Precision runway monitor

PRM uses a Monopulse Secondary Surveillance Radar (MSSR) that employs electronically-scanned antennas.

The system is designed to search, track, process, and display SSR-equipped aircraft within airspace of over 30 miles in range and over 15,000 feet in elevation.

Visual and audible alerts are generated to warn controllers to take corrective actions.

[1] PRM is one type of radar system that can be used to allow simultaneous approaches on parallel runways that are typically spaced 3,000–4,300 feet (910–1,310 m) to each other.

[1] Airports at which PRM is in use in the United States include Chicago-O'Hare, San Francisco, Detroit, and Atlanta.