Reeves AN/MSQ-77 Bomb Directing Central
US military computerized tracking radar / From Wikipedia, the free encyclopedia
The Reeves AN/MSQ-77 Bomb Directing Central, Radar[6] (nickname "Miscue 77") was a United States Air Force automatic tracking radar/computer system for command guidance of aircraft. It was often used during Vietnam War bomb runs at nighttime and during bad weather. Developed from the Reeves AN/MSQ-35,[citation needed] the AN/MSQ-77 reversed the process of Radar Bomb Scoring by continually estimating the bomb impact point before bomb release[7] with a vacuum tube ballistic computer. Unlike "Course Directing Centrals" which guided aircraft to a predetermined release point, the AN/MSQ-77 algorithm continuously predicted bomb impact points during the radar track while the AN/MSQ-77's control commands adjusted the aircraft course. A close air support regulation prohibited AN/MSQ-77 Combat Skyspot bombing within 1,000 yd (910 m) of friendly forces unless authorized by a Forward Air Controller,[8]: 135 and "on several occasions" strikes were as close as 273 yd (250 m).[5]
Country of origin | United States |
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Manufacturer | Reeves Instrument Corporation |
Type | Site area |
Frequency | 8500 to 9600 MHz (X band) |
PRF | 600 pulses/second or 300 pulses/second[citation needed] |
Pulsewidth | .25 microsecond |
RPM | 30 cycles/second feedhorn rotation →20 pulses/cycle conical scan signal |
Range | 200 nmi (370 km; 230 mi) beacon track[2] 135 nmi (250 km; 155 mi) skin track 130 nmi (150 mi) UHF radio reliability[3] |
Diameter | 8 ft (2.4 m) Cassegrain antenna |
Precision | tbd in range tbd degrees (radar track) tbd degrees (computer track w/ joystick alignment on CCTV image) GDB ACCURACY <680 ft CEP @ 200 nmi (specification)[4] 486 ft CEP @ 44 nmi (1965 testing)[5] 300-350 ft ave @ ≤100 nmi (1967 ops)[2] |
Post-war the MSQ-77 was used on US and other training ranges for Radar Bomb Scoring (RBS). The AN/MSQ-77 was also periodically used for post-Vietnam commanding of bombers during simulated ground directed bombing to maintain aircrew and radar crew GDB proficiency (RBS could be used to score the simulated GDB mission). Most AN/MSQ-77s were replaced by solid-state equipment near the end of the Cold War.