Accuracy

The degree of closeness between measured and actual physical positions, typically expressed as distance (e.g., ±30 cm). Requirements vary by application: warehouse tracking might need 1-3 meters, while precision assembly requires 10-30 cm. Affected by technology choice, environmental conditions, anchor placement, and calibration quality.

Measure of how close a reported position is to the true position, typically expressed as a distance error value. In industrial RTLS, accuracy specifications should distinguish between static accuracy (stationary tag) and dynamic accuracy (moving tag), as well as specify the confidence level (e.g., 90th percentile vs. average). UWB systems typically achieve 10-30 cm accuracy, Wi-Fi systems 3-15 meters, BLE 1-5 meters, and RFID room-level only. Accuracy degrades with distance from infrastructure, environmental obstacles (metal, water), and signal interference.

Critical to note: vendors often cite best-case accuracy; request 90th percentile values in production environments. Accuracy requirements vary by application - assembly tracking may need 30 cm, while warehouse zone tracking tolerates 2-5 meters. Technology selection based on accuracy requirements: UWB (10-30 cm) for precision manufacturing and collision avoidance, BLE AoA (0.5-2 m) for zone-level personnel and asset tracking, BLE RSSI (3-8 m) for broad area monitoring, GNSS (3-10 m) for outdoor yard and campus tracking. Hybrid deployments combining UWB indoors with GNSS outdoors provide seamless accuracy across facility boundaries.