G_Optimizing-VI-Maps.md

Optimizing VI-Maps

Commands:

optv     # Optimization based on the visual data only (landmark observations)
optvi    # Optimization based on the visual and inertial terms (landmarks and IMU)

Hints:

• The optimization can be aborted at any time using Ctrl-C, it will then abort after at the end of the current iteration.
• Important flags:

  --ba_num_iterations                # Set the maximum number of iterations of the optimization.
  --ba_visualize_every_n_iterations  # Visualize the result of the optimization at every Nth step.

• Only landmarks flagged as 'good' will be part of the optimization. The following flags can be used to set the parameters of the quality metrics:

  --elq_min_observation_angle_deg
       # Minimum angle disparity of observers for a landmark to be well constrained.
  --elq_min_observers
       # Minimum number of observers for a landmark to be well constrained.
  --elq_min_distance_from_closest_observer
       # A landmark needs to be at least as far away from the observer to be well constrained [m].
  --elq_max_distance_from_closest_observer
       # A landmark cannot be further away from the observer than this to be well constrained [m].

  The landmark quality can be (re-)evaluated using the rtl or 'evaluate_landmark_quality command (before the optimization):

  evaluate_landmark_quality  --elq_min_observers=2 ...