2016, Volume 8, Issue 2

Position accuracy and fix rate of athletes in location monitoring



Cezary Specht1, Tomasz Szot2

1Gdynia Maritime University
2Gdansk University of Physical Education and Sport


Author for correspondence: Tomasz Szot; Gdansk University of Physical Education and Sport; email: t.szot@awf.gda.pl


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Abstract

Background: The two main factors determining the quality of motion monitoring are the accuracy of determination of position coordinates and the frequency of position logging (fix rate).

Material and methods: A comparative analysis of contemporary photogrammetric, remote sensing and satellite methods shows a lack of uniform requirements in this respect with reference to the same sports. Considering the issue on an intuitive basis only, it seems obvious that the accuracy of position in 100-m sprint cannot be measured in metres, and the frequency of positioning should be sub-second. However, the precise values of these variables are not estimated. A mathematical model was created which enabled the determination of minimum requirements concerning athletes’ position accuracy and fix rate, based on statistical data from sports competitions (the results from 4 Olympic Games and 6 World Championships).

Results: The key stage for this model is selecting a representative sample of 68% best results (out of a group of results) which is described by time and speed boundary values. Both variables for the selected sport (the 100-m sprint) were calculated: Mmin=0.93 m (minimum position error value) and fmin=10.88 Hz (minimum position fix rate) which enable distinguishing competitors at the finishing line (statistically, position error 5%).

Conclusions: (a) The results achieved by sprinters in 100-m run in the world’s best sports events are sufficient to establish requirements regarding the accuracy and the frequency for the determination of athletes’ position in this event. (b) The statistical distribution best fitted to the population of 100-m results is the left-bounded Burr distribution (4P). (c) The method of establishing requirements for the 100-m run should be applied to other track events in order to verify an intuitive perception consisting in the lowering of accuracy and frequency requirements with an increase in an event’s distance.


Key words: human locomotion, sports, 100-m sprint