Restoration of observed image with an unknown space-variant blur from wide-field telescope

2012 ◽  
Author(s):  
Chaolan He ◽  
Honggang Wei ◽  
Mangzuo Shen
Keyword(s):  
Wide Field ◽  
Space Variant

scholarly journals Space Variant PSF – Deconvolution of Wide-Field Astronomical Images

10.14311/1023 ◽  
2008 ◽  
Vol 48 (3) ◽  
Author(s):  
M. Řeřábek
Keyword(s):  
Optical System ◽  
Imaging System ◽  
Real Data ◽  
Wavefront Aberration ◽  
Wide Field ◽  
Optical Aberrations ◽  
Optical Aberration ◽  
Transfer Characteristics ◽  
Astronomical Images ◽  
Space Variant

The properties of UWFC (Ultra Wide-Field Camera) astronomical systems along with specific visual data in astronomical images contribute to a comprehensive evaluation of the acquired image data. These systems contain many different kinds of optical aberrations which have a negatively effect on image quality and imaging system transfer characteristics, and reduce the precision of astronomical measurement. It is very important to figure two main questions out. At first: In which astrometric depend on optical aberrations? And at second: How optical aberrations affect the transfer characteristics of the whole optical system. If we define the PSF (Point Spread Function) [2] of an optical system, we can use some suitable methods for restoring the original image. Optical aberration models for LSI/LSV (Linear Space Invariant/Variant) [2] systems are presented in this paper. These models are based on Seidel and Zernike approximating polynomials [1]. Optical aberration models serve as suitable tool for estimating and fitting the wavefront aberration of a real optical system. Real data from the BOOTES (Burst Observer and Optical Transient Exploring System) experiment is used for our simulations. Problems related to UWFC imaging systems, especially a restoration method in the presence of space variant PSF are described in this paper. A model of the space variant imaging system and partially of the space variant optical system has been implemented in MATLAB. The “brute force” method has been used for restoration of the testing images. The results of different deconvolution algorithms are demonstrated in this paper. This approach could help to improve the precision of astronomic measurements. 

scholarly journals HST Image Restoration: Current Capabilities and Future Prospects

1994 ◽  
Vol 158 ◽  
pp. 61-69 ◽  
Author(s):  
Robert J. Hanisch ◽  
Richard L. White
Keyword(s):  
Image Restoration ◽  
Dynamic Range ◽  
Hubble Space Telescope ◽  
Spherical Aberration ◽  
Wide Field ◽  
Secondary Mirror ◽  
Faint Object ◽  
Spread Function ◽  
Restoration Algorithms ◽  
Space Variant

The spherical aberration in the primary mirror of the Hubble Space Telescope causes more than 80% of the light from a point source to be spread into a halo of radius of 2–3 arcsec. The point spread function (PSF) is both time variant (resulting from spacecraft jitter and desorption of the secondary mirror support structure) and space variant (owing to the Cassegrain repeater optics in the Wide Field / Planetary Camera). A variety of image restoration algorithms have been utilized on HST data with some success, although optimal restorations require better modeling of the PSF and the development of efficient restoration algorithms that accommodate a spacevariant PSF. The first HST servicing mission (December 1993) will deploy a corrective optics system for the Faint Object Camera and the two spectrographs and a second generation WF/PC with internal corrective optics. As simulations demonstrate, however, the restoration algorithms developed now for aberrated images will be very useful for removing the remaining diffraction features and optimizing dynamic range in post-servicing mission data.

scholarly journals PSF Estimation of Space-Variant Ultra-Wide Field of View Imaging Systems

2017 ◽  
Vol 7 (2) ◽  
pp. 151 ◽  
Author(s):  
Petr Janout ◽  
Petr Páta ◽  
Petr Skala ◽  
Jan Bednář
Keyword(s):  
Field Of View ◽  
Imaging Systems ◽  
Wide Field ◽  
Wide Field Of View ◽  
Space Variant ◽  
Psf Estimation

scholarly journals Advanced Processing of Images Obtained from Wide-field Astronomical Optical Systems

10.14311/1334 ◽  
2011 ◽  
Vol 51 (1) ◽  
Author(s):  
M. Řeřábek ◽  
P. Páta
Keyword(s):  
Image Data ◽  
Optical Systems ◽  
General View ◽  
Wide Field ◽  
Optical Aberrations ◽  
Transfer Characteristics ◽  
Astronomical Image ◽  
Wide Range ◽  
Spread Function ◽  
Space Variant

The principal aim of this paper is to present a general view of the special optical systems used for acquiring astronomical image data, commonly referred to as WFC or UWFC (Ultra Wide Field Camera), and of their transfer characteristics. UWFC image data analysis is very difficult in general, not only because the systems have so-called space variant (SV) properties. Images obtained from UWFC systems are usually incorrectly presented due to a wide range of optical aberrations and distortions. The influence of the optical aberrations increases towards the margins of the field of view. These aberrations distort the point spread function of the optical system and rapidly cut the accuracy of the measurements. This paper deals with simulation and modelling of the UWFC optical systems used in astronomy and their transfer characteristics.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

Wide-field subsecond temporal resolution optical monitoring systems for detection and study of cosmic hazards

2013 ◽  
Vol 183 (8) ◽  
pp. 888-894
Author(s):  
G.M. Beskin ◽  
S.V. Karpov ◽  
V.L. Plokhotnichenko ◽  
S.F. Bondar ◽  
A.V. Perkov ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Monitoring Systems ◽  
Wide Field ◽  
Optical Monitoring

Discovery of the fast optical variability of GRB 080319B and the prospects for wide-field optical monitoring with high time resolution

2010 ◽  
Vol 180 (4) ◽  
pp. 424 ◽  
Author(s):  
G.M. Beskin ◽  
S.V. Karpov ◽  
S.F. Bondar ◽  
V.L. Plokhotnichenko ◽  
A. Guarnieri ◽  
...  
Keyword(s):  
Time Resolution ◽  
High Time ◽  
High Time Resolution ◽  
Optical Variability ◽  
Wide Field ◽  
Optical Monitoring
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