2006 Fiscal Year Final Research Report Summary
Basic Experiments of the Lens Film Developed towards a Gigantic Radio Telescope
| Project/Area Number |
17340060
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory of Japan |
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Principal Investigator |
CHIKADA Yoshihiro National Astronomical Observatory of Japan, Div. Radio Astronomy, Professor (30126122)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAGUCHI Noriyuki National Astronomical Observatory, Div. Radio Astronomy, Professor (90214618)
KASUGA Takashi Hosei Univ., Fac. Eng., Professor (70126027)
NAKAHIRA Katsuko Nagaoka University of Technology, e-Learning Center, Assistant Professor (80339621)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Radio Astronomy / Radio telescope / Antenna / Lens / Satellite Antenna |
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| Research Abstract |
Aperture area of a radio telescope is approaching its limit. It is caused by the fact that, for a telescope whose diameter exceeds 104 of observing wavelength, it is difficult to maintain its surface error less than 1/10 of the wavelength, under actual conditions of gravity, winds, non-uniformity of temperature distributions, etc. Considering the sensitivity of the receiver front-ends are now approaching its theoretical limits, it appears for the radio astronomy of the 21st century to meet the dead-ends without realizing much larger collecting area.
A room mirror of a car swings as the car roll, and the scenery through it will suffer blur. On the other hand, eye glasses may jump on your nose without serious blur. That is, compared to reflective mirrors, the transparent lenses may easily be held maintaining their line of sight. In the latter case, only the line between the focus and the center of the lens should be kept towards the celestial object, and the tilt of the lens is allowed to a certain amount. In other words, from the view point of the symmetry, the lens could be folded or be in arbitrary shape if the thickness be kept. This is the advantage of lenses.
With an experiment in this research, it was clearly shown that a multi-frequency lens can be implemented with a pair of parallel lenses which focus different frequencies independently because each lens is transparent to other frequency.
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