OCAS meaning in Governmental ?

The Obstacle Collision Avoidance System (OCAS) is designed to alert pilots if their aircraft is in immediate danger of flying into an obstacle. OCAS uses a low power ground-based radar to provide detection and tracking of an aircraft's proximity to an obstacle such as a power line crossing, telecom tower or wind turbines. This capability allows the visual warning lights to remain passive until an aircraft is detected and known to be tracking on an unsafe heading. This leaves the nighttime sky free of unnecessary light pollution thus decreasing public annoyance issues while improving the environmental habitat.

OCAS is currently the only FAA approved Audio Visual Warning System (AVWS) approved in the National Airspace. OCAS is also the only AVWS approved by the International Dark Sky Association.

OCAS is operational in the US, Canada, Norway and Germany.