06 February, 2020

Imperative changes: automatic timing

One thing that has been bothering me since a long, long time are those pesky milliseconds, used in order to classify the athletes. I have already written a post on the absurdity of milliseconds. What does a millisecond mean in practice? Let us assume that a runner moves at a velocity of 10 m/s. In this case a millisecond corresponds to a distance of 1 cm. This means that when two athletes are separated by one millisecond their physical distance is just one centimetre. I am ready to concede the fact that the human eye is able to assess a 1 cm distance on the photo finish cliché. Where the things become fuzzy is when one reads carefully the rules which stipulate that

The time shall be taken to the moment at which any part of the body of an athlete (i.e. torso, as distinguished from the head, neck, arms, legs, hands or feet) reaches the vertical plane of the nearer edge of the finish line.

The catch word is "neck". Where does the torso end and the neck start? Can one define this with a sub-centimetric precision? What I suspect is that every photo-finish judge has his own definition of what is the neck and while he may apply it consistently in his analyses the choice may be different from that of other judges. And this is not something innocuous. The IAAF/WA is now using milliseconds in order to establish the classification of athletes competing in different series. Thus a difference in the interpretation of the photo-finish may have as a consequence the unfair elimination of an athlete from a final. I repeat that I am not criticising here the technology of the photo-finish. Modern cameras are recording with more than 10000 frames per second, so the accuracy of the final photo is perfect. What I am worried about is the human factor.


A finish Lynx camera capture

We cannot keep depending on the vagaries of human-eye interpretations. Definitely something must be done. The timing should be completely automatic, without any human intervention. What could be a solution? The current athletics rules allow for a timing provided by a transponder system but only for races not held completely in the stadium. The transponder- or chip-timing is working on a radio-frequency identification (RFID) protocol. A passive, for running events, transponder is attached to the athlete. It captures electromagnetic energy produced by a nearby source and emits a unique code. The latter is detected by strategically placed antennas and makes possible to obtain the moment at which the athlete crosses the finish line.


A chip by Innovative Timing Systems

How could such a system be implemented in the stadium? I looked around for available timing chips and it turns out that there are several, some of which can be read at speeds of more than 40 m/s and at distances of several metres. They are small, a few centimetres across and I am convinced that producing smaller ones could be possible. So let us assume that we have a timing chip in the form of a small disk with a 2 cm diameter. Such a system could be easily attached by an adhesive on the sternum of the athlete just at the top of the breastbone. What is then needed is that the chip be detected when the athlete crosses the finish line. I believe that such a thing is technically possible. It can, of course, be used in conjunction with the existing photo-finish system, the latter offering a back-up in case of failure of the chip-timing.

Speaking of possible failures I am aware of the fact that no system is totally foolproof. Chips, in particular mass-produced ones, will definitely have a finite failure rate. We can imagine chips being tested before use as an elementary precaution. Also radio waves can be perturbed and often are. Thus a chip may fail to activate at the finish line. Having more antennas can mitigate this problem (but at an additional cost). But these are practical problems for which one expects to have practical solutions. It is my opinion that it is high time the IAAF/WA decided to go this way, dispensing with the human-curated photo-finish.

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