Accuracy of satellite positioning using GNSS smartwatches

Abstract The integration of Global Navigation Satellite System (GNSS) receivers into consumer-grade smartwatches has accelerated the development of location-based services and pedestrian tracking. However, the kinematic spatial accuracy of these devices remains insufficiently quantified in the scientific literature, particularly across diverse environmental conditions. This study assesses and compares the kinematic 3D positioning accuracy of six mainstream smartwatches (two Garmin 735XT, Garmin 235, Amazfit Bip U Pro, Apple Watch SE 2, and Samsung Galaxy Watch 4). To evaluate environmental susceptibility, a pedestrian field campaign was conducted across two fundamentally distinct environments: a dense urban canyon and an unobstructed open-sky baseline. The smartwatches were evaluated simultaneously alongside a survey-grade Leica GS16 geodetic receiver to establish a highly precise kinematic ground truth. Experimental results confirm severe spatial degradation within the urban canyon, where mean horizontal errors (RMSE) ranged from 6.7 m to 13 m, and vertical deviations reached up to 9 m due to extreme multipath interference. On the other hand, under open-sky conditions, horizontal accuracy improved significantly to 1.5–3 m, with the Apple Watch SE 2 achieving the highest horizontal precision (1.45 m). Furthermore, the Samsung Galaxy Watch 4 demonstrated exceptional open-sky vertical accuracy (0.17 m). The findings indicate that modern smartwatches are highly capable spatial measurement tools in unobstructed environments. However, their high vulnerability to multipath interference currently disqualifies them from applications demanding rigorous spatial accuracy.