wat
That's what the squad leader portable UAV did in 2142. It was a little rotor drone that followed the squad leader around and spotted all enemies within a certain radius in 15 or something second intervals. And before you go "bluh op", it would always get stuck on things, could easily be destroyed, gave away your position all the time, and when I say it spotted them I mean it just showed their location through walls by a little red diamond (the same way enemies show up when a squad member spots units).