Comparing Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) Measures of Team Sport Movements

Jackson B.M., Polglaze T., Dawson B., King T., Peeling P.

Purpose:
The purpose of this study was to compare data obtained from conventional GPS devices with new GNSS-enabled tracking devices, and to assess the inter-unit reliability of GNSS devices.

Methods:

Inter-device differences between 10 Hz GPS and GNSS devices were examined during laps of a simulated game circuit (SGC, n=40) and elite hockey matches (n=21).
The inter-unit reliability of GNSS devices was also assessed during the SGC laps.
Differences in distance values and measures in three velocity categories (low <3 m/s; moderate 3-5 m/s; high >5 m/s) and acceleration/deceleration counts (>1.46 m/s^2 and < -1.46 m/s^2) were analyzed using one-way ANOVA. Inter-unit GNSS reliability was evaluated using the coefficient of variation (CV) and intra-class correlation coefficient (ICC). Results: Significant inter-device differences (P < 0.05) were found for measures of peak deceleration, low-speed distance, % total distance at low speed, and deceleration count during the SGC. For hockey matches, significant differences were found for all measures except total distance and low-speed distance. No significant inter-unit (GNSS) differences (P < 0.05) were observed. The CV was below 5% for total distance, average and peak speeds, distance, and % total distance of low-speed running. GNSS devices exhibited a lower Horizontal Dilution of Precision (HDoP) score compared to GPS devices in all conditions. Conclusions: The findings suggest that GNSS devices may offer greater sensitivity than GPS devices in quantifying the physical demands of team sport movements. However, further research is needed to assess the accuracy of GNSS devices.