Megan: Your post got me curious. I found this video on YouTube: "Heli-Expo 2015: Safe Flight Powerline Detection System" [ link is at https: // www . youtube . com / watch?v = CxsR_aA5XN8 ...once you remove the spaces]. Is that what you had in mind? I wonder if this works mainly for high tension power lines, or also simple spur lines that might have just a single wire of modest voltage?
Then again, there is also always Wire Strike Protection System if that counts as a way of detecting wires!