Tended devices must know their precise location so they can accurately alert when they enter or exit geofences (safe zones).
In this article, find more out about location reporting and how Tended devices use different technologies for accurate positioning on-site.
What is location accuracy?
When thinking about Tended devices and geofencing projects, accuracy means how precisely the device can determine and report its location within a defined area.
How accurate are the Tended devices?
The devices are highly accurate. Some circumstances may lead to device accuracy dropping below an acceptable level, but you'll always be alerted when this happens.
Devices operate at 95% confidence: You can trust your device to notify you accurately if you accidentally stray from safe working limits.
The device logs its location 4 times per second: giving you quick and responsive alerts when you need them
Why is device accuracy important?
Precision safe zones: On the Tended dashboard, safe zones (geofences) are drawn to cm accuracy around safe working limits good levels of accuracy allow the device to react quickly to these boundaries.
Real-Time Alerts: With precise location accuracy, devices will alert almost immediately if a track worker exits a safe zone, allowing quick responses.
Accurate Data Logging: When used in asset mode, Tended device locations will be visible from the Dashboard allowing you to monitor the movements and behaviour of site assets accurately.
Key technical terms
GNSS (Global Navigation Satellite System) - technology that uses satellites to provide location information anywhere on Earth. It helps devices like smartphones, cars, and planes know where they are.
RTK (Real-Time Kinematic) - a method used to make GPS (or GNSS) much more accurate. While regular GNSS can usually give you location accuracy within a few meters, RTK improves that accuracy to just a few centimetres.
Protection levels - safety margins used in GPS/GNSS systems to show how much error might exist in the system’s position estimate. They help ensure that the actual location of a receiver is within a safe distance from where it appears on the map.
How do Tended devices gain accuracy?
Tended devices use a combination of GNSS technology and RTK correction to achieve high accuracy in their location reporting.
GNSS satellites: The device receives signals from multiple GNSS satellites, which provide basic location information, similar to how your phone's GPS works. This alone is accurate to within a few meters.
RTK correction: To improve accuracy even further, Tended devices use RTK technology. This involves a base station (a fixed reference point) that knows its exact position. The base station compares the satellite signals it receives with its known location and calculates any small errors. It then sends correction data to the device in real-time.
Protection levels: To ensure that the accuracy provided by the GNSS and RTK systems is reliable, protection levels come into play. These levels quantify the maximum error that can be expected with a certain probability.
High precision: By combining GNSS data, RTK corrections and protection levels, Tended wearables can determine the device's location with centimetre-level accuracy. This level of precision is essential for supporting track worker safety in geofencing projects.
About the low accuracy alert
You're device may lose accuracy during your shift due to losing the connection to a satellite signal. Reasons for this may be:
Obstructed by site equipment or machinery
Antenna covered by worker PPE
Working in a built-up area i.e. high buildings or trees
If your device loses accuracy, you'll receive the following alert:
If you hear this alert, you can continue to carry out your work relying on your primary form of protection and remain aware of your surroundings and safe working limits.
The device will show three solid green lights once accuracy has been regained.
Any questions or issues?
We're here to help! Simply pop us an email at support@tended.co.uk, WhatsApp us on 07713682625 or drop us a message via live chat from the blue bubble in the corner of this page or within the Dashboard 😊