نتایج جستجو برای: astronomical technique

تعداد نتایج: 618591  

Journal: :Astronomy & Geophysics 2010

1999
Gerard T. van Belle

Reliable prediction of stellar diameters, particularly angular diameters, is a useful and necessary tool for the increasing number of milliarcsecond resolution studies being carried out in the astronomical community. Specifically, the task of calibrating visibility amplitude information from astronomical interferometers often requires the ability to reliably estimate diameters and uncertainties...

1999
Richard L. White

An image compression algorithm has been developed that is well-suited to astronomical images. The method has 3 steps: an intensity mapping to generate an image that has roughly constant noise in each pixel, an orthonormal wavelet transform, and quadtree coding of the bit-planes of the wavelet coe cients. The quadtree values may be further compressed by any standard compression technique, such a...

2013
Matthew J. Graham S. G. Djorgovski Ashish A. Mahabal Ciro Donalek Andrew J. Drake

High-volume feature-rich data sets are becoming the bread-and-butter of 21st century astronomy but present significant challenges to scientific discovery. In particular, identifying scientifically significant relationships between sets of parameters is non-trivial. Similar problems in biological and geosciences have led to the development of systems which can explore large parameter spaces and ...

2014
Gabriela Barenboim Javier Rasero

In this work we show that modifying the thermal history of the Universe by including an early period of matter domination can lead to the formation of astronomical objects. However, the survival of these objects can only be possible if the dominating matter decays to a daughter particle which is not only almost degenerate with the parent particle but also has an open annihilation channel. This ...

2012
Bin Fu Eugene Fink Garth Gibson

When astronomers analyze sky images, they need to identify the newly observed celestial objects in the catalog of known objects. We have developed a technique for indexing catalogs, which supports fast retrieval of closely matching catalog objects for every object in new images. It allows processing of a sky image in less than a second, and it scales to catalogs with billions of objects. Keywor...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2008
Constantino Baikouzis Marcelo O Magnasco

Plutarch and Heraclitus believed a certain passage in the 20th book of the Odyssey ("Theoclymenus's prophecy") to be a poetic description of a total solar eclipse. In the late 1920s, Schoch and Neugebauer computed that the solar eclipse of 16 April 1178 B.C.E. was total over the Ionian Islands and was the only suitable eclipse in more than a century to agree with classical estimates of the deca...

Journal: :CoRR 2017
Ivan Kolosov Sergey Gerasimov Alexander Meshcheryakov

This work explores the use of big data technologies deployed in the cloud for processing of astronomical data. We have applied Hadoop and Spark to the task of co-adding astronomical images. We compared the overhead and execution time of these frameworks. We conclude that performance of both frameworks is generally on par. The Spark API is more flexible, which allows one to easily construct astr...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید