Gunnar Aastrand Grimnes wrote: > This page does: http://wiki.openmoko.org/wiki/Accelerometer_Fundamentals > > Noise is around 3cm/s^2, i.e: > > " > It can fill in _short_ - 3-5s gaps in GPS coverage, if the orientation > of the phone is known.
Not enough for a 4km tunnel then, which is 3 min when going 80km/h. 5s is enough for a 111m tunnel, but 5s signal loss is usually not a problem anyway. Of course, the car speedometer readout can take care of speed and braking/acceleration, the accelerometer would only be needed to notice turning. Could be interesting to see where it thinks I am after 3 min, if 5s is all I can expect. I guess those 3-5s is the interval where precision matces the gps. But it will be useful for longer than that, as long as estimate is more accurate than "stopped at the tunnel entrance." The error increase with time, but so do the real distance from the entrance. Helge Hafting _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
