Quote Originally Posted by patrice View Post
Hi Guys,

I have corrected the inversion between measured and calculated value.

Initially I raised the same question about how a radar can measure the total spin.
Apparently (and making it simple...as it was explained to me), the radar is able to measure the difference of turbulences between the top and the bottom of the ball when it flies. This difference will give the total spin....
Then, the spin axis is "calculated using 3D movement of the club and tracking curvature of the ball. Wind has little effect. With no wind and a controlled environment there shouldn't be any tolerance on spin axis"

There is one point I didn't understand is the following :
With no wind and a controlled environment there shouldn't be any tolerance on spin axis, because the horizontal azimuth is so low.

Maybe, some of your advanced user could explain. We lately had the honour to welcome a valuable and very helpful new member on the forum ("OptimalFlght", owner of Optimalflight). Maybe, will he be able to give us some explanations (I dropped him a mail)...

pat
Hi Pat,

Thanks for the kind words and introduction to this forum.

I am not a radar expert but quite familiar with launch data from a variety of systems and launch maths. The total spin explanation makes sense looking at the turbulences between the top and bottom of the ball.

The last part "With no wind and a controlled environment there shouldn't be any tolerance on spin axis" - I believe they're saying that there should be no bias (or effect) on spin axis under a no wind & controlled launch environment, which makes sense to me. Not sure if tolerance is the right word. The ball is being tracked in 3D time and space and the unit is able to locate it. The tracking curvature for the length of the ball flight and club impact parameters are used to determine spin axis. In comparison, a photo based system would not need flight information because the sequence of ball images is used to determine the axis.

Regards,
Todd