[Ovmsdev] GPS location glitch (flatbed theft false alert)

[Stephen Casner]

Michael,

What would qualify as exactly the same bug behavior?  If it is
specifically that the latitude or longitude is reported as 0, that may
not be the same.  What we see is a sharp deviation in the GPS
position.

The symptom is false vehicle theft/flatbed alerts.  Gregd send a
message to ovmsdev about this in his Roadster on 2018-09-17.  In May
2019 there was more discussion on the list.  I did some logging and
caught one of these events and reported it on 2019-05-29.

Over time, the remediations we have discussed on the list were to
constrain that alert to the condition of the car being off (parked)
and to increase the radius that the jump would need to exceed.

                                                        -- Steve

On Tue, 29 Jun 2021, Michael Balzer wrote:

> The Roadster also having this bug is new to me.
>
> Does it show exactly the same bug behaviour?
>
> Regards,
> Michael
>
>
> Am 29.06.21 um 18:05 schrieb Stephen Casner:
> > For vehicles like the Tesla Roadster that don't use the modem's GPS,
> > putting the detection only in the modem NMEA code would not help.
> >
> >                                                          -- Steve
> >
> > On Tue, 29 Jun 2021, Michael Balzer wrote:
> >
> > > I'd also suggest doing this detection in the modem NMEA code already, to
> > > prevent feeding false coordinates into the metrics first place.
> > >
> > >
> > > Am 29.06.21 um 09:27 schrieb Michael Balzer:
> > > > Craig,
> > > >
> > > > Am 28.06.21 um 21:07 schrieb Craig Leres:
> > > > > Wow, this is a good bug; got another one today (see attached).
> > > > Is there a reasonable strategy for suppressing these? I'm happy to share
> > > > recent server logs offline (but I don't post them to the internet/list).
> > > >
> > > > (hint: you should use another tool to cover private information in
> > > > images...)
> > > >
> > > > How about testing latitude & longitude individually for sudden peaks
> > > > from
> > > > their previous average, and discarding a new coordinate completely while
> > > > such a peak is present?
> > > >
> > > > Regards,
> > > > Michael