The Photometric Accuracy of Astronomical Images Restored with the MEMSYS3 Code

1991 ◽  
pp. 59-65
Author(s):  
J. G. Cohen
Keyword(s):  
Astronomical Images

scholarly journals Successful application of PSF-R techniques to the case of the globular cluster NGC 6121 (M 4)

2020 ◽  
Vol 634 ◽  
pp. L5 ◽  
Author(s):  
D. Massari ◽  
A. Marasco ◽  
O. Beltramo-Martin ◽  
J. Milli ◽  
G. Fiorentino ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Globular Cluster ◽  
Hybrid Technique ◽  
Large Telescope ◽  
Point Spread ◽  
Accurate Knowledge ◽  
Viable Solution ◽  
Spread Function ◽  
Astronomical Images ◽  
Proper Analysis

Context. Precise photometric and astrometric measurements on astronomical images require an accurate knowledge of the point spread function (PSF). When the PSF cannot be modelled directly from the image, PSF-reconstruction techniques become the only viable solution. So far, however, their performance on real observations has rarely been quantified. Aims. In this Letter, we test the performance of a novel hybrid technique, called PRIME, on Adaptive Optics-assisted SPHERE/ZIMPOL observations of the Galactic globular cluster NGC 6121. Methods. PRIME couples PSF-reconstruction techniques, based on control-loop data and direct image fitting performed on the only bright point-like source available in the field of view of the ZIMPOL exposures, with the aim of building the PSF model. Results. By exploiting this model, the magnitudes and positions of the stars in the field can be measured with an unprecedented precision, which surpasses that obtained by more standard methods by at least a factor of four for on-axis stars and by up to a factor of two on fainter, off-axis stars. Conclusions. Our results demonstrate the power of PRIME in recovering precise magnitudes and positions when the information directly coming from astronomical images is limited to only a few point-like sources and, thus, paving the way for a proper analysis of future Extremely Large Telescope observations of sparse stellar fields or individual extragalactic objects.

Photometric Accuracy of Deconvolved Simulated Astronomical Images

2005 ◽  
Vol 627 (2) ◽  
pp. 701-705 ◽  
Author(s):  
Stephen R. McNeil ◽  
J. Ward Moody
Keyword(s):  
Astronomical Images

scholarly journals Straight to the Source: Detecting Aggregate Objects in Astronomical Images With Proper Error Control

2013 ◽  
Vol 108 (502) ◽  
pp. 456-468 ◽  
Author(s):  
David A. Friedenberg ◽  
Christopher R. Genovese
Keyword(s):  
Error Control ◽  
Astronomical Images

Photographic amplification of faint astronomical images

Nature ◽  
1978 ◽  
Vol 276 (5688) ◽  
pp. 591-593 ◽  
Author(s):  
DAVID F. MALIN
Keyword(s):  
Astronomical Images

A Revolutionary New Paradigm for the Reduction and Analysis of Astronomical Images

2010 ◽  
Author(s):  
Scott Michael ◽  
Patricia Knezek ◽  
Elizabeth Stobie ◽  
Robert Henschel ◽  
Stephen Simms
Keyword(s):  
New Paradigm ◽  
Astronomical Images

scholarly journals Is That Real? Understanding Astronomical Images

2015 ◽  
Vol 7 (5) ◽  
pp. 88-100
Author(s):  
F Smith Lisa ◽  
K Arcand Kimberly ◽  
K Smith Jeffrey ◽  
K Smith Randall ◽  
Bookbinder Jay
Keyword(s):  
Astronomical Images

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. 

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