PX4

PX4.launch

1. Check MAVROS Installation

   Do the following if MAVROS is not installed

   # ubuntu 18.04
   sudo apt-get install ros-melodic-mavros ros-melodic-mavros-extras ros-melodic-mavros-msgs
   
   # ubuntu 20.04
   sudo apt-get install ros-noetic-mavros ros-noetic-mavros-extras ros-noetic-mavros-msgs
   

2. Modify px4.launch

   Please check px4.launch to modify accordingly, in which the comments are pretty much explainatory.