Chip Timing for Ski Racing

This should be interesting. The JKOM series is experimenting with transponders in an attempt to remove the photocells from the center of the course. This was determined to be "unsightly" from a TV perspective. AMB transponders are active (as opposed to Champion Chip type passive) transponders. We discovered in testing that even a slight angle change in mounting the transponder caused a major difference in the time recorded. This brings up a whole new aspect of policing the installation of the transponders.

Photocells by their nature are fair because they are static. The reversal of the courses on the second run eliminates any possible bias.

There is only one definite way to verify this type of finish in my opinion. Digital photofinish. Any brand of photofinish equipment is now capable of resolution greater than 2-1000ths of a second. We are expecting a new camera any day now that with have 10,000ths of a second resolution.

PST provided "backup" photofinish systems for the Olympic dual snowboard events at Park City. It was determined by SLOOC that it was impossible to "hand time" this. We set up two EtherLynx 2000 color cameras on either side of the finish shooting at each other. This eliminates parallax. We did not need the images but they were very interesting.

I am not sure if the JKOM events are live or taped TV. We can determine a photofinish of this type in a couple of seconds. Not as thrilling as the instant readout from photocells but close.

The only true way to test this concept is to use the three technologies at once. The photocells are the "control" as they have been the sole determining factor so far.

I'm usually silent on topics in the forums, but on this topic I have first hand experience. The AMB system was used at the JKOM this past weekend to just handle the differential timing. The system was set up during the qualifiers on Saturday but was not used for any timing purpose. Some testing was done, and everything was found satisfactory.

I don't want to go in to how or where a transponder should be mounted that is something for the guys at AMB to discuss. For arguments sake, the transponders this weekend where strapped to the riders leg, under their speed suit (TV thing). Each transponders was positioned in the recommended fashion. The AMB representative that was present checked the position on each athlete.

In speaking with the timers and organizers they were pleased with the way the system worked and it's accuracy. In addition, I was pleased the way the software worked. Though, being critical of my own work there is always room for improvement. The AMB system along with the custom software provided a solution for removing the photocells, and creating a common finish.

I too am curious to compare transponder and photocell times. I’ll start on that when I arrive back in MSP.


--Ed
Finish Line Sports, Inc
WeirdWorks - It's Like Ice
Timing and scoring software for use with AMB timing systems