I will ask Glen to verify this, but I don't think SCTA/BNI has EVER used radar
to measure speed - seems
to me we are using an infrared light beam straight across the race course and
we actually measure the
time between light beam breaks - then convert that to speed - using a computer
system certified by the US
Standards agency. But I'm confused, why is the method used of any importance?
The FIA doesn't care what
the method is, so long as it has been certified as accurate by the US Standards
agency and we have the
paper work to prove it - they also don't care how the course is measured, so
long as we have paper work
proving the measurement was accurate.
Bev
Don Kerr wrote:
> Hallo, hallo........ is this thing workin'........1 2 3
> testing.......OK..
> You Know listers , it's always bothered me that the radar used to
> evaluate a speed is always at an angle to the approaching object, this
> must surely introduce an inaccuracy in the measured speed, and no I
> don't want to get into a discussion of the Max Plank theory of particle
> physics. Also like Jon pointed
> out other factors are involved too.Heat, material,light
> refraction,angle,density of medium,and so on.
> So was that speed really that speed or should we now introduce a factor,
> 'corrected', like the drag racing boys do. Am I being pedantic, or what,
> so what do you think.......DK...........Over.
>
>=====================================================================================================
> Jon Hobden wrote:
> >
> > List
> >
> > At the risk of stirring another hornet's nest, as an electronics engineer
> > involved in radar design I am used to measuring time routinely to
> > resolutions of 0.00000001 second (though it's of no use unless that
> > measurement also has ACCURACY traceable to National Standards).
> >
> > But I have been intrigued for some time, following some discussions in Fast
> > Facts on the numbers of significant figures quoted on speeds, as to the
> > accuracy of the surveyed mile and kilometre courses. Can anybody involved
> > shed any light on this? Somebody mentioned checking temperatures of
> > "tapes" - does this mean that someone goes out on the salt and tries to
> > pull a mile of measuring tape straight? And how orthogonal are the traps
> > to the axis of the measured mile?
> >
> > And I'm not looking for an argument (was that a ten minute one or the full
> > half hour?) but I think we're all old enough to remember the discredit done
> > by the Bud Rocket "record" fiasco.....
> >
> > Jon Hobden in Horley
> > (Donald Campbell's birthplace)
|