The geofence represents a hard limit to where the UAV will not fly beyond. It is useful for preventing runaway UAVs (barring other software/hardware issues). If it breaches the fence the failsafe will be activated, returning it to the home point.
It is represented as an arbitrary polygon of waypoints around the flying area in the fixed-wing APM. In Arducopter, it is a radius and altitude parameter(s) representing a cylinder around the flying area.
A fence menu is available on the GUI console.
View the currently loaded geofence on the APM.
Load a new set of geofence coordinates from file.
fence load filename.txt
Save the set of current geofence coordinates to file.
fence save filename.txt
Draw the geofence on the map (if loaded).
Enable the geofence failsafe.
Disable the geofence failsafe.
Deletes all geofence coordinates.
Move a specific fence coordinate to a new location. When entered, a new location can be selected on the map window. This requires the map module to be loaded.
fence move 6
Remove a specific geofence coordinate.
fence remove 6