# Problem #2: Device movement tracking

The problem of device movement tracking is similar to the problem of precise initial positioning, but there is a chance of using additional tools for resolving this task. Therefore, for the convenience of presenting the approaches to its resolution, it seems sensible to isolate it and examine it separately.&#x20;

The problem of device movement tracking is resolved through using the data provided by the accelerometer, gyroscope, barometer and camera video stream, processed by the internal ARKit by Apple and ARCore by Google, which, after finding natural surfaces in space, are capable of tracking the movement and determine the distance covered with reasonable preciseness, however:

* This method only works during daylight time, when ArKit/ArCore algorithms are capable of finding surfaces.
* The method allows to monitor device movement, but is still incapable of providing precise information on the direction of movement according to cardinal directions.&#x20;
* In the absence of precise data on the initial device position and precise data on the direction of its movement, all subsequent precise measurements of the distance and movement trajectory provide an erroneous superimposition of the virtual world over the real world.
