Application of the OS-EM method to the restoration of LBT images.
BERTERO M. and BOCCACCI P.
Abstract (from CDS):
The Large Binocular Telescope (LBT), which will be available in a few years from now, has been designed for high-resolution optical/infrared imaging through coherent cophasing of the two mirrors. The structure of the process of image formation in LBT is similar to that in Computed Tomography (CT) so that it is interesting to investigate the applicability to LBT of image restoration methods developed for CT. A powerful one is the so-called Expectation Maximization (EM), which is also known in the astronomical literature as Lucy-Richardson (LR) method. However slow convergence is a drawback of this method. In the case of CT an accelerated version, based on ordered subsets of projection data (OS-EM), has been proposed. In this paper we adapt OS-EM to the problem of restoring LBT images and we show that it provides an acceleration by a factor which is roughly equal to the number of independent interferometric images of the same object.
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Journal keyword(s):
image processing, data analysis
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Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
ra dec : right ascension and declination (unit and frame defined according to your Output Options)
Grey values are increasing the original precision due to the computation of frame transformations
(wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
[error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
position angle (in degrees North celestial pole to East)
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References (70 between 1850 and 2024) (Total 70)
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