Dead Reckoning For Your Car Eliminates GPS Dead Zones 151
cartechboy writes "We've all been there. You're relying on your vehicle's built-in navigation system to get to that meeting downtown, but then suddenly the car loses the satellite signal due to the concrete skyscraper canyon you're in--and you're about to be late. Swiss semiconductor manufacturer U-Blox thinks it has the solution with 3D Automotive Dead Reckoning, or 3D ADR for short. It's a new navigation chip that uses the vehicle's built-in sensors to track speed, horizontal movement, and elevation. The 3D ADR system measures movement in three dimensions, letting the navigation system can keep track of the vehicle's location even when it loses its connection to GPS satellites. Imagine never having to see your navigation screen saying connection lost again. In an age where our phones have accelerometers and compasses, it's amazing your car is still trying to catch up, right?"
don't think this really works on phones yet (Score:5, Interesting)
Actually I think it's the opposite, it's only being in a car that makes dead reckoning with any kind of accuracy feasible. A car is a reasonably large and stable platform, which already has good speed information, and can have some accelerometer-type information added relatively easily. A smartphone does have an accelerometer, but the data is far too noisy to do reasonable dead reckoning, because in addition to the macro movements (someone walking, biking, or driving down a street) there area bunch of micro-movements that produce high local acceleration (putting the phone in/out of pockets, taking steps while the phone's in your pocket, etc.). It makes for a much more complex dead-reckoning problem, because instead of just tracking broad movements (car goes 10m this way) you have to resolve a ton of tiny movements (phone was moved 0.3m into pocket, then rapidly accelerated 0.1m left due to owner being jostled on the subway, etc.), which tend to pile too much accelerometer noise on top of the broader movements that you really want to track.
In short, taking a known starting position and keeping it updated via accelerometer data is a lot easier if your accelerometer is on a car, vs. on a handheld device.
Welcome to 2000 !!! (Score:3, Interesting)