Is Android location apis' full-proof?

Question

I had a strange encounter once: The location on the phone's map application and even my application was wrong by a very large delta. As in it was quite off the actual location. Is it something many have encountered or some bug with my device ? What is the approx probability of this happening (from those who have tested this bug) ?

I am using a Samsung Galaxy SII with ICS and my application fetches info from GPS_PROVIDER.

The reason it is so hard to make things `foolproof` is because fools are so ingenious. — mwengler, Aug 22 '12 at 14:45
oops...my bad, nevertheless the question does make sense doesnt it ? ;) — Aakash, Aug 23 '12 at 06:33
Your question is fine, I just like that quote about foolproof. — mwengler, Aug 24 '12 at 14:21

score 0 · Answer 1 · answered Aug 22 '12 at 07:51

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It's pretty normal for my location to be off by a large amount for a few seconds after a device turns on, until the radios can get a fix.

answered Aug 22 '12 at 07:51

Sparky

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Is there any kind of parameter we can check to verify if the device radios have a fix or not ? I check my location on a timer or location updated event whichever is earlier. – Aakash Aug 22 '12 at 07:55
You can use a GpsStatusListener to check for a few events including the first fix, see here http://stackoverflow.com/a/9768664/1127492 – Stefan Aug 22 '12 at 14:47
Thanks stefan, I will add this Listener. – Aakash Aug 23 '12 at 06:38

score 0 · Accepted Answer · edited May 23 '17 at 12:12

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You might have an encountered a cached location if the maps application couldn't get a fix on your current location. For getting up to date locations in you app take a look at this question here

edited May 23 '17 at 12:12

Community

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answered Aug 22 '12 at 07:55

Jer

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score 0 · Answer 3 · answered Aug 22 '12 at 14:51

I have seen errors of more than 10000 km. I was looking at network fixes which come from cells and wifi only, no gps. The fix put me in England (UK) somewhere even though I was at an outlet mall in California (US). My guess is that someone had moved their wifi server from England to California and the Google WiFi database had not updated itself yet. I had a few more errors like that but not as spectacular, only 1000-5000 km reporting locations in other states of the US.

Network fixes based on cell towers will usually be 1 km off and are often 10 km off. These are based on the cell tower seen by the phone, and in hilly terrain you can often miss the closest cell tower and grab one that is on a high location a few km away.

GPS fixes also can have errors, but usually less than 1 km. These errors mostly come when some GPS signals are blocked by hills or buildings or reflected off nearby hills or buildings.

I have seen all of the above when testing Android phone positioning. Not all phones will behave identically, the quality of the GPS implementation (chip choice, rf design) can make big differences in performance.

That is exactly what I faced. I was testing in India and it showed my position somewhere near Vietnam. A totally baffling moment. Thanks for sharing your experience, I am not alone !! — Aakash, Aug 23 '12 at 06:40

Is Android location apis' full-proof?

3 Answers3