That's called OSD (On Screen Display) . I have one for my quadcopter. It has gps for location and velocity. You can get them at any Hobby vendor . It has an NTSC vid in and vid out. It OVERLAYS all the info on your primary vid signal from the GO PRO camera. (it goes in series between the camera and video transmitter) The signal received on the ground is the combination of the two. It sets POO (Point of Origin) as "Home" and shows compass heading , speed , altitude, and Home so you can tell from the screen if it is going toward home or away from home.