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| ALMA-J Site Testing |
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| ＞ALMA-J Site Testing Archive |
Last update
2005-06-07
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11 GHz Radio Seeing Monitor
Two sets of radio interferometers fabricated at Nobeyama Radio Observatory have been operating to monitor the radio seeing at 11.2 GHz. They are almost identical to those used at Nobeyama Radio Observatory. Each of these interferometers has 300 m baseline (east-west) and utilizes 11.2 GHz beacon from one of the Intelsat geosynchromous satellites as a radio source. A small set of interferometer, which is a preceder of the current system, was installed at Paranal (2400 m a.s.l.) in 1994 July. In 1995 July, the first set of the 11.2 GHz interferometer was installed at Rio Frio (4100 m a.s.l.). The second one has been operating at Pampa la Bola (4800 m a.s.l.) since 1996 July. As we decided Pampa la Bola-Chajnantor area as the first priority candidate of the LMSA site, the first interferometer was re-installed at Pampa la Bola in 1999 March. These two sets of interferometers are now operated in series to provide information on atmospheric structure up to 600 m.
Technical Description
Figure 1: Block diagram
References
- Ishizaki, H., & Sakamoto, S. 2005, "Velocity and structure function of phase screen aloft Chajnantor," ALMA Memo 529
- Butler, B. J., Radford, S. J. E., Sakamoto, S., & Kohno, K. 2001, "Atmospheric phase stability at Chajnantor and Pampa la Bola," ALMA Memo 365
- Holdaway, M. A., Matsushita, S., & Saito, M. 1997, "Preliminary phase stability comparison of the Chajnantor and Pampa la Bola sites," ALMA Memo 176
- Holdaway, M. A., Ishiguro, M., Foster, S. M., Kawabe, R., Kohno, K., Owen, F., Radford, S. J. E., & Saito, M. 1996, "Comparison of Rio Frio and Chajnantor site testing data," LMSA Memo 1996-003 (also NROTR 51)
- Holdaway, M. A., & Ishiguro, M. 1995, "Experimental determination of the dependence of tropospheric pathlength variation on airmass," LMSA Memo 1995-002 (also NROTR 46)
- Ishiguro, M. 1993, "Measurements of radio seeing and how to cope with it," LMSA Memo 1993-001 (also NROTR 37) [Text in Japanese]
- Kasuga, T., Kanzawa, T., & Ishiguro, M. 19??, "Atmospheric phase fluctuations of the millimeter-wave interferometer," NROTR 24