--- In [email protected], Patrick <wins...@...> wrote:
>
> From what you describe it sounds like you're running into GPS' flaw..
> Directionality can only be determined when you are moving.. Once you
> stop it can't tell what direction you are facing and it will start to
> shift based on the satellite drift.. Takes a little time, and doesn't
> always happen as some receivers are able to detect that you're not
> moving and not change direction until you do (this is why some gpses
> have a 'time not moving' stat).
>
> If you have a display on the gps you should be able to see it
> happening as the map will start changing direction.. The Nuvi 350 does
> this, especially when there's buildings around so you're dealing with
> reflections.
>
> p
>
> Quoting Chris <wellre...@...>:
>
> >
> >
> > --- In [email protected], James Ewen <ve6srv@> wrote:
> >>
> >> On Wed, Jul 28, 2010 at 7:24 PM, Chris <wellread1@> wrote:
> >>
> >> >However, since I don't know the details of the turning algorithm I
> >> > can only guess how to avoid this boundary condition.
> >> >
> >> > Can anyone shed some light on this?
> >>
> >> http://www.hamhud.net/hh2/smartbeacon.html
> >>
> >> James
> >> VE6SRV
> >>
> > Thanks, I looked at the HamHud description. I did not see anything
> > that would account for sudden onset rapid beaconing when the vehicle
> > is parked. The turning algorithim in the T2 also seems to be
> > implemented slightly differently than that of HamHud (At least from
> > the standpoint of the number of parameters required to specify a
> > turn event).
> >
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
>
I have done some additional test and believe that what you are describing (and
what I intially suspected) is correct. However, I think this is a really a
software glitch because 0 MPH is a boundary condition and the software should
be smart enough to disregard normal position variation in sequential GPS fixes
at very low speeds.
