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Tracking Information

Slamcore reports two types of tracking related information:

• The current SLAM Tracking Status at each frame

• Occasional SLAM Events which occur and affect pose estimation

Tracking Status

Tracking status indicates the instantaneous state of a pose estimation, explained in the table below.

	Tracking Status	Description
0	Not Initialised	The system has not discovered sufficient landmarks to begin tracking.
1	Tracking OK	Tracking is OK.
2	Tracking LOST	The system can not locate sufficient landmarks to continue tracking.

Below is a state transition flow diagram of the tracking status on SLAM.

When SLAM is running, the status should be fixed to Tracking OK most of the time. Otherwise, there may be an issue with the tracking, due to environments that are too dark, featureless walls or insufficient landmarks within a threshold distance.

Pose estimates when the system is Not Initialised or Tracking LOST are to be considered unreliable.

SLAM Events

SLAM Events report the events that are triggered at the current frame in our algorithm. Unlike the tracking status, multiple SLAM Events may occur in the same frame. In frames where no SLAM Event is reported, the trajectory file reports “None” in the slam_events column (see Guide to Trajectories).

	SLAM Event	Description
0	Relocalisation	The system has regained tracking and recovered its position on the map.
1	Loop Closure	A loop closure is detected in this frame.
2	IMU Initialization	Initial IMU parameters have been evaluated.