Volume 436, Number 1, June II 2005
|Page(s)||373 - 378|
|Published online||20 May 2005|
On super-resolution in astronomical imaging
Universitäts-Sternwarte, Geismarlandstr. 11, 37083 Göttingen, Germany e-mail: firstname.lastname@example.org
Accepted: 27 January 2005
Our work is an attempt to fulfil one of the aims of astronomical imaging, that is, to obtain information at high angular resolution. Stars as point sources can be represented by Dirac δ-functions whose Fourier transforms contain information about the position and the (integrated) intensity at all angular frequencies. Thus, we can deconvolve unresolved images of star fields even at angular distances smaller than the diffraction limit of the telescope with which the observations are performed. We give an example of reconstruction of the image of two stars with an angular separation of a factor 2.5 less than . However, we find that super-resolution is feasible only for point sources. For extended objects the information about intensity fluctuations at angular frequencies is irretrievably lost. We discuss the impossibility of super-resolution for the Sun using a numerically simulated image of solar granulation. However, one can enhance the contrast of solar images, though without increasing angular resolution beyond the diffraction limit.
Key words: techniques: high angular resolution / techniques: image processing
© ESO, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.