Currently, we have a fully operational ROS simulation so that we can test collision avoidance algorithms on it. Information describing our current system is here. Anyway, let me get to what I am trying to achieve this summer. I intend to use the current simulation system to be able to have one plane flying while reacting to the planes in the simulator. To achieve this we more or less need to be able to do two things: 1) send waypoints to planes via XBEE while in-flight and have them immediately fly to this destination, 2) receive GPS information from in-flight planes so that the collision avoidance algorithms can react accordingly. I was wondering if anyone has had any experience doing this sort of thing and if so what is the direction I should go? If not, could anyone point me in the right direction to getting started? It seems that the MAVlink system can be used to communicate between a GCS and a plane but i'm not very familiar with this system, but once the communication is established it seems pretty trivial to send waypoints and receive GPS info. Also, how much trouble will it be to format this information from MAVlink format to ROS topics.