Drone Speed Value


I’m getting the speed of bebop and I got something strange …

the documentation says:

Drone speed changed

speedX (float): Speed on the x axis (when drone moves forward, speed is > 0) (in m/s)
speedY (float): Speed on the y axis (when drone moves to right, speed is > 0) (in m/s)
speedZ (float): Speed on the z axis (when drone moves down, speed is > 0) (in m/s)

but instead I have a different behavior …
when the drone moving forward pointing north have the speed X positive when moving forward pointing south is negative !!
am I doing something wrong? or bebop returns the north south east west speeds and not the speed which is pointing?



The speed is in the North East Down coordinates. Maybe the comments of the commands are not clear enough, I’ll try to modify them.

Best regards,


So, just to be sure… moveByEnd displacements are given in body frame while SpeedChanged velocities are referred to the NED frame? Since @Djavan’s answer is almost 10 months old, is it like this in the newest firmware updates, too? It is not so clear in the developers’ guide.


Yes, it’s still like this in newest firmware.


Oups, I totally forgot to update it. It will be done in the next release.


What is the best way to convert from body frame reference to NED? Is the yaw angle relative to North? Or is it relative to its power on heading?