DSpace Collection: Volume 6 Number 1
http://hdl.handle.net/10525/1775
The Collection's search engineSearch the Channelsearch
http://sci-gems.math.bas.bg/jspui/simple-search
Hough Transform Approach to Identification of Flare Stars in Multi-exposure Plate Images
http://hdl.handle.net/10525/1786
Title: Hough Transform Approach to Identification of Flare Stars in Multi-exposure Plate Images<br/><br/>Authors: Dimov, Dimo; Tsvetkova, Katya; Tsvetkov, Milcho; Kolev, Alexander; Kounchev, Ognyan<br/><br/>Abstract: The paper discusses the progress in the automation of the detection of flare stars through astronomical observations with plates obtainedby the multi-exposure “chain” method. In spite of the fact that the astronomical plate observations are considered obsolete in modern astronomy, the computer processing of these images is an actual problem, due to the considerable number of wide-field plates in our country, in Europe and throughout the world. The solution of the problem is implemented in a sequence of three stages: (i) detection of the form of the chains, (ii) location of the chains in the input plate image and (iii) detection of chains representing “flare stars”. The paper is focused on the second stage, the implementation of which requires the use of Hough transform (HT). A theoretical and experimental analysis of the suggested approach connected with HT is presented. The “bottlenecks” in the development are discussed on the basis of a comparative analysis with a competitive approach - the “cumulative” statistic approach to chains in the given image. At the end, a combined approach is offered, uniting the various advantages, but again based on HT. Some experimental results and illustrations are presented. The perspectives for future work, connected with an implementation of a whole software system designed to solve the problem, are described.<br/><br/>Description: ACM Computing Classification System (1998): I.2.8 , I.2.10, I.5.1, J.2.Adaptive Document Image Binarization with Application in Processing Astronomical Logbooks
http://hdl.handle.net/10525/1785
Title: Adaptive Document Image Binarization with Application in Processing Astronomical Logbooks<br/><br/>Authors: Laskov, Lasko<br/><br/>Abstract: Recently, the digitalization of the astronomical scientific heritage has been considered an important task that can facilitate much researches in astronomy. The creation of digital libraries and databases of astronomical photographic plates brings up the problem of digitalization astronomical logbooks, since the data contained in them is crucial for the usage of the plates. An optical character recognition (OCR) system for the handwritten numerical data is needed in order to speed up the process of database creation and extension.In this paper document image binarization is considered since it is a critical stage for the subsequent steps in an OCR software system. A specific method is proposed which outmatches the state-of-the-art techniques in the case of the images of interest.<br/><br/>Description: ACM Computing Classification System (1998): I.7, I.7.5.Weighted ICP Algorithm for Alignment of Stars from Scanned Astronomical Photographic Plates
http://hdl.handle.net/10525/1784
Title: Weighted ICP Algorithm for Alignment of Stars from Scanned Astronomical Photographic Plates<br/><br/>Authors: Marinov, Alexander; Zlateva, Nadezhda; Dimov, Dimo; Marinov, Delian<br/><br/>Abstract: Given the coarse celestial coordinates of the centre of a platescan and the field of view, we are looking for a mapping between the starsextracted from the image and the stars from a catalogue, where the starsfrom both sources are represented by their stellar magnitudes and coordinates, relatively to the image centre. In a previous work we demonstratedthe application of Iterative Closest Point (ICP) algorithm for the alignmentproblem where stars were represented only by their geometrical coordinates.ICP leads to translation and rotation of the initial points - a correction required for one set of stars to fit over the other. This paper extends theprevious work by demonstrating significant improvement of ICP by usingthe stellar magnitudes as point weights. The improvement consists of greatdecrease of the iteration count until convergence, which helps in the case ofhighly “misaligned” initial states. The essential aspects of the ICP methodlike noise tolerance of false or missing stars are still in charge.<br/><br/>Description: ACM Computing Classification System (1998): I.2.8, I.2.10, I.5.1, J.2.AstroWeb – A Graphical Representation of an Astronomical WFPDB Database Using a Web-Based Open Source Geographical Information System
http://hdl.handle.net/10525/1783
Title: AstroWeb – A Graphical Representation of an Astronomical WFPDB Database Using a Web-Based Open Source Geographical Information System<br/><br/>Authors: Kolev, Alexander; Tsvetkov, Milcho; Dimov, Dimo; Kalaglarsky, Damyan<br/><br/>Abstract: The purpose of this study is to present the open-source Map-Server and the way it can be used as a Web-based Geographic InformationSystem. The MapServer object model is analyzed and algorithms are proposed for geo-referenced spatial data dynamic representation. The results of this analysis are used in the development of our application called AstroWeb. AstroWeb presents graphically the application data of the Plate Archives catalog (CWFPA v.2011) of Bulgarian Wide-Field Plate Database and ensures fast and easy access to the digitalized plate information.<br/><br/>Description: ACM Computing Classification System (1998): H.5.2, H.2.8, J.2, H.5.3.Technology for Scanning Astronomical Photographic Plates
http://hdl.handle.net/10525/1782
Title: Technology for Scanning Astronomical Photographic Plates<br/><br/>Authors: Tsvetkov, Milcho; Tsvetkova, Katya; Kirov, Nikolay<br/><br/>Abstract: Here we describe the technology and the experience during theastronomical photographic plate digitization with flatbed EPSON scanners.More than 275000 plates in different observatories in Europe were digitizedwith such scanners last decade.<br/><br/>Description: ACM Computing Classification System (1998): J.2.Software Tools for Digitization of Astronomical Photographic Plates
http://hdl.handle.net/10525/1781
Title: Software Tools for Digitization of Astronomical Photographic Plates<br/><br/>Authors: Kirov, Nikolay; Tsvetkov, Milcho; Tsvetkova, Katya<br/><br/>Abstract: In this paper we present tools for helping the process of digitization of astronomical photographic plates. The requirements of VirtualObservatory presume that any FITS file, which contains a digital image, has to be equipped with a complete header. Wide-Field Plate Database(WFPDB) offers most of the meta-data needed for the creation of FITS header. The header2011 software gives the user an appropriate tool forconnecting WFPDB catalogues to digitized plate images. The use of modern scanners sometimes imposes conversion of files from the inner format of the scanner (or driver) into FITS format. The tif2fits software converts VueScan row-tiff format to FITS and also separates plate image and wedge image in case of scanning with grayscale wedge.<br/><br/>Description: ACM Computing Classification System (1998): J.2.Article Disassembly - New Ways to Handle Information in Publications
http://hdl.handle.net/10525/1780
Title: Article Disassembly - New Ways to Handle Information in Publications<br/><br/>Authors: Holl, András<br/><br/>Abstract: Articles and books – the basic publication units – could be disassembled to semantic building blocks. For scientific journal articles, suchblocks include figures and tables, among others. Providing meta-data for figures and tables, and making them accessible per se, opens up new ways of presenting and using scientific information—like producing an image database on certain subjects, based on figures published in different journals. These meta-data, complete with copyright information, should be supplied by the publishers, who in turn might require authors to provide this information. Some examples are shown from a small astronomy journal, the Information Bulletin on Variable Stars.<br/><br/>Description: ACM Computing Classification System (1998): I.7.4.Digital Preservation and Web Access to the Konkoly Observatory Schmidt Telescope Plate Archive
http://hdl.handle.net/10525/1779
Title: Digital Preservation and Web Access to the Konkoly Observatory Schmidt Telescope Plate Archive<br/><br/>Authors: Tsvetkova, Katya; Tsvetkov, Milcho; Holl, András<br/><br/>Abstract: The digital preservation of the Konkoly Observatory Schmidttelescope plates, as well as the web access to the plate previews, aim forthe preservation of this scientific heritage and the re-use of the astronomicalphotographic plates in time domain astronomy. The photographic platesused as detectors and information storage at astronomical observations withthe Konkoly Schmidt telescope had been obtained in the period 1962–1996.The work on the digital plate preservation and web access started in 2001with creation of an electronic plate catalogue and the digitization of selectedrepresentative plates as well as with interlinking of the publishing in KonkolyObservatory Information Bulletin on Variable Stars (IBVS) with the Wide-Field Plate Database (WFPDB) developing in Sofia. We describe the processof the digitization of the Konkoly Schmidt telescope plates.<br/><br/>Description: ACM Computing Classification System (1998): J.2.Potsdam Library of Astronomical Photographic Plates
http://hdl.handle.net/10525/1778
Title: Potsdam Library of Astronomical Photographic Plates<br/><br/>Authors: Tsvetkova, Katya; Tsvetkov, Milcho; Kirov, Nikolay; Boehm, Petra; Steinmetz, Matthias; Arlt, Rainer; Enke, Harry; von Berlepsch, Regina<br/><br/>Abstract: We present the Potsdam photographic plate library at the Leibniz Institute for Astrophysics Potsdam. It includes plate archives, data fromplate index catalogues and extracts from astronomical logbooks, as well as digitized plate images and interfaces for accessing all the available information. The plate index catalogues and the digitized images of the Potsdam astronomical photographic plates are prepared according to the standards of the Wide-Field Plate Database and German Astrophysical Virtual Observatory. The high-resolution digitization of the plates (in standardized FITS file format), the low-resolution plate previews (in TIFF and JPEG file format), as well as suitable digitization of the catalogues, logbooks, and relevant scientific research papers (in JPEG and TIFF) are made using commercial flatbed scanners.<br/><br/>Description: ACM Computing Classification System (1998): J.2.Photographic Plate Libraries at European Astronomical Observatories
http://hdl.handle.net/10525/1777
Title: Photographic Plate Libraries at European Astronomical Observatories<br/><br/>Authors: Tsvetkova, Katya; Tsvetkov, Milcho; Kounchev, Ognyan<br/><br/>Abstract: This paper presents the efforts to organize photographic plate libraries at European astronomical observatories and institutions. The Wide-Field Plate Database project, launched in 1991, has been collecting data about the plates, including plate archives, plate index catalogue data extracted from the logbooks, and digitized plate images. Developing further the WFPDB project, we intend to complete the high-resolution digitization of the plates (in standardized FITS file format) and a suitable digitalization of the catalogues and logbooks (in JPEG and TIFF), with flatbed scanners, and also to organize links to the relevant scientific research papers. At present about 250000 plates have been digitized and await implementation of online access. The main idea is to build an Astro-Multimedia Library, based on the latest methods of Computer Science, in particular on Multiresolution Analysis techniques, which allow for efficient representation of imagescans at different resolutions.<br/><br/>Description: ACM Computing Classification System (1998): J.2.The Wide-Field Plate Database: Development and Access via Internet
http://hdl.handle.net/10525/1776
Title: The Wide-Field Plate Database: Development and Access via Internet<br/><br/>Authors: Tsvetkov, Milcho<br/><br/>Abstract: The motivations and results from the first 1.5-year period of the project “Wide-field Plate Database (WFPDB): Development and Access via Internet” (DO-02-273/18.12.2008), approved for funding through a competition held by the Bulgarian National Science Fund in the field ofPromotion of Research in Priority Areas, are described. The main direction of the development of the project is digitization and preservation of,and web access to, the astronomical plate archives of the 2-m RCC and the 50/70 cm Schmidt telescopes of the Rozhen National Astronomical Observatory received in the period 1979–1998. The basis of the work is set out in Tsvetkov (2006) [1] and Tsvetkova & Tsvetkov (2006) [2], motivating the project over the past 10 years. The WFPDB (www.wfpdb.org) represents a unique virtual instrument in astronomical research, which allows obtaining information on existing astronomical observations of celestial objects over the past 130 years with the professional astronomical telescopes at observatories around the world. Briefly, this is a unique virtual telescope working as a “Time Machine” for obtaining information on historical observations of minor planets, comets, stars and galaxies. The project also aims to continue and expand the successful work initiated during the past 15 years by extending the provision of technical work on the base, and improving and extending the internal LAN (www.skyarchive.org), which ensures rapid online access to data, based on international standards of the International Virtual Observatory Alliance (IVOA) and the European Virtual Observatory (EURO-VO). The main results of this paper are described in detail in the annual report project of July 15, 2010: http://trillian.magrathea.bg:8181/DATABASE FNI 273 2010July/<br/><br/>Description: ACM Computing Classification System (1998): J.2.