Timing Technology Behind Olympic Record Results

An anonymous reader writes "We've been on the edge of our seats cheering on the athletes at the Beijing Olympic games — but so often do athletes' victories and defeats rely on accurate timing. As the athletes compete on the world stage behind the scenes technology records their results. This interview with Omega's Christophe Berthaud (video) — the company's 23rd time as official Olympic timekeeper — explores how far the technology has come since the first time it was used in 1932."

What? TFA?

I swear I tried to RTFA, but.. uh.. it doesn't exist...

Re:What? TFA?

So what you're complaining about is that something like "WTFV" isn't in our parlance? Well OK, here you go.
 
  Why don't you WTFV before posting!!!

Re:What? TFA?

Not being able to WTFV at work, I thought the "timing technology" behind Beijing's Olympic record results was what allowed them to instantly age their gymnasts from 14 to 16.

Re:What? TFA?

... allowed them to instantly age their gymnasts from 14 to 16 ...

Do you think they could give Gary Glitter one of those?

Not accurate. Consistent.

Winning Olympic events that involve fastest finish have nothing to do with accurate timing. Getting a world record might but everything about getting a medal is relative to your performance against your peers. Consistency is all that matters. And given that most of these events are run in qualifying heats, consistency between separate races is often not a factor. Even in race Phelps won by 0.01 seconds, the photo finish was just as telling as the actual clock results.

Re:

Specifically concerning the race which Phelps one by .01 seconds, even with all the photo documentation [cnn.com] and the under water video, it was difficult to determine who did what first.

While I agree with you that timing isn't important during a contest that is head to head with a peer, this electronic timing/reporting is very helpful in events such as fencing, and swimming as the Phelps case proves.

Now if we could trust the IOC to not allow corruption, I'ld like to see more electronical surveillance in othe

Re:Not accurate. Consistent.

also track (maybe on the blocks to see who actually is leaving first)

This is already done - they no longer rely on human judging to determine false starts

Re:Not accurate. Consistent.

... I'ld like to see more electronical surveillance in other events, such as tennis ...

HawkEye [hawkeyeinnovations.co.uk]. Used in Wimbledon and all the grand slam events. Used for the first time in the Beijing olympics.

Re:Not accurate. Consistent.

given that most of these events are run in qualifying heats, consistency between separate races is often not a factor.

I disagree. Frequently the final is comprised of the three fastest from semifinal A, the three fastest from semifinal B, and then the two fastest remaining competitors from either race. Consistency between races is extremely important to these people.

Re:Not accurate. Consistent.

They do collect all that information. They know how long it takes someone to leave the platform, how long to turn, everything. While the networks don't focus on that data, if you listen to some of the commentators, they will reference that data during the race.

I don't know for certain, but I'm assuming all timing data would be made available to a country's olympic committee, which would then make it available to the coaches and athletes.

Re:The photo/camera finish was totally inconclusiv

Inconclusive? You could clearly see a gap between cavic's finger and the wall. Whereas phelps fingers were bent back a bit from contacting the wall.

http://sportsillustrated.cnn.com/multimedia/photo_gallery/0808/oly.phelps.sequence/content.5.html [cnn.com]

Re:The photo/camera finish was totally inconclusiv

That rule is intended to keep people actually swimming butterfly, and it's OK if your hands touch slightly apart time-wise. What's not OK is if you break form (by stroking with one arm while lunging with the other hand) to attempt to out-reach someone, or if you don't bring both arms forward on that next stroke.
Phelps' shoulders remained square, he brought both hands around consistent with the rules, and the judges made the right call here.

Also note- the touch pad has no way of measuring when a swimmer touches with both hands, it only measures when contact is made. It is this contact that determines one's time, not the placement of the second hand. Once the time is turned in, the decision of whether it was legally accomplished (or a DQ) is a separate one.

The clock stops when the pad is first touched

according to fucking rules, you need to press the sensor(s) with both hands, eh? That's why people complained about the lack of frame(s) which show that moment.

Actually, his post is correct. The clock stops when the sensor is touched by that first fingertip- and Phelps clearly made it to the wall first by that measure. The camera and the electronic sensors agree on this.
The decision as to whether or not he did it according to the rules is a separate one. The rules for butterfly require that your shoulders be level, that your arms come around symmetrically and above the water, and that you touch the wall with both hands at the same time- but there are allowances for slight imprecisions in this regard, and Phelps was well within those tolerances. What the judges would look for is whether Phelps galloped his stroke (i.e., brought his arms around significantly assymetrically), if he would have stroked with one hand while lunging with the other, if he'd lunged over on one side, or if he'd kicked assymetrically in such a way that would get him some advantage. He did none of these things- at the finish, his body is straight, his shoulders and hips are level and square, his feet together.

What this came down to was stroke timing. Once you commit to the glide phase of a butterfly stroke, you can't break that straight-armed glide position unless you stroke through past your shoulders and recover both hands forward above the water. Approaching the wall, the two swimmers were out of phase with each other, with Phelps gaining ground- in such cases, it's always a matter of some strategery to time your stroke most advantageously, since in that drive phase of the stroke your hands can't reach forward to the wall and you're decelerating in your glide phase. Cavic stretched his last glide/lunge really well- given where he was in his stroke cycle, it wouldn't have made much sense to take another stroke. Phelps, on the other hand, was more than half-a-stroke away from the wall at the point where he needed to decide whether to take another one, so essentially he didn't do any gliding in- he touched the wall on the down-beat drive phase of his stroke, just barely in time to out-touch Cavic.

From what I can see, (based on having swum competitively for 20 years) I agree with the result- Phelps clearly won, if only by a very teeny margin.

Re:The photo/camera finish was totally inconclusiv

Finish cameras (at least for racing events where you cross a line) are of a totally different sort than regular square format image array cameras.

They use a "line scan" camera that just photographs the finish line (and nothing around it) with a line of pixels at MHz pixel readout rates and get effectively tens of kHz rates for the whole line. The images are then reconstructions of the time series of data at the line- hence the lack of background and the distortion you often see on photo-finish cameras. There are systems now that also combine this with a regular video camera (synced) looking at the line from the front so they can read numbers off of runners.

I'm not sure how they deal with it for swimming--the line scan doesn't seem like a good approach, but a quick search will probably turn up details...

Finally!

It's about time!

Lost in translation...

The guy mentions several times that the camera takes 2000 frames per second, but unfortunately states that this gives a precision of "two thousandths" of a second. The actual precision would be "one two-thousandth" of a second... I suppose this is an understandable translation error. But I enjoyed the piece, I was interested that they used a GPS signal to synchronise their systems.

Observer Effect

"No fair! You changed the outcome by measuring it!"

Edge of our seats

... We've been on the edge of our seats cheering on the athletes at the Beijing Olympic games ...

Hey this is slashdot you insensitive clod!

Each of us to a man (and woman) was picked last for sports.

Re:Edge of our seats

I wasn't always picked last! Sometimes I was picked second to last and I felt like i was the king of the world!

In ancient Greece

Back in the days, when two runners arrived to the finish line at the "same" time - the race would be held again.

Re:Huh?

Personally, these Olympics have been full of pretty amazing feats by several athletes from my own country (Scotland/UK) and other countries and I've found them enjoyable to watch.

Agree to a point, but there have been several instances where the judging was just painfully bad [/canadian viewpoint]

Re:

No, the world I live in is so plagued with asshole politicians, evil corporations, a sinking morass of a war, and numerous other cancers on the national soul, so that having a national hero I can stand up and cheer for is the only thing that can come close to healing the rift between me and my government. I've never liked the idea of patriotism very much, but that doesn't mean I don't want it.

Re:Why the difference?

It may have to do with regulations for individual sports. Each individual sport has its own set of rules and committees. Is has been made obvious this week, gymnastics doesn't allow ties, but I believe swimming does (IIRC, during the first few days we had a tie for bronze). If 1/100 second is the accepted resolution for swimming and any smaller interval is considered a tie, there doesn't serve much purpose in taking more photos. Each photo would be precisely timed to take place exactly as the clock ticked over. Anything more might be useful for a pissing contest, but by the regulations is unnecessary, and perhaps even undesirable (as the media might try to push one as being the true winner, rather than just accept the tie and giving both their due).

Re:Why the difference?

I have officiated swimming competitions for nearly 20 years, and LordKronos has it exactly right. Both USA-Swimming and FINA (international swimming governing body) rules require that races be decided by accurate electronic timing precise to 1/100 sec, and no more. Further precision to 1/1000 sec is neither desired nor permitted, and by rule, swimmers who have the same time to the nearest 1/100 sec are tied and share equally in the place. At the velocity of Olympic swimmers (Phelps' 100 fly averaged 1.98 meters/sec), the .01 sec time difference amounts to a 2cm margin of victory.

Re:Why the difference?

If 1/100 second is the accepted resolution for swimming and any smaller interval is considered a tie, there doesn't serve much purpose in taking more photos

Indeed. There was at least one shared medal in these olympics as a result.
Note that when a tie needs to be broken (for example, to determine who advances on to semis or finals) it is done in a swim-off heat (this happened at least once during these games) rather than by going to the next decimal point.