Accuracy of satellite positioning using GNSS receivers in sports watches

Sports watches come equipped with Global Navigation Satellite System (GNSS) receivers capable of tracking GPS, GLONASS, and Galileo, and thus, can be considered low-cost GNSS receivers. In our research, we conducted three distinct experiments to evaluate the accuracy of 1) positioning, 2) distance determination, and 3) height determination based on sports watches using different GNSS combinations: GPS, GPS + GLONASS, and GPS + Galileo. For positioning, a professional GNSS receiver served as the reference. To determine height, we used a laser rangefinder. The assessment of distance measurement utilized a full-size athletics track. A noteworthy outcome of this study is that the increased cost of sports watches does not consistently correlate with higher GNSS positioning accuracy. The most accurate 2D results are achieved by the Polar M430 for the GPS case with the mean positioning error of 1.74 m, and the Garmin Fenix 6 PRO for GPS + GLONASS case with the mean error of 1.43 m.