| Project/Area Number |
05640300
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Astronomy
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| Research Institution | Hokkaido University |
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Principal Investigator |
BABA Naoshi Hokkaido Univ., Fac.Eng., Associate Professor, 工学部, 助教授 (70143261)
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| Co-Investigator(Kenkyū-buntansha) |
ISOBE Syuzo National Astronomical Obs., Associte Professor, 助教授 (20012867)
MIURA Noriaki Hokkaido Univ.Fac.Eng., Assistant, 工学部, 助手 (30209720)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Stellar speckle interferometry / Phase diversity / Image reconstruction / High-resolution imaging |
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| Research Abstract |
In ground-based observations the spatial resolution is severely limited due to atmospheric turbulence.The purpose of this research is to overcome the degradation of the spatial resolution by use of phase-diversity method.
Phase-diversity speckle imaging is a method for reconstructing a high-spatial resolution image of a stellar object from two simultaneously recorded speckle images, one of which is formed afer rendering a known phase-diversity.When a defocus ia taken as a phase-diversity, a simplified optical setup is enough for high-resolution imaging.
We developed on iterative reconstruction algorithm for phase-diversity imaging.The reconstruction algorithm is based on the iterative blind deconvolution method and the Gerchnerg-Saxfon phase retrieval procedure.We conducted computer simulations for reconstructing binary stars, planetary objects and solar photoshere.We obtained satisfactory results for compact objects.In order to reconstruct largely extended objects, it is shown that an apodization filtering ia effective fo successful reconstructions.
Further studies are necessary to improve the quality of reconstructed images.Since high-resolution obsevation of the sun is one of urgent demands in solar physics, new imaging techniques along with the phase-diversity method should be investigated.
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