Michael D. Porte writes:
Andrew Mace wrote:
>
> Per the following news item: A show of hands, please, for all of you
whose
> Triumphs were affected yesterday...I thought as much. ;-)
>
> ************************************************************************
> NAVIGATION SYSTEMS FAIL IN SOME JAPANESE CARS
> In Japan, the navigation systems using the satellite-based Global
> Positioning System failed to operate correctly in some Japanese cars
> yesterday, because they had been designed to count to only 1,024 weeks
and
> when the maximum was reached on Sunday the clocks reset to zero. Pioneer
Hmmm... I find this a most curious explanation for the problem. If the
week counter was absolute, i.e., the device began counting weeks from
the time it was first turned on, that would mean that Japanese cars have
had GPS navigation for 19.69 years... perhaps they meant days....
Cheers.
------------------------------
Michael,
The problem isn't with the individual GPS device but with the
system as a whole. Satelite location and the resulatant
calculations change over time and the algorithm needs to
know what the time is to determing proper location. The
GPS system was initially set up in 1980 and the weeks
are counted from that initial date. Regargless of when the
receiver was built.
But this is just some Techno-nerd stuff and doesn't belong
on this list.
Dave Massey (Techno-nerd)
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