Relocalisation occurs when a system loses tracking (or initialized in a new environment) and needs to assess its location based on currently observable features. If the system can match the features it observes against the available map, it will localize itself to the corresponding pose in the map and continue the VSLAM process.
To relocalise, if tracking is lost ROV pilot should follow Operating recommendations.
Tracking can be lost for numerous reasons, some of them could be that the camera is too close or too far from the object, operating vehicle in unsupported speed... Best procedure in this case would be to keep the vehicle as much as possible steady and try to find the last tracked keyframe. To enable the Last tracked keyframe please go to Project tree and enable it under active camera..
Q: My track jumped suddenly. Is this normal?
A: Yes, this is completely normal. When camera loses sight of the object and then relocalises itself, it will seem as the track jumped. In reality VSLAM engine is searching for the best fit track.