All the details.

Rotational Angle Sensor

The navigation system's rotational angle sensor senses changes in your car's direction to the left or right. This information, combined with signals from the wheel speed sensors indicating the distance travelled, allows the navigation control unit to calculate the route being taken and the curve radius. This data is used for the purpose of dead reckoning navigation. This makes car positioning more accurate and lets route calculation continue in situations where your car is unable to receive GPS signals.