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We are planning to write an application which have to track the user driving in his truck in the cities like New York city accurate upto which lane he was driving on. In the cities with those tall buildings, its not possible to get good GPS signal. So we are planning to use hardwares with accelerometers and magnetometers sensors to make up for the lost GPS signals. We tried with some Android tablets, but the sensors are not accurate enough. Right now we are going to try some hardwares from Trimble with geo position correction and motions sensors.

So any kind of suggestions on tracking a vehicle without a GPS device is welcome.

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Have you looked into WIFI Assisted GeoLocation? Other than that, you could look into hardwiring into the spedo / steeringwheel / and possibly mounting a camera to detect lanes. Then using AI to detect what road they're on. –  Geoist Jul 19 '12 at 6:25

2 Answers 2

GPS do not fail that badly with tall buildings, I have plenty of running assets in packed cities with perfect tracing. These skyscrapers actually reflect the signal in a convenient way for GPS.

Accelerometers do not give positions away and their accuracy is debatable, Detecting the difference between a starting , a running engine and a door that gets slam shut twice is tricky.

The real problem is interference, having an extra TomTom on board over your tracking GPS antenna is much more problematic. Plenty of devices that disturb this.

The best solution is to use an external antenna on the rooftop. As long as the runtime calculation tables stay intact and therefore should usually very fast be able to establish a fix again whenever the situation needs one.

All the other sensors like digital compass, magneto, vibration, acceleration etc are handy to know the state the vehicle is in (moving / non moving / engine running etc). And this in turn can be used to request coordinates to create events. Either it be GPS lat/lon or LAC/CELL information from GSM.

Just in case you absolutely do not want GPS your only other option is to use a inertial navigation method instead.

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If the signal is reflected, that won't be good. It might be convenient for metrics ("number of satellites visible") but the results will be worse. –  BradHards Jan 11 '13 at 1:36
    
Not always. Chances are not every sat is being reflected, but if it is just a question of 10 vs 8 sats used to fix position, the results of 8 will not be so off it becomes an issue for road use. I don't even look at visible metrix, only sats used to determine a fix. You could even hang your GPS receiver upside down under your car using reflections. This is not theory, we've tested this a lot. But I agree with you it's that it's not optimal, you just need to ask the question, how accurate do I really need it... –  Glenn Plas Jan 12 '13 at 20:26

Cell Tower Triangulation

enter image description here

SkyHook provide this service:

http://www.skyhookwireless.com/location-technology/coverage.php

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Will it be accurate enough to get up to which lane are they driving? –  Kevin Peter Jul 19 '12 at 13:51
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No way. Not with Cell Towers only. –  MLowry Jul 19 '12 at 14:56
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With Lane Assist (Volkswagen group) euroncap.com/rewards/vw_lane_assist.aspx it can be possible –  Mapperz Jul 19 '12 at 16:26

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