ALTAIR (Radar)
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ALTAIR (ARPA Long-Range Tracking And Instrumentation Radar) is a radar tracking station on Roi-Namur island in the north part of the Kwajalein atoll in the Marshall Islands. It is a high-sensitivity, wide-bandwidth, coherent, instrumentation and tracking radar that is capable of collecting precise measurements on small targets at long-ranges. ALTAIR supports several operating modes, including tracking and signature collection at VHF and UHF. It is part of a network of contributing radar sensors that perform deep-space tracking.[2]
Country of origin | US |
---|---|
Designer | MIT Lincoln Laboratory |
Introduced | 1969 |
Frequency | 162 and 422 mc |
PRF | 300 pps |
Beamwidth | 1.1° (UHF) 2.8° (VHF) |
Pulsewidth | 80 µsec |
Range | 42,000 km |
Diameter | 45.7 m (150 ft) |
Precision | 20 m (66 ft) |
Power | 5 MW |
The antenna uses a steerable 150-ft dish (46-m-diameter) and employs a focal point VHF feed and multimode Cassegrain UHF feed in conjunction with a frequency selective sub-reflector (5.5 m diameter).[3]
The radar became operational in 1969.[4] The original task was to detect and track intercontinental ballistic missiles. It is currently used to measure satellite orbits and meteor echoes in low-Earth orbit,[5] and to observe ionospheric irregularities and background densities.[6]