Transponder timing
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Transponder timing is a technique for measuring performance in athletic events. A radio transponder, attached to the athlete, emits a unique code that is detected by radio receivers located at the strategic points in an event.
Prior to the use of this technology, races were either timed by hand (with operators pressing a stop-watch) or using video camera systems.
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[edit] Transponder systems
- See also: Radio-frequency identification
Generically, there are two types of transponder timing systems; active and passive. An active transponder consists of a battery-powered transceiver, connected to the athlete, that emits its unique code when it is interrogated.
A passive transponder does not contain a power source inside the transponder. Instead, the transponder captures electromagnetic energy produced by a near-by exciter and utilizes that energy to emit its unique code.
In both systems, an antenna is placed at the start, finish, and in some cases, intermediate time points and is connected to a decoder. This decoder identifies the unique transponder code and calculates the exact time when the transponder passes a timing point.
[edit] History
The first manufacture to introduce transponder timing was AMB Identification & Timing, although it was in motorized racing. Since 1983, AMB active transponders are used in several motorized sports ranging from RC model car racing, high speed car racing, motor cross, motor cycle racing, kart racing to snow cross. Since 1992 AMB transponders are also used in non motorized sports such as cycling, marathon, horse racing and triathlon.
The first manufacturer to use passive RFID technology was ChampionChip. Because each passive tag must be energized before it emits its code, there can be a delay in the tags response to the mat. Subsequently, a number of other manufacturers have offered similar technology. Subsequently, IPICO improved the passive system by energizing the tags at 125 KHz to allow the tags to start charging at a further distance from the timing mats, and then the tags emit their numeric codes at 6.8 MHz giving them the same range as ChampionChips.[1]
[edit] Usage
As events draw very large numbers of participants (in some cases over 60,000 runners), there are delays in participants reaching the start line, which penalize their performance. Some races place timing mats at both the start line and the finish line, which allow the exact net time to be calculated. A controversy has developed as to whether awards in a race should be based on the "gun time" (which ignores any delay at the start) or "net time" (which subtracts the delay.) The USA Track and Field rules have decided that performance is based on "gun time." However, some races use "net time."
When transponder timing was first introduced, the running community hoped for a universal standard, so that timing systems could operated interchangeably, with no overlap in chip serial numbers. However, race management companies have invested in incompatible systems, and individual runners who purchase a chip from one manufacturer, find that the chip is not operable in races that use a competitor's equipment. The market share of the different, incompatible transponder systems vary in each local market, depending upon which system was adopted by the local clubs or timing companies.
[edit] References
- ^ http://www.ipicosports.com/datacapture.html Retrieved 2008-03-21.
