Remap ROS topics

The gisnav ROS 2 package depends on ROS for both external and internal communication, and ROS is also the natural way to integrate GISNav with other systems. To integrate GISNav with another ROS system, some topic name remapping may be required.

Remapping GISNav output

The most interesting ROS message is most likely the filtered camera pose and twist published as nav_msgs/Odometry by the ekf_localization_node from the robot_localization package (a dependency of gisnav), or the raw camera pose published as geometry_msgs/PoseWithCovarianceStamped by pose_node from the gisnav package.

The gisnav_msgs package includes message definitions that GISNav uses internally which are probably not interesting from an integration perspective.

See the ROS topography diagram for more context.

Prerequisites

These instructions assume you have installed GISNav locally.

Example commands

See the examples below on how to launch and run GISNav ROS nodes with remapped topic names.

ros2 launch

The below Python launch file diff shows an example remapping of the camera topics for StereoNode:

ld.add_action(
        Node(
            package="gisnav",
            name="stereo_node",
            namespace="gisnav",
            executable="stereo_node",
            parameters=[
                os.path.join(package_share_dir, "launch/params/stereo_node.yaml")
            ],
            remappings=[ 
                ("camera/camera_info", "camera_info"), 
                ("camera/image_raw", "image"), 
            ], 
        )
    )

ros2 run

The below example shows a remapping of camera topics for StereoNode on the command line:

cd ~/colcon_ws
ros2 run gisnav stereo_node --ros-args \
    --params-file src/gisnav/launch/params/stereo_node.yaml \
    -r camera/camera_info:=camera_info \
    -r camera/image_raw:=image