Placement of team sport GPS devices for reliability assessment

Abstract

The goal of this study was to determine the effect of unit placement on signal integrity and measurement output obtained during reliability trials for global positioning system (GPS) devices. Two of the same model GPS units were worn in four separate unit configurations (Piggyback, Above-Below, Front-Back and Lateral) during 4 × 2 lap repeats of a team sport simulation circuit. Differences in signal integrity indicators (# satellites, horizontal dilution of precision (HDoP), signal-to-noise ratio (SNR) and signal strength (SS)), total distance covered in each lap, and distance covered above and below 3 m·s⁻¹, were compared between the two units. The results showed that for signal integrity measures, differences between units were negligible for Above-Below and Lateral, but comparatively high for Piggyback and Front-Back. For distance measures, values were similar between units for Above-Below, however, discrepancies occurred in both total distance and speed distribution for the other configurations. This study concluded that the Above-Below unit configuration yielded the smallest differences between units for signal integrity and measurement output. Therefore, the Above-Below configuration is recommended for future GPS reliability investigations.