmental conditions being just right for all cases - something you really don't have much control over as a developer. Even standing in the radio-shadow of a 3-story building can radically affect your accuracy. The best thing to do is to just accept the fact that locations will have varying degrees of accuracy, and deal with it .. there is no 'tried and proven' way to ensure that the Location you get is where you really are. In your case, warn your users, and try to make it convenient for them to keep your app running as long as possible so that the accuracy of the GPS fix is more likely to be greater over time ..
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I'm confused

Postby cmack13 » Tue Mar 16, 2010 10:07 pm

When I get the lat and long from the Location object, created with ACCURACY_FINE, I get values, according to the returned accuracy from the LocationManager, that are 90 to 300 meters off.

However, when i go into Google Maps App. the accuracy is dead on. Why the difference? If it is hardware dependant, shouldn't my coordinates be the same as Google's? Are they refining their result somehow?
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Re: I'm confused

Postby zehunter » Tue Mar 30, 2010 9:14 pm

cmack13 wrote:When I get the lat and long from the Location object, created with ACCURACY_FINE, I get values, according to the returned accuracy from the LocationManager, that are 90 to 300 meters off.

However, when i go into Google Maps App. the accuracy is dead on. Why the difference? If it is hardware dependant, shouldn't my coordinates be the same as Google's? Are they refining their result somehow?


i have the same feeling about using SDK 1.6 / Map and use google map. sometime my app see me in another street than which i am :)

btw does any google dev guy pass from time to time to help us? :-) it can be good i think :-)
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