Question: How does Auto-Survey work?

Just curious.. how does Auto Survey work? Seems like every time I double click my flagship and try to tell it to auto-survey.. it says something along the lines of "There are no anomolies in the area, turning off autosurvey".. so.... what gives?

I dont really care if there are anomolies in the area.. I just want the ship to fly around on its own and find anomolies where it can. If the Anomolies were visible on my screen..id just send it there myself.