Image restoration of exoplanets observed with a hypertelescope

2015 Fiscal Year Final Research Report

• Project/Area Number: 25287032
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: Hokkaido University
• Principal Investigator: BABA Naoshi 北海道大学, ー, 名誉教授 (70143261)
• Co-Investigator(Renkei-kenkyūsha): TAMURA Motohide 東京大学, 大学院理学研究科, 教授 (00260018) ; MURAKAMI Naoshi 北海道大学, 大学院工学研究院, 助教 (80450188) ; MIURA Noriaki 北見工業大学, 工学部, 教授 (30209720)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 光学赤外線天文学 / 望遠鏡 / 系外惑星 / 像再生

Outline of Final Research Achievements

In order to resolve exoplanets an effective aperture with several tens or more kilometers is needed. A hypertelescope consists of many elemental telescopes. The beams from the elemental telescopes are enlarged and arranged compactly on the imaging lens to form the snap-shot image. This procedure is referred to densification.
Snap-shot images formed with a limited number of elemental telescopes do not exhibit high quality features. Some image restoration should be implemented to reveal the surface structures of exoplanets. One of annoying problems in hypertelescope image restoration is shift-variant characteristic of PSF that is caused by the pupil densification. We show that the CLEAN algorithm manages to restore images formed with shift-variant PSF and works well for noise-less images. For noisy images the pseudo Wiener filtering works better to restore the images.

Free Research Field

天文光学