Concurrent validity and between-device reliability of the Catapult Vector S8 GNSS device

TL;DR

This study shows the Catapult Vector S8 GNSS device is accurate and reliable for measuring distance, speed, and acceleration in team sports.

Contribution

This is the first validation of the Catapult Vector S8 GNSS device for sport-specific movements.

Findings

The device showed minimal errors in measuring instantaneous distance, speed, and acceleration.

Accumulated distance was slightly underestimated, but with high precision.

Between-device reliability was excellent with no significant bias observed.

Abstract

This study assessed the concurrent validity and between-device reliability of the Catapult Vector S8 GNSS device for measuring distance, speed, acceleration and banded distance metrics. Twelve male sub-elite team sport athletes completed a testing protocol consisting of linear sprints, change of direction drills and a modified small-sided game. Validity was evaluated against criterion reference systems, a VICON motion capture system for most trials and a Stalker ATS radar for 50 m sprints, evaluated using root mean square error (RMSE) and mean bias. Between-device reliability was assessed using interclass correlation coefficients (ICC) and typical error (TE%). The Vector S8 demonstrated good validity with minimal errors for instantaneous distance (RMSE: 0.03 ± 0.01 m), speed (RMSE: 0.14 ± 0.05 m·s−1) and acceleration (RMSE: 0.29 ± 0.14 m·s−2). No overall bias was detected for instantaneous distance and speed, and the bias for acceleration (−0.016) was minimal. Accumulated distance showed a small underestimation across trials (mean bias −1.42%), with consistently low RMSE values (0.26–3.06 m), indicating high measurement precision. The 50 m sprint results showed similar validity, with minimal RMSE for instantaneous speed (0.14 ± 0.15 m·s−1) and acceleration (0.22 ± 0.22 m·s−2). Between device reliability demonstrated excellent agreement across all measured variables (ICC ≥ 0.95) with good precision (TE as CV < 3.13%). No significant systematic bias was observed between devices for any variable (p > 0.05). This is the first study to validate the Catapult Vector S8 GNSS device, demonstrating that it is valid and reliable for measuring distance, speed and acceleration during sport-specific movements.

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