The GPS of your dashcam tracks the vehicle's location. The vehicle's location is then used to calculate the speed of the vehicle. This information gets updated every five seconds while the dashcam is online, and is uploaded to the Surfsight Portal every five minutes.
If information cannot be uploaded to the Surfsight Portal due to a loss of cellular connection, approximately 4 hours of GPS data and 1 GB of event video or snapshots are saved in the dashcam's internal memory. When the cellular connection is restored this information is sent to the Surfsight Portal and regular uploads continue.
Note
The accelerometer is not used to calculate speed. It measures G-force when detecting sudden acceleration/deceleration or violent turns.