Terrain awareness and warning system
GPS/GLONASS and Terrain awareness and warning system - details see: https://www.vehicleto.com/terrain-awareness-and-warning-system-10000780

GPS/GLONASS and Terrain awareness and warning systems are designed for providing aircrew with adequate information, as well as for sonic awareness of the true location of a helicopter in space that help to identify potential danger of collision with ground (with underlying surface or other obstacles) and to take effective actions to prevent collision dangerous effects.