The ARSR-4 is the FAA's most recent (late 1980s, early 1990s) addition to the "Long Range" series of radars.
ARSR-4 systems are installed along the borders and coastal areas of the contiguous United States, Guantanamo Bay Naval Base in Cuba, the municipality of Yigo on Guam, and a training site at the FAA's Mike Monroney Aeronautical Center in Oklahoma City.
CARSR has a 200-nautical-mile (370 km; 230 mi) range, and shares transmitter components and software with the FAA's new airport surveillance radar, the ASR-11.
The radar operated in the L-band at 1250 to 1350 MHz and detected targets at distances beyond 210 nautical miles; 390 kilometres (240 mi).
This article incorporates public domain material from the Air Force Historical Research Agency