How do augmented reality browsers track the exact location to overlay relevant information?
AR browsers include wikitude, Layar, etc. which are available for Iphone and Android smartphones.
When you point your camera at a landmark, they automatically overlay previously available location information above it (like the name of a restaurant above its door).
If the accuracy of GPS as some state is ~ 10 m, how can this be done exactly?
I mean, if they track your phone's location to display geographically accurate information, even a 2-3m difference can lead to chaos.
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you can test it yourself in code mixare, which is an augmented reality browser released under the free software license (GPLv3). The source code is available on github for both Android and iPhone.
To answer your question: there are errors, mostly due to compass readings (digital compasses are unreliable because they make every noise). What helps is that you usually look at objects that are quite large (buildings, etc.), so the error is not visible to the end user, but it's still there, trust me :)
NTN Daniele
Disclosure: I am the leader of the mixare project and the main developer of the Android version.
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