On 7/17/14 4:51 AM, Felix Baumann wrote:
Am 17.07.2014 12:04, schrieb Gervase Markham:
They get an option to alter the submitted location every time. This
doesn't work well with apps which ask for location on a continuous
basis, like turn-by-turn routing, but you can't do that without a GPS
anyway. Perhaps we cache the answer. I assume using the motion sensors
for dead reckoning gets inaccurate very fast...
I have to disagree with that:
scientists tested it out with a system called SmartLoc that does exactly
that on a Samsung Galaxy S3 in Chicago, where the GPS connection is
really bad because of the skyscrapers.
And they got down to 20m accuracy in 90% of the cases which is really
impressive and better than GPS.
They used databases and analyzed the streets and the car behaviour so
that they could say whether an acceleration was caused by a turn,
changing lanes, a broken street or for example a bridge (wind).
So SmartLoc would position the device in their Chicago map (probably on
a street) and then track the most likely paths based on acceleration
changes for speed and turning? That's pretty clever.
The company WiFiSLAM (acquired by Apple) did the reverse: they
constructed (indoor building) maps based on device movement. This video
is a good talk about their technology. A big challenge is combining
low-quality results from cheap hardware.
https://youtu.be/OGdvjvla1Tc
chris
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