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  Reply # 1612479 16-Aug-2016 13:47
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Perhaps they could take into account who is the nicest guy, or the kindest to animals, or has the most twitter followers.... (joking).




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  Reply # 1612516 16-Aug-2016 14:41
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frankv:

 

joker97: Where/How do you put the points in the lake such that they do not move at all with the waves?

 

Why in the lake? Why not on the banks? If you insist on in the lake, then on poles stuck into the bottom of the lake.

 

 

 

 

I was replying to fred who says the line needs to be 100m across. 

 

I disagreed.

 

It probably needs to be across the entire lake. Which is what ... 2000-3000m?

 

Anyone not heard of parallax error?


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  Reply # 1612517 16-Aug-2016 14:42
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trig42:

 

joker97:
frankv:

 

I don't think a straight line (e.g. laser) across a lake is that difficult. It's not a "giant" lake, although maybe 100m across as opposed to 10m for a running track.

 

 

 

But if you're going to be this accurate on the finish line, then you should have the same accuracy at the start positions. And the start and finish lines must also be absolutely parallel. And the boats must be exactly the same length.

 

 

 

And natural variations (e.g.) wind from one lane to another could cause that much time difference... so now the medal is awarded to the lucky guy as opposed to the fastest.

 

 

 

 

 



Where/How do you put the points in the lake such that they do not move at all with the waves?

 

 

 

A pole to the bottom?

 

 

I'd like to see one build a 30m pole to the bottom that does not move 1cm with the waves. That's the winner's margin it comes down to ... if the line moves a few mm at either end the parallax error will change the winner.


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  Reply # 1612521 16-Aug-2016 15:00
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joker97:

 

 

 

I'd like to see one build a 30m pole to the bottom that does not move 1cm with the waves. That's the winner's margin it comes down to ... if the line moves a few mm at either end the parallax error will change the winner.

 

 

That's really my point... it's the difference between precision and accuracy. We have time precision of ms, but the accuracy of measurement is at best 10ms. Any time that there's a difference less than 10ms, the correct answer is "We can't actually tell who is the best athlete."

 

Give them both a gold medal.

 

 


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  Reply # 1612578 16-Aug-2016 16:45
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frankv: That's really my point... it's the difference between precision and accuracy. We have time precision of ms, but the accuracy of measurement is at best 10ms. Any time that there's a difference less than 10ms, the correct answer is "We can't actually tell who is the best athlete."

 

Give them both a gold medal.

 

The Omega line-scan camera can easily do 0.001s accuracy.  Once the camera is correctly aligned there is no "line" to move in the wind/waves.  There is no parallax or alignment error unless the camera moves, which can be demonstrably shown not to happen.

 

So in this case the camera can easily distinguish between first and second, as the image shows.

 

The elapsed time is recorded to 0.01s accuracy because that's FISA rules. Same recorded times, but one boat clearly ahead of the other.





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  Reply # 1612841 16-Aug-2016 21:51
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mclean:

 

frankv: That's really my point... it's the difference between precision and accuracy. We have time precision of ms, but the accuracy of measurement is at best 10ms. Any time that there's a difference less than 10ms, the correct answer is "We can't actually tell who is the best athlete."

 

Give them both a gold medal.

 

The Omega line-scan camera can easily do 0.001s accuracy.  Once the camera is correctly aligned there is no "line" to move in the wind/waves.  There is no parallax or alignment error unless the camera moves, which can be demonstrably shown not to happen.

 

So in this case the camera can easily distinguish between first and second, as the image shows.

 

The elapsed time is recorded to 0.01s accuracy because that's FISA rules. Same recorded times, but one boat clearly ahead of the other.

 

 

Such is the belief in unfallible systems, I guess I don't know anything about Rowing finish line cameras huh. Wow So accurate!


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  Reply # 1612936 17-Aug-2016 07:19
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mclean:

 

frankv: That's really my point... it's the difference between precision and accuracy. We have time precision of ms, but the accuracy of measurement is at best 10ms. Any time that there's a difference less than 10ms, the correct answer is "We can't actually tell who is the best athlete."

 

Give them both a gold medal.

 

The Omega line-scan camera can easily do 0.001s accuracy.  Once the camera is correctly aligned there is no "line" to move in the wind/waves.  There is no parallax or alignment error unless the camera moves, which can be demonstrably shown not to happen.

 

 

Right. But my point is that the objective is to identify the best athlete, which is not necessarily the person who crossed the line first.

 

 


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  Reply # 1612974 17-Aug-2016 08:41
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frankv:

 

mclean:

 

frankv: That's really my point... it's the difference between precision and accuracy. We have time precision of ms, but the accuracy of measurement is at best 10ms. Any time that there's a difference less than 10ms, the correct answer is "We can't actually tell who is the best athlete."

 

Give them both a gold medal.

 

The Omega line-scan camera can easily do 0.001s accuracy.  Once the camera is correctly aligned there is no "line" to move in the wind/waves.  There is no parallax or alignment error unless the camera moves, which can be demonstrably shown not to happen.

 

 

Right. But my point is that the objective is to identify the best athlete, which is not necessarily the person who crossed the line first.

 

 

That might be your point, but your point is wrong. The gold medal goes to the person who crossed the line first. Always has. The person who crosses the line first on the day is the winner, doesn't matter if the other person would normally have won, but ate bad clams the night before, or if she was off her form because she had her period, the first across the line is the winner.


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  Reply # 1613055 17-Aug-2016 09:45
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But no one can see the line ... There is no line ... Only imagination!

But yes the winner is definitely the first to get to the line. Otherwise the best athlete would always be usain bolt no matter the event. Or Michael Phelps if water it's involved.

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  Reply # 1613070 17-Aug-2016 10:39
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Also the line may be accurate (I don't know for sure, jsut taking peoples word on it**) to that degree, but are the layout of the lanes and buoys that accurate!?

 

 

 

** They said ball tracking was accurate, the Aussie bounce over the top where tracker said it was hitting springs to mind!


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  Reply # 1613098 17-Aug-2016 10:54
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itxtme:

 

Also the line may be accurate (I don't know for sure, jsut taking peoples word on it**) to that degree, but are the layout of the lanes and buoys that accurate!?

 

 

 

** They said ball tracking was accurate, the Aussie bounce over the top where tracker said it was hitting springs to mind!

 

 

I was going to bring up ball tracking, that is 100% inaccurate. But I'm sure these guys will argue that ball tracking is predicting the future is not the same as drawing a straight line across a body of water ... where my argument is that it's not possible to draw a straight line across a body of water that is 90.00000000000000 degrees to the race course to give such an accurate margin to the winner in what seems like a dead heat to me.


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