Purpose

rosbag_extract_traj aims at extracting all trajectories from all topics in a ROS bag (.bag, .db3 or .mcap ) recorded in different message types. It currently supports the following types

This executable also allows to filter the measurements based on quality filter and covariance for instance.

The extracted trajectories are aimed at being used in the exwayz_georef.exe executable for georeferencing SLAM session.

Command line options

Name Command line prefix Default value Definition
Input bag(s) -i Required Path to the input bag or directory containing bags
Output directory -0 . Output directory
Topic name -t 30 Name of the topic to extract. If not set, all topics will be extracted accordingly with their type.
Destination projection CRS -p 50.0 CRS for projecting the NavSatFix messages if any is found.
Offset --offset Optional offset to substract to the output trajectory. This option can be used to get a trajectory with smaller coordinates.
Quality --quality Set of accepted quality filters. If not left empty, all measures with whose quality is not in the input quality set will be removed.
Max standard deviation --std-max Maximum accepted standard deviation on inputs measurements. If set, all measures with a greater standard deviation than the thresthold will be removed. /!\ Choose wisely the threshold: if too low, you could get an empty trajectory.
Minimum time step between consecutive measurements --dt-min Minimum required time step between consecutive measures. This option can help removing duplicated measurements, which would mess up later with the geo-referencing step, but could also be used to sample temporaly the output trajectory
Begin index --begin Begin index. Useful for ignoring first measurements that can be erroneous.
Help -h - Display the help.

Output

<message_name>.ply Output trajectory or trajectories in PLY format (see ‣)