Ian, I had one like that a while back. Everyone who looked at it said it looked ok.....but Vando did the Doplier V Trackpoints and his verdict was- NO. Send it to him if you want it checked.

Hi Ian,

I've had this happen to me as well, we concluded that it was a 'spike' that was automatically smoothed out by the NAVI firmware.  Some of the smart boys in the Pit Crew have figured out what's happening, unfortunately it doesn't count as 35 knots  

Thanks for the advice Nebbian and Mike.  Vando's had a look and agrees that it must be a problem with the trackpoints.

It makes sense to me that the trackpoint data was way wrong in this instance.  I certainly didn't recall having any standout runs in that direction.  All the same, it is strange that a spike can end up changing the speed in what appears to be a realistic manner over an entire 20 second period.  Without the doppler tracks you would have no idea to scrap it.

BTW I've only ever posted doppler results (except for alphas) from the GT11 due to the greater accuracy.  When I was calculating the alpha speed I noticed the big discrepancy in 2s, had  a closer look and was suprised that it looked like a realistic track and not an obvious spike.