The Role of VLBI in Astrophysics, Astrometry and Geodesy

The Role of VLBI in Astrophysics, Astrometry and Geodesy
Author: Franco Mantovani
Publisher: Springer Science & Business Media
Total Pages: 416
Release: 2005-12-31
Genre: Science
ISBN: 1402024061

Download The Role of VLBI in Astrophysics, Astrometry and Geodesy Book in PDF, Epub and Kindle

A masterly survey of the last 13 years of Very Long Baseline Interferometry, reviewed in light of the most advanced astronomical observations. Topics covered include: Nonthermal emission from extragalactic radio sources; Principles of synchrotron emission in relation to astrophysics; Theory of relativistic jets; Young, powerful radio sources and their evolution; Scintillation in extragalactic radio sources; Radio and optical interferometry; Radio polarimetry; Unified schemes; Deep fields; Tropospheric and ionospheric phase calibration; Supernovae; VLBI for geodesy and geodynamics.

Very Long Baseline Interferometry

Very Long Baseline Interferometry
Author: Marcello Felli
Publisher: Springer Science & Business Media
Total Pages: 436
Release: 2012-12-06
Genre: Science
ISBN: 9400924283

Download Very Long Baseline Interferometry Book in PDF, Epub and Kindle

The quest for high resolution has preoccupied radio astronomers ever since radio waves were first detected from space fifty years ago. This venture was par ticularly stimulated by the discovery of quasars, and led to the development of interferometer techniques using baselines of transglobal dimensions. These meth ods have become known as Very Long Baseline Interferometry (VLBI). Arrays of radio telescopes situated all over the Earth (or even in space) are regularly used for researches in radio astronomy, reaching resolutions as small as a fraction of a milli arcsecond. The technique also allows the measurement of the positions of the radio telescopes to a few millimeters and so VLBI has become a major tool in geodesy and the study of the rotation of the Earth. VLBI has now passed the pioneer stage and is becoming a standard facility available to astronomers and geodesists, requiring the coordination of the operations of indpendently owned radio telescopes around the world. In Europe observatories from England, Federal Republic of Germany, France, Italy, Poland, Sweden and The Netherlands are coordinated in their VLBI activity by the European VLBI Network Consortium (EVN). The Programme Committee of the EVN allocates time to scientific projects on a routine basis three times a year. The Unites States has a similar arrangement of a network of independent radio observatories, and joint experiments using 'Global Network' are often made.

Relativity in Astrometry, Celestial Mechanics and Geodesy

Relativity in Astrometry, Celestial Mechanics and Geodesy
Author: Michael H. Soffel
Publisher: Springer Science & Business Media
Total Pages: 221
Release: 2012-12-06
Genre: Science
ISBN: 3642734065

Download Relativity in Astrometry, Celestial Mechanics and Geodesy Book in PDF, Epub and Kindle

The book "Relativity in Astrometry, Celestial Mechanics and Geodesy" repre sents a significant contribution to modern relativistic celestial mechanics and astrometry. In these branches of astronomy the theory of general relativity is used nowadays as an efficient practical framework for constructing accurate dynamical theories of motion of celestial bodies and discussing high-precision observations. The author develops the useful tools for this purpose and intro duces the reader into the modern state of the art in these domains. More specifically, the distinctive feature of the book is the wide application of the tetrad formalism to astronomical problems. One may not agree with the author's opinion that this is the only method so far to be able to treat the rel ativistic astronomical problems in a consistent and satisfactory manner. (On the contrary, one may foresee in the nearest future other books on relativistic celestial mechanics and astrometry based on different approaches solving the same problems. ) However, we are now at the beginning of practical relativis tic astronomy and it will demand much effort to reconstruct in a relativistic manner all Newtonian conceptions of ephemeris astronomy and geodesy. In particular, this concern. s the definitions of reference frames, time scales and astronomical units of measurement. This book is one of the first steps in the correct direction. V. A.

Reference Frames

Reference Frames
Author: Jean Kovalevsky
Publisher: Springer Science & Business Media
Total Pages: 470
Release: 2012-12-06
Genre: Science
ISBN: 9400909330

Download Reference Frames Book in PDF, Epub and Kindle

This book on reference systems is the first comprehensive review of the problem of celestial and terrestrial reference systems and frames. Over 20 years, the importance of this problem emerged slowly as the accuracy of new observational techniques improved. The topic has already been approached in several symposia such as Stresa (1967), Morioka (1971), Perth (1973), Columbus (1975, 1978 and 1985), Kiev (1977) and San Fernando (1978). Two IAU colloquia held in Turin (1974) and in Warsaw (1980) were exclusively devoted to discuss reference systems. During this time, the problem of terrestrial and celestial reference systems has been discussed also in many astronomical and geodetic symposia, but always among other topics. Thus, a review devoted solely to the definition and practical realization of such systems was needed. It is hoped that this book, containing modern comprehensive reviews of important facets of this problem will contribute not only to a better and wider understanding of the mathematics and the physics that are behind the concepts and the realizations, but also to future development in a field that can only expand with the rapidly increasing accuracy of geodetic and astronomical observations. We are pleased to thank all the authors of the book who have enthusiastically agreed to contribute to the book in their field of competence and have gracefully accepted guidance from the editors in the definition of the subject and of the interfaces with other chapters. We thank Prof. Y.

Interferometry and Synthesis in Radio Astronomy

Interferometry and Synthesis in Radio Astronomy
Author: A. Richard Thompson
Publisher: John Wiley & Sons
Total Pages: 715
Release: 2008-11-20
Genre: Science
ISBN: 352761785X

Download Interferometry and Synthesis in Radio Astronomy Book in PDF, Epub and Kindle

Comprehensive, authoritative coverage of interferometric techniques for radio astronomy In this Second Edition of Interferometry and Synthesis in Radio Astronomy, three leading figures in the development of large imaging arrays, including very-long-baseline interferometry (VLBI), describe and explain the technology that provides images of the universe with an angular resolution as fine as 1/20,000 of an arcsecond. This comprehensive volume begins with a historical review followed by detailed coverage of the theory of interferometry and synthesis imaging, analysis of interferometer response, geometrical relationships, polarimetry, antennas, and arrays. Discussion of the receiving system continues with analysis of the response to signals and noise, analog design requirements, and digital signal processing. The authors detail special requirements of VLBI including atomic frequency standards, broadband recording systems, and antennas in orbit. Further major topics include: * Calibration of data and synthesis of images * Image enhancement using nonlinear algorithms * Techniques for astrometry and geodesy * Propagation in the neutral atmosphere and ionized media * Radio interference * Related techniques: intensity interferometry, moon occultations, antenna holography, and optical interferometry Interferometry and Synthesis in Radio Astronomy, Second Edition is comprehensive in that it provides an excellent overview of most radio astronomical instrumentation and techniques.

Interferometry and Synthesis in Radio Astronomy

Interferometry and Synthesis in Radio Astronomy
Author: A. Richard Thompson
Publisher: Wiley-Interscience
Total Pages: 568
Release: 1986-04-28
Genre: Nature
ISBN:

Download Interferometry and Synthesis in Radio Astronomy Book in PDF, Epub and Kindle

A unified description of the theory and practice of radio interferometry and synthesis mapping techniques as they apply to astronomy and geology. Beginning with an historical review, it goes on to provide a detailed description of all aspects of radio inferometry, from basic principles through instrumental design to data reduction. Over 450 original papers and monographs are cited.

Space-Time Reference Systems

Space-Time Reference Systems
Author: Michael Soffel
Publisher: Springer Science & Business Media
Total Pages: 321
Release: 2012-10-19
Genre: Science
ISBN: 3642302262

Download Space-Time Reference Systems Book in PDF, Epub and Kindle

The high accuracy of modern astronomical spatial-temporal reference systems has made them considerably complex. This book offers a comprehensive overview of such systems. It begins with a discussion of ‘The Problem of Time’, including recent developments in the art of clock making (e.g., optical clocks) and various time scales. The authors address the definitions and realization of spatial coordinates by reference to remote celestial objects such as quasars. After an extensive treatment of classical equinox-based coordinates, new paradigms for setting up a celestial reference system are introduced that no longer refer to the translational and rotational motion of the Earth. The role of relativity in the definition and realization of such systems is clarified. The topics presented in this book are complemented by exercises (with solutions). The authors offer a series of files, written in Maple, a standard computer algebra system, to help readers get a feel for the various models and orders of magnitude. Beyond astrometry, the main fields of application of high-precision astronomical spatial-temporal reference systems and frames are navigation (GPS, interplanetary spacecraft navigation) and global geodynamics, which provide a high-precision Celestial Reference System and its link to any terrestrial spatial-temporal reference system. Mankind’s urgent environmental questions can only be answered in the context of appropriate reference systems in which both aspects, space and time, are realized with a sufficiently high level of accuracy. This book addresses all those interested in high-precision reference systems and the various techniques (GPS, Very Long Baseline Interferometry, Satellite Laser Ranging, Lunar Laser Ranging) necessary for their realization, including the production and dissemination of time signals.

Theory and Experiment in Gravitational Physics

Theory and Experiment in Gravitational Physics
Author: Clifford M. Will
Publisher: Cambridge University Press
Total Pages: 363
Release: 2018-09-27
Genre: Science
ISBN: 1107117445

Download Theory and Experiment in Gravitational Physics Book in PDF, Epub and Kindle

A comprehensive review of the testing and research conducted on Einstein's theory of general relativity.

Interferometry and Synthesis in Radio Astronomy

Interferometry and Synthesis in Radio Astronomy
Author: A. Richard Thompson
Publisher: Springer
Total Pages: 910
Release: 2017-02-22
Genre: Science
ISBN: 331944431X

Download Interferometry and Synthesis in Radio Astronomy Book in PDF, Epub and Kindle

This book is open access under a CC BY-NC 4.0 license. The third edition of this indispensable book in radio interferometry provides extensive updates to the second edition, including results and technical advances from the past decade; discussion of arrays that now span the full range of the radio part of the electromagnetic spectrum observable from the ground, 10 MHz to 1 THz; an analysis of factors that affect array speed; and an expanded discussion of digital signal-processing techniques and of scintillation phenomena and the effects of atmospheric water vapor on image distortion, among many other topics. With its comprehensiveness and detailed exposition of all aspects of the theory and practice of radio interferometry and synthesis imaging, this book has established itself as a standard reference in the field. It begins with an overview of the basic principles of radio astronomy, a short history of the development of radio interferometry, and an elementary discussion of the operation of an interferometer. From this foundation, it delves into the underlying relationships of interferometry, sets forth the coordinate systems and parameters to describe synthesis imaging, and examines configurations of antennas for multielement synthesis arrays. Various aspects of the design and response of receiving systems are discussed, as well as the special requirements of very-long-baseline interferometry (VLBI), image reconstruction, and recent developments in image enhancement techniques and astrometric observations. Also discussed are propagation effects in the media between the source and the observer, and radio interference, factors that limit performance. Related techniques are introduced, including intensity interferometry, optical interferometry, lunar occultations, tracking of satellites in Earth orbit, interferometry for remote Earth sensing, and holographic measurements of antenna surfaces. This book will benefit anyone who is interested in radio interferometry techniques for astronomy, astrometry, geodesy, or electrical engineering.

Open Skies

Open Skies
Author: Kenneth I. Kellermann
Publisher: Springer Nature
Total Pages: 652
Release: 2020-01-01
Genre: Astronomy
ISBN: 3030323455

Download Open Skies Book in PDF, Epub and Kindle

This open access book on the history of the National Radio Astronomy Observatory covers the scientific discoveries and technical innovations of late 20th century radio astronomy with particular attention to the people and institutions involved. The authors have made extensive use of the NRAO Archives, which contain an unparalleled collection of documents pertaining to the history of radio astronomy, including the institutional records of NRAO as well as the personal papers of many of the pioneers of U.S. radio astronomy. Technical details and extensive citations to original sources are given in notes for the more technical readers, but are not required for an understanding of the body of the book. This book is intended for an audience ranging from interested lay readers to professional researchers studying the scientific, technical, political, and cultural development of a new science, and how it changed the course of 20th century astronomy.