Topics¶

ROS nodes publish data using topics. These topics are represented by a path, such as “/sensors/eo/visible/image_raw”. Whilst topics can be trivially remapped within ROS, we recommend using the following conventions for simplicity.

Sensors¶

The root category for sensors not used by the flight control unit, such as cameras and thermal imagers.

/sensors/eo/visible/image_raw

Message: sensor_msgs/Image

Use this feed for general purpose onboard colour cameras (IDS UEye, GoPro Hero HD3).

/sensors/eo/ir/image_raw

Message: sensor_msgs/Image

Use this feed for a general purpose onboard Far Infra-Red feed (FLIR Tau 2).

/sensors/eo/nir/image_raw

Message: sensor_msgs/Image

Use this feed for a general purpose onboard Near Infra-Red camera (IDS UEye NIR).

Communications¶

/comms/RadioStatus

Message: mavros/RadioStatus

Information about the current state of the communications link.

Aircraft State¶

Topics used to obtain information about the status of the FCU and aircraft power buses.

/fcs/summary

Message: mavros/VFR_HUD

Summarises some important information on the current state of the aircraft, like airspeed, groundspeed, heading, altitude, etc.

/fcs/state

Message: mavros/State

Can be used to obtain information about the flight controller’s arming state and guidance modes. Unlikely to be relevant for the majority of applications.

/fcs/battery

Message: mavros/BatteryStatus

Used to obtain information about the airframe battery status. On airframes with internal combustion engines, voltage returned will be that of the 12VDC bus. The remaining value is an estimate used internally by the FCS for failsafe trigger actions and should not be relied upon.

Aircraft Position¶

/fcs/global_position/global

Message: sensor_msgs/NavSatFix

Information about the aircraft global position, fused by FCU.

/fcs/global_position/rel_alt

Message: std_msgs/Float64

Information about the aircraft relative altitude in metres above ground level.

/fcs/global_position/compass_hdg

Message: std_msgs/Float64

Information about the aircraft current heading in degrees.

/fcs/global_position/gps_vel

Message: geometry_msgs/Vector3Stamped

Information about the aircraft ground velocity vector, as fused by FCU in m/s.

Mission¶

/mission/WaypointList

Message: mavros/WaypointList

Information about current waypoint list loaded into FCS, updated whenever a change is made.

Applications¶

/apps/<application_name>/*

If you wish to take advantage of ROS’s interprocess communication functionality by publishing your own services use this namespace. We recommend namespacing under your application name.