Results 251 to 260 of about 140,683 (272)
Some of the next articles are maybe not open access.
Data Reduction Techniques for Direct Astronomical Electronography
1972Publisher Summary This chapter discusses the data reduction techniques for direct astronomical electronography. There are a number of ways in which the retrieval of information from the Spectracon exposure can be attempted. A preliminary analysis showed that the shape of the star profile was not strongly dependent on the star's intensity. It is found
M.J. Cullum, C.L. Stephens
openaire +1 more source
Radio astronomical image formation using sparse reconstruction techniques
2008 IEEE 25th Convention of Electrical and Electronics Engineers in Israel, 2008In this paper we present a sparse reconstruction algorithm for the deconvolution of radio astronomical synthesis images. We present the deconvolution problem as an ?1 optimization. Using the sparsity of the astronomical image we obtain that the ?1 reconstruction recovers the sparse image consistent with the observed data.
Runny Levanda, Amir Leshem
openaire +1 more source
Cross-spectrum Techniques Applied To Astronomical Speckle Interferometry
SPIE Proceedings, 1985A cross spectrum analysis technique, which makes it possible to compute an unbiased estimate of the speckle pattern Wiener spectrum, has been developed at the Nice University Astrophysics Department. The technique is based upon the use of a dual channel experiment, each of the channels giving a record of the image intensity with its specific noise.
Claude Aime +4 more
openaire +1 more source
2009 First International Conference on Information Science and Engineering, 2009
In astronomical telescope systems, the image quality is strongly influenced by the focus scattering effect and Gaussian white noise. We apply Wiener filtering method to regressing the blurred images in terms of the point spread function of the lens system. The result shows that this method can effectively restore the original image.
Cheng-hua Sui, Yi-jun Tang
openaire +1 more source
In astronomical telescope systems, the image quality is strongly influenced by the focus scattering effect and Gaussian white noise. We apply Wiener filtering method to regressing the blurred images in terms of the point spread function of the lens system. The result shows that this method can effectively restore the original image.
Cheng-hua Sui, Yi-jun Tang
openaire +1 more source
The technique and possibilities of astronomical spectrophotometry
Vistas in Astronomy, 1956Abstract The present capabilities of photographic spectrophotometry are reviewed; with large reflectors and modern optics accurate work on all naked-eye stars is possible. Photo-electric spectral scanning is best suited for low-resolution; image intensification will be needed to avoid losses due to scanning.
openaire +1 more source
The use of derivative techniques in astronomical spectroscopy
Astrophysics and Space Science, 1983Some remarks on the use of derivative spectroscopy in astronomy are considered. The advantages and the problems which arise with this technique are outlined.
openaire +1 more source
A Rapid Computer Search Technique for Astronomical Catalogs
Publications of the Astronomical Society of the Pacific, 1964During 1963 Hynek and Crull put a modified form of the Yale Catalogue of Bright Stars on punched cards. The writer has used a scan program to convert these cards to a binary tape, i.e., a tape on which the data are in a form immediately usable by the computer.
openaire +1 more source
Shapelets and related techniques in radio-astronomical imaging
2011 XXXth URSI General Assembly and Scientific Symposium, 2011We present the use of orthonormal basis functions, in particular, shapelets and prolate spheroidal wave functions, in radio astronomical imaging. By using such methods, it is possible to overcome some limitations of traditional pixel based image deconvolution.
openaire +1 more source