Hi,
If you are able to setup a ground truth (e.g., with VICON or Optitrack), this data can be fed to rtabmap (by setting
ground_truth_frame_id and
ground_truth_base_frame_id parameters, which are the origin of the localization system and a fake base frame representing same frame than base_link, but in a different TF tree than the standard map->odom->base_link tree) to compute some quantitative results (like the absolute trajectory error of
TUM's RGB-D dataset).
EDIT see this example:
https://github.com/introlab/rtabmap_ros/blob/master/launch/tests/rgbdslam_datasets.launchcheers,
Mathieu