[trhway]

>turn on your radar transmitter and reveal your location".

That was in the past. Even if you don't turn your radar on, in IR cameras widespread today your engines are visible from tens of kilometers, and without your radar on the missile comes to you without you being aware of it.

[dumah]

Missile approach warning systems don’t need radar. Most use IR sensing and lasers.

Even in radar-based MAW systems, they are not multipurpose and do not detect aircraft by design.