ARSR-4: unique solutions to long-recognized radar problems

Forty L-band three dimensional radars will be deployed on the periphery of the United States for joint use by the United States Air Force and the Federal Aviation Administration. The unattended radar system is designed to scan a range of 250 nautical miles up to an altitude of 100000 feet with look-down capability from high sites. The radar must detect fast, small-radar cross-section aircraft in a realistic man-made and natural interference environment (including up to 65000 flocks of birds), while minimizing false alarms. The radar also must generate weather intensity contours. The detection of aircraft over surface clutter, control of alarms due to birds, and performance imposed by the antenna are discussed, and the ARSR-4 characteristics are given