I believe that all aircraft must be controlled under ATC's instructions to fly safely especially when take-off and landing. And, most ATC instructions are conducted by ground radar which controllers use.
But I know that the stealth aircraft (including B-2, F-22 etc.) aren't captured on radar display owing to their stealth ability. If so, how does a controller give instructions like radar vectors to stealth aircraft?
I know that there's are primary and secondary target when using radar, and the controller must use primary target to vector aircraft. I guess stealth aircraft can be captured by secondary radar but not primary target.