Better choice in GPS denied flight: Offboard or Mission?


I am currently working in a GPS-denied environment and exploring the usage of PX4 with external vision sources and optical flow. I initially attempted to use QGroundControl to create mission scripts. However, I noticed that the missions only functioned in simulation and not in the real world.

  • I was wondering if Mission mode requires a GPS signal to operate. Is it possible to utilize mission mode with an external vision system?

  • Additionally, I attempted to switch to Offboard mode while connecting PX4 through MAVROS, but I encountered difficulties in doing so. Are there any preconditions or specific requirements for using Offboard mode?

I would greatly appreciate any recommendations regarding the appropriate choice between these modes.

my setup:
PX4 1.13

Some preconditions to switch to Offboard mode:

  1. The vehicle must be armed before this mode can be engaged.
  2. The vehicle must be already be receiving a stream of target set-points (>2Hz) before this mode can be engaged. The vehicle will exit the Offboard mode if target set-points are not received at a rate of > 2Hz.
  3. This mode requires position or pose/attitude information - e.g. GPS, optical flow, visual-inertial odometry, mocap, etc.

Thanks for your reply. I believe my question arises from a lack of understanding regarding Offboard Mode.

Additionally, do you know if it is possible to use Mission Mode without a global position? I haven’t been able to find any documentation mentioning this.