 Cassegrain antenna of ALTAIR | |
| 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 |
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.
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).
The radar became operational in 1969. 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, and to observe ionospheric irregularities and background densities.
References
- J. A. Nelson and K. R. Roth, History of Lincoln Laboratory at the Reagan Test Site, Lincoln Laboratory Journal Number 2 2012 (online PDF)
- Card Index of Radar Sets in Radartutorial
- S. Close, S. M. Hunt, F. M. McKeen and M. J. Minardi: “Characterization of Leonid meteor head echo data collected using the VHF-UHF Advanced Research Projects Agency Long-Range Tracking and Instrumentation Radar (ALTAIR)”, MIT Lincoln Laboratory, Lexington, Massachusetts, USA, in RADIO SCIENCE, VOL. 37, NO. 1, 1009, 10.1029/2000RS002602, 2002 (online PDF)
- Sidney G. Reed, Richard H. Van Atta und Seymour J. Deitchman DARPA technical accomplishments : an historical review of selected DARPA projects, Institute for Defense Analyses, Alexandria, Va. und
- Sigrid Close et al.: “Simultaneous dual-frequency observations of meteor head echoes using ALTAIR”, In: Proceedings of the Third European Conference on Space Debris, 19–21 March 2001, Darmstadt, Germany. Ed.: Huguette Sawaya-Lacoste. ESA SP-473, Vol. 1, Noordwijk, Netherlands: ESA Publications Division, ISBN 92-9092-733-X, 2001, p. 237 - 242 (online PDF)
- D.M.Towle: "VHF and UHF radar observations of equatorial F region ionospheric irregularities and background densities", Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02173, in Radio Science 1980, p. 71 ()
This article incorporates text available under the CC BY-SA 3.0 license.