How to change horizontal velocity using MAVROS GlobalPositionTarget topic

Greetings all,

I am using the /mavros/setpoint_raw/global (mavros msg: GlobalPositionTarget) topic within MAVROS to guide my multirotor to a GPS position. My first attempts did not utilize the velocity vector within the topic as I masked the velocity, acceleration and yaw. The aircraft flew at ~ 8 m/s even though the WP nav speed in Mission Planner is set at 20 m/s.

FYI…I have migrated from Dronekit / pymavlink to MAVROS for flexibility of integrating sensors. The simple_goto command within Dronekit works well and updates the horizontal speed properly. I would like to have use of this same functionality in MAVROS.

ArduCopter 4.0.7
Ubuntu 20.04
ROS Noetic

My questions are:

  1. If I do not use the velocity vector within the GlobalPositionTarget topic, how is the horizontal velocity being determined?
  2. Will the DO_CHANGE_SPEED command alter the horizontal speed? (I have not been able to get the speed to change with this command.)

Thanks for everyone’s feedback.