The RA-4000 Radar Altimeter provides highly accurate altitude above-ground-level (AGL) information from 2,000 feet down to ground level. This real-time system offers an extra measure of operational safety during landing, navigation, and hovering. It is especially useful in flying search and rescue missions, forestry operations, pipeline maintenance, offshore helicopter operations, aeromedical emergency medical services, border patrol, and electronic news gathering operations. Its patented "anti-rotor-modulation" capability prevents altitude wandering while hovering in a helicopter. The RA-4000 radar altimeter consists of a remote unit and dual antennas for greater accuracy. Extensive I/O capabilities allow seamless integration with other on-board equipment such as flight director systems and TAWS.