WorldWideScience

Sample records for generation radio astronomy

  1. Next Generation Radio Astronomy Receiver Systems

    CERN Document Server

    Morgan, Matthew A

    2009-01-01

    Radio astronomy observations in the coming decade will require new levels of sensitivity while mapping large regions of space with much greater efficiency than is achieved with current telescopes. This requires new instrumentation with the greatest achievable sensitivity, dynamic range, and field of view. Receiver noise is quickly approaching fundamental limits at most radio wavelengths, so significant gains in sensitivity can only be made by increasing collecting area. Jointly, these requirements suggest using large arrays of smaller antennas, or many moderate-size antennas equipped with multi-beam arrays. The challenge is to develop receivers and wide bandwidth data transport systems which are lower cost, more compact, more reliable, lower weight, and more reproducible than the best current systems, with no compromise to performance. This can be achieved with a greater degree of component integration, extensive use of digital signal processing and transport, and replacement of functions currently performed ...

  2. Radio astronomy

    CERN Document Server

    Alder, Berni

    1975-01-01

    Methods in Computational Physics, Volume 14: Radio Astronomy is devoted to the role of the digital computer both as a control device and as a calculator in addressing problems related to galactic radio noise. This volume contains four chapters and begins with a technical description of the hardware and the special data-handling problems of using radioheliography, with an emphasis on a selection of observational results obtained with the Culgoora radioheliograph and their significance to solar physics and to astrophysics in general. The subsequent chapter examines interstellar dispersion, i

  3. Galactic radio astronomy

    CERN Document Server

    Sofue, Yoshiaki

    2017-01-01

    This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

  4. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2013-01-01

    This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

  5. Division x: Radio Astronomy

    Science.gov (United States)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    2012-04-01

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North America, and the development of new facilities such as LOFAR, ALMA, FAST, and Square Kilometre Array precursor telescopes in Australia and South Africa. These developments are driven by advances in radio-frequency, digital and information technologies that tremendously enhance the capabilities in radio astronomy. These new developments foreshadow major scientific advances driven by radio observations in the next triennium. We highlight these facility developments in section 3 of this report. A selection of science highlight from this triennium are summarized in section 2.

  6. Division x: Radio Astronomy

    NARCIS (Netherlands)

    Taylor, Russ; Chapman, Jessica; Rendong, Nan; Carilli, Christopher; Giovannini, Gabriele; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin; Lazio, Joseph; Morganti, Raffaella; Rubio, Monica; Shastri, Prajval

    This triennium has seen a phenomenal investment in development of observational radio astronomy facilities in all parts of the globe at a scale that significantly impacts the international community. This includes both major enhancements such as the transition from the VLA to the EVLA in North

  7. Classics in radio astronomy

    CERN Document Server

    Sullivan, Woodruff Turner

    1982-01-01

    Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

  8. Tools of radio astronomy

    CERN Document Server

    Wilson, Thomas L; Hüttemeister, Susanne

    2009-01-01

    The recent years have seen breathtaking progress in technology, especially in the receiver and digital technologies relevant for radio astronomy, which has at the same time advanced to shorter wavelengths. This is the updated and completely revised 5th edition of the most used introductory text in radio astronomy. It presents a unified treatment of the entire field from centimeter to sub-millimeter wavelengths. Topics covered include instruments, sensitivity considerations, observational methods and interpretations of the data recorded with both single dishes and interferometers. This text is useful to both students and experienced practicing astronomers. Besides making major updates and additions throughout the book, the authors have re-organized a number of chapters to more clearly separate basic theory from rapidly evolving practical aspects. Further, problem sets have been added at the end of each chapter.

  9. Radio astronomy from space

    Science.gov (United States)

    Woan, G.

    2011-04-01

    At frequencies below about 30 MHz, radio astronomy becomes increasingly difficult from the Earth's surface, mainly due to a combination of poor ionospheric seeing and strong terrestrial interference. The obvious move is to space, either as free-flying spacecraft or with a telescope located somewhere on the Moon. All the major space agencies have a renewed interest in the Moon as a site for exploration and science, and low-frequency radio astronomy is probably the strongest of the astronomical objectives put forward in these programmes. Although the Sun is a strong source of interference in extra-solar system work, it is also a prime target for study in itself. A constellation of satellites (as proposed for the SIRA mission) would be able to image both the Sun and the inner heliosphere over the entire low-frequency band. Here we investigate some of the advantages and limitations of astronomy at these very low frequencies, using space- and lunar-based antennas.

  10. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  11. The Radio JOVE Project - Shoestring Radio Astronomy

    Science.gov (United States)

    Thieman, J.; Flagg, R.; Greenman, W.; Higgins, C.; Reyes, F.; Sky, J.

    2010-01-01

    Radio JOVE is an education and outreach project intended to give students and other interested individuals hands-on experience in learning radio astronomy. They can do this through building a radio telescope from a relatively inexpensive kit that includes the parts for a receiver and an antenna as well as software for a computer chart recorder emulator (Radio Skypipe) and other reference materials

  12. Extragalactic radio continuum surveys and the transformation of radio astronomy

    Science.gov (United States)

    Norris, Ray P.

    2017-10-01

    Next-generation radio surveys are about to transform radio astronomy by discovering and studying tens of millions of previously unknown radio sources. These surveys will provide fresh insights for understanding the evolution of galaxies, measuring the evolution of the cosmic star-formation rate, and rivalling traditional techniques in the measurement of fundamental cosmological parameters. By observing a new volume of observational parameter space, they are also likely to discover unexpected phenomena. This Review traces the evolution of extragalactic radio continuum surveys from the earliest days of radio astronomy to the present, and identifies the challenges that must be overcome to achieve this transformational change.

  13. Utrecht and Galactic Radio Astronomy

    NARCIS (Netherlands)

    van Woerden, H.

    Important roles in early Dutch Galactic radio astronomy were played by several Utrecht astronomers: Van de Hulst, Minnaert and Houtgast. The poster announcing the conference contained a number of pictures referring to scientific achievements of the Astronomical Institute Utrecht. One of these

  14. Shoestring Budget Radio Astronomy

    Science.gov (United States)

    Hoot, John E.

    2017-06-01

    The commercial exploitation of microwave frequencies for cellular, WiFi, Bluetooth, HDTV, and satellite digital media transmission has brought down the cost of the components required to build an effective radio telescope to the point where, for the cost of a good eyepiece, you can construct and operate a radio telescope. This paper sets forth a family of designs for 1421 MHz telescopes. It also proposes a method by which operators of such instruments can aggregate and archive data via the Internet. With 90 or so instruments it will be possible to survey the entire radio sky for transients with a 24 hour cadence.

  15. Large Radio Astronomy: next 70 Years Step

    CERN Document Server

    Parijskij, Y N

    2003-01-01

    Some attempts to predict the very distant future of Radio Astronomy are given. It is not easy to predict a list of the first priority problems which may appear, but the facilities potential is more predictable. It is suggested, that in addition to the "dedicated for Radio Astronomy", facilities may be extended greatly by integration with the next generation living standards facilities, connected with People-to-People communications through the global networks and by incorporating of the "Natural facilities", such as grav. lensing, maser amplification in the ISM etc. As an examples of the extreme cases of the $10^9 m^2$ class of the new generation Radio Telescopes, utilization of the personal dipole size communication facilities by SKA type instrument, and array from the asteroids first "Frehnel zones" will be mentioned. Radio Astronomy from the secondary to optical facilities tool will be the only tool in the exploration of the $z>10$ Universe. The reality of all predictions depend mostly on the way, the Civi...

  16. Orbiting low frequency array for radio astronomy

    NARCIS (Netherlands)

    Rajan, Rai Thilak; Rajan, Raj; Engelen, Steven; Bentum, Marinus Jan; Verhoeven, Chris

    2011-01-01

    Recently new and interesting science drivers have emerged for very low frequency radio astronomy from 0.3 MHz to 30 MHz. However Earth bound radio observations at these wavelengths are severely hampered by ionospheric distortions, man made interference, solar flares and even complete reflection belo

  17. Orbiting low frequency array for radio astronomy

    NARCIS (Netherlands)

    Rajan, Rai Thilak; Engelen, Steven; Bentum, Mark; Verhoeven, Chris

    2011-01-01

    Recently new and interesting science drivers have emerged for very low frequency radio astronomy from 0.3 MHz to 30 MHz. However Earth bound radio observations at these wavelengths are severely hampered by ionospheric distortions, man made interference, solar flares and even complete reflection belo

  18. JPL Big Data Technologies for Radio Astronomy

    Science.gov (United States)

    Jones, Dayton L.; D'Addario, L. R.; De Jong, E. M.; Mattmann, C. A.; Rebbapragada, U. D.; Thompson, D. R.; Wagstaff, K.

    2014-04-01

    During the past three years the Jet Propulsion Laboratory has been working on several technologies to deal with big data challenges facing next-generation radio arrays, among other applications. This program has focused on the following four areas: 1) We are investigating high-level ASIC architectures that reduce power consumption for cross-correlation of data from large interferometer arrays by one to two orders of magnitude. The cost of operations for the Square Kilometre Array (SKA), which may be dominated by the cost of power for data processing, is a serious concern. A large improvement in correlator power efficiency could have a major positive impact. 2) Data-adaptive algorithms (machine learning) for real-time detection and classification of fast transient signals in high volume data streams are being developed and demonstrated. Studies of the dynamic universe, particularly searches for fast (system for eventual deployment on ASKAP. In addition, a real-time transient detection experiment is now running continuously and commensally on NRAO's Very Long Baseline Array. 3) Scalable frameworks for data archiving, mining, and distribution are being applied to radio astronomy. A set of powerful open-source Object Oriented Data Technology (OODT) tools is now available through Apache. OODT was developed at JPL for Earth science data archives, but it is proving to be useful for radio astronomy, planetary science, health care, Earth climate, and other large-scale archives. 4) We are creating automated, event-driven data visualization tools that can be used to extract information from a wide range of complex data sets. Visualization of complex data can be improved through algorithms that detect events or features of interest and autonomously generate images or video to display those features. This work has been carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  19. Grote Reber, Radio Astronomy Pioneer, Dies

    Science.gov (United States)

    2002-12-01

    Grote Reber, one of the earliest pioneers of radio astronomy, died in Tasmania on December 20, just two days shy of his 91st birthday. Reber was the first person to build a radio telescope dedicated to astronomy, opening up a whole new "window" on the Universe that eventually produced such landmark discoveries as quasars, pulsars and the remnant "afterglow" of the Big Bang. His self- financed experiments laid the foundation for today's advanced radio-astronomy facilities. Grote Reber Grote Reber NRAO/AUI photo "Radio astronomy has changed profoundly our understanding of the Universe and has earned the Nobel Prize for several major contributions. All radio astronomers who have followed him owe Grote Reber a deep debt for his pioneering work," said Dr. Fred Lo, director of the National Radio Astronomy Observatory (NRAO). "Reber was the first to systematically study the sky by observing something other than visible light. This gave astronomy a whole new view of the Universe. The continuing importance of new ways of looking at the Universe is emphasized by this year's Nobel Prizes in physics, which recognized scientists who pioneered X-ray and neutrino observations," Lo added. Reber was a radio engineer and avid amateur "ham" radio operator in Wheaton, Illinois, in the 1930s when he read about Karl Jansky's 1932 discovery of natural radio emissions coming from outer space. As an amateur operator, Reber had won awards and communicated with other amateurs around the world, and later wrote that he had concluded "there were no more worlds to conquer" in radio. Learning of Jansky's discovery gave Reber a whole new challenge that he attacked with vigor. Analyzing the problem as an engineer, Reber concluded that what he needed was a parabolic-dish antenna, something quite uncommon in the 1930s. In 1937, using his own funds, he constructed a 31.4-foot-diameter dish antenna in his back yard. The strange contraption attracted curious attention from his neighbors and became

  20. 47 CFR 2.107 - Radio astronomy station notification.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy stations...

  1. Teaching radio astronomy with Affordable Small Radio Telescope (ASRT)

    Science.gov (United States)

    Joshi, Bhal Chandra

    A simple, easy to build and portable radio telescope, called Affordable Small Radio Telescope (ASRT), has been developed by the Radio Physics Laboratory (RPL), a radio astronomy teaching unit associated with the National Centre for Radio Astrophysics (TIFR) and Inter-University Centre for Astronomy and Astrophysics (IUCAA), which are two premier astronomy institutes in India. ASRT consists of off-the-shelf available Direct to Home television dishes and is easy to assemble. Our design is scalable from simple very low cost telescope to more complex yet moderately costing instrument. ASRT provides a platform for demonstrating radio physics concepts through simple hands-on experiment as well as for carrying out solar monitoring by college/University students. The presentation will highlight the concept of ASRT and the different experiments that can be carried out using it. The solar monitoring observations will be discussed along-with details of methods for calibrating these measurements. The pedagogical usefulness of ASRT in introducing undergraduatephysics students to astrophysics, measurements and analysis methods used in radio astronomy will also be discussed. Use of ASRT in the last three years in the programs of RPL, namely the annual Radio Astronomy Winter School for College students (RAWSC) and Pulsar Observing for Students (POS) is also presented. This year a new program was initiated to form a virtual group of an ASRT community, which will not only share their measurements, but also think of improving the pedagogical usefulness of ASRT by innovative experiments. This initiative is presented with the best practices drawn from our experience in using ASRT as a tool for student training in space sciences. The talk will also point out future ideas in involving a larger body of students in simple radio astronomy experiments with the ASRT, which RPL is likely to nucleate as part of its mandate.

  2. Signal Processing Techniques Applied in RFI Mitigation of Radio Astronomy

    Directory of Open Access Journals (Sweden)

    Sixiu Wang

    2012-08-01

    Full Text Available Radio broadcast and telecommunications are present at different power levels everywhere on Earth. Radio Frequency Interference (RFI substantially limits the sensitivity of existing radio telescopes in several frequency bands and may prove to be an even greater obstacle for next generation of telescopes (or arrays to overcome. A variety of RFI detection and mitigation techniques have been developed in recent years. This study describes various signal process methods of RFI mitigation in radio astronomy, choose the method of Time-frequency domain cancellation to eliminate certain interference and effectively improve the signal to noise ratio in pulsar observations. Finally, RFI mitigation researches and implements in China radio astronomy will be also presented.

  3. Impact of cognitive radio on radio astronomy

    NARCIS (Netherlands)

    Bentum, M.J.; Boonstra, A.J.; Baan, W.A.

    2010-01-01

    The introduction of new communication techniques requires an increase in the efficiency of spectrum usage. Cognitive radio is one of the new techniques that fosters spectrum efficiency by using unoccupied frequency spectrum for communications. However, cognitive radio will increase the transmission

  4. Division X, XII / Commission 40, 41 / Working Group Radio Astronomy

    NARCIS (Netherlands)

    Kellermann, Kenneth; Orchiston, Wayne; Davies, Rod; Gurvits, Leonid; Ishiguro, Masato; Lequeux, James; Swarup, Govind; Wall, Jasper; Wielebinski, Richard; van Woerden, Hugo

    2012-01-01

    The IAU Working Group on Historical Radio Astronomy (WGHRA) was formed at the 2003 General Assembly of the IAU as a Joint Working Group of Commissions 40 (Radio Astronomy) and 41 (History of Astronomy), in order to: a) assemble a master list of surviving historically-significant radio telescopes and

  5. Division X, XII / Commission 40, 41 / Working Group Radio Astronomy

    NARCIS (Netherlands)

    Kellermann, Kenneth; Orchiston, Wayne; Davies, Rod; Gurvits, Leonid; Ishiguro, Masato; Lequeux, James; Swarup, Govind; Wall, Jasper; Wielebinski, Richard; van Woerden, Hugo

    The IAU Working Group on Historical Radio Astronomy (WGHRA) was formed at the 2003 General Assembly of the IAU as a Joint Working Group of Commissions 40 (Radio Astronomy) and 41 (History of Astronomy), in order to: a) assemble a master list of surviving historically-significant radio telescopes and

  6. Internet Resources for Radio Astronomy

    Science.gov (United States)

    Andernach, H.

    A subjective overview of Internet resources for radio-astronomical information is presented. Basic observing techniques and their implications for the interpretation of publicly available radio data are described, followed by a discussion of existing radio surveys, their level of optical identification, and nomenclature of radio sources. Various collections of source catalogues and databases for integrated radio source parameters are reviewed and compared, as well as the web interfaces to interrogate the current and ongoing large-area surveys. Links to radio observatories with archives of raw (uv-) data are presented, as well as services providing images, both of individual objects or extracts (``cutouts'') from large-scale surveys. While the emphasis is on radio continuum data, a brief list of sites providing spectral line data, and atomic or molecular information is included. The major radio telescopes and surveys under construction or planning are outlined. A summary is given of a search for previously unknown optically bright radio sources, as performed by the students as an exercise, using Internet resources only. Over 200 different links are mentioned and were verified, but despite the attempt to make this report up-to-date, it can only provide a snapshot of the situation as of mid-1998.

  7. Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

    Directory of Open Access Journals (Sweden)

    Ayodele Abiola Periola

    2016-01-01

    Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

  8. Radio Astronomy Transformed: Aperture Arrays - Past, Present & Future

    CERN Document Server

    Garrett, Michael A

    2012-01-01

    I review the early development of Aperture Arrays and their role in radio astronomy. The demise of this technology at the end of the 1960's, and the reasons for the rise of parabolic dishes is also considered. The parallels with the Antikythera mechanism (see these proceedings) as a lost technology are briefly presented. Aperture Arrays re-entered the world of radio astronomy as the idea to build a huge radio telescope with a collecting area of one square kilometre (the Square Kilometre Array, SKA) arose. Huge ICT technology advances had transformed Aperture Arrays in terms of their capability, flexibility and reliability. In the mid-1990s, ASTRON started to develop and experiment with the first high frequency aperture array tiles for radio astronomy - AAD, OSMA, THEA & EMBRACE. In the slipstream of these efforts, Phased Array Feeds (PAFs) for radio astronomy were invented and LOFAR itself emerged as a next generation telescope and a major pathfinder for the SKA. Meanwhile, the same advantages that apertu...

  9. The faint radio sky: radio astronomy becomes mainstream

    Science.gov (United States)

    Padovani, Paolo

    2016-09-01

    Radio astronomy has changed. For years it studied relatively rare sources, which emit mostly non-thermal radiation across the entire electromagnetic spectrum, i.e. radio quasars and radio galaxies. Now, it is reaching such faint flux densities that it detects mainly star-forming galaxies and the more common radio-quiet active galactic nuclei. These sources make up the bulk of the extragalactic sky, which has been studied for decades in the infrared, optical, and X-ray bands. I follow the transformation of radio astronomy by reviewing the main components of the radio sky at the bright and faint ends, the issue of their proper classification, their number counts, luminosity functions, and evolution. The overall "big picture" astrophysical implications of these results, and their relevance for a number of hot topics in extragalactic astronomy, are also discussed. The future prospects of the faint radio sky are very bright, as we will soon be flooded with survey data. This review should be useful to all extragalactic astronomers, irrespective of their favourite electromagnetic band(s), and even stellar astronomers might find it somewhat gratifying.

  10. The faint radio sky: radio astronomy becomes mainstream

    CERN Document Server

    Padovani, Paolo

    2016-01-01

    Radio astronomy has changed. For years it studied relatively rare sources, which emit mostly non-thermal radiation across the entire electromagnetic spectrum, i.e. radio quasars and radio galaxies. Now it is reaching such faint flux densities that it detects mainly star-forming galaxies and the more common radio-quiet active galactic nuclei. These sources make up the bulk of the extragalactic sky, which has been studied for decades in the infrared, optical, and X-ray bands. I follow the transformation of radio astronomy by reviewing the main components of the radio sky at the bright and faint ends, the issue of their proper classification, their number counts, luminosity functions, and evolution. The overall "big picture" astrophysical implications of these results, and their relevance for a number of hot topics in extragalactic astronomy, are also discussed. The future prospects of the faint radio sky are very bright, as we will soon be flooded with survey data. This review should be useful to all extragalac...

  11. Radio Astronomy Explorer /RAE/. I - Observations of terrestrial radio noise.

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.; Stone, R. G.

    1973-01-01

    Radio Astronomy Explorer (RAE) I data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial radio noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 dB and more above cosmic noise background, on frequencies above the F-layer critical frequency.

  12. Spectrometers and Polyphase Filterbanks in Radio Astronomy

    CERN Document Server

    Price, Danny C

    2016-01-01

    This review gives an introduction to spectrometers and discusses their use within radio astronomy. While a variety of technologies are introduced, particular emphasis is given to digital systems. Three different types of digital spectrometers are discussed: autocorrelation spectrometers, Fourier transform spectrometers, and polyphase filterbank spectrometers. Given their growing ubiquity and significant advantages, polyphase filterbanks are detailed at length. The relative advantages and disadvantages of different spectrometer technologies are compared and contrasted, and implementation considerations are presented.

  13. Phenomenology of Neptune's radio emissions observed by the Voyager planetary radio astronomy experiment

    Science.gov (United States)

    Pedersen, B. M.; Lecacheux, A.; Zarka, P.; Aubier, M. G.; Kaiser, M. L.; Desch, M. D.

    1992-01-01

    The Neptune flyby in 1989 added a new planet to the known number of magnetized planets generating nonthermal radio emissions. We review the Neptunian radio emission morphology as observed by the planetary radio astronomy experiment on board Voyager 2 during a few weeks before and after closest approach. We present the characteristics of the two observed recurrent main components of the Neptunian kilometric radiation, i.e., the 'smooth' and the 'bursty' emissions, and we describe the many specific features of the radio spectrum during closest approach.

  14. Multichannel interference mitigation methods in radio astronomy

    CERN Document Server

    Leshem, A; Boonstra, A J; Leshem, Amir; Veen, Alle-Jan van der; Boonstra, Albert-Jan

    2000-01-01

    Radio-astronomical observations are increasingly corrupted by RF interference, and online detection and filtering algorithms are becoming essential. To facilitate the introduction of such techniques into radio astronomy, we formulate the astronomical problem in an array signal processing language, and give an introduction to some elementary algorithms from that field. We consider two topics in detail: interference detection by rank estimation of short-term covariance matrices, and spatial filtering by subspace estimation and projection. We discuss experimental data collected at the Westerbork radio telescope, and illustrate the effectiveness of the space-time detection and blanking process on the recovery of a 3C48 absorption line in the presence of GSM mobile telephony interference.

  15. Interferometry and synthesis in radio astronomy

    CERN Document Server

    Thompson, A Richard; Swenson Jr , George W

    2017-01-01

    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 interferomete...

  16. The Importance of Site Selection for Radio Astronomy

    Science.gov (United States)

    Umar, Roslan; Zainal Abidin, Zamri; Abidin Ibrahim, Zainol

    2014-10-01

    Radio sources are very weak since this object travel very far from outer space. Radio astronomy studies are limited due to radio frequency interference (RFI) that is made by man. If the harassment is not stopped, it will provide critical problems in their radio astronomy scientists research. The purpose of this study is to provide RFI map Peninsular Malaysia with a minimum mapping techniques RFI interference. RFI mapping technique using GIS is proposed as a tool in mapping techniques. Decision-making process for the selection requires gathering information from a variety of parameters. These factors affecting the selection process are also taken account. In this study, various factors or parameters involved such as availability of telecommunications transmission (including radio and television), rainfall, water line and human activity. This study will benefit radio astronomy research especially in the RFI profile in Malaysia. Keywords: Radio Astronomy, Radio Frequency Interference (RFI), RFI mapping technique : GIS.

  17. The first radio astronomy from space - RAE

    Science.gov (United States)

    Kaiser, M. L.

    1987-01-01

    The spacecraft design, instrumentation, and performance of the Radio Astronomy Explorer (RAE) satellites (RAE-1 launched to earth orbit in 1968 and RAE-2 launched to lunar orbit in 1972) are reviewed and illustrated with drawings, diagrams, and graphs of typical data. Consideration is given to the three pairs of antennas, the Ryle-Vonberg and burst radiometers, and problems encountered with antenna deployment and observing patterns. Results summarized include observations of type III solar bursts, the spectral distribution of cosmic noise in broad sky regions, Jupiter at low frequencies, and auroral kilometric radiation (AKR) from the earth. The importance of avoiding the AKR bands in designing future space observatories is stressed.

  18. The importance of Radio Quiet Zone (RQZ) for radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin

    2013-05-01

    Most of radio observatories are located in isolated areas. Since radio sources from the universe is very weak, astronomer need to avoid radio frequency interference (RFI) from active spectrum users and radio noise produced by human made (telecommunication, mobile phone, microwave user and many more. There are many observatories around the world are surrounded by a Radio Quiet Zone (RQZ), which is it was set up using public or state laws. A Radio Quiet Zone normally consists of two areas: an exclusive area in which totally radio emissions are forbidden, with restrictions for residents and business developments, and a larger (radius up to 100 km above) coordination area where the power of radio transmission limits to threshold levels. Geographical Information System (GIS) can be used as a powerful tool in mapping large areas with varying RQZ profiles. In this paper, we report the initial testing of the usage of this system in order to identify the areas were suitable for Radio Quiet Zone. Among the important parameters used to develop the database for our GIS are population density, information on TV and telecommunication (mobile phones) transmitters, road networks (highway), and contour shielding. We will also use other information gathered from on-site RFI level measurements on selected 'best' areas generated by the GIS. The intention is to find the best site for the purpose of establishing first radio quiet zones for radio telescope in Malaysia.

  19. Large Instrument Development for Radio Astronomy

    CERN Document Server

    Fisher, J R; Brisken, W F; Cotton, W D; Emerson, D T; Kerr, A R; Lacasse, R J; Morgan, M A; Napier, P J; Norrod, R D; Payne, J M; Pospieszalski, M W; Symmes, A; Thompson, A R; Webber, J C

    2009-01-01

    This white paper offers cautionary observations about the planning and development of new, large radio astronomy instruments. Complexity is a strong cost driver so every effort should be made to assign differing science requirements to different instruments and probably different sites. The appeal of shared resources is generally not realized in practice and can often be counterproductive. Instrument optimization is much more difficult with longer lists of requirements, and the development process is longer and less efficient. More complex instruments are necessarily further behind the technology state of the art because of longer development times. Including technology R&D in the construction phase of projects is a growing trend that leads to higher risks, cost overruns, schedule delays, and project de-scoping. There are no technology breakthroughs just over the horizon that will suddenly bring down the cost of collecting area. Advances come largely through careful attention to detail in the adoption of ...

  20. The invisible universe the story of radio astronomy

    CERN Document Server

    Verschuur, Gerrit

    2015-01-01

    Hidden from human view, accessible only to sensitive receivers attached to huge radio telescopes, the invisible universe beyond our senses continues to fascinate and intrigue our imaginations. Closer to home, in the Milky Way galaxy, radio astronomers listen patiently to the ticking of pulsars that tell of star death and states of matter of awesome densities. All of this happens out there in the universe hidden from our eyes, even when aided by the Hubble Space Telescope. This is the story of radio astronomy, of how radio waves are generated by stars, supernova, quasars, colliding galaxies and by the very beginnings of the universe itself. The author discusses what radio astronomers are doing in the New Mexico desert, in a remote valley in Puerto Rico, and in the green Pocahontas Valley in West Virginia, as well as dozens of other remote sites around the world. With each of these observatories, the scientists collect and analyze their data, "listening" to the radio signals from space in order to learn what, ...

  1. International Agreement Will Advance Radio Astronomy

    Science.gov (United States)

    2007-12-01

    Two of the world's leading astronomical institutions have formalized an agreement to cooperate on joint efforts for the technical and scientific advancement of radio astronomy. The National Radio Astronomy Observatory (NRAO) in the United States and the Max-Planck Institute for Radioastronomy (MPIfR) in Germany concluded a Memorandum of Understanding outlining planned collaborative efforts to enhance the capabilities of each other's telescopes and to expand their cooperation in scientific research. The VLBA The VLBA CREDIT: NRAO/AUI/NSF In the first project pursued under this agreement, the MPIfR will contribute $299,000 to upgrade the continent-wide Very Long Baseline Array's (VLBA) capability to receive radio emissions at a frequency of 22 GHz. This improvement will enhance the VLBA's scientific productivity and will be particularly important for cutting-edge research in cosmology and enigmatic cosmic objects such as gamma-ray blazars. "This agreement follows many years of cooperation between our institutions and recognizes the importance of international collaboration for the future of astronomical research," said Fred K.Y. Lo, NRAO Director. "Our two institutions have many common research goals, and joining forces to keep all our telescopes at the forefront of technology will be highly beneficial for the science," said Anton Zensus, Director at MPIfR. In addition to the VLBA, the NRAO operates the Very Large Array (VLA) in New Mexico and the Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. The MPIfR operates the 100-meter Effelsberg Radio Telescope in Germany and the 12-meter APEX submillimeter telescope in 5100 m altitude in the Cilean Atacama desert (together with the European Southern Observatory and the Swedish Onsala Space Observatory). With the 100-meter telescope, it is part of the VLBA network in providing transatlantic baselines. Both institutions are members of a global network of telescopes (the Global VLBI Network) that uses simultaneous

  2. The History of Radio Astronomy and the National Radio Astronomy Observatory: Evolution Toward Big Science

    Science.gov (United States)

    Malphrus, Benjamin Kevin

    1990-01-01

    The purpose of this study is to examine the sequence of events that led to the establishment of the NRAO, the construction and development of instrumentation and the contributions and discovery events and to relate the significance of these events to the evolution of the sciences of radio astronomy and cosmology. After an overview of the resources, a brief discussion of the early days of the science is given to set the stage for an examination of events that led to the establishment of the NRAO. The developmental and construction phases of the major instruments including the 85-foot Tatel telescope, the 300-foot telescope, the 140-foot telescope, and the Green Bank lnterferometer are examined. The technical evolution of these instruments is traced and their relevance to scientific programs and discovery events is discussed. The history is told in narrative format that is interspersed with technical and scientific explanations. Through the use of original data technical and scientific information of historical concern is provided to elucidate major developments and events. An interpretive discussion of selected programs, events and technological developments that epitomize the contributions of the NRAO to the science of radio astronomy is provided. Scientific programs conducted with the NRAO instruments that were significant to galactic and extragalactic astronomy are presented. NRAO research programs presented include continuum and source surveys, mapping, a high precision verification of general relativity, and SETI programs. Cosmic phenomena investigated in these programs include galactic and extragalactic HI and HII, emission nebula, supernova remnants, cosmic masers, giant molecular clouds, radio stars, normal and radio galaxies, and quasars. Modern NRAO instruments including the VLA and VLBA and their scientific programs are presented in the final chapter as well as plans for future NRAO instruments such as the GBT.

  3. Large-N correlator systems for low frequency radio astronomy

    Science.gov (United States)

    Foster, Griffin

    Low frequency radio astronomy has entered a second golden age driven by the development of a new class of large-N interferometric arrays. The low frequency array (LOFAR) and a number of redshifted HI Epoch of Reionization (EoR) arrays are currently undergoing commission and regularly observing. Future arrays of unprecedented sensitivity and resolutions at low frequencies, such as the square kilometer array (SKA) and the hydrogen epoch of reionization array (HERA), are in development. The combination of advancements in specialized field programmable gate array (FPGA) hardware for signal processing, computing and graphics processing unit (GPU) resources, and new imaging and calibration algorithms has opened up the oft underused radio band below 300 MHz. These interferometric arrays require efficient implementation of digital signal processing (DSP) hardware to compute the baseline correlations. FPGA technology provides an optimal platform to develop new correlators. The significant growth in data rates from these systems requires automated software to reduce the correlations in real time before storing the data products to disk. Low frequency, widefield observations introduce a number of unique calibration and imaging challenges. The efficient implementation of FX correlators using FPGA hardware is presented. Two correlators have been developed, one for the 32 element BEST-2 array at Medicina Observatory and the other for the 96 element LOFAR station at Chilbolton Observatory. In addition, calibration and imaging software has been developed for each system which makes use of the radio interferometry measurement equation (RIME) to derive calibrations. A process for generating sky maps from widefield LOFAR station observations is presented. Shapelets, a method of modelling extended structures such as resolved sources and beam patterns has been adapted for radio astronomy use to further improve system calibration. Scaling of computing technology allows for the

  4. The beginnings of radio astronomy in the Netherlands

    NARCIS (Netherlands)

    van Woerden, Hugo; Strom, Richard G.

    2006-01-01

    The birth of Dutch radio astronomy can be rather precisely dated to 15 April 1944, when H.C. van de Hulst presented the results of his theoretical research into the origin of radio waves from space. We have investigated the events leading up to the momentous suggestion that hydrogen emission at 21 c

  5. Communicating radio astronomy with the public: Another point of view

    Science.gov (United States)

    Varano, S.

    2008-06-01

    Radio waves cannot be sensed directly, but they are used in daily life by almost everybody. Even so, the majority of the general public do not even know that celestial bodies emit radio waves. Presenting invisible radiation to a general audience with little or no background knowledge in physics is a difficult task. In addition, much important technology now commonplace in many other scientific fields was pioneered by radio observatories in their efforts to detect and process radio signals from the Universe. Radio astronomy outreach does not have such a well-established background as optical astronomy outreach. In order to make radio astronomy accessible to the public, it is necessary either to add more scientific detail or to find a different way of communicating. In this paper we present examples from our work at the Visitor Centre "Marcello Ceccarelli", which is part of the Medicina Radio Observatory, operated by the Institute of Radio Astronomy (IRA) in Bologna, which in turn is part of the National Institute for Astrophysics (INAF).

  6. MPS/CAS Partner Group on Radio Astronomy

    Institute of Scientific and Technical Information of China (English)

    Han Jinlin; Richard Wielebinski

    2004-01-01

    @@ The Partner Group does research on cosmic magnetic fields using radio astronomy methods. Magnetic fields are found in every astronomical object: the Earth, the Sun,planets, stars, pulsars, the Milky Way,nearby galaxies and in distant radio galaxies. The role of the magnetic fields in the cosmic universe has not been well investigated, mainly because of the difficulties of their observation.

  7. Gravitational wave astronomy with radio galaxy surveys

    CERN Document Server

    Raccanelli, Alvise

    2016-01-01

    In the next decade, new astrophysical instruments will deliver the first large-scale maps of gravitational waves and radio sources. Therefore, it is timely to investigate the possibility to combine them to provide new and complementary ways to study the Universe. Using simulated catalogues appropriate to the planned surveys, it is possible to predict measurements of the cross-correlation between radio sources and GW maps and the effects of a stochastic gravitational wave background on galaxy maps. Effects of GWs on the large scale structure of the Universe can be used to investigate the nature of the progenitors of merging BHs, the validity of Einstein's General Relativity, models for dark energy, and detect a stochastic background of GW. The results obtained show that the galaxy-GW cross-correlation can provide useful information in the near future, while the detection of tensor perturbation effects on the LSS will require instruments with capabilities beyond the currently planned next generation of radio ar...

  8. A Radio Astronomy Curriculum for the Middle School Classroom

    Science.gov (United States)

    Davis, J.; Finley, D. G.

    2000-12-01

    In the summer of 2000, two teachers working on a Masters of Science Teaching program at New Mexico Institute of Mining and Technology, spent eight weeks as interns at the Array Operations Center for the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, under the auspices of the National Science Foundation's (NSF) Research Experience for Teachers (RET) program. The resulting projects will directly benefit students in the indvidual classrooms, as well as provide an easy-to-access resource for other educators. One of the products is a Radio Astronomy Curriculum for upper middle school classes. Radio astronomy images, based on scientific research results using NRAO's Very Large Array, are featured on trading cards which include an explanation, a ``web challenge'', and in some cases, a comparison of radio and optical images. Each trading card has corresponding lesson plans with background information about the images and astronomy concepts needed to do the lessons. Comparison of optical and radio astronomy is used as much as possible to explain the information from research using visible and radio wavelengths. New Mexico's Content Standards and Benchmarks (developed using national standards) for science education was used as a guide for the activities. The three strands of science listed in the standards, Unifying Concepts and Processes, Science as Inquiry, and Science Content are addressed in the lessons. Higher level thinking and problem solving skills are featured throughout the curriculum. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. The NSF's RET program is gratefully acknowledged.

  9. The School of Galactic Radio Astronomy: An Internet Classroom

    Science.gov (United States)

    Castelaz, M. W.; Cline, J. D.; Osborne, C. S.; Moffett, D. A.; Case, J.

    2001-12-01

    The School of Galactic Radio Astronomy (SGRA) takes its name from the source SGR-A, the center of the Milky Way Galaxy. SGRA is based at the Pisgah Astronomical Research Institute (PARI) as an experience-based school room for use by middle and high school teachers and their students. Their scientific educational experience at SGRA relies on Internet access to PARI's remote-controlled 4.6-m radio telescope which is equipped with a 1420 MHz receiver. The 1420 MHz signal may either be recorded as a spectrum over a 4 MHz bandpass, or mapped over extended regions. Teachers, classes, and Independent Study students access the 4.6-m radio telescope via the SGRA webpage. The SGRA webpage has four components: Radio Astronomy Basics, Observing, Guides, and Logbook. The Radio Astronomy Basics section summarizes the concepts of electromagnetic waves, detection of electromagnetic waves, sources of astronomical radio waves, and how astronomers use radio telescopes. The Observing section is the link to controlling the radio telescope and receiver. The Observing page is designed in the same way a control room at an observatory is designed. Controls include options of source selection, coordinate entry, slew, set, and guide selection, and tracking. Also within the Observing section is the curriculum which presents eight modules based on relevant radio astronomy topics and objects. The Guides webpage contains atlases of the astronomical sky, catalogs, examples of observing sessions, and data reduction software that can be downloaded for analysis offline. The LOGBOOK page is primarily a guestbook, and evaluation form. We acknowledge support from the Space Telescope Science Institute IDEAS Program, and the South Carolina State University PAIR Program.

  10. 47 CFR 5.91 - Notification of the National Radio Astronomy Observatory.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Notification of the National Radio Astronomy... Astronomy Observatory. In order to minimize possible harmful interference at the National Radio Astronomy... Astronomy Observatory, P.O. Box NZ2, Green Bank, West Virginia, 24944, in writing, of the technical...

  11. Genetic programming applied to RFI mitigation in radio astronomy

    Science.gov (United States)

    Staats, K.

    2016-12-01

    Genetic Programming is a type of machine learning that employs a stochastic search of a solutions space, genetic operators, a fitness function, and multiple generations of evolved programs to resolve a user-defined task, such as the classification of data. At the time of this research, the application of machine learning to radio astronomy was relatively new, with a limited number of publications on the subject. Genetic Programming had never been applied, and as such, was a novel approach to this challenging arena. Foundational to this body of research, the application Karoo GP was developed in the programming language Python following the fundamentals of tree-based Genetic Programming described in "A Field Guide to Genetic Programming" by Poli, et al. Karoo GP was tasked with the classification of data points as signal or radio frequency interference (RFI) generated by instruments and machinery which makes challenging astronomers' ability to discern the desired targets. The training data was derived from the output of an observation run of the KAT-7 radio telescope array built by the South African Square Kilometre Array (SKA-SA). Karoo GP, kNN, and SVM were comparatively employed, the outcome of which provided noteworthy correlations between input parameters, the complexity of the evolved hypotheses, and performance of raw data versus engineered features. This dissertation includes description of novel approaches to GP, such as upper and lower limits to the size of syntax trees, an auto-scaling multiclass classifier, and a Numpy array element manager. In addition to the research conducted at the SKA-SA, it is described how Karoo GP was applied to fine-tuning parameters of a weather prediction model at the South African Astronomical Observatory (SAAO), to glitch classification at the Laser Interferometer Gravitational-wave Observatory (LIGO), and to astro-particle physics at The Ohio State University.

  12. Need a Classroom Stimulus? Introduce Radio Astronomy

    Science.gov (United States)

    Derman, Samuel

    2010-01-01

    Silently, invisibly, ceaselessly, our planet Earth is showered by radio waves from every direction and from every region of space. This radio energy originates in our solar system, throughout the Milky Way galaxy, and far beyond, out to the remotest reaches of the universe. Detecting and unraveling the origins of these invisible signals is what…

  13. Radio astronomy in Africa: the case of Ghana

    CERN Document Server

    Asabere, Bernard Duah; Horellou, Cathy; Winkler, Hartmut; Jarrett, Thomas

    2015-01-01

    South Africa has played a leading role in radio astronomy in Africa with the Hartebeesthoek Radio Astronomy Observatory (HartRAO). It continues to make strides with the current seven-dish MeerKAT precursor array (KAT-7), leading to the 64-dish MeerKAT and the giant Square Kilometer Array (SKA), which will be used for transformational radio astronomy research. Ghana, an African partner to the SKA, has been mentored by South Africa over the past six years and will soon emerge in the field of radio astronomy. The country will soon have a science-quality 32m dish converted from a redundant satellite communication antenna. Initially, it will be fitted with 5 GHz and 6.7 GHz receivers to be followed later by a 1.4 - 1.7 GHz receiver. The telescope is being designed for use as a single dish observatory and for participation in the developing African Very Long Baseline Interferometry (VLBI) Network (AVN) and the European VLBI Network. Ghana is earmarked to host a remote station during a possible SKA Phase 2. The loca...

  14. PARTNeR for Teaching and Learning Radio Astronomy Basics

    Science.gov (United States)

    Vaquerizo, Juan Ángel

    2010-10-01

    NASA has three satellite tracking stations around the world: CDSCC (Canberra, Australia), GDSCC (Goldstone, USA) and MDSCC (Madrid, Spain). One of the antennas located at MDSCC, DSS-61, is not used for satellite tracking any more and thanks to an agreement between INTA (Instituto Nacional de TA~l'cnica Aeroespacial) and NASA, it has been turned into an educational radio telescope. PARTNeR (Proyecto Académico con el RadioTelescopio de NASA en Robledo, Academic Project with the NASA Radio Telescope at Robledo) is a High School and University radio astronomy educational program that allows teachers and students to control this 34-meter radio telescope and conduct radio astronomical observations via the Internet. As radio astronomy is not a popular subject and astronomy has little presence in the High School Curriculum, teachers need specific training in those subjects to implement PARTNeR. Thus, High School teachers joining the project take a course to learn about the science of radio astronomy and how to use the antenna in their classrooms. Also, teachers are provided with some learning activities they can do with their students. These lesson plans are focused on the implementation of the project within an interdisciplinary framework. All educational resources are available on PARTNeR website. PARTNeR is an inquiry based approach to science education. Nowadays, students can join in three different observational programmes: variability studies in quasars, studies of radio-bursts in X-ray binaries (microquasars), and mapping of radio sources in the galactic plane. Nevertheless, any other project can be held after an evaluation by the scientific committee. The operational phase of the project started in the academic year 2003-04. Since then, 85 High Schools, seven Universities and six societies of amateur astronomers have been involved in the project. During the 2004-09 period, 103 High School teachers from Spain and Portugal have attended the training courses, and 105

  15. A Virtual Tour of the Radio Astronomy Process

    Science.gov (United States)

    Conrad, S. B.; Finley, D. G.; Claussen, M. J.; Ulvestad, J. S.

    2000-12-01

    In the summer of 2000, two teachers working on a Masters of Science Teaching Degree at New Mexico Tech and participating in the Research Experience for Teachers (RET) program sponsored by the National Science Foundation, spent eight weeks as interns researching and working on projects at the National Radio Astronomy Observatory (NRAO) which will directly benefit students in their classrooms and also impact other science educators. One of the products of the interships is a set of web pages for NRAO's web page educational section. The purpose of these web pages is to familiarize students, teachers, and other people with the process that a radio astronomer goes through to do radio astronomy science. A virtual web tour was created of this process. This required interviewing radio astronomers and other professionals involved with this process at the NRAO (e.g. engineers, data analysts, and operations people), and synthesizing the interviews into a descriptive, visual-based set of web pages. These pages do meet the National as well as New Mexico Standards and Benchmarks for Science Education. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. The NSF's RET program is gratefully acknowledged.

  16. Space Radio Astronomy in the next 1000001 (binary) years

    CERN Document Server

    Gurvits, L I

    2012-01-01

    Radio astronomy and active exploration of space are peers: both began by efforts of enthusiasts in the 1930s and got a major technological boost in the 1940s-50s. Thus, for the sake of a brief review at this very special conference, it is fair to estimate the present age of these human endeavours as 1000001 (binary) years. These years saw a lot of challenging and fruitful concerted efforts by radio astronomers and space explorers. Among the high points one can mention several highly successful space-borne CMB observatories, three orbital VLBI missions, the first examples of radio observations at spectral windows hitherto closed for Earth-based observers and many yet to be implemented initiatives which are at various stages of their paths toward launch-pads of all major world space agencies. In this review I will give a bird-eye picture of the past achievements of space-oriented radio astronomy and zoom into several projects and ideas that will further push the presence of radio astronomy into the space agenda...

  17. FPGA-based digital signal processing for the next generation radio astronomy instruments: ultra-pure sideband separation and polarization detection

    Science.gov (United States)

    Alvear, Andrés.; Finger, Ricardo; Fuentes, Roberto; Sapunar, Raúl; Geelen, Tom; Curotto, Franco; Rodríguez, Rafael; Monasterio, David; Reyes, Nicolás.; Mena, Patricio; Bronfman, Leonardo

    2016-07-01

    Field Programmable Gate Arrays (FPGAs) capacity and Analog to Digital Converters (ADCs) speed have largely increased in the last decade. Nowadays we can find one million or more logic blocks (slices) as well as several thousand arithmetic units (ALUs/DSP) available on a single FPGA chip. We can also commercially procure ADC chips reaching 10 GSPS, with 8 bits resolution or more. This unprecedented power of computing hardware has allowed the digitalization of signal processes traditionally performed by analog components. In radio astronomy, the clearest example has been the development of digital sideband separating receivers which, by replacing the IF hybrid and calibrating the system imbalances, have exhibited a sideband rejection above 40dB; this is 20 to 30dB higher than traditional analog sideband separating (2SB) receivers. In Rodriguez et al.,1 and Finger et al.,2 we have demonstrated very high digital sideband separation at 3mm and 1mm wavelengths, using laboratory setups. We here show the first implementation of such technique with a 3mm receiver integrated into a telescope, where the calibration was performed by quasi-optical injection of the test tone in front of the Cassegrain antenna. We also reported progress in digital polarization synthesis, particularly in the implementation of a calibrated Digital Ortho-Mode Transducer (DOMT) based on the Morgan et al. proof of concept.3 They showed off- line synthesis of polarization with isolation higher than 40dB. We plan to implement a digital polarimeter in a real-time FPGA-based (ROACH-2) platform, to show ultra-pure polarization isolation in a non-stop integrating spectrometer.

  18. Gravitational wave astronomy with radio galaxy surveys

    OpenAIRE

    Raccanelli, Alvise

    2016-01-01

    In the next decade, new astrophysical instruments will deliver the first large-scale maps of gravitational waves and radio sources. Therefore, it is timely to investigate the possibility to combine them to provide new and complementary ways to study the Universe. Using simulated catalogues appropriate to the planned surveys, it is possible to predict measurements of the cross-correlation between radio sources and GW maps and the effects of a stochastic gravitational wave background on galaxy ...

  19. Communicating astronomy in a small island state: The unique role of the Mauritius Radio Telescope

    Science.gov (United States)

    Saddul-Hauzaree, S.

    2008-06-01

    The Mauritius Radio Telescope (MRT) is a 2 km x 1 km T-shaped aperture synthesis array that can generate radio images of the southern sky at 151.6 MHz. The sky surveyed can be in the declination range of -70o to -10o. It is located at Bras d'Eau, northeast of Mauritius at latitude 20oS and longitude 60oE. The MRT is a joint project of the University of Mauritius, the Indian Institute of Astrophysics and the Raman Research Institute. One of the main objectives of the MRT is to generate public interest in astronomy. Thus, it is involved in a wide range of onsite outreach activities for young school children. More mature students visiting the telescope learn about sky observation with a radio telescope, get to explore some sets of data, interact with the scientific personnel, get the opportunity to have hands-on experience with image manipulation and can ask a lot of questions on astronomy. This poster gives an overview of the Mauritius Radio Telescope and the attempts of MRT ito communicate astronomy to students as a process and not just as a vast expanse of knowledge. The challenges and dilemmas faced by MRT in conveying astronomy to the general public in a small island state are investigated and presented.

  20. The coexistence of cognitive radio and radio astronomy

    NARCIS (Netherlands)

    Bentum, Marinus Jan; Boonstra, A.J.; Baan, W.A.

    2009-01-01

    An increase of the efficiency of spectrum usage requires the development of new communication techniques. Cognitive radio may be one of those new technique, which uses unoccupied frequency bands for communications. This will lead to more power in the bands and therefore an increasing level of Radio

  1. The coexistence of cognitive radio and radio astronomy

    NARCIS (Netherlands)

    Bentum, M.J.; Boonstra, A.J.; Baan, W.A.

    2009-01-01

    An increase of the efficiency of spectrum usage requires the development of new communication techniques. Cognitive radio may be one of those new technique, which uses unoccupied frequency bands for communications. This will lead to more power in the bands and therefore an increasing level of Radio

  2. Hartebeesthoek Radio Astronomy Observatory (HartRAO)

    Science.gov (United States)

    Nickola, Marisa; Gaylard, Mike; Quick, Jonathan; Combrinck, Ludwig

    2013-01-01

    HartRAO provides the only fiducial geodetic site in Africa, and it participates in global networks for VLBI, GNSS, SLR, and DORIS. This report provides an overview of geodetic VLBI activities at HartRAO during 2012, including the conversion of a 15-m alt-az radio telescope to an operational geodetic VLBI antenna.

  3. Astronomy: Radio burst caught red-handed

    Science.gov (United States)

    Falcke, Heino

    2017-01-01

    For almost a decade, astronomers have observed intense bursts of radio waves from the distant cosmos whose origins were unknown. The source of one such burst has now been identified, but this has only deepened the mystery. See Letter p.58

  4. A Radio Astronomy Science Education Partnership - GAVRT and Radio JOVE

    Science.gov (United States)

    Higgins, C. A.; Thieman, J. R.; Bunnell, K.; Soholt, G.

    2009-12-01

    The planet Jupiter provides an excellent subject to educate, engage, and inspire students and teachers to learn science. The Goldstone Apple-Valley Radio Telescope (GAVRT) program (http://www.lewiscenter.org/gavrt) and The Radio JOVE project (http://radiojove.gsfc.nasa.gov) each have a long history of allowing students and teachers to interact with scientists and real radio telescopes. The upcoming Juno mission to Jupiter (2011 launch) allows both GAVRT and Radio JOVE to combine efforts and engage with the NASA Juno mission, thus increasing the excitement and learning potential for teachers, students, and the general public. Teachers can attend workshops for training to operate a 34-meter radio telescope and/or build their own simple radio telescope, both of which can be used directly in the classroom. We will overview some classroom activities and highlight some teacher-student experiences. In addition, we will update our efforts on greater Web-based control of the radio telescopes, as well as highlight our upcoming workshops to allow better access for teachers in different parts of the Country.

  5. Getting started in radio astronomy beginner projects for the amateur

    CERN Document Server

    Arnold, Steven

    2013-01-01

    Radio astronomy is a mystery to the majority of amateur astronomers, yet it is the best subject to turn to when desirous of an expanded knowledge of the sky. This guide intends to instruct complete newcomers to radio astronomy, and provides help for the first steps on the road towards the study of this fascinating subject. In addition to a history of the science behind the pursuit, directions are included for four easy-to-build projects, based around long-term NASA and Stanford Solar Center projects. The first three projects constitute self-contained units available as kits, so there is no nee

  6. On the Development of Radio Astronomy and Protected Astronomy Reserves in South Africa

    Science.gov (United States)

    Tiplady, Adrian John

    2015-08-01

    Recent initiatives to take advantage of various geographic locations in South Africa that exhibit excellent conditions for astronomical observations (optical and radio) has resulted in the establishment of a number of world class astronomical facilities. This includes the 10m class Southern African Large Telescope, the 64 dish MeerKAT radio telescope (under construction), and future Square Kilometre Array.To preserve these areas that exhibit natural astronomical advantage, unique legislation was promulgated to establish 'astronomy reserves'. These reserves are protected through a unique set of regulations that enable protection of astronomical facilities located in declared areas from any current, and future, sources of potential interference. This paper will look at the development and implementation of a protection regime, and review some of practical implications of the construction and operation of a radio telescope in what has become to be known as a 'radio quiet zone'.

  7. Accurate Weather Forecasting for Radio Astronomy

    Science.gov (United States)

    Maddalena, Ronald J.

    2010-01-01

    The NRAO Green Bank Telescope routinely observes at wavelengths from 3 mm to 1 m. As with all mm-wave telescopes, observing conditions depend upon the variable atmospheric water content. The site provides over 100 days/yr when opacities are low enough for good observing at 3 mm, but winds on the open-air structure reduce the time suitable for 3-mm observing where pointing is critical. Thus, to maximum productivity the observing wavelength needs to match weather conditions. For 6 years the telescope has used a dynamic scheduling system (recently upgraded; www.gb.nrao.edu/DSS) that requires accurate multi-day forecasts for winds and opacities. Since opacity forecasts are not provided by the National Weather Services (NWS), I have developed an automated system that takes available forecasts, derives forecasted opacities, and deploys the results on the web in user-friendly graphical overviews (www.gb.nrao.edu/ rmaddale/Weather). The system relies on the "North American Mesoscale" models, which are updated by the NWS every 6 hrs, have a 12 km horizontal resolution, 1 hr temporal resolution, run to 84 hrs, and have 60 vertical layers that extend to 20 km. Each forecast consists of a time series of ground conditions, cloud coverage, etc, and, most importantly, temperature, pressure, humidity as a function of height. I use the Liebe's MWP model (Radio Science, 20, 1069, 1985) to determine the absorption in each layer for each hour for 30 observing wavelengths. Radiative transfer provides, for each hour and wavelength, the total opacity and the radio brightness of the atmosphere, which contributes substantially at some wavelengths to Tsys and the observational noise. Comparisons of measured and forecasted Tsys at 22.2 and 44 GHz imply that the forecasted opacities are good to about 0.01 Nepers, which is sufficient for forecasting and accurate calibration. Reliability is high out to 2 days and degrades slowly for longer-range forecasts.

  8. Daris, a low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Bentum, Marinus Jan; van 't Klooster, K.; Falcke, H.

    2010-01-01

    DARIS (Distributed Aperture Array for Radio Astronomy in Space) is a radio astronomy space mission concept aimed at observing the low-frequency radio sky in the range 1-10 MHz. Because of the Earth's ionospheric disturbances and opaqueness, this frequency range can only be observed from space. The a

  9. Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

    Science.gov (United States)

    Herman, J. R.; Caruso, J. A.

    1971-01-01

    Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

  10. Plasma Diagnostics of the Interstellar Medium with Radio Astronomy

    CERN Document Server

    Haverkorn, Marijke

    2013-01-01

    We discuss the degree to which radio propagation measurements diagnose conditions in the ionized gas of the interstellar medium (ISM). The "signal generators" of the radio waves of interest are extragalactic radio sources (quasars and radio galaxies), as well as Galactic sources, primarily pulsars. The polarized synchrotron radiation of the Galactic non-thermal radiation also serves to probe the ISM, including space between the emitting regions and the solar system. Radio propagation measurements provide unique information on turbulence in the ISM as well as the mean plasma properties such as density and magnetic field strength. Radio propagation observations can provide input to the major contemporary questions on the nature of ISM turbulence, such as its dissipation mechanisms and the processes responsible for generating the turbulence on large spatial scales. Measurements of the large scale Galactic magnetic field via Faraday rotation provide unique observational input to theories of the generation of the ...

  11. Astrochemistry in The Age of Broadband Radio Astronomy

    Science.gov (United States)

    Corby, Joanna

    2016-05-01

    This dissertation explores the challenges and advancements introduced by the arrival of new-generation radio telescopes for understanding the physical and chemical structure of the Interstellar Medium (ISM). New-generation broadband radio instruments, and particularly broadband interferometers, provide the opportunity to obtain a comprehensive view of the coupled physical and chemical structure of the interstellar medium (ISM). This is required in order to transform the field of astrochemistry into a predictive science with diagnostic power for astronomy. However, significant challenges are posed by the new wealth of data, and in order to extract even a reasonable fraction of the capacity of these data sets, automated data handling is necessary. This work addresses the challenge with scripts written to perform automated spectral line fitting and semi-automated line identification in order to fully characterize broadband data sets. Besides providing scientific results from the spectral analysis, the spectral characterization is a required first step needed in order to interpret spatial distribution information. We test the performance of the scripts on spectral line data from 4 to 6 GHz and 30 to 50 GHz towards the most complex spectral line source in the Galaxy, namely the high mass star forming region Sagittarius B2 (Sgr B2).Additionally, the results of the automated line fitter are coupled with image data to constrain the physical and chemical conditions in gas located in Sgr B2(N). This material contains multiple exotic molecules of prebiotic relevance, and the gas conditions include moderate densities, warm temperatures, and a complex mechanical and radiative environment with shocks and turbulence as well as strong UV, X-ray, and cosmic ray irradiation. Finally, we utilize broadband single dish and interferometric data to explore the coupled physical and chemical structure of material in diffuse and translucent clouds located in the Galactic Center and disk

  12. Optical, infrared and radio astronomy from techniques to observation

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents the established sciences of optical, infrared, and radio astronomy as distinct research areas, focusing on the science targets and the constraints that they place on instrumentation in the different domains. It aims to bridge the gap between specialized books and practical texts, presenting the state of the art in different techniques. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities that drive the building of instrumentation and the development of advanced techniques. The specific telescopes and detectors are then presented, together with the techniques used to measure fluxes and spectra. Finally, the instruments and their limits are discussed to assist readers in choice of setup, planning and execution of observations, and data reduction. The volume also includes worked examples and problem sets to improve student understanding; tables and figures in chapters summarize the state of the art of instrumentation and techniques.

  13. A Radio-Frequency-over-Fiber link for large-array radio astronomy applications

    CERN Document Server

    Mena, Juan; Cliche, Jean-Francois; Dobbs, Matt; Gilbert, Adam; Tang, Qing Yang

    2013-01-01

    A prototype 425-850 MHz Radio-Frequency-over-Fiber (RFoF) link for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) is presented. The design is based on a directly modulated Fabry-Perot (FP) laser, operating at ambient temperature, and a single-mode fiber. The dynamic performance, gain stability, and phase stability of the RFoF link are characterized. Tests on a two-element interferometer built at the Dominion Radio Astrophysical Observatory for CHIME prototyping demonstrate that RFoF can be successfully used as a cost-effective solution for analog signal transport on the CHIME telescope and other large-array radio astronomy applications

  14. A Brief History of Radio Astronomy in the USSR A Collection of Scientific Essays

    CERN Document Server

    Salomonovich, A; Samanian, V; Shklovskii, I; Sorochenko, R; Troitskii, V; Kellermann, K; Dubinskii, B; Kaidanovskii, N; Kardashev, N; Kobrin, M; Kuzmin, A; Molchanov, A; Pariiskii, Yu; Rzhiga, O

    2012-01-01

    This translation from Russian makes the history of radio astronomy in the USSR available in the English language for the first time. The book includes descriptions of the antennas and instrumentation used in the USSR, the astronomical discoveries, as well as interesting personal backgrounds of many of the early key players in Soviet radio astronomy. A Brief History of Radio Astronomy in the USSR is a collection of memoirs recounting an interesting but largely still dark era of Soviet astronomy. The arrangement of the essays is determined primarily by the time when radio astronomy studies began at the institutions involved. These include the Lebedev Physical Institute (FIAN), Gorkii State University and the affiliated Physical-Technical Institute (GIFTI), Moscow State University Sternberg Astronomical institute (GAISH) and Space Research Institute (IKI), the Department of Radio Astronomy of the Main Astronomical Observatory in Pulkovo (GAO), Special Astrophysical Observatory (SAO), Byurakan Astrophysical Obse...

  15. Application of Lossless Data Compression Techniques to Radio Astronomy Data flows

    CERN Document Server

    Natusch, Tim

    2014-01-01

    The modern practice of Radio Astronomy is characterized by extremes of data volume and rates, principally because of the direct relationship between the signal to noise ratio that can be achieved and the need to Nyquist sample the RF bandwidth necessary by way of support. The transport of these data flows is costly. By examining the statistical nature of typical data flows and applying well known techniques from the field of Information Theory the following work shows that lossless compression of typical radio astronomy data flows is in theory possible. The key parameter in determining the degree of compression possible is the standard deviation of the data. The practical application of compression could prove beneficial in reducing the costs of data transport and (arguably) storage for new generation instruments such as the Square Kilometer Array.

  16. Automating Radio Astronomy in the NASA Deep Space Network

    Science.gov (United States)

    Kuiper, T. B. H.; Leflang, J. G.; Trinh, T.

    1996-12-01

    Radio astronomy observations with the DSN are being automated to simplify operations for DSN personnel, enable remote directing and monitoring by investigators, allow the use of short blocks of antenna time, and use of unanticipated antenna availability on very short notice. The key elements of the system are the Equipment Activity Controller (EAC), which performs the same functions as a DSN operator's console but with additional capabilities, the Radio Astronomy Controller (RAC), which controls radio astronomy and other R&D equipment, and the PC Field System (PCFS), which controls the VLBI recorders. Normally, the EAC is client to both the RAC and the PCFS. The EAC graphical user interface (GUI) normally runs on the EAC, but need not, allowing for remote operation. Messages between the client and servers are Extended Tcl (TclX) commands and are passed using a simple TCP/IP protocol called Net Services. The Tcl command set has been augmented with Net Services commands. The EAC will accept commands from both the PCFS and RAC, enabling either of those to be the focus of the experiment, with the EAC acting effectively as a client providing access to DSN antennas and receivers. The design also allows a user developed program (e.g. a Tk script) on a remote computer (e.g. at JPL) to be the focus of the experiment. All communications and the DSN's operational network are secured through the use of hardware encryption units. This poster describes primarily the RAC and the design of its server software. Each connection to the server is assigned its own Tcl interpreter. All have access to specific commonly shared data. While only certain tasks can control resources, a large number of monitoring connections can be accepted. In addition, the server executes specific Tcl scripts at predefined intervals. These timed scripts can be edited in real-time for greater experiment flexibility.

  17. Radio Astronomy transformed: Aperture Arrays - Past, Present and Future

    CERN Document Server

    Garrett, M A

    2013-01-01

    Aperture Arrays have played a major role in radio astronomy since the field emerged from the results of long-distance communication tests performed by Karl Jansky in the early 1930's. The roots of this technology extend back beyond Marconi, although the first electronically scanned instrument only appeared in the run-up to World War II. After the war, phased arrays had a major impact in many walks of life, including astronomy and astrophysics. Major progress was made in understanding the nature of the radio sky, including the discovery of Pulsars. Despite these early successes, parabolic dishes largely replaced aperture arrays through the 1960's, and right up until the end of the 20th century. Technological advances in areas such as signal processing, digital electronics, low-power/high performance super-computing and large capacity data storage systems have recently led to a substantial revival in the use of aperture arrays - especially at frequencies below 300 MHz. Composed of simple antennas with commercia...

  18. Inter-Division IV-V-IX / Working Group Historic Radio Astronomy

    NARCIS (Netherlands)

    Orchiston, Wayne; Kellermann, Kenneth I.; Davies, Rodney D.; Débarbat, Suzanne V.; Morimoto, Masaki; Slysh, Slava; Swarup, Govind; van Woerden, Hugo; Wall, Jasper V.; Wielebinski, Richard

    2009-01-01

    The Working Group was formed at the IAU XXV General Assembly in Sydney, 2003, as a joint initiative of Commissions 40 Radio Astronomy and Commission 41 History of Astronomy, in order to assemble a master list of surviving historically-significant radio telescopes and associated instrumentation found

  19. Inter-Division IV-V-IX / Working Group Historic Radio Astronomy

    NARCIS (Netherlands)

    Orchiston, Wayne; Kellermann, Kenneth I.; Davies, Rodney D.; Débarbat, Suzanne V.; Morimoto, Masaki; Slysh, Slava; Swarup, Govind; van Woerden, Hugo; Wall, Jasper V.; Wielebinski, Richard

    2009-01-01

    The Working Group was formed at the IAU XXV General Assembly in Sydney, 2003, as a joint initiative of Commissions 40 Radio Astronomy and Commission 41 History of Astronomy, in order to assemble a master list of surviving historically-significant radio telescopes and associated instrumentation found

  20. The statistics of low frequency radio interference at the Murchison Radio-astronomy Observatory

    CERN Document Server

    Sokolowski, Marcin; Lewis, Morgan

    2016-01-01

    We characterize the low frequency radio-frequency interference (RFI) environment at the Murchison Radio-astronomy Observatory (MRO), the location selected for the low-frequency component of the Square Kilometre Array. Data were collected from the BIGHORNS instrument, located at the MRO, which records a contiguous bandwidth between 70 and 300 MHz, between November 2014 to March 2015 inclusive. The data were processed to identify RFI, and we describe a series of statistics in both the time and frequency domain, including modeling of the RFI occupancy and signal power as a series of distribution functions, with the goal of aiding future scientists and operation staff in observation planning.

  1. DSP-Enabled Radio Astronomy: Towards IIIZW35 Reconquest

    Directory of Open Access Journals (Sweden)

    Alain Lecacheux

    2005-09-01

    Full Text Available In radio astronomy, the radio spectrum is used to detect weak emission from celestial sources. By spectral averaging, observation noise is reduced and weak sources can be detected. However, more and more observations are polluted by man-made radio frequency interferences (RFI. The impact of these RFIs on power spectral measurement ranges from total saturation to subtle distortions of the data. To some extent, elimination of artefacts can be achieved by blanking polluted channels in real time. With this aim in view, a complete real-time digital system has been implemented on a set of FPGA and DSP. The current functionalities of the digital system have high dynamic range of 70 dB, bandwidth selection facilities ranging from 875 kHz to 14 MHz, high spectral resolution through a polyphase filter bank with up to 8192 channels with 49 152 coefficients and real-time time-frequency blanking with a robust threshold detector. This receiver has been used to reobserve the IIIWZ35 astronomical source which has been scrambled by a strong satellite RFI for several years.

  2. RadioNet3 Study Group White Paper on: The Future Organisation and Coordination of Radio Astronomy in Europe

    CERN Document Server

    Garrett, M A; Garrington, S T; Klöckner, H-R; van Langevelde, H; Mantovani, F; Russel, A; Schuster, K; Vermeulen, R C; Zensus, A

    2016-01-01

    The QueSERA Study Group (QSG) have been tasked by the RadioNet Board to produce a White Paper on the future organisation and coordination of radio astronomy in Europe. This White Paper describes the options discussed by the QSG, and our conclusions on how to move forward. We propose, that as a first step, RadioNet-work, be established as an entity that persists between EC contracts, and that takes responsibility for preparing or coordinating responses to EC opportunities specific to the field of radio astronomy research infrastructures. RadioNet-work should provide a safety net that ensures that cooperation and collaboration between the various radio astronomy partners in Europe is maintained with or without EC funding.

  3. High-Sensitivity Phased Arrays for Radio Astronomy and Satellite Communications

    Science.gov (United States)

    Diao, Junming

    Radio astronomy is used to study stars, galaxies, black holes and gas clouds radiation at radio frequencies. Detecting extremely weak signals from deep space radio sources requires high sensitive feed system associated with large dish antennas. The key figure of merit is survey speed, or the time required to map a region of the sky to a given source flux density. Survey speed is proportional to the frequency bandwidth, the field of view or observable region of the sky, and the squared sensitivity, where sensitivity is related to reflector aperture efficiency and system noise temperature. Compared to the traditional single feed, phased array feeds with significantly expanded field of view are considered as the next generation feed for radio telescope. This dissertation outlines the design, analysis and measurement of high sensitivity L-band and mm-wave phased array feeds for the 100-meter Green Bank Telescope. Theoretical works for radio astronomy includes design guideline for high sensitivity phased array feed, fundamental frequency bandwidth limit, array antenna loss influenced by mutual coupling and beamformer coefficients and possibility of superdirectivity for radio telescopes and other antennas. These study are helpful to understand and guide the design of a phased array feed system. In the absence of dish antennas, sparse phased arrays with aperiodic structure have been developed for satellite communications. A compromise between the peak side lobe level, array element density, directivity and design complexity is studied. We have found that the array peak side lobe level can be reduced by enhancing the array element direction at the main lobe direction, increasing the array element density and enlarging the array size. A Poynting streamline approach develops to understand the properties of a receiving antenna and the mutual coupling effects between array elements. This method has been successfully used to generate effective area shape for many types of

  4. Alternative Adaptive Filter Structures for Improved Radio Frequency Interference Cancellation in Radio Astronomy

    CERN Document Server

    Mitchell, D A; Sault, R J

    2010-01-01

    In radio astronomy, reference signals from auxiliary antennas that receive only the radio frequency interference (RFI) can be modified to model the RFI environment at the astronomy receivers. The RFI can then be canceled from the astronomy signal paths. However, astronomers typically only require signal statistics. If the RFI statistics are changing slowly, the cancellation can be applied to the signal correlations at a much lower rate than is required for standard adaptive filters. In this paper we describe five canceler setups; precorrelation and postcorrelation cancelers that use one or two reference signals in different ways. The theoretical residual RFI and added noise levels are examined and are demonstrated using microwave television RFI at the Australia Telescope Compact Array. The RFI is attenuated to below the system noise, a reduction of at least 20 dB. While dual-reference cancelers add more reference noise than single-reference cancelers, this noise is zero-mean and only adds to the system noise,...

  5. Development of a Multi-frequency Interferometer Telescope for Radio Astronomy (MITRA)

    Science.gov (United States)

    Ingala, Dominique Guelord Kumamputu

    2015-03-01

    This dissertation describes the development and construction of the Multi-frequency Interferometer Telescope for Radio Astronomy (MITRA) at the Durban University of Technology. The MITRA station consists of 2 antenna arrays separated by a baseline distance of 8 m. Each array consists of 8 Log-Periodic Dipole Antennas (LPDAs) operating from 200 MHz to 800 MHz. The design and construction of the LPDA antenna and receiver system is described. The receiver topology provides an equivalent noise temperature of 113.1 K and 55.1 dB of gain. The Intermediate Frequency (IF) stage was designed to produce a fixed IF frequency of 800 MHz. The digital Back-End and correlator were implemented using a low cost Software Defined Radio (SDR) platform and Gnu-Radio software. Gnu-Octave was used for data analysis to generate the relevant received signal parameters including total power, real, and imaginary, magnitude and phase components. Measured results show that interference fringes were successfully detected within the bandwidth of the receiver using a Radio Frequency (RF) generator as a simulated source. This research was presented at the IEEE Africon 2013 / URSI Session Mauritius, and published in the proceedings.

  6. Under the Radar: The First Woman in Radio Astronomy, Ruby Payne-Scott

    Science.gov (United States)

    Miller Goss, W.

    2012-05-01

    Under the Radar, the First Woman in Radio Astronomy, Ruby Payne-Scott W. Miller Goss, NRAO Socorro NM Ruby Payne-Scott (1912-1981) was an eminent Australian scientist who made major contributions to the WWII radar effort (CSIR) from 1941 to 1945. In late 1945, she pioneered radio astronomy efforts at Dover Heights in Sydney, Australia at a beautiful cliff top overlooking the Tasman Sea. Again at Dover Heights, Payne-Scott carried out the first interferometry in radio astronomy using an Australian Army radar antenna as a radio telescope at sun-rise, 26 January 1946. She continued these ground breaking activities until 1951. Ruby Payne-Scott played a major role in discovering and elucidating the properties of Type III bursts from the sun, the most common of the five classes of transient phenomena from the solar corona. These bursts are one of the most intensively studied forms of radio emission in all of astronomy. She is also one of the inventors of aperture synthesis in radio astronomy. I examine her career at the University of Sydney and her conflicts with the CSIR hierarchy concerning the rights of women in the work place, specifically equal wages and the lack of permanent status for married women. I also explore her membership in the Communist Party of Australia as well as her partially released Australian Scientific Intelligence Organization file. Payne-Scott’s role as a major participant in the flourishing radio astronomy research of the post war era remains a remarkable story. She had a number of strong collaborations with the pioneers of early radio astronomy in Australia: Pawsey, Mills, Christiansen, Bolton and Little. I am currently working on a popular version of the Payne-Scott story; “Making Waves, The Story of Ruby Payne-Scott: Australian Pioneer Radio Astronomer” will be published in 2013 by Springer in the Astronomers’ Universe Series.

  7. Origins of Radio Astronomy at the Tata Institute of Fundamental Research and the role of J. L. Pawsey

    Science.gov (United States)

    Goss, W. M.

    I will discuss the interactions of a number of individuals that played major roles in the formation of radio astronomy in India in the period 1952-1962, particularly Dr. Joseph L. Pawsey. The story began in 1953-1954: Pawsey brought Govind Swarup to Australia as a Colombo Fellow in 1953, where he worked with Christiansen, Mills, Wild and Bolton. Later, Swarup went to Stanford where he completed a PhD with Ron Bracewell working on the new Solar Microwave Spectroheliograph. In the era 1960-1963, with the encouragement of Pawsey, several colleagues in Australia and Bracewell, discussions began among a number of Indian colleagues to form a radio astronomy group in India. The main players were G. Swarup, T.K. Menon, M.R. Kundu and T. Krishnan. Homi J. Bhabha, the Director of TIFR, made the decisive offer to this group to start a radio astronomy project in early 1962. Swarup joined TIFR in early April 1963. Many factors contributed to the successful formation of the new group: international networking among scientists of several generations, rapid decisions by Bhabha and the readiness to take chances in choosing promising, young, energetic scientists. In December 2013, we have celebrated 50 years of ground breaking research by the TIFR radio astronomers as well as the outstanding decade of research with the GMRT- the Giant Metrewave Radio Telescope. Govind Swarup has provided the inspiration and leadership for this remarkable achievement.

  8. Astroinformatics Challenges from Next-generation Radio Continuum Surveys

    CERN Document Server

    Norris, Ray P

    2016-01-01

    The tens of millions of radio sources to be detected with next-generation surveys pose new challenges, quite apart from the obvious ones of processing speed and data volumes. For example, existing algorithms are inadequate for source extraction or cross-matching radio and optical/IR sources, and a new generation of algorithms are needed using machine learning and other techniques. The large numbers of sources enable new ways of testing astrophysical models, using a variety of "large-n astronomy" techniques such as statistical redshifts. Furthermore, while unexpected discoveries account for some of the most significant discoveries in astronomy, it will be difficult to discover the unexpected in large volumes of data, unless specific software is developed to mine the data for the unexpected.

  9. Solar Radio Astronomy and Plasma Non-thermal Proccsscs in Solar Atmosphere

    Institute of Scientific and Technical Information of China (English)

    YAN Yihua; TAN Baolin

    2011-01-01

    1. Introduction Solar radio astronomy is an important branch of solar physics, which deals with the radio emission from the solar atmosphere. In solar physics, one of the greatest challenges is to understand the energy storing in the hot atmospheric plasma above sunspots and its sudden releasing in eruptive processes, such as solar flares, eruptive filaments, and coronal mass ejections (CME). Intrinsically,

  10. Infrared Submillimeter and Radio Astronomy Research and Analysis Program

    Science.gov (United States)

    Traub, Wesley A.

    2000-01-01

    This program entitled "Infrared Submillimeter and Radio Astronomy Research and Analysis Program" with NASA-Ames Research Center (ARC) was proposed by the Smithsonian Astrophysical Observatory (SAO) to cover three years. Due to funding constraints only the first year installment of $18,436 was funded, but this funding was spread out over two years to try to maximize the benefit to the program. During the tenure of this contact, the investigators at the SAO, Drs. Wesley A. Traub and Nathaniel P. Carleton, worked with the investigators at ARC, Drs. Jesse Bregman and Fred Wittebom, on the following three main areas: 1. Rapid scanning SAO and ARC collaborated on purchasing and constructing a Rapid Scan Platform for the delay arm of the Infrared-Optical Telescope Array (IOTA) interferometer on Mt. Hopkins, Arizona. The Rapid Scan Platform was tested and improved by the addition of stiffening plates which eliminated a very small but noticeable bending of the metal platform at the micro-meter level. 2. Star tracking Bregman and Wittebom conducted a study of the IOTA CCD-based star tracker system, by constructing a device to simulate star motion having a specified frequency and amplitude of motion, and by examining the response of the tracker to this simulated star input. 3. Fringe tracking. ARC, and in particular Dr. Robert Mah, developed a fringe-packet tracking algorithm, based on data that Bregman and Witteborn obtained on IOTA. The algorithm was tested in the laboratory at ARC, and found to work well for both strong and weak fringes.

  11. Unformatted Digital Fiber-Optic Data Transmission for Radio Astronomy Front-Ends

    CERN Document Server

    Morgan, Matthew A; Castro, Jason J

    2013-01-01

    We report on the development of a prototype integrated receiver front-end that combines all conversions from RF to baseband, from analog to digital, and from copper to fiber into one compact assembly, with the necessary gain and stability suitable for radio astronomy applications. The emphasis in this article is on a novel digital data link over optical fiber which requires no formatting in the front-end, greatly reducing the complexity, bulk, and power consumption of digital electronics inside the antenna, facilitating its integration with the analog components, and minimizing the self-generated radio-frequency interference (RFI) which could leak into the signal path. Management of the serial data link is performed entirely in the back-end based on the statistical properties of signals with a strong random noise component. In this way, the full benefits of precision and stability afforded by conventional digital data transmission are realized with far less overhead at the focal plane of a radio telescope.

  12. Characterization of a Low-Frequency Radio Astronomy Prototype Array in Western Australia

    CERN Document Server

    Sutinjo, A T; Wayth, R B; Hall, P J; Acedo, E de Lera; Booler, T; Faulkner, A J; Feng, L; Hurley-Walker, N; Juswardy, B; Padhi, S K; Razavi-Ghods, N; Sokolowski, M; Tingay, S J; de Vaate, J G Bij

    2015-01-01

    We report characterization results for an engineering prototype of a next-generation low-frequency radio astronomy array. This prototype, which we refer to as the Aperture Array Verification System 0.5 (AAVS0.5), is a sparse pseudo-random array of 16 log-periodic antennas designed for 70-450 MHz. It is co-located with the Murchison Widefield Array (MWA) at the Murchison Radioastronomy Observatory (MRO) near the Australian Square Kilometre Array (SKA) core site. We characterize the AAVS0.5 using two methods: in-situ radio interferometry with astronomical sources and an engineering approach based on detailed full-wave simulation. In-situ measurement of the small prototype array is challenging due to the dominance of the Galactic noise and the relatively weaker calibration sources easily accessible in the southern sky. The MWA, with its 128 "tiles" and up to 3 km baselines, enabled in-situ measurement via radio interferometry. We present array sensitivity and beam pattern characterization results and compare to ...

  13. The paraboloidal reflector antenna in radio astronomy and communication theory and practice

    CERN Document Server

    Baars, Jacob W M

    2007-01-01

    Reflector antennas are widely used in the microwave and millimeter wavelength domain. Radio astronomers have developed techniques of calibration of large antennas with radio astronomical methods. These have not been comprehensively described. This text aims to fill this gap. The Paraboloidal Reflector Antenna in Radio Astronomy and Communication: Theory and Practice takes a practical approach to the characterization of antennas. All calculations and results in the form of tables and figures have been made with Mathematica by Wolfram Research. The reader can use the procedures for the implementation of his/her own input data. The book should be of use to all who are involved in the design and calibration of large antennas, like ground station managers and engineers, practicing radio astronomers, and finally, graduate students in radio astronomy and communication technology.

  14. Early Dutch radio astronomy (1940-1970) : the people and the politics

    Science.gov (United States)

    Elbers, Astrid

    2015-12-01

    Radio astronomy was born during the Second World War. The early post-war radio astronomy group in the Netherlands was one of the most important radio astronomy groups in the world. There are several reasons for this. Firstly: Dutch radio astronomers were trained as (optical) astronomers, while in most countries engineers and physicists with a background in wartime radar research were the first radio 'astronomers'. This was because radio telescopes shared the technology of wartime radar installations. Because Dutch astronomers were not familiar with the new kind of instrumentation, they had to conclude strategic alliances with industrial partners such as Philips, the PTT and the KNMI. These alliances would offer much more than merely technical know-how, which means that the disadvantage would prove to be an advantage in the end. Secondly: astronomy was still a very small-scale undertaking in the early post-war period. Even so, ZWO was still a very small organisation. The fact that so few people were involved meant that the impact of a personal network could be enormous. Thirdly: the Dutch post-war context was remarkably favourable to science: it was considered to be a key factor in the rebuilding of the country.

  15. Scalable desktop visualisation of very large radio astronomy data cubes

    Science.gov (United States)

    Perkins, Simon; Questiaux, Jacques; Finniss, Stephen; Tyler, Robin; Blyth, Sarah; Kuttel, Michelle M.

    2014-07-01

    Observation data from radio telescopes is typically stored in three (or higher) dimensional data cubes, the resolution, coverage and size of which continues to grow as ever larger radio telescopes come online. The Square Kilometre Array, tabled to be the largest radio telescope in the world, will generate multi-terabyte data cubes - several orders of magnitude larger than the current norm. Despite this imminent data deluge, scalable approaches to file access in Astronomical visualisation software are rare: most current software packages cannot read astronomical data cubes that do not fit into computer system memory, or else provide access only at a serious performance cost. In addition, there is little support for interactive exploration of 3D data. We describe a scalable, hierarchical approach to 3D visualisation of very large spectral data cubes to enable rapid visualisation of large data files on standard desktop hardware. Our hierarchical approach, embodied in the AstroVis prototype, aims to provide a means of viewing large datasets that do not fit into system memory. The focus is on rapid initial response: our system initially rapidly presents a reduced, coarse-grained 3D view of the data cube selected, which is gradually refined. The user may select sub-regions of the cube to be explored in more detail, or extracted for use in applications that do not support large files. We thus shift the focus from data analysis informed by narrow slices of detailed information, to analysis informed by overview information, with details on demand. Our hierarchical solution to the rendering of large data cubes reduces the overall time to complete file reading, provides user feedback during file processing and is memory efficient. This solution does not require high performance computing hardware and can be implemented on any platform supporting the OpenGL rendering library.

  16. Space-based Aperture Array For Ultra-Long Wavelength Radio Astronomy

    CERN Document Server

    Rajan, Raj Thilak; Bentum, Mark; Klein-Wolt, Marc; Belien, Frederik; Arts, Michel; Saks, Noah; van der Veen, Alle-Jan

    2015-01-01

    The past decade has seen the rise of various radio astronomy arrays, particularly for low-frequency observations below 100MHz. These developments have been primarily driven by interesting and fundamental scientific questions, such as studying the dark ages and epoch of re-ionization, by detecting the highly red-shifted 21cm line emission. However, Earth-based radio astronomy below frequencies of 30MHz is severely restricted due to man-made interference, ionospheric distortion and almost complete non-transparency of the ionosphere below 10MHz. Therefore, this narrow spectral band remains possibly the last unexplored frequency range in radio astronomy. A straightforward solution to study the universe at these frequencies is to deploy a space-based antenna array far away from Earths' ionosphere. Various studies in the past were principally limited by technology and computing resources, however current processing and communication trends indicate otherwise. We briefly present the achievable science cases, and dis...

  17. A Sustainable approach to large ICT Science based infrastructures; the case for Radio Astronomy

    CERN Document Server

    Barbosa, Domingos; Boonstra, Albert-Jan; Aguiar, Rui; van Ardenne, Arnold; de Santander-Vela, Juande; Verdes-Montenegro, Lourdes

    2014-01-01

    Large sensor-based infrastructures for radio astronomy will be among the most intensive data-driven projects in the world, facing very high power demands. The geographically wide distribution of these infrastructures and their associated processing High Performance Computing (HPC) facilities require Green Information and Communications Technologies (ICT). A combination is needed of low power computing, efficient data storage, local data services, Smart Grid power management, and inclusion of Renewable Energies. Here we outline the major characteristics and innovation approaches to address power efficiency and long-term power sustainability for radio astronomy projects, focusing on Green ICT for science.

  18. 47 CFR 73.6027 - Class A TV notifications concerning interference to radio astronomy, research and receiving...

    Science.gov (United States)

    2010-10-01

    ... radio astronomy, research and receiving installations. An applicant for digital operation of an existing Class A TV station or to change the facilities of an existing Class A TV or digital Class A TV station... interference to radio astronomy, research and receiving installations. 73.6027 Section...

  19. Population density effect on radio frequencies interference (RFI) in radio astronomy

    Science.gov (United States)

    Umar, Roslan; Abidin, Zamri Zainal; Ibrahim, Zainol Abidin; Hassan, Mohd Saiful Rizal; Rosli, Zulfazli; Hamidi, Zety Shahrizat

    2012-06-01

    Radio astronomical observation is infected by wide range of Radio Frequency Interference (RFI). We will also use information gathered from on-site RFI level measurements on selected 'good' areas generated by this study. After investigating a few suitable sites we will commence to the site and construct the RFI observation. Eventually, the best area we will be deciding from the observations soon. The result of this experiment will support our planning to build the first radio telescope in Malaysia. Radio observatories normally are located in remote area, in order to combat RFI from active spectrum users and radio noise produced in industrial or residential areas. The other solution for this problem is regulating the use of radio frequencies in the country (spectrum management). Measurement of RFI level on potential radio astronomical site can be done to measure the RFI levels at sites. Seven sites are chosen divide by three group, which is A, B and C. In this paper, we report the initial testing RFI survey for overall spectrum (0-2GHz) for those sites. The averaged RFI level above noise level at the three group sites are 19.0 (+/-1.79) dBm, 19.5 (+/-3.71) dBm and 17.0 (+/-3.71) dBm and the averaged RFI level above noise level for without main peaks are 20.1 (+/-1.77) dBm, 19.6 (+/-3.65) dBm and 17.2 (+/-1.43) dBm respectively.

  20. Low frequency solar radio astronomy at the Indian Institute of Astrophysics (IIA)

    Science.gov (United States)

    Ramesh, R.

    IIA is presently involved in the expansion of its existing radioheliograph operating in the frequency 120-40 MHz at the Gauribidanur radio observatory located about 80 km north of Bangalore. Once completed, the expanded array will have an angular resolution of ≈ 1' at a typical frequency of 100 MHz. This paper describes the development of solar radio astronomy activities at IIA since 1952 when the first observations were carried out.

  1. Millimeter wavelength spectroscopy of trace atmospheric constituents from the Five College Radio Astronomy Observatory

    Science.gov (United States)

    Huguenin, G. R.; Irvine, W. M.

    1978-01-01

    The Five College Radio Astronomy Observatory system, located in western Massachusetts, is described. It is suggested that high sensitivity in the three-millimeter wavelength band facilitates detection and monitoring of a number of trace molecules in the earth's atmosphere as well as astonomical observation at radio wavelengths. Line formation and radiative transfer in the earth's atmosphere are discussed, and the receiver sensitivity is considered.

  2. DARIS : a low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Falcke, H.; Klein-Wolt, M.; Bentum, M.J.; Rajan, R.T.; Wijnholds, M.; Arts, M.; Klooster, van 't K.; Beliën, F.

    2010-01-01

    The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, sp

  3. A low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Falcke, H.; Klein-Wolt, M.; Bentum, M.J.; Rajan, R.T.; Wijnholds, S.J.; Arts, M.; Klooster, van 't K.; Beliën, F.

    2010-01-01

    The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, sp

  4. The TF1 Radio Astronomy Working Group in the Andean ROAD: goals and challenges for 2025

    Science.gov (United States)

    Chaparro Molano, G.

    2017-07-01

    Since the creation of the Andean Regional Office of Astronomy for Development (OAD) of the International Astronomical Union, one of the main goals has been to foster a scientific culture of radio astronomy in countries of the central and northern Andes (Bolivia, Colombia, Ecuador, Perú, and Venezuela). For this reason, Andean ROAD Task Force 1 (Research and Education in Universities) created the Radio Astronomy Working Group to set a path along which collaborative endeavors can grow and yield scientific results. The first official meeting of the Working Group took place in Bogotá, Colombia during the 2nd Astronomá en los Andes Workshop (2015) where scientists actively developing projects in radio astronomy set goals for the near future, such as improving mobility for researchers and students, developing collaborations in related areas such as engineering and data science, and building transnational collaborations aiming at developing VLBI across the countries of the Andean ROAD and beyond. In this poster, I present current projects and associated research groups (ROAS - Perú, SiAMo - Colombia, Alfa-Orion UTP - Colombia, RAIG - Chile) and discuss goalposts and current challenges in the development of transnational radioastronomical projects. As a case study, I present the development and early astronomical results of the privately funded UECCI 4m Radio Telescope for 21 cm line observations in Bogotá, Colombia.

  5. DARIS : a low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Falcke, H.; Klein-Wolt, M.; Bentum, Marinus Jan; Rajan, R.T.; Rajan, Raj; Wijnholds, M.; Arts, M.; van 't Klooster, K.; Beliën, F.

    2010-01-01

    The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, sp

  6. A low-frequency distributed aperture array for radio astronomy in space

    NARCIS (Netherlands)

    Boonstra, A.J.; Saks, N.; Falcke, H.; Klein-Wolt, M.; Bentum, Marinus Jan; Rajan, R.T.; Rajan, Raj; Wijnholds, S.J.; Arts, M.; van 't Klooster, K.; Beliën, F.

    2010-01-01

    The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, sp

  7. Next-Generation X-Ray Astronomy

    Science.gov (United States)

    White, Nicholas E.

    2011-01-01

    The future timing capabilities in X-ray astronomy will be reviewed. This will include reviewing the missions in implementation: Astro-H, GEMS, SRG, and ASTROSAT; those under study: currently ATHENA and LOFT; and new technologies that may enable future missions e.g. Lobster eye optics. These missions and technologies will bring exciting new capabilities across the entire time spectrum from micro-seconds to years that e.g. will allow us to probe close to the event horizon of black holes and constrain the equation of state of neutron stars.

  8. Radio Astronomy Data Transfer and eVLBI using KAREN

    CERN Document Server

    Weston, Stuart; Gulyaev, Sergei

    2011-01-01

    Kiwi Advanced Research and Education Network (KAREN) has been used to transfer large volumes of radio astronomical data between the Radio Astronomical Observatory at Warkworth, New Zealand and various international organizations involved in joint projects and VLBI observations. Here we report on the current status of connectivity and on the results of testing different data transfer protocols. We investigate new UDP protocols such as 'tsunami' and UDT and demonstrate that the UDT protocol is more efficient than 'tsunami' and 'ftp'. We also report on the tests on direct data streaming from the radio telescope receiving system to the correlation centre without intermediate buffering or recording (real-time eVLBI).

  9. Multiphase turbulent interstellar medium: some recent results from radio astronomy

    CERN Document Server

    Roy, Nirupam

    2015-01-01

    The radio frequency 1.4 GHz transition of the atomic hydrogen is one of the important tracers of the diffuse neutral interstellar medium. Radio astronomical observations of this transition, using either a single dish telescope or an array interferometer, reveal different properties of the interstellar medium. Such observations are particularly useful to study the multiphase nature and turbulence in the interstellar gas. Observations with multiple radio telescopes have recently been used to study these two closely related aspects in greater detail. Using various observational techniques, the density and the velocity fluctuations in the Galactic interstellar medium was found to have a Kolmogorov-like power law power spectra. The observed power law scaling of the turbulent velocity dispersion with the length scale can be used to derive the true temperature distribution of the medium. Observations from a large ongoing atomic hydrogen absorption line survey have also been used to study the distribution of gas at d...

  10. Radio Astronomy and eVLBI using KAREN

    CERN Document Server

    Weston, Stuart; Gulyaev, Sergei

    2010-01-01

    Kiwi Advanced Research and Education Network (KAREN) has been used to transfer large volumes of radio astronomical data between the AUT Radio Astronomical Observatory at Warkworth, New Zealand and the international organisations with which we are collaborating and conducting observations. Here we report on the current status of connectivity and on the results of testing different data transfer protocols. We investigate new UDP protocols such as "tsunami" and UDT and demonstrate that the UDT protocol is more efficient than "tsunami" and ftp. We report on our initial steps towards real-time eVLBI and the attempt to directly stream data from the radio telescope receiving system to the correlation centre without intermediate buffering/recording.

  11. A Decade of Developing Radio-Astronomy Instrumentation using CASPER Open-Source Technology

    CERN Document Server

    Hickish, Jack; Ali, Zaki; Buch, Kaushal D; Chaudhari, Sandeep C; Chen, Hong; Dexter, Matthew; Domagalski, Rachel Simone; Ford, John; Foster, Griffin; George, David; Greenberg, Joe; Greenhill, Lincoln; Isaacson, Adam; Jiang, Homin; Jones, Glenn; Kapp, Francois; Kriel, Henno; Lacasse, Rich; Lutomirski, Andrew; MacMahon, David; Manley, Jason; Martens, Andrew; McCullough, Randy; Muley, Mekhala V; New, Wesley; Parsons, Aaron; Price, Daniel C; Primiani, Rurik A; Ray, Jason; Siemion, Andrew; Van Tonder, Verees'e; Vertatschitsch, Laura; Wagner, Mark; Weintroub, Jonathan; Werthimer, Dan

    2016-01-01

    The Collaboration for Astronomy Signal Processing and Electronics Research (CASPER) has been working for a decade to reduce the time and cost of designing, building and deploying new digital radio-astronomy instruments. Today, CASPER open-source technology powers over 45 scientific instruments worldwide, and is used by scientists and engineers at dozens of academic institutions. In this paper we catalog the current offerings of the CASPER collaboration, and instruments past and present built by CASPER users and developers. We describe the ongoing state of software development, as CASPER looks to support a broader range of programming environments and hardware and ensure compatibility with the latest vendor tools.

  12. The renaissance of radio astronomy: towards the Square Kilometre Array

    Science.gov (United States)

    Ferrari, C.

    2016-09-01

    In this paper, I will give a brief overview of the largest radio telescope in the world, the Square Kilometre Array (SKA). The history of this instrument, its development as a huge international project, as well as its main scientific goals, will be summarised. I will then focus on a particular science case by presenting how the first phase of the SKA (SKA1), whose observations are expected to start in the early 2020's, will change our radio view of the largest gravitationally bound structures of the Universe: galaxy clusters.

  13. Division X Working Group on Historic Radio Astronomy

    NARCIS (Netherlands)

    Orchiston, Wayne; Kellermann, Kenneth I.; Davies, Rodney D.; Débarbat, Suzanne V.; Morimoto, Masaki; Slysh, Slava; Swarup, Govind; van Woerden, Hugo; Wall, Jasper V.; Wielebinski, Richard

    During the Rio General Assembly we held the following meetings of the Working Group: a Business Meeting, a Science Meeting on “The Development of Aperture Synthesis Imaging in Radio Astronomy”, and a Science Meeting on “Recent Research”.

  14. Low Frequency Radio Astronomy Summary: A Festschrift For Bill Erickson

    Science.gov (United States)

    Clark, B. G.; Kassim, N. E.; Perez, M. R.

    2005-12-01

    The science and technological issues presented at this workshop in honor of Bill Erickson's 74th birthday, are certainly opening up a new window of astronomical observations at the low end of the radio frequency spectrum. We briefly review some of the contributions concentrating our comments on the topics of science, technology, and history.

  15. International Colloquium on Scattering and Scintillation in Radio Astronomy

    CERN Document Server

    Coles, W A; Rickett, B J; Bird, M K; Efimov, A I; Samoznaev, L N; Rudash, V K; Chashei, I V; Plettemeier, D; Spangler, S R; Tokarev, Y; Belov, Y; Boiko, G; Komrakov, G; Chau, J; Harmon, J; Sulzer, M; Kojima, M; Tokumaru, M; Fujiki, K; Janardhan, P; Jackson, B V; Hick, P P; Buffington, A; Olyak, M R; Fallows, R A; Nechaeva, M B; Gavrilenko, V G; Gorshenkov, Yu N; Alimov, V A; Molotov, I E; Pushkarev, A B; Shanks, R; Tuccari, G; Lotova, N A; Vladimirski, K V; Obridko, V N; Gubenko, V N; Andreev, V E; Stinebring, D R; Gwinn, C; Lovell, J E J; Jauncey, D L; Senkbeil, C; Shabala, S; Bignall, H E; MacQuart, J P; Kedziora-Chudczer, L; Smirnova, T V; Malofeev, V M; Malov, O I; Tyulbashev, S A; Jessner, A; Sieber, W; Wielebinski, R; Scattering and Scintillation in Radio Astronomy

    2006-01-01

    Topics of the Colloquium: a) Interplanetary scintillation b) Interstellar scintillation c) Modeling and physical origin of the interplanetary and the interstellar plasma turbulence d) Scintillation as a tool for investigation of radio sources e) Seeing through interplanetary and interstellar turbulent media Ppt-presentations are available on the Web-site: http://www.prao.ru/conf/Colloquium/main.html

  16. Bayesian estimation for ionospheric calibration in radio astronomy

    NARCIS (Netherlands)

    Van der Tol, S.

    2009-01-01

    Radio astronomical observations at low frequencies (< 250 MHz), can be severely distorted by fluctuations in electron density in the ionosphere. The free electrons cause a phase change of electromagnetic waves traveling through the ionosphere. This effect increases for lower frequencies. For this re

  17. New Book Recounts Exciting, Colorful History Of Radio Astronomy in Green Bank, West Virginia

    Science.gov (United States)

    2007-07-01

    A new book published by the National Radio Astronomy Observatory (NRAO) tells the story of the founding and early years of the Observatory at Green Bank, West Virginia. But it was Fun: the first forty years of radio astronomy at Green Bank, is not a formal history, but rather a scrapbook of early memos, recollections, anecdotes and reports. But it was Fun... is liberally illustrated with archival photographs. It includes historical and scientific papers from symposia held in 1987 and 1995 to celebrate the birthdays of two of the radio telescopes at the Observatory. Book cover The National Radio Astronomy Observatory was formed in 1956 after the National Science Foundation decided to establish an observatory in the eastern United States for the study of faint radio signals from distant objects in the Universe. But it was Fun... reprints early memos from the group of scientists who searched the mountains for a suitable site -- an area free from radio transmitters and other sources of radio interference -- "in a valley surrounded by as many ranges of high mountains in as many directions as possible," which was "at least 50 miles distant from any city or other concentration of people." The committee settled on Green Bank, a small village in West Virginia, and the book documents the struggles that followed to create a world-class scientific facility in an isolated area more accustomed to cows than computers. Groundbreaking at the Observatory, then a patchwork of farms and fields, took place in October 1957, only a few days after the launch of Sputnik by the Soviet Union. A year later, Green Bank's first telescope was dedicated, and the book contains a transcription of speeches given at that ceremony, when the Cold War, the space race and America's scientific stature were issues of the hour. The centerpiece of the new Observatory was to be a highly-precise radio telescope 140 feet in diameter, but it was expected that it would soon be surpassed by dishes of much greater

  18. Space-based aperture array for ultra-long wavelength radio astronomy

    Science.gov (United States)

    Rajan, Raj Thilak; Boonstra, Albert-Jan; Bentum, Mark; Klein-Wolt, Marc; Belien, Frederik; Arts, Michel; Saks, Noah; van der Veen, Alle-Jan

    2016-02-01

    The past decade has seen the advent of various radio astronomy arrays, particularly for low-frequency observations below 100 MHz. These developments have been primarily driven by interesting and fundamental scientific questions, such as studying the dark ages and epoch of re-ionization, by detecting the highly red-shifted 21 cm line emission. However, Earth-based radio astronomy observations at frequencies below 30 MHz are severely restricted due to man-made interference, ionospheric distortion and almost complete non-transparency of the ionosphere below 10 MHz. Therefore, this narrow spectral band remains possibly the last unexplored frequency range in radio astronomy. A straightforward solution to study the universe at these frequencies is to deploy a space-based antenna array far away from Earths' ionosphere. In the past, such space-based radio astronomy studies were principally limited by technology and computing resources, however current processing and communication trends indicate otherwise. Furthermore, successful space-based missions which mapped the sky in this frequency regime, such as the lunar orbiter RAE-2, were restricted by very poor spatial resolution. Recently concluded studies, such as DARIS (Disturbuted Aperture Array for Radio Astronomy In Space) have shown the ready feasibility of a 9 satellite constellation using off the shelf components. The aim of this article is to discuss the current trends and technologies towards the feasibility of a space-based aperture array for astronomical observations in the Ultra-Long Wavelength (ULW) regime of greater than 10 m i.e., below 30 MHz. We briefly present the achievable science cases, and discuss the system design for selected scenarios such as extra-galactic surveys. An extensive discussion is presented on various sub-systems of the potential satellite array, such as radio astronomical antenna design, the on-board signal processing, communication architectures and joint space-time estimation of the

  19. Applications of Microwave Photonics in Radio Astronomy and Space Communication

    Science.gov (United States)

    D'Addario, Larry R.; Shillue, William P.

    2006-01-01

    An overview of narrow band vs wide band signals is given. Topics discussed included signal transmission, reference distribution and photonic antenna metrology. Examples of VLA, ALMA, ATA and DSN arrays are given. . Arrays of small antennas have become more cost-effective than large antennas for achieving large total aperture or gain, both for astronomy and for communication. It is concluded that emerging applications involving arrays of many antennas require low-cost optical communication of both wide bandwidth and narrow bandwidth; development of round-trip correction schemes enables timing precision; and free-space laser beams with microwave modulation allow structural metrology with approx 100 micrometer precision over distances of 200 meters.

  20. A New Approach to Interference Excision in Radio Astronomy: Real-Time Adaptive Cancellation

    Science.gov (United States)

    Barnbaum, Cecilia; Bradley, Richard F.

    1998-11-01

    Every year, an increasing amount of radio-frequency (RF) spectrum in the VHF, UHF, and microwave bands is being utilized to support new commercial and military ventures, and all have the potential to interfere with radio astronomy observations. Such services already cause problems for radio astronomy even in very remote observing sites, and the potential for this form of light pollution to grow is alarming. Preventive measures to eliminate interference through FCC legislation and ITU agreements can be effective; however, many times this approach is inadequate and interference excision at the receiver is necessary. Conventional techniques such as RF filters, RF shielding, and postprocessing of data have been only somewhat successful, but none has been sufficient. Adaptive interference cancellation is a real-time approach to interference excision that has not been used before in radio astronomy. We describe here, for the first time, adaptive interference cancellation in the context of radio astronomy instrumentation, and we present initial results for our prototype receiver. In the 1960s, analog adaptive interference cancelers were developed that obtain a high degree of cancellation in problems of radio communications and radar. However, analog systems lack the dynamic range, noised performance, and versatility required by radio astronomy. The concept of digital adaptive interference cancellation was introduced in the mid-1960s as a way to reduce unwanted noise in low-frequency (audio) systems. Examples of such systems include the canceling of maternal ECG in fetal electrocardiography and the reduction of engine noise in the passenger compartments of automobiles. These audio-frequency applications require bandwidths of only a few tens of kilohertz. Only recently has high-speed digital filter technology made high dynamic range adaptive canceling possible in a bandwidth as large as a few megahertz, finally opening the door to application in radio astronomy. We have

  1. The history of early low frequency radio astronomy in Australia. 2: Tasmania

    Science.gov (United States)

    George, Martin; Orchiston, Wayne; Slee, Bruce; Wielebinski, Richard

    2015-03-01

    Significant contributions to low frequency radio astronomy were made in the Australian state of Tasmania after the arrival of Grote Reber in 1954. Initially, Reber teamed with Graeme Ellis, who was then working with the Ionospheric Prediction Service, and they carried out observations as low as 0.52 MHz during the 1955 period of exceptionally low sunspot activity. In the early 1960s, Reber established a 2.085 MHz array in the southern central region of the State and used this to make the first map of the southern sky at this frequency. In addition, in the 1960s the University of Tasmania constructed several low frequency arrays near Hobart, including a 609m × 609m array designed for operation between about 2 MHz and 20 MHz. In this paper we present an overview of the history of low frequency radio astronomy in Tasmania.

  2. Explosive and radio-selected Transients: Transient Astronomy with SKA and its Precursors

    CERN Document Server

    Chandra, Poonam; Arun, K G; Iyyani, Shabnam; Misra, Kuntal; Narasimha, D; Ray, Alak; Roy, Subhashis; Sutaria, Firoza

    2016-01-01

    With the high sensitivity and wide-field coverage of the Square Kilometre Array (SKA), large samples of explosive transients are expected to be discovered. Radio wavelengths, especially in commensal survey mode, are particularly well suited for uncovering the complex transient phenomena. This is because observations at radio wavelengths may suffer less obscuration than in other bands (e.g. optical/IR or X-rays) due to dust absorption. At the same time, multiwaveband information often provides critical source classification rapidly than possible with only radio band data. Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of gamma ray bursts (GRBs) with SKA will uncover not only much fainter bursts and verifying claims of sensitivity limited population versus intrinsically dim GRBs, they will also unravel the enigmatic po...

  3. Workshop on Satellite Power Systems (SPS) effects on optical and radio astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, G.M.; Ekstrom, P.A. (eds.)

    1980-04-01

    The impacts of the SPS on astronomy were concluded to be: increased sky brightness, reducing the effective aperture of terrestrial telescopes; microwave leakage radiation causing erroneous radioastronomical signals; direct overload of radioastronomical receivers at centimeter wavelengths; and unintentional radio emissions associated with massive amounts of microwave power or with the presence of large, warm structures in orbit causing the satellites to appear as individual stationary radio sources; finally, the fixed location of the geostationary satellite orbits would result in fixed regions of the sky being unusable for observations. (GHT)

  4. First Radio Astronomy Examination of the Low-Frequency Broadband Active Antenna Subarray

    Directory of Open Access Journals (Sweden)

    A. A. Stanislavsky

    2014-01-01

    Full Text Available We present the 25-element active antenna array and its remote control in the framework of the GURT project, the Ukrainian Radio Telescope of a new age. To implement beamforming, the array is phased with the help of discrete cable delay lines in analog manner. The remote control of the array is carried out through the paired encoder and decoder that can transmit parallel data about antenna codes serially. The microcontroller provides the online interaction between personal computer and beamformers with the help of the encoder-decoder system through wires or wireless. The antenna pattern has been measured by radio astronomy methods.

  5. Remote Sensing of the Heliospheric Solar Wind using Radio Astronomy Methods and Numerical Simulations

    Indian Academy of Sciences (India)

    S. Ananthakrishnan

    2000-09-01

    The ground-based radio astronomy method of interplanetary scintillations (IPS) and spacecraft observations have shown, in the past 25 years, that while coronal holes give rise to stable, recurring high speed solar wind streams during the minimum of the solar activity cycle, the slow speed wind seen more during the solar maximum activity is better associated with the closed field regions, which also give rise to solar flares and coronal mass ejections (CME's). The latter events increase significantly, as the cycle maximum takes place. We have recently shown that in the case of energetic flares one may be able to track the associated disturbances almost on a one to one basis from a distance of 0.2 to 1 AU using IPS methods. Time dependent 3D MHD models which are constrained by IPS observations are being developed. These models are able to simulate general features of the solar-generated disturbances. Advances in this direction may lead to prediction of heliospheric propagation of these disturbances throughout the solar system.

  6. Low-Power Architectures for Large Radio Astronomy Correlators

    Science.gov (United States)

    D'Addario, Larry R.

    2011-01-01

    The architecture of a cross-correlator for a synthesis radio telescope with N greater than 1000 antennas is studied with the objective of minimizing power consumption. It is found that the optimum architecture minimizes memory operations, and this implies preference for a matrix structure over a pipeline structure and avoiding the use of memory banks as accumulation registers when sharing multiply-accumulators among baselines. A straw-man design for N = 2000 and bandwidth of 1 GHz, based on ASICs fabricated in a 90 nm CMOS process, is presented. The cross-correlator proper (excluding per-antenna processing) is estimated to consume less than 35 kW.

  7. Distributed image reconstruction for very large arrays in radio astronomy

    CERN Document Server

    Ferrari, André; Flamary, Rémi; Richard, Cédric

    2015-01-01

    Current and future radio interferometric arrays such as LOFAR and SKA are characterized by a paradox. Their large number of receptors (up to millions) allow theoretically unprecedented high imaging resolution. In the same time, the ultra massive amounts of samples makes the data transfer and computational loads (correlation and calibration) order of magnitudes too high to allow any currently existing image reconstruction algorithm to achieve, or even approach, the theoretical resolution. We investigate here decentralized and distributed image reconstruction strategies which select, transfer and process only a fraction of the total data. The loss in MSE incurred by the proposed approach is evaluated theoretically and numerically on simple test cases.

  8. Low-Power Architectures for Large Radio Astronomy Correlators

    Science.gov (United States)

    D'Addario, Larry R.

    2011-01-01

    The architecture of a cross-correlator for a synthesis radio telescope with N greater than 1000 antennas is studied with the objective of minimizing power consumption. It is found that the optimum architecture minimizes memory operations, and this implies preference for a matrix structure over a pipeline structure and avoiding the use of memory banks as accumulation registers when sharing multiply-accumulators among baselines. A straw-man design for N = 2000 and bandwidth of 1 GHz, based on ASICs fabricated in a 90 nm CMOS process, is presented. The cross-correlator proper (excluding per-antenna processing) is estimated to consume less than 35 kW.

  9. Scientific Visualization of Radio Astronomy Data using Gesture Interaction

    Science.gov (United States)

    Mulumba, P.; Gain, J.; Marais, P.; Woudt, P.

    2015-09-01

    MeerKAT in South Africa (Meer = More Karoo Array Telescope) will require software to help visualize, interpret and interact with multidimensional data. While visualization of multi-dimensional data is a well explored topic, little work has been published on the design of intuitive interfaces to such systems. More specifically, the use of non-traditional interfaces (such as motion tracking and multi-touch) has not been widely investigated within the context of visualizing astronomy data. We hypothesize that a natural user interface would allow for easier data exploration which would in turn lead to certain kinds of visualizations (volumetric, multidimensional). To this end, we have developed a multi-platform scientific visualization system for FITS spectral data cubes using VTK (Visualization Toolkit) and a natural user interface to explore the interaction between a gesture input device and multidimensional data space. Our system supports visual transformations (translation, rotation and scaling) as well as sub-volume extraction and arbitrary slicing of 3D volumetric data. These tasks were implemented across three prototypes aimed at exploring different interaction strategies: standard (mouse/keyboard) interaction, volumetric gesture tracking (Leap Motion controller) and multi-touch interaction (multi-touch monitor). A Heuristic Evaluation revealed that the volumetric gesture tracking prototype shows great promise for interfacing with the depth component (z-axis) of 3D volumetric space across multiple transformations. However, this is limited by users needing to remember the required gestures. In comparison, the touch-based gesture navigation is typically more familiar to users as these gestures were engineered from standard multi-touch actions. Future work will address a complete usability test to evaluate and compare the different interaction modalities against the different visualization tasks.

  10. Accelerating Radio Astronomy Cross-Correlation with Graphics Processing Units

    CERN Document Server

    Clark, M A; Greenhill, L J

    2011-01-01

    We present a highly parallel implementation of the cross-correlation of time-series data using graphics processing units (GPUs), which is scalable to hundreds of independent inputs and suitable for the processing of signals from "Large-N" arrays of many radio antennas. The computational part of the algorithm, the X-engine, is implementated efficiently on Nvidia's Fermi architecture, sustaining up to 79% of the peak single precision floating-point throughput. We compare performance obtained for hardware- and software-managed caches, observing significantly better performance for the latter. The high performance reported involves use of a multi-level data tiling strategy in memory and use of a pipelined algorithm with simultaneous computation and transfer of data from host to device memory. The speed of code development, flexibility, and low cost of the GPU implementations compared to ASIC and FPGA implementations have the potential to greatly shorten the cycle of correlator development and deployment, for case...

  11. Enhancing the Radio Astronomy Capabilities at NASA's Deep Space Network

    Science.gov (United States)

    Lazio, Joseph; Teitelbaum, Lawrence; Franco, Manuel M.; Garcia-Miro, Cristina; Horiuchi, Shinji; Jacobs, Christopher; Kuiper, Thomas; Majid, Walid

    2015-08-01

    NASA's Deep Space Network (DSN) is well known for its role in commanding and communicating with spacecraft across the solar system that produce a steady stream of new discoveries in Astrophysics, Heliophysics, and Planetary Science. Equipped with a number of large antennas distributed across the world, the DSN also has a history of contributing to a number of leading radio astronomical projects. This paper summarizes a number of enhancements that are being implemented currently and that are aimed at increasing its capabilities to engage in a wide range of science observations. These enhancements include* A dual-beam system operating between 18 and 27 GHz (~ 1 cm) capable of conducting a variety of molecular line observations, searches for pulsars in the Galactic center, and continuum flux density (photometry) of objects such as nearby protoplanetary disks* Enhanced spectroscopy and pulsar processing backends for use at 1.4--1.9 GHz (20 cm), 18--27 GHz (1 cm), and 38--50 GHz (0.7 cm)* The DSN Transient Observatory (DTN), an automated, non-invasive backend for transient searching* Larger bandwidths (>= 0.5 GHz) for pulsar searching and timing; and* Improved data rates (2048 Mbps) and better instrumental response for very long baseline interferometric (VLBI) observations with the new DSN VLBI processor (DVP), which is providing unprecedented sensitivity for maintenance of the International Celestial Reference Frame (ICRF) and development of future versions.One of the results of these improvements is that the 70~m Deep Space Station 43 (DSS-43, Tidbinbilla antenna) is now the most sensitive radio antenna in the southern hemisphere. Proposals to use these systems are accepted from the international community.Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics & Space Administration.

  12. Surface Accuracy and Pointing Error Prediction of a 32 m Diameter Class Radio Astronomy Telescope

    Science.gov (United States)

    Azankpo, Severin

    2017-03-01

    The African Very-long-baseline interferometry Network (AVN) is a joint project between South Africa and eight partner African countries aimed at establishing a VLBI (Very-Long-Baseline Interferometry) capable network of radio telescopes across the African continent. An existing structure that is earmarked for this project, is a 32 m diameter antenna located in Ghana that has become obsolete due to advances in telecommunication. The first phase of the conversion of this Ghana antenna into a radio astronomy telescope is to upgrade the antenna to observe at 5 GHz to 6.7 GHz frequency and then later to 18 GHz within a required performing tolerance. The surface and pointing accuracies for a radio telescope are much more stringent than that of a telecommunication antenna. The mechanical pointing accuracy of such telescopes is influenced by factors such as mechanical alignment, structural deformation, and servo drive train errors. The current research investigates the numerical simulation of the surface and pointing accuracies of the Ghana 32 m diameter radio astronomy telescope due to its structural deformation mainly influenced by gravity, wind and thermal loads.

  13. The road to OLFAR - a roadmap to interferometric long-wavelength radio astronomy using miniaturized distributed space systems

    NARCIS (Netherlands)

    Engelen, Steven; Quillien, Kevin A.; Verhoeven, Chris; Noroozi, Arash; Sundaramoorthy, Prem; Veen, van der Alle-Jan; Rajan, Raj Thilak; Boonstra, Albert-Jan; Bentum, Mark; Meijerink, Arjan; Budianu, Alex

    2013-01-01

    The Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR) project aims to develop a space-based low frequency radio telescope that will explore the universe's so-called dark ages, map the interstellar medium, and discover planetary and solar bursts in other solar systems. The telescope, compos

  14. The road to OLFAR - a roadmap to interferometric long-wavelength radio astronomy using miniaturized distributed space systems

    NARCIS (Netherlands)

    Engelen, Steven; Quillien, Kevin A.; Verhoeven, Chris; Noroozi, Arash; Sundaramoorthy, Prem; van der Veen, Alle-Jan; Rajan, Raj; Rajan, Raj Thilak; Boonstra, Albert Jan; Bentum, Marinus Jan; Meijerink, Arjan; Budianu, A.

    2013-01-01

    The Orbiting Low Frequency Antennas for Radio Astronomy (OLFAR) project aims to develop a space-based low frequency radio telescope that will explore the universe's so-called dark ages, map the interstellar medium, and discover planetary and solar bursts in other solar systems. The telescope,

  15. Tether enabled spacecraft systems for ultra long wavelength radio astronomy

    Science.gov (United States)

    Gemmer, Thomas; Yoder, Christopher D.; Reedy, Jacob; Mazzoleni, Andre P.

    2017-09-01

    This paper describes a proposed CubeSat mission to perform unique experiments involving interferometry and tether dynamics. A 3U CubeSat is to be placed in orbit where it will separate into three 1U CubeSats connected by a total of 100 m of tether. The separation between the three units will allow for the demonstration of high resolution radio interferometry. The increased resolution will provide access to the Ultra-Long Wavelength (ULW) scale of the electromagnetic spectrum, which is largely unexplored. During and after completion of the primary experiment, the CubeSat will be able to gather data on tethered dynamics of a space vehicle. Maneuvers to be performed and studied include direct testing of tether deployment and tethered formation flying. Tether deployment is a vital area where more data is needed as this is the phase where many tethered missions have experienced complications and failures. There are a large number of complex dynamical responses predicted by the theory associated with the deployment of an orbiting tethered system. Therefore, it is imperative to conduct an experiment that provides data on what dynamic responses actually occur.

  16. The Contribution of an Experimental WWII Radar Antenna to Australian Radio Astronomy

    Science.gov (United States)

    Orchiston, Wayne; Wendt, H.

    2011-01-01

    During the late 1940s and throughout the1950s Australia was one of the world's foremost astronomical nations owing primarily to the dynamic Radio Astronomy Group within the Commonwealth Scientific and Industrial Organisation's Division of Radiophysics. The earliest celestial observations were made with former WWII radar antennas and simple Yagi aerials, before more sophisticated purpose-built radio telescopes of various types were designed and developed. One of the recycled WWII antennas that was used extensively for pioneering radio astronomical research was an experimental radar antenna that initially was located at the Division's short-lived Georges Heights field station but in 1948 was relocated to the new Potts Hill field station in suburban Sydney. In this paper we describe this unique antenna, and discuss the wide-ranging solar, Galactic and extragalactic research programs that it was used for.

  17. Prototyping scalable digital signal processing systems for radio astronomy using dataflow models

    CERN Document Server

    Sane, Nimish; Harris, Andrew I; Bhattacharyya, Shuvra S

    2012-01-01

    There is a growing trend toward using high-level tools for design and implementation of radio astronomy digital signal processing (DSP) systems. Such tools, for example, those from the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER), are usually platform-specific, and lack high-level, platform-independent, portable, scalable application specifications. This limits the designer's ability to experiment with designs at a high-level of abstraction and early in the development cycle. We address some of these issues using a model-based design approach employing dataflow models. We demonstrate this approach by applying it to the design of a tunable digital downconverter (TDD) used for narrow-bandwidth spectroscopy. Our design is targeted toward an FPGA platform, called the Interconnect Break-out Board (IBOB), that is available from the CASPER. We use the term TDD to refer to a digital downconverter for which the decmation factor and center frequency can be reconfigured without the nee...

  18. DSN radio science system description and requirements. [for satellite radio astronomy experiments

    Science.gov (United States)

    Mulhall, B. D. L.

    1977-01-01

    The data system created to collect the functions performed by the Deep Space Network in support of spacecraft radio science experiments is described. Some of the major functional requirements presently being considered for the system are delineated.

  19. DSN radio science system description and requirements. [for satellite radio astronomy experiments

    Science.gov (United States)

    Mulhall, B. D. L.

    1977-01-01

    The data system created to collect the functions performed by the Deep Space Network in support of spacecraft radio science experiments is described. Some of the major functional requirements presently being considered for the system are delineated.

  20. Educational Programs for Graduate Level Learners and Professionals - National Radio Astronomy Observatory National and International Non-Traditional Exchange Program

    Science.gov (United States)

    Wingate, Lory Mitchell

    2017-01-01

    The National Radio Astronomy Observatory’s (NRAO) National and International Non-Traditional Exchange (NINE) Program teaches concepts of project management and systems engineering to chosen participants within a nine-week program held at NRAO in New Mexico. Participants are typically graduate level students or professionals. Participation in the NINE Program is through a competitive process. The program includes a hands-on service project designed to increase the participants knowledge of radio astronomy. The approach demonstrate clearly to the learner the positive net effects of following methodical approaches to achieving optimal science results.The NINE teaches participants important sustainable skills associated with constructing, operating and maintaining radio astronomy observatories. NINE Program learners are expected to return to their host sites and implement the program in their own location as a NINE Hub. This requires forming a committed relationship (through a formal Letter of Agreement), establishing a site location, and developing a program that takes into consideration the needs of the community they represent. The anticipated outcome of this program is worldwide partnerships with fast growing radio astronomy communities designed to facilitate the exchange of staff and the mentoring of under-represented groups of learners, thereby developing a strong pipeline of global talent to construct, operate and maintain radio astronomy observatories.

  1. Inspiring the next generation of scientists with their observations of quasars, black holes, Jupiter, and SETI with the Goldstone Apple Valley Radio Telescope, GAVRT

    Science.gov (United States)

    Jauncey, D. L.; Levin, S.; Teitelbaum, L.; Hofstadter, M.; Arballo, J.; McConnell, S.; Dorcey, R.; Cole, K.; Kreuser-Jenkins, N.; Leflang, J.; Kruzins, E.; Ricardo, L.; Horiuchi, S.; Nagle, G.; Miro, C. G.

    2017-04-01

    This paper describes a radio astronomy programfor schools, the Goldstone-AppleValley Radio Telescope,GAVRT. The GAVRT program is designed to bring the inspiration and enthusiasm to a younger generation of teachers and children who learn about science by doing real science, just as Iosif Shklovsky brought to an older generation.

  2. Radio lighting based on dynamic chaos generators

    CERN Document Server

    Dmitriev, Alexander; Gerasimov, Mark; Itskov, Vadim

    2016-01-01

    A problem of lighting objects and surfaces with artificial sources of noncoherent microwave radiation with the aim to observe them using radiometric equipment is considered. Transmitters based on dynamic chaos generators are used as sources of noncoherent wideband microwave radiation. An experimental sample of such a device, i.e., a radio lighting lamp based on a chaos microgenerator and its performance are presented.

  3. The Pushchino Radio Astronomy Observatory of the P N Lebedev Physical Institute Astro Space Center: yesterday, today, and tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Dagkesamanskii, Rustam D [Pushchino Radio Astronomy Observatory, Astro Space Center, Lebedev Physical Institute, Russian Academy of Sciences, Pushchino, Moscow region (Russian Federation)

    2009-11-30

    The development of Russian (formerly Soviet) radio astronomy is indissolubly linked with the P N Lebedev Physical Institute (LPI), Russian Academy of Sciences. From the late 1940s, the institute conducted most of its radio astronomy research in the Crimea, at stations or on field trips; in the late 1950s, the center of gravity of research moved to the southern Moscow region, where one of the largest radio astronomy observatories in the country and in the world was developed within less than twenty years. The observatory unique instrumentation system is briefly reviewed in a historical perspective. Key research areas and some major achievements are outlined, and the prospects of the observatory as (currently) part of the LPI Astro Space Center are examined. (conferences and symposia)

  4. The Allen Telescope Array: The First Widefield, Panchromatic, Snapshot Radio Camera for Radio Astronomy and SETI

    CERN Document Server

    Welch, Jack; Blitz, Leo; Bock, Douglas; Bower, Geoffrey C; Cheng, Calvin; Croft, Steve; Dexter, Matt; Engargiola, Greg; Fields, Ed; Forster, James; Gutierrez-Kraybill, Colby; Heiles, Carl; Helfer, Tamara; Jorgensen, Susanne; Keating, Garrett; Lugten, John; MacMahon, Dave; Milgrome, Oren; Thornton, Douglas; Urry, Lynn; van Leeuwen, Joeri; Werthimer, Dan; Williams, Peter H; Tarter, Melvin Wright Jill; Ackermann, Robert; Atkinson, Shannon; Backus, Peter; Barott, William; Bradford, Tucker; Davis, Michael; DeBoer, Dave; Dreher, John; Harp, Gerry; Jordan, Jane; Kilsdonk, Tom; Pierson, Tom; Randall, Karen; Ross, John; Fleming, Seth Shostak Matt; Cork, Chris; Wadefalk, Artyom Vitouchkine Niklas; Weinreb, Sander

    2009-01-01

    The first 42 elements of the Allen Telescope Array (ATA-42) are beginning to deliver data at the Hat Creek Radio Observatory in Northern California. Scientists and engineers are actively exploiting all of the flexibility designed into this innovative instrument for simultaneously conducting surveys of the astrophysical sky and conducting searches for distant technological civilizations. This paper summarizes the design elements of the ATA, the cost savings made possible by the use of COTS components, and the cost/performance trades that eventually enabled this first snapshot radio camera. The fundamental scientific program of this new telescope is varied and exciting; some of the first astronomical results will be discussed.

  5. Recollections of Tucson Operations The Millimeter-Wave Observatory of the National Radio Astronomy Observatory

    CERN Document Server

    Gordon, M A

    2005-01-01

    This book is a personal account of the evolution of millimeter-wave astronomy at the National Radio Astronomy Observatory. It begins with the construction of the hugely successful, but flawed, 36 ft radio telescope on Kitt Peak, Arizona, and continues through the funding of its ultimate successor, the Atacama Large Millimeter-wave Array (ALMA), being constructed on a 5.000 m (16.500 ft) site in northern Chile. The book describes the behind-the-scene activities of the NRAO Tucson staff. These include the identification and solution of technical problems, the scheduling and support of visiting astronomers, and the preparations and the politics of the proposal to replace the 36 ft telescope with a 25 m telescope on Mauna Kea, Hawaii. The book also describes the installation of a new 12 m surface and the involvement of the Tucson staff in the ALMA project. Finally, it describes events leading to the closing of the 36 ft telescope and, eventually, of the NRAO offices in Tucson.

  6. Radio astronomy with the Lunar Lander: opening up the last unexplored frequency regime

    CERN Document Server

    Wolt, Marc Klein; Zarka, Philippe; Schrader, Jan-Rutger; Boonstra, Albert-Jan; Falcke, Heino

    2012-01-01

    The active broadband (1 kHz-100 MHz) tripole antenna now envisaged to be placed on the European Lunar Lander located at the Lunar South Pole allows for sensitive measurements of the exosphere and ionosphere, and their interaction with the Earths magnetosphere, solar particles, wind and CMEs and studies of radio communication on the moon, that are essential for future lunar human and science exploration. In addition, the lunar South pole provides an excellent opportunity for radio astronomy. Placing a single radio antenna in an eternally dark crater or behind a mountain at the south (or north) pole would potentially provide perfect shielding from man-made radio interference (RFI), absence of ionospheric distortions, and high temperature and antenna gain stability that allows detection of the 21 cm wave emission from pristine hydrogen formed after the big bang and into the period where the first stars formed. A detection of the 21 cm line from the moon at these frequencies would allow for the first time a clue ...

  7. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors

    Indian Academy of Sciences (India)

    Poonam Chandra; G. C. Anupama; K. G. Arun; Shabnam Iyyani; Kuntal Misra; D. Narasimha; Alak Ray; L. Resmi; Subhashis Roy; Firoza Sutaria

    2016-12-01

    With the high sensitivity and wide-field coverage of the Square Kilometre Array (SKA), large samples of explosive transients are expected to be discovered. Radio wavelengths, especially in commensal survey mode, are particularly well-suited for uncovering the complex transient phenomena. This is because observations at radio wavelengths may suffer less obscuration than in other bands (e.g. optical/IR or X-rays) due to dust absorption. At the same time, multiwaveband information often provides critical source classification rapidly than possible with only radio band data. Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of Gamma Ray Bursts (GRBs) with SKA will uncover not only much fainter bursts and verifying claims of sensitivity-limited population versus intrinsically dim GRBs, they will also unravel the enigmatic population of orphan afterglows. The supernova rate problem caused by dust extinction in optical bands is expected to be lifted in the SKA era. In addition, the debate of single degenerate scenario versus double degenerate scenario will be put to rest for the progenitors of thermonuclear supernovae, since highly sensitive measurements will lead to very accurate mass loss estimation in these supernovae. One also expects to detect gravitationally lensed supernovae in far away Universe in the SKA bands. Radio counterparts of the gravitational waves are likely to become a reality once SKA comes online. In addition, SKA is likely to discover various new kinds of transients.

  8. Astronomy

    CERN Document Server

    Seymour, Percy

    2014-01-01

    With a blend of exciting discoveries and important scientific theory,this innovative and readable introduction to astronomy is ideal for anyone who wants to understand what we know about the universe,and how we know it. Each chapter starts with details of a method of jow astronomers over time have observed the world,and then uses this as a springboard to discuss what they discovered,and why this was important for understanding the cosmos. The last chapter,on dark matter,also focuses on the many things we don''t yet know - reminding us that astronomy,like this book,is a fast-paced and fascinati

  9. Supermassive black hole binaries and transient radio events: studies in pulsar astronomy

    Science.gov (United States)

    Burke-Spolaor, S.

    2011-06-01

    The field of pulsar astronomy encompasses a rich breadth of astrophysical topics. The research in this thesis contributes to two particular subjects of pulsar astronomy: gravitational wave science, and identifying celestial sources of pulsed radio emission. We first investigated the detection of supermassive black hole (SMBH) binaries, which are the brightest expected source of gravitational waves for pulsar timing. We considered whether two electromagnetic SMBH tracers, velocity-resolved emission lines in active nuclei, and radio galactic nuclei with spatially-resolved, flat-spectrum cores, can reveal systems emitting gravitational waves in the pulsar timing band. We found that there are systems which may in principle be simultaneously detectable by both an electromagnetic signature and gravitational emission, however the probability of actually identifying such a system is low (they will represent much less than 1% of a randomly selected galactic nucleus sample). This study accents the fact that electromagnetic indicators may be used to explore binary populations down to the 'stalling radii' at which binary inspiral evolution may stall indefinitely at radii exceeding those which produce gravitational radiation in the pulsar timing band. We then performed a search for binary SMBH holes in archival Very Long Baseline Interferometry data for 3114 radio-luminous active galactic nuclei. One source was detected as a double nucleus. This result is interpreted in terms of post-merger timescales for SMBH centralisation, implications for 'stalling', and the relationship of radio activity in nuclei to mergers. Our analysis suggested that binary pair evolution of SMBHs (both of masses >108M circled bullet) spends less than 500Myr in progression from the merging of galactic stellar cores to within the purported stalling radius for SMBH pairs, giving no evidence for an excess of stalled binary systems at small separations. Circumstantial evidence showed that the relative state

  10. A 23 GHz high-temperature superconducting microstrip filter for radio astronomy

    Institute of Scientific and Technical Information of China (English)

    GAO Lu; GUO Jin; WANG YueHui; YU Tao; ZHANG Qiang; LI ChunGuang; ZHANG XueQiang; LI Hong; LI JunJie; LI WuXia; GU ChangZhi; MENG JiBao; FENG Ji; HE YuSheng

    2009-01-01

    This paper reports a 6-pole high-temperature superconducting (HTS) microstrip bandpass filter for radio astronomy applications. The filter has a center frequency of 23 GHz and a bandwidth the 2 GHz. We have made many efforts, such as adopting 0.25-mm-thick substrate, carefully designing the housing box and filter layout, to solve the problems in realizing a K-band planar filter. A special straight-line half-wavelength resonator (center-widen resonator) was also designed to reduce the insertion loss of the filter. The measured results showed a midband insertion loss of 0.11 dB with a ripple of 0.4 dB, and a return loss better than 11.5 dB. Good agreement was obtained between simulated and measured re-suits.

  11. Development of an Experimental Phased Array Feed System and Algorithms for Radio Astronomy

    Science.gov (United States)

    Landon, Jonathan C.

    Phased array feeds (PAFs) are a promising new technology for astronomical radio telescopes. While PAFs have been used in other fields, the demanding sensitivity and calibration requirements in astronomy present unique new challenges. This dissertation presents some of the first astronomical PAF results demonstrating the lowest noise temperature and highest sensitivity at the time (66 Kelvin and 3.3 m^2/K, respectively), obtained using a narrowband (425 kHz bandwidth)prototype array of 19 linear co-polarized L-band dipoles mounted at the focus of the Green Bank 20 Meter Telescope at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia. Results include spectral line detection of hydroxyl (OH) sources W49N and W3OH, and some of the first radio camera images made using a PAF, including an image of the Cygnus X region. A novel array Y-factor technique for measuring the isotropic noise response of the array is shown along with experimental measurements for this PAF. Statistically optimal beamformers (Maximum SNR and MVDR) are used throughout the work. Radio-frequency interference (RFI) mitigation is demonstrated experimentally using spatial cancelation with the PAF. Improved RFI mitigation is achieved in the challenging cases of low interference-to-noise ratio (INR) and moving interference by combining subspace projection (SP) beamforming with a polynomial model to track a rank 1 subspace. Limiting factors in SP are investigated including sample estimation error, subspace smearing, noise bias, and spectral scooping; each of these factors is overcome with the polynomial model and prewhitening. Numerical optimization leads to the polynomial subspace projection (PSP) method, and least-squares fitting to the series of dominant eigenvectors over a series of short term integrations (STIs) leads to the eigenvector polynomial subspace projection (EPSP) method. Expressions for the gradient, Hessian, and Jacobian are given for use in numerical optimization

  12. Improvements to Host Country Radio Astronomy at Robledo: Another antenna, a new receiver, a new backend

    Science.gov (United States)

    Rizzo, J. R.; García-Miró, G.

    2013-05-01

    NASA hosts three complexes worldwide built for spacecraft tracking, whose sensitive antennas are suitable for radio astronomy. Since more than a decade, INTA has managed guaranteed Spanish time at the complex located in Robledo de Chavela, in the frame of the Host Country Radio Astronomy (HCRA) program. Until now, the vast majority of the scientific results were achieved using a K-band (18 to 26 GHz) receiver, attached to the 70m antenna, and a narrow-band autocorrelator. In the recent years, we have undertaken two large instrumental projects: (1) the incorporation of a second antenna (34m in diameter), working in Q-band (38 to 50 GHz); and (2) the design and construction of a wideband backend, which may operate with both the Q- and K-band receivers, providing instantaneous bandwidths from 100 MHz to 6 GHz, and resolutions from 6 to 200 kHz. The new wideband backend is expanding the HCRA possibilities due its bandwidth, versatility, spectral resolution and stability of the baselines. Its IF processor splits each of the two circular-polarization signals, and downconverts them to four base-band channels, 1.5 GHz width. Two different frequencies may be tuned independently. Digitalisation is done through FPGA-based FFT spectrometers, which may be independently configured. Once end-to-end assembled, the commissioning of the new backend was done using the 34m antenna in Q-band. We report the main characteristics of both the antenna recently incorporated to HCRA, and the wideband backend.

  13. PULSE@Parkes, Engaging Students through Hands-On Radio Astronomy

    Science.gov (United States)

    Hollow, Robert; Hobbs, George; Shannon, Ryan M.; Kerr, Matthew

    2015-08-01

    PULSE@Parkes is an innovative, free educational program run by CSIRO Astronomy and Space Science (CASS) in which high school students use the 64m Parkes radio telescope remotely in real time to observe pulsars then analyse their data. The program caters for a range of student ability and introduces students to hands-on observing and radio astronomy. Students are guided by professional astronomers, educators and PhD students during an observing session. They have ample time to interact with the scientists and discuss astronomy, careers and general scientific questions. Students use a web-based module to analyse pulsar properties. All data from the program are streamed via a web browser and are freely available from the online archive and may be used for open-ended student investigations. The data are also used by the team for ongoing pulsar studies with two scientific papers published to date.Over 100 sessions have been held so far. Most sessions are held at CASS headquarters in Sydney, Australia but other sessions are regularly held in other states with partner institutions. The flexibility of the program means that it is also possible to run sessions in other countries. This aspect of the program is useful for demonstrating capability, engaging students in diverse settings and fostering collaborations. The use of Twitter (@pulseatparkes) during allows followers worldwide to participate and ask questions.Two tours of Japan plus sessions in the UK, Netherlands and Canada have reached a wide audience. Plans for collaborations in China are well underway with the possibility of use with other countries also being explored. The program has also been successfully used in helping to train international graduate students via the International Pulsar Timing Array Schools. We have identified strong demand and need for programs such as this for training undergraduate students in Asia and the North America in observing and data analysis techniques so one area of planned

  14. New Mexico Fiber-Optic Link Marks Giant Leap Toward Future of Radio Astronomy

    Science.gov (United States)

    1998-12-01

    SOCORRO, NM -- Scientists and engineers at the National Radio Astronomy Observatory (NRAO) have made a giant leap toward the future of radio astronomy by successfully utilizing the Very Large Array (VLA) radio telescope in conjunction with an antenna of the continent-wide Very Long Baseline Array (VLBA) using the longest fiber-optic data link ever demonstrated in radio astronomy. The 65-mile fiber link will allow scientists to use the two National Science Foundation (NSF) facilities together in real time, and is the first step toward expanding the VLA to include eight proposed new radio-telescope antennas throughout New Mexico. LEFT: Miller Goss, NRAO's director of VLA/VLBA Operations, unveils graphic showing success of the Pie Town-VLA fiber link. The project, funded by the NSF and Associated Universities, Inc. (AUI), which operates NRAO for the NSF, links the VLA and the VLBA antenna in Pie Town, NM, using a Western New Mexico Telephone Co. fiber-optic cable. The successful hookup was announced at a ceremony that also marked the 10th anniversary of NRAO's Operations Center in Socorro. "Linking the Pie Town antenna to the VLA quadruples the VLA's ability to make detailed images of astronomical objects," said Paul Vanden Bout, NRAO's Director. "This alone makes the link an advance for science, but its greater importance is that it clearly demonstrates the technology for improving the VLA's capabilities even more in the future." "Clearly, the big skies and wide open spaces in New Mexico create near perfect conditions for the incredible astronomical assets located in our state. This new fiber-optic link paves the way for multiplying the already breathtaking scientific capabilities of the VLA," Senator Pete Domenici (R-NM) said. The VLA is a system of 27 radio-telescope antennas distributed over the high desert west of Socorro, NM, in the shape of a giant "Y." Made famous in movies, commercials and numerous published photos, the VLA has been one of the most productive

  15. Astronomy in India a historical perspective

    CERN Document Server

    2014-01-01

    India has a strong and ancient tradition of astronomy, which seamlessly merges with the current activities in Astronomy and Astrophysics in the country. While the younger generation of astronomers and students are reasonably familiar with the current facilities and the astronomical research, they might not have an equally good knowledge of the rich history of Indian astronomy. This particular volume, brought out as a part of the Platinum Jubilee Celebrations of Indian National Science Academy, concentrates on selected aspects of historical development of Indian astronomy in the form of six invited chapters. Two of the chapters – by Balachandra Rao and M.S. Sriram – cover ancient astronomy and the development of calculus in the ancient Kerela text Yuktibhasa. The other four chapters by B.V. Sreekantan, Siraj Hasan, Govind Swarup and Jayant Narlikar deal with the contemporary history of Indian astronomy covering space astronomy, optical astronomy, radio astronomy and developments in relativistic astrophysic...

  16. Advances in Composite Reflectors: From X-Ray to Radio Wave Astronomy

    Science.gov (United States)

    Connell, S. J.; Abusafieh, A. A.; Mehle, G. V.; Sheikh, D. A.; Giles, D. C.

    2000-12-01

    In recent years, Composite Optics, Inc. (COI) has made significant advances in the use of graphite fiber reinforced composite (GFRC) materials for astronomical instrument applications. The inherent low density, high stiffness, and thermal stability makes GFRC a natural candidate for many astronomy applications. In order to reap these inherent benefits in astronomical applications, basic research has focused on material and process improvement. This has been accompanied by the design, fabrication, and test of several prototype reflectors that cover a broad wavelength spectrum of astronomical interests. The results of, and applications for, these efforts are summarized in the following list. X-Ray Carrier Shell: Innovative composite process yields accuracy and moisture stability. Demonstrated by vacuum optical test of 6" Wolter-I shell. Applicable to Con-X, etc. Lightweight Mirror Substrate for Visible Astronomy: Composite/glass hybrid design. Areal density Glass-like coating applied to composite. Polishable by conventional methods. Multiple six-inch substrates polished to 20 angstroms. Technology will enable future 5 kg/m2 visible to UV optics. 10 kg/m2 Submillimeter Reflector: Apertures to 5m possible with economical, all-composite mirror design, diffraction limited at 80 microns. Demonstrated with cryo-optical test (to 70K) of FIRST 2-meter prototype mirror. Applicable to FIRST and other IR astronomy. Large, Ultra-Stable Optical Support Structure: Uniform and near-zero CTE over broad dimensions. Demonstrated with cryo-optical test of 2-meter FIRST prototype. Applicable to NGST, SIM, LISSA. Ground Based Radio Telescope Reflector: Low-cost, accurate, stable, durable all-composite design for support structure & reflective surface. Demonstrated via fab & test of 3m adjustable and 5m static prototypes. Applicable to LMT, ALMA, etc. These recent accomplishments represent new enabling technologies to meet the needs of numerous astronomical instrument concepts. COI will

  17. An amplitude modulated radio frequency plasma generator

    Science.gov (United States)

    Lei, Fan; Li, Xiaoping; Liu, Yanming; Liu, Donglin; Yang, Min; Xie, Kai; Yao, Bo

    2017-04-01

    A glow discharge plasma generator and diagnostic system has been developed to study the effects of rapidly variable plasmas on electromagnetic wave propagation, mimicking the plasma sheath conditions encountered in space vehicle reentry. The plasma chamber is 400 mm in diameter and 240 mm in length, with a 300-mm-diameter unobstructed clear aperture. Electron densities produced are in the mid 1010 electrons/cm3. An 800 W radio frequency (RF) generator is capacitively coupled through an RF matcher to an internally cooled stainless steel electrode to form the plasma. The RF power is amplitude modulated by a waveform generator that operates at different frequencies. The resulting plasma contains electron density modulations caused by the varying power levels. A 10 GHz microwave horn antenna pair situated on opposite sides of the chamber serves as the source and detector of probe radiation. The microwave power feed to the source horn is split and one portion is sent directly to a high-speed recording oscilloscope. On mixing this with the signal from the pickup horn antenna, the plasma-induced phase shift between the two signals gives the path-integrated electron density with its complete time dependent variation. Care is taken to avoid microwave reflections and extensive shielding is in place to minimize electronic pickup. Data clearly show the low frequency modulation of the electron density as well as higher harmonics and plasma fluctuations.

  18. Origins of Radio Astronomy at the Tata Institute of Fundamental Research and the Role of J.L. Pawsey

    CERN Document Server

    Goss, W M

    2014-01-01

    I will discuss the interactions of a number of individuals that played major roles in the formation of radio astronomy in India in the period 1952-1962, particularly Dr. Joseph L. Pawsey. The story began in 1953-1954: Pawsey brought Govind Swarup to Australia as a Colombo Fellow in 1953, where he worked with Christiansen, Mills, Wild and Bolton. Later, Swarup went to Stanford where he completed a PhD with Ron Bracewell working on the new Solar Microwave Spectroheliograph. In the era 1960-1963, with the encouragement of Pawsey, several colleagues in Australia and Bracewell, discussions began among a number of Indian colleagues to form a radio astronomy group in India. The main players were G. Swarup, T.K. Menon, M.R. Kundu and T. Krishnan. Homi J. Bhabha, the Director of TIFR, made the decisive offer to this group to start a radio astronomy project in early 1962. Swarup joined TIFR in early April 1963. Many factors contributed to the successful formation of the new group: international networking among scienti...

  19. Low input reflection cryogenic low noise amplifier for Radio Astronomy multipixel receivers

    Science.gov (United States)

    Amils, R. I.; Gallego, J. D.; Diez, C.; López Fernández, I.; Barcia, A.; Muñoz, S.; Sebastián, J. L.; Malo, I.

    2016-10-01

    The advancement of Radio Astronomy instruments pushes innovation in several fronts. Sensitivity aside, one way in which cryogenic receivers can be upgraded is by increasing the number of beams in single dish antennas, building what is commonly known as a Focal Plane Array (FPA). In this paper we present a novel reduced input reflection 4-12 GHz cryogenic Low Noise Amplifier (LNA) for the Intermediate Frequency (IF) of millimeter wave superheterodyne multipixel receivers with Superconductor-Insulator-Superconductor (SIS) mixers. The aim of this development is to reduce the input reflection of the amplifier to a level at which the bulky cryogenic isolators traditionally used in this type of receivers are no longer necessary and can be avoided. Ultimately this simplification would allow complying with the tight mass and volume restrictions imposed over FPAs. However, the improvement of the input reflection has a cost in terms of noise and gain performance. This effect is critically evaluated by comparing it with other alternative options built with devices of the same technology. The results show that this approach may have advantages in terms of sensitivity of the complete receiver.

  20. Inspiring the Next Generation: Astronomy Catalyzes K12 STEM Education

    Science.gov (United States)

    Borders, Kareen; Thaller, Michelle; Winglee, Robert; Borders, Kyla

    2017-06-01

    K-12 educators need effective and relevant astronomy professional development. NASA's Mission Science provides innovative and accessible opportunities for K-12 teachers. Science questions involve scale and distance, including Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers can gain an understanding of basic telescopes, the history of telescopes, ground and satellite based telescopes, and models of JWST Telescope. An in-depth explanation of JWST and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. During teacher training, we taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of lenticulars and diagramming of infrared data, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars.We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development.Funding was provided by Washington STEM, NASA, and the Washington Space Grant Consortium.

  1. MULTI-MESSENGER ASTRONOMY OF GRAVITATIONAL-WAVE SOURCES WITH FLEXIBLE WIDE-AREA RADIO TRANSIENT SURVEYS

    Energy Technology Data Exchange (ETDEWEB)

    Yancey, Cregg C.; Shawhan, Peter [Department of Physics, University of Maryland, College Park, MD 20742 (United States); Bear, Brandon E.; Akukwe, Bernadine; Simonetti, John H.; Tsai, Jr-Wei [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Chen, Kevin [Department of Physics, The College of New Jersey, Ewing, NJ 08628 (United States); Dowell, Jayce; Obenberger, Kenneth; Taylor, Gregory B. [Department of Physics and Astronomy, University of New Mexico, Albuquerque NM, 87131 (United States); Gough, Jonathan D. [Department of Chemistry, Lehman College, Bronx, NY 10468 (United States); Kanner, Jonah [LIGO-California Institute of Technology, Pasadena, California CA 91125 (United States); Kavic, Michael [Department of Physics, Long Island University, Brooklyn, NY 11201 (United States)

    2015-10-20

    We explore opportunities for multi-messenger astronomy using gravitational waves (GWs) and prompt, transient low-frequency radio emission to study highly energetic astrophysical events. We review the literature on possible sources of correlated emission of GWs and radio transients, highlighting proposed mechanisms that lead to a short-duration, high-flux radio pulse originating from the merger of two neutron stars or from a superconducting cosmic string cusp. We discuss the detection prospects for each of these mechanisms by low-frequency dipole array instruments such as LWA1, the Low Frequency Array and the Murchison Widefield Array. We find that a broad range of models may be tested by searching for radio pulses that, when de-dispersed, are temporally and spatially coincident with a LIGO/Virgo GW trigger within a ∼30 s time window and ∼200–500 deg{sup 2} sky region. We consider various possible observing strategies and discuss their advantages and disadvantages. Uniquely, for low-frequency radio arrays, dispersion can delay the radio pulse until after low-latency GW data analysis has identified and reported an event candidate, enabling a prompt radio signal to be captured by a deliberately targeted beam. If neutron star mergers do have detectable prompt radio emissions, a coincident search with the GW detector network and low-frequency radio arrays could increase the LIGO/Virgo effective search volume by up to a factor of ∼2. For some models, we also map the parameter space that may be constrained by non-detections.

  2. Gigabit impulse radio UWB signal generation and fiber transmission

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Gibbon, Timothy Braidwood; Yu, Xianbin

    We demonstrate 3.125 Gb/s photonic impulse radio UWB generation using an uncooled distributed feedback laser. After 50km fiber transmission the signal is recovered without errors using a digital signal processing receiver.......We demonstrate 3.125 Gb/s photonic impulse radio UWB generation using an uncooled distributed feedback laser. After 50km fiber transmission the signal is recovered without errors using a digital signal processing receiver....

  3. Design, Environmental and Sustainability Constraints of new African Observatories: The example of the Mozambique Radio Astronomy Observatory

    CERN Document Server

    Barbosa, Domingos; Ribeiro, Valerio A R M; Loots, Anita; Thondikulam, Venkatasubramani L; Gaylard, Michael; van Ardenne, Arnold; Colafrancesco, Sergio; Bergano, Miguel; Amador, Jose Carlos; Maia, Rodrigo; Melo, Rui

    2013-01-01

    The Mozambique Radio Astronomy Observatory (MRAO) will be a first milestone towards development of radioastronomy in Mozambique. Development of MRAO will constitute a preparation step towards participation in the upcoming Africa VLBI Network and the Square Kilometer Array project. The MRAO first antenna is planned to serve as a capacitation and training facility and will be installed after the conversion of a 7-meter telecom dish in South Africa. Therefore, this first radiotelescope design has to comply with local spectral and environmental constraints. Furthermore, power availability and long term sustainability with potential inclusion of solar power and control of Radio Frequency Interference are analyzed. Here we outline some of the design, environmental and power sustainability constraints.

  4. Optimization of Positioning of Interferometric Array Antennas Using Division Algorithm for Radio Astronomy Applications

    Science.gov (United States)

    Kiehbadroudinezhad, Shahideh; Valente, Daniela; Cada, Michael; Kamariah Noordin, Nor; Shahabi, Adib

    2017-10-01

    The Square Kilometre Array (SKA) ushers in the new generation of large radio telescopes that will work at wavelengths between meters and centimeters. In order to competitively design interferometric antenna arrays such as SKA, it is crucial to focus on the optimization of system performance. In this paper, we contribute to the solution by introducing a new optimization algorithm called Division Algorithm (DA). This algorithm finds the optimal positions of antennas to simultaneously maximize u–v coverage and decrease sidelobe level (SLL). The DA is able to optimize the configuration of the interferometric array in both snapshot and Earth rotation synthesis observations. To demonstrate its efficiency, the DA is applied to configure an optimum 30-element array for the Giant Metrewave Radio Telescope. The proposed algorithm is able to improve the overlapped samples parameter by about 4% and the unsampled cells parameter by about 12%, at snapshot observation, compared to the Genetic Algorithm (GA). DA is able to improve these two parameters for a 6-hr tracking observation as well. Finally, the proposed algorithm is compared with the GA for different source declination. Results show that the DA is able to decrease the SLL better than the GA.

  5. ICE-based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    CERN Document Server

    Bandura, Kevin; Dobbs, Matt; Gilbert, Adam; Ittah, David; Parra, Juan Mena; Smecher, Graeme

    2016-01-01

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2048 digitizer inputs across 400~MHz of bandwidth. Measured in $N^2~\\times $ bandwidth, it is the largest radio correlator that has been built. Its digital back-end must exchange and reorganize the 6.6~terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256-node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. `corner-turn'). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct,...

  6. Development of Radio Astronomy at Centre for Basic Space Science Observatory, Nsukka Nigeria

    Science.gov (United States)

    Aliyu, Nasiru; Okere, Bonaventure I.; Lanre, Daniyan O.; Ezechi, Nwachukwu E.

    2015-08-01

    Radio telescopes for research, teaching and learning at Centre for Basic Space Science (CBSS) observatory are currently in place of development. A small parabolic radio telescope with diameter of 3.0 m working at 1420 MHz is already available for general purpose of radio astronomical observations. In addition, a Radio Jove telescope with dual dipole antenna working at 20 MHz and Sudden Ionospheric Disturbance (SID) monitor working at 24 KHz are also available. It is suitable to monitor daily solar burst, solar flares as well as Jupiter decametric emission. More over, CBSS radio interferometers are now under construction. It consists of non-tracking Radio Jove array and SID monitor as well as two radio telescope tracking interferometers. The latter is planned to utilize up to 4 antennas. Multi frequency receivers are made available at 24 KHz, 20 and 1420 MHz and will be used for VLBI in the near future.

  7. ICE-Based Custom Full-Mesh Network for the CHIME High Bandwidth Radio Astronomy Correlator

    Science.gov (United States)

    Bandura, K.; Cliche, J. F.; Dobbs, M. A.; Gilbert, A. J.; Ittah, D.; Mena Parra, J.; Smecher, G.

    New generation radio interferometers encode signals from thousands of antenna feeds across large bandwidth. Channelizing and correlating this data requires networking capabilities that can handle unprecedented data rates with reasonable cost. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) correlator processes 8-bits from N=2,048 digitizer inputs across 400MHz of bandwidth. Measured in N2× bandwidth, it is the largest radio correlator that is currently commissioning. Its digital back-end must exchange and reorganize the 6.6terabit/s produced by its 128 digitizing and channelizing nodes, and feed it to the 256 graphics processing unit (GPU) node spatial correlator in a way that each node obtains data from all digitizer inputs but across a small fraction of the bandwidth (i.e. ‘corner-turn’). In order to maximize performance and reliability of the corner-turn system while minimizing cost, a custom networking solution has been implemented. The system makes use of Field Programmable Gate Array (FPGA) transceivers to implement direct, passive copper, full-mesh, high speed serial connections between sixteen circuit boards in a crate, to exchange data between crates, and to offload the data to a cluster of 256 GPU nodes using standard 10Gbit/s Ethernet links. The GPU nodes complete the corner-turn by combining data from all crates and then computing visibilities. Eye diagrams and frame error counters confirm error-free operation of the corner-turn network in both the currently operating CHIME Pathfinder telescope (a prototype for the full CHIME telescope) and a representative fraction of the full CHIME hardware providing an end-to-end system validation. An analysis of an equivalent corner-turn system built with Ethernet switches instead of custom passive data links is provided.

  8. Peta-Flop Real Time Radio Astronomy Signal Processing Instrumentation and the CASPER Collaboration

    Science.gov (United States)

    Werthimer, Dan

    2014-04-01

    I will briefly describe next generation radio telescopes, such as HERA and the Square Kilometer Array (SKA), which will require 1E15 to 1E17 operations per second of real time processing. I'll present some of the new architectures we've used to develop a variety of heterogeneous FPGA-GPU-CPU based signal processing systems for such telescopes, including spectrometers, correlators, and beam formers. I will also describe the CASPER collaboration, which has developed architectures, open source programming tools, libraries and reference designs that make it relatively easy to develop a variety of scalable, upgradeable, fault tolerant, low power, real time digital signal processing instrumentation. CASPER utilizes commercial 10Gbit and 40 Gbit ethernet switches to interconnect open source general purpose field programmable gate array (FPGA) boards with GPUs and software modules. CASPER collaborators at hundreds of universities, government labs and observatories have used these techniques to rapidly develop and deploy a variety of correlators, beamformers, spectrometers, pulsar/transient machines, and VLBI instrumentation. CASPER instrumentation is also utilized in physics, medicine, genomics and engineering. Open source source hardware, software, libraries, tools, tutorials, reference designs, information about workshops, and how to join the collaboration are available at http://casper.berkeley.edu

  9. Effect of Parasitic Element on 408 MHz Antenna for Radio Astronomy Application

    Directory of Open Access Journals (Sweden)

    Radial Anwar

    2014-01-01

    Full Text Available Antenna is one of the important subsystem components in a radio telescope system. In this paper, analysis on the effect of parasitic element on 408 MHz antenna in a radio telescope system is presented. Higher gain up to 10.24 dBi with reduction on beamwidth size has been achieved by optimizing the position of parasitic element relative to the driven element. The proposed antenna is suitable to be utilized in a transient radio telescope array.

  10. The wideband backend at the MDSCC in Robledo. A new facility for radio astronomy at Q- and K- bands

    CERN Document Server

    Rizzo, J R; Gutiérrez, M; Sotuela, I; Larrañaga, J R; Ojalvo, L; Franco, M; Cernicharo, J; Miró, C García; Cerón, J M Castro; Kuiper, T B H; Vázquez, M; Calvo, J; Baquero, A

    2012-01-01

    The antennas of NASA's Madrid Deep Space Communications Complex (MDSCC) in Robledo de Chavela are available as single-dish radio astronomical facilities during a significant percentage of their operational time. Current instrumentation includes two antennas of 70 and 34 m in diameter, equipped with dual-polarization receivers in K (18 - 26 GHz) and Q (38 - 50 GHz) bands, respectively. We have developed and built a new wideband backend for the Robledo antennas, with the objectives (1) to optimize the available time and enhance the efficiency of radio astronomy in MDSCC; and (2) to tackle new scientific cases impossible to that were investigated with the old, narrow-band autocorrelator. The backend consists of an IF processor, a FFT spectrometer (FFTS), and the software that interfaces and manages the events among the observing program, antenna control, the IF processor, the FFTS operation, and data recording. The whole system was end-to-end assembled in August 2011, at the start of commissioning activities, an...

  11. Characterizing Interference in Radio Astronomy Observations through Active and Unsupervised Learning

    Science.gov (United States)

    Doran, G.

    2013-01-01

    In the process of observing signals from astronomical sources, radio astronomers must mitigate the effects of manmade radio sources such as cell phones, satellites, aircraft, and observatory equipment. Radio frequency interference (RFI) often occurs as short bursts (< 1 ms) across a broad range of frequencies, and can be confused with signals from sources of interest such as pulsars. With ever-increasing volumes of data being produced by observatories, automated strategies are required to detect, classify, and characterize these short "transient" RFI events. We investigate an active learning approach in which an astronomer labels events that are most confusing to a classifier, minimizing the human effort required for classification. We also explore the use of unsupervised clustering techniques, which automatically group events into classes without user input. We apply these techniques to data from the Parkes Multibeam Pulsar Survey to characterize several million detected RFI events from over a thousand hours of observation.

  12. Broadband detuned Sagnac interferometer for future generation gravitational wave astronomy

    CERN Document Server

    Voronchev, N V; Danilishin, S L

    2015-01-01

    Broadband suppression of quantum noise below the Standard Quantum Limit (SQL) becomes a top-priority problem for the future generation of large-scale terrestrial detectors of gravitational waves, as the interferometers of the Advanced LIGO project, predesigned to be quantum-noise-limited in the almost entire detection band, are phased in. To this end, among various proposed methods of quantum noise suppression or signal amplification, the most elaborate approach implies a so-called *xylophone* configuration of two Michelson interferometers, each optimised for its own frequency band, with a combined broadband sensitivity well below the SQL. Albeit ingenious, it is a rather costly solution. We demonstrate that changing the optical scheme to a Sagnac interferometer with weak detuned signal recycling and frequency dependent input squeezing can do almost as good a job, as the xylophone for significantly lower spend. We also show that the Sagnac interferometer is more robust to optical loss in filter cavity, used f...

  13. The modern radio astronomy network in Ukraine: UTR-2, URAN and GURT

    Science.gov (United States)

    Konovalenko, A.; Sodin, L.; Zakharenko, V.; Zarka, P.; Ulyanov, O.; Sidorchuk, M.; Stepkin, S.; Tokarsky, P.; Melnik, V.; Kalinichenko, N.; Stanislavsky, A.; Koliadin, V.; Shepelev, V.; Dorovskyy, V.; Ryabov, V.; Koval, A.; Bubnov, I.; Yerin, S.; Gridin, A.; Kulishenko, V.; Reznichenko, A.; Bortsov, V.; Lisachenko, V.; Reznik, A.; Kvasov, G.; Mukha, D.; Litvinenko, G.; Khristenko, A.; Shevchenko, V. V.; Shevchenko, V. A.; Belov, A.; Rudavin, E.; Vasylieva, I.; Miroshnichenko, A.; Vasilenko, N.; Olyak, M.; Mylostna, K.; Skoryk, A.; Shevtsova, A.; Plakhov, M.; Kravtsov, I.; Volvach, Y.; Lytvinenko, O.; Shevchuk, N.; Zhouk, I.; Bovkun, V.; Antonov, A.; Vavriv, D.; Vinogradov, V.; Kozhin, R.; Kravtsov, A.; Bulakh, E.; Kuzin, A.; Vasilyev, A.; Brazhenko, A.; Vashchishin, R.; Pylaev, O.; Koshovyy, V.; Lozinsky, A.; Ivantyshin, O.; Rucker, H. O.; Panchenko, M.; Fischer, G.; Lecacheux, A.; Denis, L.; Coffre, A.; Grießmeier, J.-M.; Tagger, M.; Girard, J.; Charrier, D.; Briand, C.; Mann, G.

    2016-08-01

    The current status of the large decameter radio telescope UTR-2 (Ukrainian T-shaped Radio telescope) together with its VLBI system called URAN is described in detail. By modernization of these instruments through implementation of novel versatile analog and digital devices as well as new observation techniques, the observational capabilities of UTR-2 have been substantially enhanced. The total effective area of UTR-2 and URAN arrays reaches 200 000 m2, with 24 MHz observational bandwidth (within the 8-32 MHz frequency range), spectral and temporal resolutions down to 4 kHz and 0.5 msec in dynamic spectrum mode or virtually unlimited in waveform mode. Depending on the spectral and temporal resolutions and confusion effects, the sensitivity of UTR-2 varies from a few Jy to a few mJy, and the angular resolution ranges from ~ 30 arcminutes (with a single antenna array) to a few arcseconds (in VLBI mode). In the framework of national and international research projects conducted in recent years, many new results on Solar system objects, the Galaxy and Metagalaxy have been obtained. In order to extend the observation frequency range to 8-80 MHz and enlarge the dimensions of the UTR-2 array, a new instrument - GURT (Giant Ukrainian Radio Telescope) - is now under construction. The radio telescope systems described herein can be used in synergy with other existing low-frequency arrays such as LOFAR, LWA, NenuFAR, as well as provide ground-based support for space-based instruments.

  14. Study of the magnetospheres of active regions on the sun by radio astronomy techniques

    Science.gov (United States)

    Bogod, V. M.; Kal'tman, T. I.; Peterova, N. G.; Yasnov, L. V.

    2017-01-01

    In the 1990s, based on detailed studies of the structure of active regions (AR), the concept of the magnetosphere of the active region was proposed. This includes almost all known structures presented in the active region, ranging from the radio granulation up to noise storms, the radiation of which manifests on the radio waves. The magnetosphere concept, which, from a common point of view, considers the manifestations of the radio emission of the active region as a single active complex, allows one to shed light on the relation between stable and active processes and their interrelations. It is especially important to identify the basic ways of transforming nonthermal energy into thermal energy. A dominant role in all processes is attributed to the magnetic field, the measurement of which on the coronal levels can be performed by radio-astronomical techniques. The extension of the wavelength range and the introduction of new tools and advanced modeling capabilities makes it possible to analyze the physical properties of plasma structures in the AR magnetosphere and to evaluate the coronal magnetic fields at the levels of the chromosphere-corona transition zone and the lower corona. The features and characteristics of the transition region from the S component to the B component have been estimated.

  15. The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy

    Science.gov (United States)

    Yonekura, Yoshinori; Saito, Yu; Sugiyama, Koichiro; Soon, Kang Lou; Momose, Munetake; Yokosawa, Masayoshi; Ogawa, Hideo; Kimura, Kimihiro; Abe, Yasuhiro; Nishimura, Atsushi; Hasegawa, Yutaka; Fujisawa, Kenta; Ohyama, Tomoaki; Kono, Yusuke; Miyamoto, Yusuke; Sawada-Satoh, Satoko; Kobayashi, Hideyuki; Kawaguchi, Noriyuki; Honma, Mareki; Shibata, Katsunori M.; Sato, Katsuhisa; Ueno, Yuji; Jike, Takaaki; Tamura, Yoshiaki; Hirota, Tomoya; Miyazaki, Atsushi; Niinuma, Kotaro; Sorai, Kazuo; Takaba, Hiroshi; Hachisuka, Kazuya; Kondo, Tetsuro; Sekido, Mamoru; Murata, Yasuhiro; Nakai, Naomasa; Omodaka, Toshihiro

    2016-10-01

    The Hitachi and Takahagi 32 m radio telescopes (former satellite communication antennas) were so upgraded as to work at 6, 8, and 22 GHz. We developed the receiver systems, IF systems, back-end systems (including samplers and recorders), and reference systems. We measured the performance of the antennas. The system temperature including the atmosphere toward the zenith, T_sys^{ast }, is measured to be ˜30-40 K for 6 GHz and ˜25-35 K for 8 GHz. T_sys^{ast } for 22 GHz is measured to be ˜40-100 K in winter and ˜150-500 K in summer seasons, respectively. The aperture efficiency is 55%-75% for Hitachi at 6 GHz and 8 GHz, and 55%-65% for Takahagi at 8 GHz. The beam sizes at 6 GHz and 8 GHz are ˜4.6° and ˜3.8°, respectively. The side-lobe level is less than 3%-4% at 6 and 8 GHz. Pointing accuracy was measured to be better than ˜0.3° for Hitachi and ˜0.6° for Takahagi. We succeeded in VLBI observations in 2010 August, indicating good performance of the antenna. We started single-dish monitoring observations of 6.7 GHz methanol maser sources in 2012 December, and found several new sources showing short-term periodic variation of the flux density.

  16. The application of compressive sampling to radio astronomy II: Faraday rotation measure synthesis

    CERN Document Server

    Li, Feng; Cornwell, Tim J; de Hoog, Frank

    2011-01-01

    Faraday rotation measure (RM) synthesis is an important tool to study and analyze galactic and extra-galactic magnetic fields. Since there is a Fourier relation between the Faraday dispersion function and the polarized radio emission, full reconstruction of the dispersion function requires knowledge of the polarized radio emission at both positive and negative square wavelengths $\\lambda^2$. However, one can only make observations for $\\lambda^2 > 0$. Furthermore observations are possible only for a limited range of wavelengths. Thus reconstructing the Faraday dispersion function from these limited measurements is ill-conditioned. In this paper, we propose three new reconstruction algorithms for RM synthesis based upon compressive sensing/sampling (CS). These algorithms are designed to be appropriate for Faraday thin sources only, thick sources only, and mixed sources respectively. Both visual and numerical results show that the new RM synthesis methods provide superior reconstructions of both magnitude and p...

  17. Low noise, 0.4-3 GHz cryogenic receiver for radio astronomy.

    Science.gov (United States)

    Gawande, R; Bradley, R; Langston, G

    2014-10-01

    We present the design and measurement of a radio telescope receiver front end cooled to 100 K physical temperature, and working over 400 MHz to 3 GHz frequency band. The system uses a frequency independent feed developed for operation as a feed for parabola using sinuous elements and integrated with an ultra-wideband low noise amplifier. The ambient temperature system is tested on the 43 m radio telescope in Green Bank, WV and the system verification results on the sky are presented. The cryogenic receiver is developed using a Stirling cycle, one stage cryocooler. The measured far field patterns and the system noise less than 80 K over a 5:1 bandwidth are presented.

  18. RESOLVE: A new algorithm for aperture synthesis imaging of extended emission in radio astronomy

    CERN Document Server

    Junklewitz, H; Selig, M; Enßlin, T A

    2013-01-01

    We present RESOLVE, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. The algorithm is derived using Bayesian statistical inference techniques, estimating the surface brightness in the sky assuming a priori log-normal statistics. RESOLVE not only estimates the measured sky brightness in total intensity, but also its spatial correlation structure, which is used to guide the algorithm to an optimal reconstruction of extended and diffuse sources. For a radio interferometer, it succeeds in deconvolving the effects of the instrumental point spread function during this process. Additionally, RESOLVE provides a map with an uncertainty estimate of the reconstructed surface brightness. Furthermore, with RESOLVE we introduce a new, optimal visibility weighting scheme that can be viewed as an extension to robust weighting. In tests using simulated observations, the algorithm shows improved performance against two standard imaging approaches for extended sources, Mu...

  19. RESOLVE: A new algorithm for aperture synthesis imaging of extended emission in radio astronomy

    Science.gov (United States)

    Junklewitz, H.; Bell, M. R.; Selig, M.; Enßlin, T. A.

    2016-02-01

    We present resolve, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. The algorithm is derived using Bayesian statistical inference techniques, estimating the surface brightness in the sky assuming a priori log-normal statistics. resolve estimates the measured sky brightness in total intensity, and the spatial correlation structure in the sky, which is used to guide the algorithm to an optimal reconstruction of extended and diffuse sources. During this process, the algorithm succeeds in deconvolving the effects of the radio interferometric point spread function. Additionally, resolve provides a map with an uncertainty estimate of the reconstructed surface brightness. Furthermore, with resolve we introduce a new, optimal visibility weighting scheme that can be viewed as an extension to robust weighting. In tests using simulated observations, the algorithm shows improved performance against two standard imaging approaches for extended sources, Multiscale-CLEAN and the Maximum Entropy Method.

  20. Low noise, 0.4-3 GHz cryogenic receiver for radio astronomy

    Science.gov (United States)

    Gawande, R.; Bradley, R.; Langston, G.

    2014-10-01

    We present the design and measurement of a radio telescope receiver front end cooled to 100 K physical temperature, and working over 400 MHz to 3 GHz frequency band. The system uses a frequency independent feed developed for operation as a feed for parabola using sinuous elements and integrated with an ultra-wideband low noise amplifier. The ambient temperature system is tested on the 43 m radio telescope in Green Bank, WV and the system verification results on the sky are presented. The cryogenic receiver is developed using a Stirling cycle, one stage cryocooler. The measured far field patterns and the system noise less than 80 K over a 5:1 bandwidth are presented.

  1. Generation of OAM Radio Waves Using Circular Vivaldi Antenna Array

    Directory of Open Access Journals (Sweden)

    Changjiang Deng

    2013-01-01

    Full Text Available This paper gives a feasible and simple solution of generating OAM-carrying radio beams. Eight Vivaldi antenna elements connect sequentially and fold into a hollow cylinder. The circular Vivaldi antenna array is fed with unit amplitude but with a successive phase difference from element to element. By changing the phase difference at the steps of 0, ±45°, ±90°, ±135°, and 180°, the OAM radio beam can be generated with mode numbers 0, ±1, ±2, ±3, and 4. Simulations show that the OAM states of ±2 and ±3 are the same as the traditional states, while the OAM states of 0, ±1, and 4 differ at the boresight. This phenomenon can be explained by the radiation pattern difference between Vivaldi antenna and tripole antenna. A solution of distinguishing OAM states is also proposed. The mode number of OAM can be distinguished with only 2 receivers.

  2. Radio Astronomy Demonstrator: Assessment of the Appropriate Sites through a GIS Open Source Application

    Directory of Open Access Journals (Sweden)

    Lia Duarte

    2016-11-01

    Full Text Available In the framework of Portuguese radio astronomical capacitation towards participation in the Square Kilometer Array (SKA project, a site was selected for radio astronomical testing purposes and the development of a radio astronomical infrastructure. The site is within Herdade da Contenda (HC, a large national forest perimeter, located in Alentejo (Portugal. In order to minimize the impacts in the ecosystem and landscape, an application based on the Geographic Information System (GIS open source environment was created, the HC Environmental Integrated Management System. This application combines several functionalities and menus with different characterization methods allowing the creation of multiple maps regarding the HC characteristics, such as Digital Elevation Model (DEM, Land Use Land Cover (LULC, Normalized Difference Vegetation Index (NDVI, groundwater vulnerability, erosion risk, flood risk and forest fire risk. Other geographical information can be added if necessary (human heritage visualization and fauna and flora. A decision making support tool was also developed. It incorporates an algorithm running through a series of assigned weights and eliminatory factors to find the locations best suited for the infrastructure with minimal impact to the local ecosystem. In order to test the application and the decision making tool, several maps were used as input in order to decide which sites are more adequate. The application developed can be adopted for other protected or natural areas.

  3. WTF? Discovering the Unexpected in next-generation radio continuum surveys

    CERN Document Server

    Crawford, Evan; Polsterer, Kai

    2016-01-01

    Most major discoveries in astronomy have come from unplanned discoveries made by surveying the Universe in a new way, rather than by testing a hypothesis or conducting an investigation with planned outcomes. Next generation radio continuum surveys such as the Evolutionary Map of the Universe (EMU: the radio continuum survey on the new Australian SKA Pathfinder telescope), will significantly expand the volume of observational phase space, so we can be reasonably confident that we will stumble across unexpected new phenomena or new types of object. However, the complexity of the instrument and the large data volumes mean that it may be non-trivial to identify them. On the other hand, if we don't, then we may be missing out on the most exciting science results from EMU. We have therefore started a project called "WTF", which explicitly aims to mine EMU data to discover unexpected science that is not part of our primary science goals, using a variety of machine-learning techniques and algorithms. Although targete...

  4. Application of Field System-FS9 and a PC to Antenna Control Unit interface in Radio Astronomy in Peru

    Science.gov (United States)

    Vidal, E. V. S.; Ishitsuka, J. I. I.; Koyama, K. Y.

    2006-08-01

    We are in the process to transform a 32m antenna in Peru, used for telecommunications, into a Radio Telescope to perform Radio Astronomy in Peru. The 32m antenna of Peru constructed by NEC was used for telecommunications with communications satellites at 6 GHz for transmission, and 4 GHz for reception. In collaboration of National Institute of Information and Communications Technology (NICT) Japan, and National Observatory of Japan we developed an Antenna Control System for the 32m antenna in Peru. It is based on the Field System FS9, software released by NASA for VLBI station, and an interface to link PC within FS9 software (PC-FS9) and Antenna Control Unit (ACU) of the 32 meters antenna. The PC-FS9 controls the antenna, commands are translated by interface into control signals compatibles with the ACU using: an I/O digital card with two 20bits ports to read azimuth and elevation angles, one 16bits port for reading status of ACU, one 24bits port to send pulses to start or stop operations of antenna, two channels are analogic outputs to drive the azimuth and elevation motors of the antenna, a LCD display to show the status of interface and error messages, and one serial port for communications with PC-FS9,. The first experiment of the control system was made with 11m parabolic antenna of Kashima Space Research Center (NICT), where we tested the right working of the routines implemented for de FS9 software, and simulations was made with looped data between output and input of the interface, both test were done successfully. With this scientific instrument we will be able to contribute with researching of astrophysics. We expect to into a near future to work at 6.7GHz to study Methanol masers, and higher frequencies with some improvements of the surface of the dish.

  5. Gravity-gradient dynamics experiments performed in orbit utilizing the Radio Astronomy Explorer (RAE-1) spacecraft

    Science.gov (United States)

    Walden, H.

    1973-01-01

    Six dynamic experiments were performed in earth orbit utilizing the RAE spacecraft in order to test the accuracy of the mathematical model of RAE dynamics. The spacecraft consisted of four flexible antenna booms, mounted on a rigid cylindrical spacecraft hub at center, for measuring radio emissions from extraterrestrial sources. Attitude control of the gravity stabilized spacecraft was tested by using damper clamping, single lower leading boom operations, and double lower boom operations. Results and conclusions of the in-orbit dynamic experiments proved the accuracy of the analytic techniques used to model RAE dynamical behavior.

  6. Controller-area-network bus control and monitor system for a radio astronomy interferometer.

    Science.gov (United States)

    Woody, David P; Wiitala, Bradley; Scott, Stephen L; Lamb, James W; Lawrence, Ronald P; Giovanine, Curt; Fredsti, Sancar J; Beard, Andrew; Pryke, Clem; Loh, Michael; Greer, Christopher H; Cartwright, John K; Gutierrez-Kraybill, Colby; Bolatto, Alberto D; Muchovej, Stephen J C

    2007-09-01

    We describe the design and implementation of a controller-area-network bus (CANbus) monitor and control system for a millimeter wave interferometer. The Combined Array for Research in Millimeter-wave Astronomy (CARMA) is a 15-antenna connected-element interferometer for astronomical imaging, created by the merger of two university observatories. Its new control system relies on a central computer supervising a variety of subsystem computers, many of which control distributed intelligent nodes over CANbus. Subsystems are located in the control building and in individual antennas and communicate with the central computer via Ethernet. Each of the CAN modules has a very specific function, such as reading an antenna encoder or tuning an oscillator. Hardware for the modules was based on a core design including a commercial CANbus-enabled single-board computer and some standard circuitry for interfacing to peripherals. Hardware elements were added or changed as necessary for the specific module types. Similarly, a base set of embedded code was implemented for essential common functions such as CAN message handling and time keeping and extended to implement the required functionality for the different hardware. Using a standard CAN messaging protocol designed to fit the requirements of CARMA and a well-defined interface to the high-level software allowed separate development of high-level code and embedded code with minimal integration problems. Over 30 module types have been implemented and successfully deployed in CARMA, which is now delivering excellent new science data.

  7. Highlighting the history of Japanese radio astronomy. 4: early solar research in Osaka

    Science.gov (United States)

    Orchiston, Wayne; Nakamura, Tsuko; Ishiguro, Masato

    2016-12-01

    For about two years, from late 1949, Minoru Oda and Tatsuo Takakura carried out solar observations from Osaka, initially with a hand-made horn and later with a small parabolic antenna connected to a 3.3 GHz receiver, but they only published one short paper on this work. At about the same time, Ojio and others at Osaka City University presented the concept of a solar grating array at a meeting of the Japan Physical Society, but this was never built. In this paper, we provide brief biographical accounts of Oda and Takakura before examining their radio telescopes and the observations that they made. We also briefly discuss the proposed Japanese solar grating array.

  8. Interactive Lab to Learn Radio Astronomy, Microwave & Antenna Engineering at the Technical University of Cartagena (Spain

    Directory of Open Access Journals (Sweden)

    Fernando Daniel Quesada-Pereira

    2011-02-01

    Full Text Available An initiative carried out at the Technical University of Cartagena (UPCT, Spain to encourage students and promote the interest for Scientific and Engineering Culture between society is presented in this contribution. For this purpose, a long-term project based on the set-up of an interactive laboratory surrounding a small Radio Telescope (SRT system has been carried out. The main novelty is that this project is entirely being developed by students of last courses of our Telecommunication Engineering Faculty, under the supervision of four lecturers. This lab offers the possibility to remotely control the SRT, and it provides a set of multimedia web-based applications to produce a novel, practical, multidisciplinary virtual laboratory to improve the learning and teaching processes in related sciences and technologies.

  9. fastRESOLVE: fast Bayesian imaging for aperture synthesis in radio astronomy

    CERN Document Server

    Greiner, Maksim; Junklewitz, Henrik; Enßlin, Torsten A

    2016-01-01

    The standard imaging algorithm for interferometric radio data, CLEAN, is optimal for point source observations, but suboptimal for diffuse emission. Recently, RESOLVE, a new Bayesian algorithm has been developed, which is ideal for extended source imaging. Unfortunately, RESOLVE is computationally very expensive. In this paper we present fastRESOLVE, a modification of RESOLVE based on an approximation of the interferometric likelihood that allows us to avoid expensive gridding routines and consequently gain a factor of roughly 100 in computation time. Furthermore, we include a Bayesian estimation of the measurement uncertainty of the visibilities into the imaging, a procedure not applied in aperture synthesis before. The algorithm requires little to no user input compared to the standard method CLEAN while being superior for extended and faint emission. We apply the algorithm to VLA data of Abell 2199 and show that it resolves more detailed structures.

  10. Radio Astronomy Data Model for Single-Dish Multiple-Feed Telescopes, and Robledo Archive Architecture

    CERN Document Server

    Santander-Vela, J D; Gómez, J F; Verdes-Montenegro, L; Leon, S; Gutíerrez, R; Rodrigo, C; Morata, O; Solano, E; Suárez, O

    2008-01-01

    All the effort that the astrophysical community has put into the development of the Virtual Observatory (VO) has surpassed the non-return point: the VO is a reality today, and an initiative that will self-sustain, and to which all archival projects must adhere. We have started the design of the scientific archive for the DSS-63 70-m antenna at NASA's DSN station in Robledo de Chavela (Madrid). Here we show how we can use all VO proposed data models to build a VO-compliant single-dish, multiple-feed, radio astronomical archive data model (RADAMS) suitable for the archival needs of the antenna. We also propose an exhaustive list of Universal Content Descriptors (UCDs) and FITS keywords for all relevant metadata. We will further refine this data model with the experience that we will gain from that implementation.

  11. Fast gain calibration in radio astronomy using alternating direction implicit methods: Analysis and applications

    CERN Document Server

    Salvini, Stefano

    2014-01-01

    Context. Modern radio astronomical arrays have (or will have) more than one order of magnitude more receivers than classical synthesis arrays, such as the VLA and the WSRT. This makes gain calibration a computationally demanding task. Several alternating direction implicit (ADI) approaches have therefore been proposed that reduce numerical complexity for this task from $\\mathcal{O}(P^3)$ to $\\mathcal{O}(P^2)$, where $P$ is the number of receive paths to be calibrated. Aims. We present an ADI method, show that it converges to the optimal solution, and assess its numerical, computational and statistical performance. We also discuss its suitability for application in self-calibration and report on its successful application in LOFAR standard pipelines. Methods. Convergence is proved by rigorous mathematical analysis using a contraction mapping. Its numerical, algorithmic, and statistical performance, as well as its suitability for application in self-calibration, are assessed using simulations. Results. Our simu...

  12. A scientific program for infrared, submillimeter and radio astronomy from space: A report by the Management Operations Working Group

    Science.gov (United States)

    1989-01-01

    Important and fundamental scientific progress can be attained through space observations in the wavelengths longward of 1 micron. The formation of galaxies, stars, and planets, the origin of quasars and the nature of active galactic nuclei, the large scale structure of the Universe, and the problem of the missing mass, are among the major scientific issues that can be addressed by these observations. Significant advances in many areas of astrophysics can be made over the next 20 years by implementing the outlined program. This program combines large observatories with smaller projects to create an overall scheme that emphasized complementarity and synergy, advanced technology, community support and development, and the training of the next generation of scientists. Key aspects of the program include: the Space Infrared Telescope Facility; the Stratospheric Observatory for Infrared Astronomy; a robust program of small missions; and the creation of the technology base for future major observatories.

  13. Multifunctional radio-frequency generator for cold atom experiments

    Science.gov (United States)

    Wei, Chun-hua; Yan, Shu-hua

    2016-05-01

    We present a low cost radio-frequency (RF) generator suitable for experiments with cold atoms. The RF source achieves a sub-hertz frequency with tunable resolution from 0 MHz to 400 MHz and a maximum output power of 33 dBm. Based on a direct digital synthesizer (DDS) chip, we implement a ramping capability for frequency, amplitude and phase. The system can also operate as an arbitrary waveform generator. By measuring the stability in a duration of 600 s, we find the presented device performs comparably as Agilent33522A in terms of short-term stability. Due to its excellent performance, the RF generator has been already applied to cold atom trapping experiments.

  14. Digital Signal Processing using Stream High Performance Computing: A 512-input Broadband Correlator for Radio Astronomy

    CERN Document Server

    Kocz, J; Barsdell, B R; Price, D; Bernardi, G; Bourke, S; Clark, M A; Craig, J; Dexter, M; Dowell, J; Eftekhari, T; Ellingson, S; Hallinan, G; Hartman, J; Jameson, A; MacMahon, D; Taylor, G; Schinzel, F; Werthimer, D

    2014-01-01

    A "large-N" correlator that makes use of Field Programmable Gate Arrays and Graphics Processing Units has been deployed as the digital signal processing system for the Long Wavelength Array station at Owens Valley Radio Observatory (LWA-OV), to enable the Large Aperture Experiment to Detect the Dark Ages (LEDA). The system samples a ~100MHz baseband and processes signals from 512 antennas (256 dual polarization) over a ~58MHz instantaneous sub-band, achieving 16.8Tops/s and 0.236 Tbit/s throughput in a 9kW envelope and single rack footprint. The output data rate is 260MB/s for 9 second time averaging of cross-power and 1 second averaging of total-power data. At deployment, the LWA-OV correlator was the largest in production in terms of N and is the third largest in terms of complex multiply accumulations, after the Very Large Array and Atacama Large Millimeter Array. The correlator's comparatively fast development time and low cost establish a practical foundation for the scalability of a modular, heterogeneo...

  15. An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

    CERN Document Server

    D'Addario, Larry R

    2016-01-01

    Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. For $N$ antennas, the cost and power consumption of cross-correlation are proportional to $N^2$ and dominate at sufficiently large $N$. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals ($N$=32 antennas with 2 opposite-polarization signals per antenna). When $N$ is larger, the input data are buffered in an on-chip memory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulat...

  16. WSClean: an implementation of a fast, generic wide-field imager for radio astronomy

    CERN Document Server

    Offringa, A R; Hurley-Walker, N; Briggs, F H; Wayth, R B; Kaplan, D L; Bell, M E; Feng, L; Neben, A R; Hughes, J D; Rhee, J; Murphy, T; Bhat, N D R; Bernardi, G; Bowman, J D; Cappallo, R J; Corey, B E; Deshpande, A A; Emrich, D; Ewall-Wice, A; Gaensler, B M; Goeke, R; Greenhill, L J; Hazelton, B J; Hindson, L; Johnston-Hollitt, M; Jacobs, D C; Kasper, J C; Kratzenberg, E; Lenc, E; Lonsdale, C J; Lynch, M J; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Kudryavtseva, N; Oberoi, D; Ord, S M; Pindor, B; Procopio, P; Prabu, T; Riding, J; Roshi, D A; Shankar, N Udaya; Srivani, K S; Subrahmanyan, R; Tingay, S J; Waterson, M; Webster, R L; Whitney, A R; Williams, A; Williams, C L

    2014-01-01

    Astronomical widefield imaging of interferometric radio data is computationally expensive, especially for the large data volumes created by modern non-coplanar many-element arrays. We present a new widefield interferometric imager that uses the w-stacking algorithm and can make use of the w-snapshot algorithm. The performance dependencies of CASA's w-projection and our new imager are analysed and analytical functions are derived that describe the required computing cost for both imagers. On data from the Murchison Widefield Array, we find our new method to be an order of magnitude faster than w-projection, as well as being capable of full-sky imaging at full resolution and with correct polarisation correction. We predict the computing costs for several other arrays and estimate that our imager is a factor of 2-12 faster, depending on the array configuration. We estimate the computing cost for imaging the low-frequency Square-Kilometre Array observations to be 60 PetaFLOPS with current techniques. We find that...

  17. Development of the radio astronomical method of cosmic particle detection for extremely high-energy cosmic ray physics and neutrino astronomy

    Directory of Open Access Journals (Sweden)

    Zheleznykh Igor

    2017-01-01

    Full Text Available The proposal to use ground based radio telescopes for detection of Askaryan radio pulses from particle cascades arising when extremely high-energy (EHE > 1020 eV cosmic rays (including neutrinos interact with the lunar regolith of multi gigaton mass was made at the end of 1980s in the framework of the Russian (Soviet DUMAND Program. During more than a quarter of century a number of lunar experiments were carried out mainly in the 1–3 GHz frequency range using the large radio telescopes of Australia, USA, Russia and other countries but these experiments only put upper limits to the EHE cosmic rays fluxes. For this reason, it would be of great interest to search for nanosecond radio pulses from the Moon in a wider interval of frequencies (including lower ones of 100–350 MHz with larger radio detectors – for example the giant radio telescope SKA (Square Kilometer Array which is constructed in Australia, New Zealand and South Africa. In this paper possibilities are discussed to use one of the most sensitive meter-wavelength (∼ 110 MHz Large Phased Array (LPA of 187 × 384 m2 and the wide field of view meter-wavelength array of the Pushchino Radio Astronomy Observatory as prototypes of low frequency radio detectors for lunar experiments. The new scheme for fast simulation of ultrahigh and extremely high-energy cascades in dense media is also suggested. This scheme will be used later for calculations of radio emission of cascades in the lunar regolith with energies up to 1020 eV and higher in the wide frequency band of 0.1− a few GHz.

  18. Development of the radio astronomical method of cosmic particle detection for extremely high-energy cosmic ray physics and neutrino astronomy

    Science.gov (United States)

    Zheleznykh, Igor; Dagkesamanskii, Rustam; Dedenko, Leonid; Dedenko, Grigorii

    2017-06-01

    The proposal to use ground based radio telescopes for detection of Askaryan radio pulses from particle cascades arising when extremely high-energy (EHE > 1020 eV) cosmic rays (including neutrinos) interact with the lunar regolith of multi gigaton mass was made at the end of 1980s in the framework of the Russian (Soviet) DUMAND Program. During more than a quarter of century a number of lunar experiments were carried out mainly in the 1-3 GHz frequency range using the large radio telescopes of Australia, USA, Russia and other countries but these experiments only put upper limits to the EHE cosmic rays fluxes. For this reason, it would be of great interest to search for nanosecond radio pulses from the Moon in a wider interval of frequencies (including lower ones of 100-350 MHz) with larger radio detectors - for example the giant radio telescope SKA (Square Kilometer Array) which is constructed in Australia, New Zealand and South Africa. In this paper possibilities are discussed to use one of the most sensitive meter-wavelength (˜ 110 MHz) Large Phased Array (LPA) of 187 × 384 m2 and the wide field of view meter-wavelength array of the Pushchino Radio Astronomy Observatory as prototypes of low frequency radio detectors for lunar experiments. The new scheme for fast simulation of ultrahigh and extremely high-energy cascades in dense media is also suggested. This scheme will be used later for calculations of radio emission of cascades in the lunar regolith with energies up to 1020 eV and higher in the wide frequency band of 0.1- a few GHz.

  19. The NSF Undergraduate ALFALFA Team: Partnering with Arecibo Observatory to Offer Undergraduate and Faculty Extragalactic Radio Astronomy Research Opportunities

    Science.gov (United States)

    Ribaudo, Joseph; Koopmann, Rebecca A.; Haynes, Martha P.; Balonek, Thomas J.; Cannon, John M.; Coble, Kimberly A.; Craig, David W.; Denn, Grant R.; Durbala, Adriana; Finn, Rose; Hallenbeck, Gregory L.; Hoffman, G. Lyle; Lebron, Mayra E.; Miller, Brendan P.; Crone-Odekon, Mary; O'Donoghue, Aileen A.; Olowin, Ronald Paul; Pantoja, Carmen; Pisano, Daniel J.; Rosenberg, Jessica L.; Troischt, Parker; Venkatesan, Aparna; Wilcots, Eric M.; ALFALFA Team

    2017-01-01

    The NSF-sponsored Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team (UAT) is a consortium of 20 institutions across the US and Puerto Rico, founded to promote undergraduate research and faculty development within the extragalactic ALFALFA HI blind survey project and follow-up programs. The objective of the UAT is to provide opportunities for its members to develop expertise in the technical aspects of observational radio spectroscopy, its associated data analysis, and the motivating science. Partnering with Arecibo Observatory, the UAT has worked with more than 280 undergraduates and 26 faculty to date, offering 8 workshops onsite at Arecibo (148 undergraduates), observing runs at Arecibo (69 undergraduates), remote observing runs on campus, undergraduate research projects based on Arecibo science (120 academic year and 185 summer projects), and presentation of results at national meetings such as the AAS (at AAS229: Ball et al., Collova et al., Davis et al., Miazzo et al., Ruvolo et al, Singer et al., Cannon et al., Craig et al., Koopmann et al., O'Donoghue et al.). 40% of the students and 45% of the faculty participants have been women and members of underrepresented groups. More than 90% of student alumni are attending graduate school and/or pursuing a career in STEM. 42% of those pursuing graduate degrees in Physics or Astronomy are women.In this presentation, we summarize the UAT program and the current research efforts of UAT members based on Arecibo science, including multiwavelength followup observations of ALFALFA sources, the UAT Collaborative Groups Project, the Survey of HI in Extremely Low-mass Dwarfs (SHIELD), and the Arecibo Pisces-Perseus Supercluster Survey (APPSS). This work has been supported by NSF grants AST-0724918/0902211, AST-075267/0903394, AST-0725380, AST-121105, and AST-1637339.

  20. An Integrated Circuit for Radio Astronomy Correlators Supporting Large Arrays of Antennas

    Science.gov (United States)

    D'Addario, Larry R.; Wang, Douglas

    2016-01-01

    Radio telescopes that employ arrays of many antennas are in operation, and ever larger ones are being designed and proposed. Signals from the antennas are combined by cross-correlation. While the cost of most components of the telescope is proportional to the number of antennas N, the cost and power consumption of cross-correlationare proportional to N2 and dominate at sufficiently large N. Here we report the design of an integrated circuit (IC) that performs digital cross-correlations for arbitrarily many antennas in a power-efficient way. It uses an intrinsically low-power architecture in which the movement of data between devices is minimized. In a large system, each IC performs correlations for all pairs of antennas but for a portion of the telescope's bandwidth (the so-called "FX" structure). In our design, the correlations are performed in an array of 4096 complex multiply-accumulate (CMAC) units. This is sufficient to perform all correlations in parallel for 64 signals (N=32 antennas with 2 opposite-polarization signals per antenna). When N is larger, the input data are buffered in an on-chipmemory and the CMACs are re-used as many times as needed to compute all correlations. The design has been synthesized and simulated so as to obtain accurate estimates of the IC's size and power consumption. It isintended for fabrication in a 32 nm silicon-on-insulator process, where it will require less than 12mm2 of silicon area and achieve an energy efficiency of 1.76 to 3.3 pJ per CMAC operation, depending on the number of antennas. Operation has been analyzed in detail up to N = 4096. The system-level energy efficiency, including board-levelI/O, power supplies, and controls, is expected to be 5 to 7 pJ per CMAC operation. Existing correlators for the JVLA (N = 32) and ALMA (N = 64) telescopes achieve about 5000 pJ and 1000 pJ respectively usingapplication-specific ICs in older technologies. To our knowledge, the largest-N existing correlator is LEDA atN = 256; it

  1. Tracing High Redshift Starformation in the Current and Next Generation of Radio Surveys

    CERN Document Server

    Seymour, Nick

    2009-01-01

    The current deepest radio surveys detect hundreds of sources per square degree below 0.1mJy. There is a growing consensus that a large fraction of these sources are dominated by star formation although the exact proportion has been debated in the literature. However, the low luminosity of these galaxies at most other wavelengths makes determining the nature of individual sources difficult. If future, deeper surveys performed with the next generation of radio instrumentation are to reap high scientific reward we need to develop reliable methods of distinguishing between radio emission powered by active galactic nuclei (AGN) and that powered by star formation. In particular, we believe that such discriminations should be based on purely radio, or relative to radio, diagnostics. These diagnostics include radio morphology, radio spectral index, polarisation, variability, radio luminosity and flux density ratios with non-radio wavelengths e.g. with different parts of the infrared (IR) regime. We discuss the advant...

  2. Society News: Monica Grady awarded CBE; Grubb Parsons Lecture 2012; Join the RAS; Astronomy on radio for kids; New Fellows; Peter D Hingley

    Science.gov (United States)

    2012-08-01

    RAS Fellow Prof. Monica Grady has been made a Commander of the Most Excellent Order of the British Empire (CBE), in recognition of her services to space science. The RAS sponsors the annual Grubb Parsons Lecture, which this year took place on 6 June at the University of Durham. If you are a professional astronomer, geophysicist, or similar, a student studying these disciplines, or simply someone with a serious interest in them, we urge you to apply for membership of the RAS. Outreach is an important activity for the RAS. We recently supported an astronomy series called Deep Space High on the digital radio channel Fun Kids.

  3. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    Science.gov (United States)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  4. New cryogenic system of the next-generation infrared astronomy mission SPICA

    Science.gov (United States)

    Ogawa, H.; Nakagawa, T.; Matsuhara, H.; Shinozaki, K.; Goto, K.; Isobe, N.; Kawada, M.; Mizutani, T.; Sato, Y.; Sugita, H.; Takeuchi, S.; Yamawaki, T.; Shibai, H.

    2016-07-01

    We present the new design of the cryogenic system of the next-generation infrared astronomy mission SPICA under the new framework. The new design employs the V-groove design for radiators, making the best use of the Planck heritage. The new design is based on the ESA-JAXA CDF study (NG-CryoIRTel, CDF-152(A)) with a 2 m telescope, and we modified the CDF design to accommodate the 2.5 m telescope to meet the science requirements of SPICA. The basic design concept of the SPICA cryogenic system is to cool the Science Instrument Assembly (SIA, which is the combination of the telescope and focal-plane instruments) below 8K by the combination of the radiative cooling system and mechanical cryocoolers without any cryogen.

  5. Infrared Astronomy with Arrays: The Next Generation; Sunset Village, Los Angeles, CA, Oct. 1993

    Science.gov (United States)

    Mclean, Ian S.

    1994-01-01

    Conference papers on infrared array techniques and methods for infrared astronomy are presented. Topics covered include the following: infrared telescopes; infrared spectrometers; spaceborne astronomy; astronomical observatories; infrared cameras; imaging techniques; sky surveys; infrared photography; infrared photometry; infrared spectroscopy; equipment specifications; data processing and analysis; control systems; cryogenic equipment; adaptive optics; image resolution; infrared detector materials; and focal plane arrays.

  6. The MeqTrees software system and its use for third-generation calibration of radio interferometers

    Science.gov (United States)

    Noordam, J. E.; Smirnov, O. M.

    2010-12-01

    Context. The formulation of the radio interferometer measurement equation (RIME) for a generic radio telescope by Hamaker et al. has provided us with an elegant mathematical apparatus for better understanding, simulation and calibration of existing and future instruments. The calibration of the new radio telescopes (LOFAR, SKA) would be unthinkable without the RIME formalism, and new software to exploit it. Aims: The MeqTrees software system is designed to implement numerical models, and to solve for arbitrary subsets of their parameters. It may be applied to many problems, but was originally geared towards implementing Measurement Equations in radio astronomy for the purposes of simulation and calibration. The technical goal of MeqTrees is to provide a tool for rapid implementation of such models, while offering performance comparable to hand-written code. We are also pursuing the wider goal of increasing the rate of evolution of radio astronomical software, by offering a tool that facilitates rapid experimentation, and exchange of ideas (and scripts). Methods: MeqTrees is implemented as a Python-based front-end called the meqbrowser, and an efficient (C++-based) computational back-end called the meqserver. Numerical models are defined on the front-end via a Python-based Tree Definition Language (TDL), then rapidly executed on the back-end. The use of TDL facilitates an extremely short turn-around time (hours rather than weeks or months) for experimentation with new ideas. This is also helped by unprecedented visualization capabilities for all final and intermediate results. A flexible data model and a number of important optimizations in the back-end ensures that the numerical performance is comparable to that of hand-written code. Results: MeqTrees is already widely used as the simulation tool for new instruments (LOFAR, SKA) and technologies (focal plane arrays). It has demonstrated that it can achieve a noise-limited dynamic range in excess of a million, on

  7. An Ultra Fast Image Generator (UFig) for wide-field astronomy

    CERN Document Server

    Bergé, Joel; Réfrégier, Alexandre; Amara, Adam

    2012-01-01

    Simulated wide-field images are becoming an important part of observational astronomy, either to prepare for new surveys or to test measurement methods. In order to efficiently explore vast parameter spaces, the computational speed of simulation codes is a central requirement to their implementation. We introduce the Ultra Fast Image Generator (UFig) which aims to bring wide-field imaging simulations to the current limits of computational capabilities. We achieve this goal through: (1) models of galaxies, stars and observational conditions, which, while simple, capture the key features necessary for realistic simulations, and (2) state-of-the-art computational and implementation optimizations. We present the performances of UFig and show that it is faster than existing public simulation codes by several orders of magnitude. It allows us to produce images more quickly than SExtractor needs to analyze them. For instance, it can simulate a typical 0.25 deg^2 Subaru SuprimeCam image (10k x 8k pixels) with a 5-sig...

  8. Astronomy as a Tool for Training the Next Generation Technical Workforce

    Science.gov (United States)

    Romero, V.; Walsh, G.; Ryan, W.; Ryan, E.

    A major challenge for today's institutes of higher learning is training the next generation of scientists, engineers, and optical specialists to be proficient in the latest technologies they will encounter when they enter the workforce. Although research facilities can offer excellent hands-on instructional opportunities, integrating such experiential learning into academic coursework without disrupting normal operations at such facilities can be difficult. Also, motivating entry level students to increase their skill levels by undertaking and successfully completing difficult coursework can require more creative instructional approaches, including fostering a fun, non-threatening environment for enhancing basic abilities. Astronomy is a universally appealing subject area, and can be very effective as a foundation for cultivating advanced competencies. We report on a project underway at the New Mexico Institute of Mining and Technology (NM Tech), a science and engineering school in Socorro, NM, to incorporate a state-of-the-art optical telescope and laboratory experiments into an entry-level course in basic engineering. Students enrolled in an explosive engineering course were given a topical problem in Planetary Astronomy: they were asked to develop a method to energetically mitigate a potentially hazardous impact between our planet and a Near-Earth asteroid to occur sometime in the future. They were first exposed to basic engineering training in the areas of fracture and material response to failure under different environmental conditions through lectures and traditional laboratory exercises. The students were then given access to NM Tech's Magdalena Ridge Observatory's (MRO) 2.4-meter telescope to collect physical characterization data, (specifically shape information) on two potentially hazardous asteroids (one roughly spherical, the other an elongated ellipsoid). Finally, the students used NM Tech's Energetic Materials Research and Testing Center (EMRTC) to

  9. AROMA: Automatic Generation of Radio Maps for Localization Systems

    CERN Document Server

    Eleryan, Ahmed; Youssef, Moustafa

    2010-01-01

    WLAN localization has become an active research field recently. Due to the wide WLAN deployment, WLAN localization provides ubiquitous coverage and adds to the value of the wireless network by providing the location of its users without using any additional hardware. However, WLAN localization systems usually require constructing a radio map, which is a major barrier of WLAN localization systems' deployment. The radio map stores information about the signal strength from different signal strength streams at selected locations in the site of interest. Typical construction of a radio map involves measurements and calibrations making it a tedious and time-consuming operation. In this paper, we present the AROMA system that automatically constructs accurate active and passive radio maps for both device-based and device-free WLAN localization systems. AROMA has three main goals: high accuracy, low computational requirements, and minimum user overhead. To achieve high accuracy, AROMA uses 3D ray tracing enhanced wi...

  10. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  11. Big Data Challenges for Large Radio Arrays

    Science.gov (United States)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  12. Next generation wireless communications using radio over fiber

    CERN Document Server

    Gomes, Nathan J; Gameiro, Atilio

    2012-01-01

    Taking a coherent and logical approach, this book describes the potential use of co-ordinated multipoint systems supported by radio over fiber. It covers an impressive breadth of topics, ranging from components, subsystem and system architecture, to network management and business perspectives. The authors show the importance of radio over fiber in eliminating or mitigating against the current, perceived barriers to the use of co-ordinated multipoint, and the drivers for standardisation activities in future mobile/wireless systems over the next few years. The book brings together the

  13. OBSERVATIONS OF PLANETS AND QUASI-STELLAR RADIO SOURCES AT 3 MM.

    Science.gov (United States)

    EXTRATERRESTRIAL RADIO WAVES), (* PLANETS , STARS, VENUS( PLANET ), MARS( PLANET ), MERCURY ( PLANET ), PLANETARY ATMOSPHERES, GALAXIES, ASTROPHYSICS, TEMPERATURE, MEASUREMENT, MICROWAVE FREQUENCY, ASTRONOMY, RADIO ASTRONOMY.

  14. SETI reloaded, Next Generation Radio Telescopes, Transients and Cognitive Computing

    CERN Document Server

    Garrett, Michael A

    2015-01-01

    The Search for Extra-terrestrial Intelligence (SETI) using radio telescopes is an area of research that is now more than 50 years old. Thus far, both targeted and wide-area surveys have yet to detect artificial signals from intelligent civilisations. In this paper, I argue that the incidence of co-existing intelligent and communicating civilisations is probably small in the Milky Way. While this makes successful SETI searches a very difficult pursuit indeed, the huge impact of even a single detection requires us to continue the search. A substantial increase in the overall performance of radio telescopes (and in particular future wide-field instruments such as the Square Kilometre Array, SKA), provide renewed optimism in the field. Evidence for this is already to be seen in the success of SETI researchers in acquiring observations on some of the world's most sensitive radio telescope facilities via open, peer-reviewed processes. The increasing interest in the dynamic radio sky, and our ability to detect new a...

  15. Deconvolution of images in centimeter-band radio astronomy for the exploitation of new radio interferometers: characterization of non thermal components in galaxy clusters

    Science.gov (United States)

    Dabbech, A.

    2015-04-01

    Within the framework of the preparation for the Square Kilometre Array (SKA), that is the world largest radio telescope, new imaging challenges has to be conquered. The data acquired by SKA will have to be processed on real time because of their huge rate. In addition, thanks to its unprecedented resolution and sensitivity, SKA images will have very high dynamic range over wide fields of view. Hence, there is an urgent need for the design of new imaging techniques that are robust and efficient and fully automated. The goal of this thesis is to develop a new technique aiming to reconstruct a model image of the radio sky from the radio observations. The method have been designed to estimate images with high dynamic range with a particular attention to recover faint extended emission usually completely buried in the PSF sidelobes of the brighter sources and the noise. We propose a new approach, based on sparse representations, called MORESANE. The radio sky is assumed to be a summation of sources, considered as atoms of an unknown synthesis dictionary. These atoms are learned using analysis priors from the observed image. Results obtained on realistic simulations show that MORESANE is very promising in the restoration of radio images; it is outperforming the standard tools and very competitive with the newly proposed methods in the literature. MORESANE is also applied on simulations of observations using the SKA1 with the aim to investigate the detectability of the intracluster non thermal component. Our results indicate that these diffuse sources, characterized by very low surface brightness will be investigated up to the epoch of massive cluster formation with the SKA.

  16. Radio-location of mobile stations in third generation networks

    Directory of Open Access Journals (Sweden)

    Milan Manojle Šunjevarić

    2013-06-01

    Full Text Available Mobile station localization in mobile networks started with simple methods (e.g. Cell-ID method which required only slight modifications of network infrastructures. Principally, it was about network localization by which a localization service became available to all types of mobile phones. Due to low precision, the initiated development of more sophisticated methods has not been finished yet. Among the advanced location-based methods are those based on the measurement of location parameters in the time domain. In this paper the general consideration of radio location methods in 3G (UMTS radio networks is presented. The use of time based measurement methods was analysed in detail. Due to the limited article length, the use of other locating methods in 3G networks (based on power measurements, on radio direction measurement, and on cells identification – Cell ID and global positioning system - GPS are not described. Introduction Mobile station localization within modern cellular networks increases the level of user security and opens wide opportunities for commercial operators who provide this service. The major obstacle for the implementation of this service, which also prevents its practical usage, is the modification of the existing network infrastructure. In general, depending on the infrastructure used, positioning methods can be divided into two groups: integrated and independent. Integrated methods are primarily created for communication networks. A possibility to locate users represents just an additional service within a radio network. Independent methods are totally detached from the communication network in which the user whose location is being determined is. Radio location methods Determining the location of a mobile radio station is performed by determining the intersection of two or more lines of position. These lines represent the position of the set of points at which the mobile station may be located. These lines can be: (a

  17. A New Approach to Suppress the Effect of Machining Error for Waveguide Septum Circular Polarizer at 230 GHz Band in Radio Astronomy

    Science.gov (United States)

    Hasegawa, Yutaka; Harada, Ryohei; Tokuda, Kazuki; Kimura, Kimihiro; Ogawa, Hideo; Onishi, Toshikazu; Nishimura, Atsushi; Han, Johnson; Inoue, Makoto

    2017-02-01

    A new stepped septum-type waveguide circular polarizer (SST-CP) was developed to operate in the 230 GHz band for radio astronomy, especially submillimeter-band VLBI observations. For previously reported SST-CP models, the 230 GHz band is too high to achieve the design characteristics in manufactured devices because of unexpected machining errors. To realize a functional SST-CP that can operate in the submillimeter band, a new method was developed, in which the division surface is shifted from the top step of the septum to the second step from the top, and we simulated the expected machining error. The SST-CP using this method can compensate for specified machining errors and suppress serious deterioration. To verify the proposed method, several test pieces were manufactured, and their characteristics were measured using a VNA. These results indicated that the insertion losses were approximately 0.75 dB, and the input return losses and the crosstalk of the left- and right-hand circular polarization were greater than 20 dB at 220-245 GHz on 300 K. Moreover, a 230 GHz SST-CP was developed by the proposed method and installed in a 1.85-m radio telescope receiver systems, and then had used for scientific observations during one observation season without any problems. These achievements demonstrate the successful development of a 230 GHz SST-CP for radio astronomical observations. Furthermore, the proposed method can be applicable for observations in higher frequency bands, such as 345 GHz.

  18. A simplified approach for generating GNSS radio occultation refractivity climatologies

    Directory of Open Access Journals (Sweden)

    H. Gleisner

    2012-07-01

    Full Text Available The possibility of simplifying the retrieval scheme required to produce GNSS radio occultation refractivity climatologies is investigated. In a new, simplified retrieval approach, the main statistical analysis is performed in bending angle space and an estimate of the average bending angle profile is then propagated through an Abel transform. The average is composed of means and medians of ionospheric corrected bending angles up to 80 km. Above that, the observed profile is exponentially extrapolated to infinity using a fixed a priori scale height. The new approach circumvents the need to introduce a "statistical optimization" processing step in which individual bending-angle profiles are merged with a priori data, often taken from a climatology. This processing step can be complex, difficult to interpret, and is generally recognized as a potential source of structural uncertainty. The new scheme is compared with the more conventional approach of averaging individual refractivity profiles, produced with the implementation of statistical optimization used in the EUMETSAT Radio Occultation Meteorology Satellite Application Facility (ROM SAF operational processing. It is shown that the two GNSS radio occultation climatologies agree to within 0.1% from 5 km up to 35–40 km, for the three months January, February, and March 2011. During this time period, the new approach also produces slightly better agreement with ECMWF analyses between 40–50 km, which is encouraging. The possible limitations of the new approach caused by mean residual ionospheric errors and low observation numbers are discussed briefly, and areas for future work are suggested.

  19. Radio resource management for next generation mobile communication systems

    DEFF Research Database (Denmark)

    Wang, Hua

    technological novelties. Those technological breaks impose significant challenges on the design of advanced and completely new Radio Resource Management (RRM) algorithms, such as channel assignments and packet scheduling. Among the emerging technologies for broadband wireless access, special attention has been...... paid on IEEE 802.16 based technology, also known as WiMAX, for its capability to support high transmission rates and diverse QoS requirements. The objective of this Ph.D. thesis has two-fold: to design advanced RRM algorithms with different QoS support in single-hop 802.16j relay network, from physical...

  20. A Multi-Feed Receiver in the 18 to 26.5 GHz Band for Radio Astronomy

    Science.gov (United States)

    Orfei, A.; Carbonaro, L.; Cattani, A.; Cremonini, A.; Cresci, L.; Fiocchi, F.; Maccaferri, A.; Maccaferri, G.; Mariotti, S.; Monari, J.; Morsiani, M.; Natale, V.; Nesti, R.; Panella, D.; Poloni, M.; Roda, J.; Scalambra, A.; Tofani, G.

    2010-08-01

    A large-bandwidth, state-of-the-art multi-feed receiver has been constructed to be used on the new 64 m Sardinia Radio Telescope (SRT) (http://www.srt.inaf.itl), an antenna aiming to work from 300 MHz to 100 GHz with an almost continuous frequency coverage. The goal of this new receiver is to speed up the survey of the sky with high sensitivity in a frequency band that is very interesting to radio astronomers. In the meantime, the antenna erection has been finalized, and the receiver has been mounted on the Medicina 32 m antenna to be tested (http://www.med.ira.inaf.itl). We present a complete description of the system, including a dedicated backend, and the results of the tests.

  1. Generation of a Bending Angle Radio Occultation Climatology (BAROCLIM and its use in radio occultation retrievals

    Directory of Open Access Journals (Sweden)

    B. Scherllin-Pirscher

    2014-08-01

    Full Text Available In this paper, we introduce a bending angle radio occultation climatology (BAROCLIM based on Formosat-3/COSMIC (F3C data. This climatology represents the monthly-mean atmospheric state from 2006 to 2012. Bending angles from radio occultation (RO measurements are obtained from the accumulation of the change in the raypath direction of Global Positioning System (GPS signals. Best quality of these near-vertical profiles is found from the middle troposphere up to the mesosphere. Beside RO bending angles we also use data from the Mass Spectrometer and Incoherent Scatter Radar (MSIS model to expand BAROCLIM in a spectral model, which (theoretically reaches from the surface up to infinity. Due to the very high quality of BAROCLIM up to the mesosphere, it can be used to detect deficiencies in current state-of-the-art analysis and reanalysis products from numerical weather prediction (NWP centers. For bending angles derived from European Centre for Medium-Range Weather Forecasts (ECMWF analysis fields from 2006 to 2012, e.g., we find a positive bias of 0.5% to % at 40 km, which increases to more than 2% at 50 km. BAROCLIM can also be used as a priori information in RO profile retrievals. In contrast to other a priori information (i.e., MSIS we find that the use of BAROCLIM better preserves the mean of raw RO measurements. Global statistics of statistically optimized bending angle and refractivity profiles also confirm that BAROCLIM outperforms MSIS. These results clearly demonstrate the utility of BAROCLIM.

  2. Elementary astronomy

    Science.gov (United States)

    Fierro, J.

    2006-08-01

    In developing nations such as Mexico, basic science education has scarcely improved. There are multiple reasons for this problem; they include poor teacher training and curricula that are not challenging for students. I shall suggest ways in which astronomy can be used to improve basic education, it is so attractive that it can be employed to teach how to read and write, learn a second language, mathematics, physics, as well as geography. If third world nations do not teach science in an adequate way, they will be in serious problems when they will try to achieve a better standard of living for their population. I shall also address informal education, it is by this means that most adults learn and keep up to date with subjects that are not their specialty. If we provide good outreach programs in developing nations we can aid adult training; astronomy is ideal since it is particularly multidisciplinary. In particular radio and television programs are useful for popularization since they reach such wide audiences.

  3. Comparison of Site Velocities Derived from Collocated GPS, VLBI and SLR Techniques at The Hartebeesthoek Radio Astronomy Observatory (Comparison of Site Velocities

    Directory of Open Access Journals (Sweden)

    Munghemezulu C.

    2014-04-01

    Full Text Available Space geodetic techniques provide highly accurate methods for estimating bedrock stability at subcentimetre level. We utilize data derived from Satellite Laser Ranging (SLR, Very Long Baseline Interferometry (VLBI and Global Positioning Systems (GPS techniques, collocated at the Hartebeesthoek Radio Astronomy Observatory, to characterise local plate motion and compare the solutions from the three techniques. Data from the GNSS station were processed using the GAMIT/GLOBK (version 10.4 software, data from the SLR station (MOBLAS-6were processed using the Satellite Laser Ranging Data Analysis Software (SDAS and the VLBI data sets were processed using the Vienna VLBI Software (VieVS software. Results show that there is a good agreement between horizontal and vertical velocity components with a maximum deviation of 1.7 mm/yr, 0.7 mm/yr and 1.3 mm/yr between the North, East and Up velocity components respectively for the different techniques. At HartRAO there is no significant trend in the vertical component and all the techniques used are consistent with the a-priori velocities when compared with each other. This information is crucial in monitoring the local motion variations since geodetic instruments require a very stable base to minimise measurement errors. These findings demonstrate that station coordinate time-series derived with different techniques and analysis strategies provide comparable results.

  4. Multi-Purpose Radio Signal Generation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The MRSiG will be able to replace many of the expensive, highly specialized RF signal generators with cheaper generic boxes that can be customized as the...

  5. The New Generation Atlas of Quasar Spectral Energy Distributions from Radio to X-rays

    CERN Document Server

    Shang, Zhaohui; Wills, Beverley J; Wills, Derek; Cales, Sabrina; Dale, Daniel A; Green, Richard F; Runnoe, Jessie; Nemmen, Rodrigo S; Gallagher, Sarah; Ganguly, Rajib; Hines, Dean C; Kelly, Benjamin; Kriss, Gerard A; Li, Jun; Tang, Baitian; Xie, Yanxia

    2011-01-01

    We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. (1994) by using high-quality data obtained with several space and ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58 radio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical spectroscopic data, supplemented with some far-ultraviolet spectra, and more than half also have Spitzer mid-infrared IRS spectra. The X-ray spectral parameters are collected from the literature where available. The radio, far-infrared, and near-infrared photometric data are also obtained from either the literature or new observations. We construct composite spectral energy distributions for radio-loud and radio-quiet objects and compare these to those of Elvis et al., finding that ours have similar...

  6. School-Based Extracurricular Astronomy

    Science.gov (United States)

    Stanger, Jeffrey J.

    2010-01-01

    The International Year of Astronomy in 2009 focused considerable public attention on Astronomy and generated valuable resources for educators. These activities are an effective vehicle for promoting Science to students and to the wider school community. The most engaging practical astronomy activities are best delivered with sustained support from…

  7. School-Based Extracurricular Astronomy

    Science.gov (United States)

    Stanger, Jeffrey J.

    2010-01-01

    The International Year of Astronomy in 2009 focused considerable public attention on Astronomy and generated valuable resources for educators. These activities are an effective vehicle for promoting Science to students and to the wider school community. The most engaging practical astronomy activities are best delivered with sustained support from…

  8. Dynamic modes of microwave signal autogeneration in a radio photonic ring generator

    Science.gov (United States)

    Kondrashov, A. V.; Ustinov, A. B.; Kalinikos, B. A.

    2017-02-01

    Dynamic modes of microwave signal autogeneration in a radio photonic generator have been investigated. The generator is a ring circuit with a low-pass filter and microwave amplifier in its microwave path. The optical path contains an optical fiber delay line. The generator demonstrates the periodical, chaotic, and noise dynamics. It has been shown that the correlation dimensionality of the random signal attractor in the chaotic generation mode saturates with increasing phase space dimensionality. Saturation is not observed in the noise-generation mode.

  9. Solid state generator for powerful radio frequency ion sources in neutral beam injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, W.; Fantz, U.; Heinemann, B.; Franzen, P.

    2015-02-15

    Radio frequency ion sources used in neutral beam injection systems (NBI) of fusion machines are currently supplied by self-excited RF generators. These generators have both a low power efficiency and a limited frequency stability, therefore transistorized amplifiers are being considered for the power supply of the next generation of RF sources. A 75 kW generator, originally designed for broadcasting, has been tested with a negative ion source. High operational reliability and a very good matching to the plasma load has been demonstrated. These results make this generator type a very promising candidate for future NBI systems.

  10. Surface plasma source with saddle antenna radio frequency plasma generator.

    Science.gov (United States)

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  11. FURTHER OBSERVATIONS OF PLANETS AND QUASI-STELLAR RADIO SOURCES AT 3 MM.

    Science.gov (United States)

    EXTRATERRESTRIAL RADIO WAVES), (* MERCURY ( PLANET ), (*RADIO ASTRONOMY, EXTRATERRESTRIAL RADIO WAVES), PLANETARY ATMOSPHERES, SKY BRIGHTNESS, ANTENNAS...EPHEMERIDES, ASTROPHYSICS, JUPITER( PLANET ), VENUS( PLANET ), BRIGHTNESS, ATMOSPHERIC TEMPERATURE, INTENSITY, MEASUREMENT.

  12. Blind search for 21-cm absorption systems using a new generation of Chinese radio telescopes

    Science.gov (United States)

    Yu, Hao-Ran; Pen, Ue-Li; Zhang, Tong-Jie; Li, Di; Chen, Xuelei

    2017-05-01

    Neutral hydrogen clouds are known to exist in the Universe, however their spatial distributions and physical properties are poorly understood. Such missing information can be studied by the new generation of Chinese radio telescopes through a blind search of 21-cm absorption systems. We forecast the capabilities of surveys of 21-cm absorption systems by two representative radio telescopes in China -the Five-hundred-meter Aperture Spherical radio Telescope (FAST) and Tianlai 21-cm cosmology experiment (Tianlai). Facilitated by either the high sensitivity (FAST) or wide field of view (Tianlai) of these telescopes, more than a thousand 21-cm absorption systems can be discovered in a few years, representing orders of magnitude improvement over the cumulative discoveries in the past half a century.

  13. Radio Telescope Focal Container for the Russian VLBI Network of New Generation

    Science.gov (United States)

    Ipatov, Alexander; Mardyshkin, Vyacheslav; Cherepanov, Andrey; Chernov, Vitaly; Diky, Dmitry; Khvostov, Evgeny; Yevstigneyev, Alexander

    2010-01-01

    This article considers the development of the structure of receivers for Russian radio telescopes. The development of these radio telescopes is undertaken within the project for creating a Russian small-antenna-based radio interferometer of new generation. It is shown that for small antennas (10. 12 meter) the principal unit, which provides the best SNR, is the so-called focal container placed at primary focus. It includes the primary feed, HEMT LNA, and cryogenic cooling system down to 20. K. A new multi-band feed based on traveling wave resonators is used. It has small dimensions, low weight, and allows working with circular polarizations. Thus it can be placed into focal container and cooled with the LNA. A sketch of the focal container, with traveling-wave-resonator feed, and calculations of the expected parameters of the multi-band receiver are presented.

  14. Concept study for the next generation medium-energy gamma-ray astronomy mission: MEGA

    Science.gov (United States)

    Kanbach, Gottfried; Andritschke, Robert; Bloser, Peter F.; Schopper, Florian; Schoenfelder, Volker; Zoglauer, Andreas

    2003-03-01

    A new telescope for Medium Energy Gamma-Ray Astronomy, MEGA, is being developed for the energy band 0.4 - 50 MeV as a successor to COMPTEL on CGRO. MEGA aims to improve the sensitivity for astronomical sources by at least an order of magnitude with respect to past instruments and will fill a severe sensitivity gap between already scheduled hard-X-ray and high-energy gamma-ray missions. MEGA records and images gamma rays by completely tracking Compton and pair creation events in a stack of double sided Si-strip track detectors surrounded by a pixelated CsI calorimeter. MEGA will have an effective area of ~100 square cm, a large field of view of ~130 degrees, angular resolution of ~2 degrees, and energy resolution of ~8% (all FWHM at ~2 MeV). Key science objectives for MEGA are the investigation of cosmic high-energy accelerators, nucleosynthesis sites with gamma-ray lines, and the mapping of large-scale structures in the Galaxy and beyond. If operated on a zenith pointing satellite MEGA will be an ideal continuous all-sky monitor for transient sources. This paper describes the development of a small scale prototype and the concept of a space mission for MEGA.

  15. Astronomy and Culture

    Science.gov (United States)

    Stavinschi, M.

    2006-08-01

    Astronomy is, by definition, the sum of the material and spiritual values created by mankind and of the institutions necessary to communicate these values. Consequently, astronomy belongs to the culture of each society and its scientific progress does nothing but underline its role in culture. It is interesting that there is even a European society which bears this name "Astronomy for Culture" (SEAC). Its main goal is "the study of calendric and astronomical aspects of culture". Owning ancient evidence of astronomical knowledge, dating from the dawn of the first millennium, Romania is interested in this topic. But Astronomy has a much deeper role in culture and civilization. There are many aspects that deserve to be discussed. Examples? The progress of astronomy in a certain society, in connection with its evolution; the place held by the astronomy in literature and, generally, in art; the role of the SF in the epoch of super-mediatization; astronomy and belief; astronomy and astrology in the modern society, and so forth. These are problems that can be of interest for IAU, but the most important one could be her educational role, in the formation of the culture of the new generation, in the education of the population for the protection of our planet, in the ensuring of a high level of spiritual development of the society in the present epoch.

  16. Strategic Plan for Astronomy in the Netherlands 2011-2020

    OpenAIRE

    Groot, P. J. (Paul J.); Kuijken, K.; Stark, R.

    2012-01-01

    Strategic Plan for Astronomy in the Netherlands 2011 - 2020, written by the Netherlands Committee for Astronomy (NCA), on behalf of the excellence research school in astronomy NOVA, (combining the university astronomy institutes of the universities of Amsterdam, Groningen, Leiden and Nijmegen), the NWO division of Physical Sciences, the Netherlands Institute for Radio Astronomy ASTRON and the Netherlands Institute for Space Research SRON. The Strategic plan outlines the scientific priorities ...

  17. Big Computing in Astronomy: Perspectives and Challenges

    Science.gov (United States)

    Pankratius, Victor

    2014-06-01

    Hardware progress in recent years has led to astronomical instruments gathering large volumes of data. In radio astronomy for instance, the current generation of antenna arrays produces data at Tbits per second, and forthcoming instruments will expand these rates much further. As instruments are increasingly becoming software-based, astronomers will get more exposed to computer science. This talk therefore outlines key challenges that arise at the intersection of computer science and astronomy and presents perspectives on how both communities can collaborate to overcome these challenges.Major problems are emerging due to increases in data rates that are much larger than in storage and transmission capacity, as well as humans being cognitively overwhelmed when attempting to opportunistically scan through Big Data. As a consequence, the generation of scientific insight will become more dependent on automation and algorithmic instrument control. Intelligent data reduction will have to be considered across the entire acquisition pipeline. In this context, the presentation will outline the enabling role of machine learning and parallel computing.BioVictor Pankratius is a computer scientist who joined MIT Haystack Observatory following his passion for astronomy. He is currently leading efforts to advance astronomy through cutting-edge computer science and parallel computing. Victor is also involved in projects such as ALMA Phasing to enhance the ALMA Observatory with Very-Long Baseline Interferometry capabilities, the Event Horizon Telescope, as well as in the Radio Array of Portable Interferometric Detectors (RAPID) to create an analysis environment using parallel computing in the cloud. He has an extensive track record of research in parallel multicore systems and software engineering, with contributions to auto-tuning, debugging, and empirical experiments studying programmers. Victor has worked with major industry partners such as Intel, Sun Labs, and Oracle. He holds

  18. Early Astronomy

    Science.gov (United States)

    Thurston, Hugh

    The earliest investigations that can be called scientific are concerned with the sky: they are the beginnings of astronomy. Many early civilizations produced astronomical texts, and several cultures that left no written records left monuments and artifacts-ranging from rock paintings to Stonehenge-that show a clear interest in astronomy. Civilizations in China, Mesopotamia, India and Greece had highly developed astronomies, and the astronomy of the Mayas was by no means negligible. Greek astronomy, as developed by the medieval Arab philosophers, evolved into the astronomy of Copernicus. This displaced the earth from the central stationary position that almost all earlier astronomies had assumed. Soon thereafter, in the first decades of the seventeenth century, Kepler found the true shape of the planetary orbits and Galileo introduced the telescope for astronomical observations.

  19. 64-GHz millimeter-wave photonic generation with a feasible radio over fiber system

    Science.gov (United States)

    Al-Dabbagh, Rasha K.; Al-Raweshidy, Hamed S.

    2017-02-01

    A full-duplex radio over fiber (RoF) link with the generation of a 64-GHz millimeter wave (mm-wave) is investigated. This system is proposed as a solution to cope with the demands of a multi-Gb/s data transmission in the fifth generation (5G) and beyond for small cell networks. Cost reduction and performance improvement are achieved by simplifying the mm-wave generation method with an RoF technique. High-frequency radio signals are considered challenging in the electrical generation domain; therefore, our photonic generation method is introduced and examined. RoF design is proposed for mm-wave generation using both phase modulation and the effect of stimulated Brillouin scattering in the optical fiber for the first time. RoF system with transmission rates of 5 Gb/s is successfully achieved. In our scheme, one laser source is utilized and a fiber Bragg grating is used for wavelength reuse for the uplink connection. Stable mm-wave RoF link is successfully achieved in up to a 100-km fiber link length with high quality carrier. Simulation results show a reduction in fiber nonlinearity effects and the mm-wave signal has low noise equal to -75 dBm. This study ensures a practical mm-wave RoF link, and it could be appropriate for small cell 5G networks by reducing the installation cost.

  20. Rotman Lens-Based Circular Array for Generating Five-mode OAM Radio Beams

    Science.gov (United States)

    Bai, Xu-Dong; Liang, Xian-Ling; Li, Jian-Ping; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2016-06-01

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams remain up to now mainly at simulation level, since their implementations are of complicated structure and very high cost. This paper provides an effective design of generating five-mode OAM radio beams by using the Rotman lens-fed antenna array. The Rotman lens is a viable beamforming approach instead of electronically scanned arrays for its low cost and the ease of implementation. The lens-fed array employs a two-layer structure for size reduction, and the lens body and the antenna array are segregated by a common ground plane to eliminate spurious radiation and thus improve the performance of the OAM beams. The measured results coincide with the simulated ones, which verified the effectiveness of the proposed design for generating multi-mode OAM beams.

  1. Searches for radio transients

    CERN Document Server

    Bhat, N D R

    2011-01-01

    Exploration of the transient Universe is an exciting and fast-emerging area within radio astronomy. Known transient phenomena range in time scales from sub-nanoseconds to years or longer, thus spanning a huge range in time domain and hinting a rich diversity in their underlying physical processes. Transient phenomena are likely locations of explosive or dynamic events and they offer tremendous potential to uncover new physics and astrophysics. A number of upcoming next-generation radio facilities and recent advances in computing and instrumentation have provided a much needed impetus for this field which has remained a relatively uncharted territory for the past several decades. In this paper we focus mainly on the class of phenomena that occur on very short time scales (i.e. from $\\sim$ milliseconds to $\\sim$ nanoseconds), known as {\\it fast transients}, the detections of which involve considerable signal processing and data management challenges, given the high time and frequency resolutions required in the...

  2. 射电天文终端电子设备辐射特性测试%Measurements of Radiation Characteristics of a Set of Electronic Backend Devices for Radio Astronomy

    Institute of Scientific and Technical Information of China (English)

    刘奇; 王凯; 王洋; 刘烽

    2014-01-01

    In the developing radio astronomy increasingly more high-speed digital backend systems and control systems are being used , worsening electromagnetic environments for observation .Measurement of radiation characteristics of such electronic devices can help mitigate Radio Frequency Interferences ( RFI) with the shielding technology .To meet the requirements of electromagnetic compatibility of the system improvement for the XJAO ( Xinjiang Astronomical Observatory ) Nanshan 25m telescope and the design of the planned XJAO 110m telescope , we have developed a system to measure radiation characteristics of electronic devices in radio astronomy .We have calibrated the system using a noise source Agilent 346C and the Y-factor method .Using the system we can obtain the radiation spectra of each electronic device in its on and off statuses with other devices turned off .We present some processed spectra of the backend systems of the Nanshan 25m telescope so measured by this system .The presentation includes their calibration and plots .The spectra show the radiation characteristics .Overall our system can provide RFI data for effective analyses , and thus it can appreciably help improving and designing systems in radio astronomy .It should have significant engineering applications .%针对新疆乌鲁木齐市南山25 m射电望远镜终端电磁屏蔽改造,以及新疆拟建的110 m射电望远镜电磁兼容性设计等需求,开发了电子设备辐射特性测试系统,基于标准噪声源Agilent346C,运用Y因子法对系统进行校准。通过关闭其它电子设备,分别打开和关闭测试设备获得环境电平频谱和设备辐射频谱;对测试数据进行了数据处理、成图与分析;给出了25 m射电望远镜典型终端电子设备的辐射频谱。针对终端电子设备辐射特性测试与分析,对系统电磁屏蔽改造提供重要依据。

  3. The future of astronomy in Australia

    Science.gov (United States)

    Sadler, Elaine M.

    2017-09-01

    Australian astronomy has a bright future, thanks largely to recent government investments in major new telescopes, instruments and research centres. There are some short-term challenges as Australia's focus continues to shift from the current (mainly) national facilities for radio and optical astronomy to new multinational and global facilities.

  4. Evolution of a Reconfigurable Processing Platform for a Next Generation Space Software Defined Radio

    Science.gov (United States)

    Kacpura, Thomas J.; Downey, Joseph A.; Anderson, Keffery R.; Baldwin, Keith

    2014-01-01

    The National Aeronautics and Space Administration (NASA)Harris Ka-Band Software Defined Radio (SDR) is the first, fully reprogrammable space-qualified SDR operating in the Ka-Band frequency range. Providing exceptionally higher data communication rates than previously possible, this SDR offers in-orbit reconfiguration, multi-waveform operation, and fast deployment due to its highly modular hardware and software architecture. Currently in operation on the International Space Station (ISS), this new paradigm of reconfigurable technology is enabling experimenters to investigate navigation and networking in the space environment.The modular SDR and the NASA developed Space Telecommunications Radio System (STRS) architecture standard are the basis for Harris reusable, digital signal processing space platform trademarked as AppSTAR. As a result, two new space radio products are a synthetic aperture radar payload and an Automatic Detection Surveillance Broadcast (ADS-B) receiver. In addition, Harris is currently developing many new products similar to the Ka-Band software defined radio for other applications. For NASAs next generation flight Ka-Band radio development, leveraging these advancements could lead to a more robust and more capable software defined radio.The space environment has special considerations different from terrestrial applications that must be considered for any system operated in space. Each space mission has unique requirements that can make these systems unique. These unique requirements can make products that are expensive and limited in reuse. Space systems put a premium on size, weight and power. A key trade is the amount of reconfigurability in a space system. The more reconfigurable the hardware platform, the easier it is to adapt to the platform to the next mission, and this reduces the amount of non-recurring engineering costs. However, the more reconfigurable platforms often use more spacecraft resources. Software has similar considerations

  5. Generation of the jovian radio emission by the maser cyclotron instability: first lessons from JUNO

    Science.gov (United States)

    Louarn, Philippe; Allegrini, Frederic; Kurth, WilliamS.; Valek, Philips. W.; McComas, Dave; Bagenal, Fran; Bolton, Scott; Connerney, John; Ebert, Robert W.; Levin, Steven; Szalay, Jamey; Wilson, Robert; Zink, Jenna; André, Nicolas; Imai, Masafumi

    2017-04-01

    Using JUNO plasma and wave observations (JADE and Waves instruments), the scenario for the generation of jovian auroral radio emissions are analyzed. The sources of radiation are identified by localized intensifications of the radio flux at frequencies close to the electron gyrofrequency. Not surprisingly, it is shown that the cyclotron maser instability is perfectly adapted to the plasma conditions prevailing in the radio sources. However, it appears that different forms of activation of the cyclotron maser are observed. For radiation at hectometric wavelengths (one of the main emissions), pronounced loss-cones in the electron distribution functions are likely the source of free energy. The sources would be extended over several thousand km in directions traverse to the magnetic field. The applications of the theory reveals that sufficient growth rates are obtained from the distributions functions that are actually measured by JADE. This differs from the Earth scenario for which 'trapped' distribution functions drive the maser. More localized sources are also observed, possibly linked to local acceleration process. These examples may present analogies with the 'Earth' scenario, with other forms of free energy than the loss-cone. A first lesson of these direct in-situ JADE and RPWS observations is thus to confirm the maser cyclotron scenario with, however, conditions for the wave amplification and detailed maser processes that appear to be different than at Earth.

  6. Experimental Array for Generating Dual Circularly-Polarized Dual-Mode OAM Radio Beams

    Science.gov (United States)

    Bai, Xu-Dong; Liang, Xian-Ling; Sun, Yun-Tao; Hu, Peng-Cheng; Yao, Yu; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2017-01-01

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams. The antenna consists of four dual-CP elements which are sequentially rotated 90 degrees in the clockwise direction. Different from all previous published research relating to OAM generation by phased arrays, the four elements are fed with the same phase for both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). The dual-mode operation for OAM is achieved through the opposite phase differences generated for LHCP and RHCP, when the dual-CP elements are sequentially rotated in the clockwise direction. The measured results coincide well with the simulated ones, which verified the effectiveness of the proposed design.

  7. Generating topological optical flux lattices for ultracold atoms by modulated Raman and radio-frequency couplings

    Science.gov (United States)

    Yu, Jinlong; Xu, Zhi-Fang; You, Li

    2017-01-01

    We propose a scheme to dynamically generate optical flux lattices with nontrivial band topology using amplitude-modulated Raman lasers and radio-frequency (rf) magnetic fields. By tuning the strength of Raman and rf fields, three distinct phases are realized at unit filling for a unit cell. Respectively, these three phases correspond to normal insulator, topological Chern insulator, and semimetal. Nearly nondispersive bands are found to appear in the topological phase, which promises opportunities for investigating strongly correlated quantum states within a simple cold-atom setup. The validity of our proposal is confirmed by comparing the Floquet quasienergies from the evolution operator with the spectrum of the effective Hamiltonian.

  8. Unseen cosmos the universe in radio

    CERN Document Server

    Graham-Smith, Francis

    2013-01-01

    Radio telescopes have transformed our understanding of the Universe. Pulsars, quasars, Big Bang cosmology: all are discoveries of the new science of radio astronomy. Here, Francis Graham-Smith describes the birth, development, and maturity of radio astronomy, from the first discovery of cosmic radio waves to its present role as a major part of modern astronomy. Radio is part of the electromagnetic spectrum, covering infra-red, visible light, ultraviolet, X-rays, and gamma-rays, and Graham-Smith explains why it is that radio waves give us a unique view of the Universe. Tracing the development o

  9. Handbook of pulsar astronomy

    CERN Document Server

    Lorimer, Duncan

    2005-01-01

    Radio pulsars are rapidly rotating highly magnetized neutron stars. Studies of these fascinating objects have provided applications in solid-state physics, general relativity, galactic astronomy, astrometry, planetary physics and even cosmology. Most of these applications and much of what we know about neutron stars are derived from single-dish radio observations using state-of-the-art receivers and data acquisition systems. This comprehensive 2004 book is a unique resource that brings together the key observational techniques, background information and a review of results, including the discovery of a double pulsar system. Useful software tools are provided which can be used to analyse example data, made available on a related website. This work will be of great value not only to graduate students but also to researchers wishing to carry out and interpret a wide variety of radio pulsar observations.

  10. Dual-polarization and dual-mode orbital angular momentum radio vortex beam generated by using reflective metasurface

    Science.gov (United States)

    Yu, Shixing; Li, Long; Shi, Guangming

    2016-08-01

    A metasurface, which is composed of printed cross-dipole elements with different arm lengths, is designed, fabricated, and experimentally demonstrated to generate orbital angular momentum (OAM) vortex waves of dual polarizations and dual modes in the radio frequency domain simultaneously. The prototype of a practical metasurface is fabricated and measured to validate the results of theoretical analysis and design at 5.8 GHz. Numerical and experimental results verify that vortex waves with dual OAM modes and dual polarizations can be flexibly generated by using a reflective metasurface. The proposed method paves a way to generate diverse OAM vortex waves for radio frequency and microwave wireless communication applications.

  11. Control and Non-Payload Communications Generation 1 Prototype Radio Flight Test Report

    Science.gov (United States)

    Shalkhauser, Kurt A.; Young, Daniel P.; Bretmersky, Steven C.; Ishac, Joseph A.; Walker, Steven H.; Griner, James H.; Kachmar, Brian A.

    2014-01-01

    regularity of flight. Only recently has radiofrequency (RF) spectrum been allocated by the International Telecommunications Union specifically for commercial UA C2, LOS communication (L-Band: 960 to 1164 MHz, and C-Band: 5030 to 5091 MHz). The safe and efficient integration of UA into the NAS requires the use of protected RF spectrum allocations and a new data communications system that is both secure and scalable to accommodate the potential growth of these new aircraft. Data communications for UA-referred to as control and non-payload communications (CNPC)-will be used to exchange information between a UA and a ground station (GS) to ensure safe, reliable, and effective UA flight operation. The focus of this effort is on validating and allocating new RF spectrum and data link communications to enable civil UA integration into the NAS. Through a cost-sharing cooperative agreement with Rockwell Collins, Inc., the NASA Glenn Research Center is exploring and performing the necessary development steps to realize a prototype UA CNPC system. These activities include investigating signal waveforms and access techniques, developing representative CNPC radio hardware, and executing relevant testing and validation activities. There is no intent to manufacture the CNPC end product, rather the goals are to study, demonstrate, and validate a typical CNPC system that will allow safe and efficient communications within the L-Band and C-Band spectrum allocations. The system is addressing initial "seed" requirements from RTCA, Inc., Special Committee 203 (SC-203) and is on a path to Federal Aviation Administration certification. This report provides results from the flight testing campaign of the Rockwell Collins Generation 1 prototype radio, referred hereafter as the "radio." The radio sets operate within the 960- to 977-MHz frequency band with both air and ground radios using identical hardware. Flight tests involved one aircraft and one GS. Results include discussion of aircraft flight

  12. Greek astronomy

    CERN Document Server

    Heath, Sir Thomas L

    2011-01-01

    Astronomy as a science began with the Ionian philosophers, with whom Greek philosophy and mathematics also began. While the Egyptians and Babylonians had accomplished much of astronomical worth, it remained for the unrivalled speculative genius of the Greeks, in particular, their mathematical genius, to lay the foundations of the true science of astronomy. In this classic study, a noted scholar discusses in lucid detail the specific advances made by the Greeks, many of whose ideas anticipated the discoveries of modern astronomy.Pythagoras, born at Samos about 572 B.C., was probably the first

  13. Career Outcomes for Astronomy Ph.D. Graduates of the University of Texas at Austin: The Next Generation

    Science.gov (United States)

    Dinerstein, Harriet L.

    2011-01-01

    Sixteen years ago I conducted a survey of the career trajectories and outcomes of 78 individuals who earned Ph.D.s from the Department of Astronomy at the University of Texas at Austin during the period 1984-1995 (Dinerstein, H. 1996, AAS, 189.0501). In the current poster I extend these statistics up to the present, adding 68 Ph.D. recipients from 1996-2010. This is a sufficiently large sample to search for secular trends such as possible changes in duration of the postdoctoral stage, redistribution of demographics among different kinds of long-term positions, and the emergence of new categories of astronomy-related employment. The picture is less discouraging than one might expect. As of 2010, about 75% of the Texas graduates 7 - 14 years past the Ph.D. are still doing astronomy, and most of those in non-astronomical careers left the field by choice (and often have had considerable success in their alternate careers). Of those 6 years or less past the Ph.D., 50% were in postdoctoral positions and less than 10% had left astronomy. Recent reconsiderations of the employment market (Metcalfe, T.S. 2008, PASP, 120, 229; Seth, A. 2009, Astro2010: The Astronomy and Astrophysics Decadal Survey, Position Paper No. 51) make the point that a typical astronomer who ultimately achieves a permanent position will have held two or three prior temporary positions; this was equally true three decades ago. There has been notable growth nationwide in the number of astronomers employed as faculty at small liberal arts colleges and other undergraduate-centered institutions, a trend that to some degree was anticipated by the University of Texas cohort, which included a number of students for whom this was their personal goal. In a world where job certainty is no longer so prevalent, motivated and resourceful astronomers are finding ways to remain active members of our community.

  14. Fundamental Astronomy

    CERN Document Server

    Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

    2007-01-01

    Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

  15. Astronomy Communication

    Science.gov (United States)

    Heck, A.; Madsen, C.

    2003-07-01

    Astronomers communicate all the time, with colleagues of course, but also with managers and administrators, with decision makers and takers, with social representatives, with the news media, and with the society at large. Education is naturally part of the process. Astronomy communication must take into account several specificities: the astronomy community is rather compact and well organized world-wide; astronomy has penetrated the general public remarkably well with an extensive network of associations and organizations of aficionados all over the world. Also, as a result of the huge amount of data accumulated and by necessity for their extensive international collaborations, astronomers have pioneered the development of distributed resources, electronic communications and networks coupled to advanced methodologies and technologies, often much before they become of common world-wide usage. This book is filling up a gap in the astronomy-related literature by providing a set of chapters not only of direct interest to astronomy communication, but also well beyond it. The experts contributing to this book have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy nor in communication techniques while providing specific detailed information, as well as plenty of pointers and bibliographic elements. This book will be very useful for researchers, teachers, editors, publishers, librarians, computer scientists, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as for students aiming at a career in astronomy or related space science. Link: http://www.wkap.nl/prod/b/1-4020-1345-0

  16. Spectral Structures and Their Generation Mechanisms for Solar Radio Type-I Bursts

    CERN Document Server

    Iwai, Kazumasa; Masuda, Satoshi; Tsuchiya, Fuminori; Morioka, Akira; Misawa, Hiroaki

    2014-01-01

    The fine spectral structures of solar radio type-I bursts were observed by the solar radio telescope AMATERAS. The spectral characteristics, such as the peak flux, duration, and bandwidth, of the individual burst elements were satisfactorily detected by the highly resolved spectral data of AMATEAS with the burst detection algorithm that is improved in this study. The peak flux of the type-I bursts followed a power-law distribution with a spectral index of 2.9-3.3, whereas their duration and bandwidth were distributed more exponentially. There were almost no correlations between the peak flux, duration, and bandwidth. That means there were no similarity shapes in the burst spectral structures. We defined the growth rate of a burst as the ratio between its peak flux and duration. There was a strong correlation between the growth rate and peak flux. These results suggest that the free energy of type-I bursts that is originally generated by non-thermal electrons is modulated in the subsequent stages of the genera...

  17. Reminiscence of my Sixty-five year Voyage in Astronomy

    Science.gov (United States)

    Wang, Shouguan

    2016-06-01

    I returned to China from the United Kingdom in 1953, then worked in Purple Mountain Observatory. It was the early days of new China. The elder generation of astronomers was undertaking an effort of “repairing broken and filling defect” during those post-war years, and started planning and laying the foundation of modern astronomy. Under their leadership, I started a journey of astronomy whose main task was construction. The journey has been full of twists and turns. As a result of the “Great Leap Forward” in 1958 and the 1966 launch of the decade-long “Cultural Revolution” period, the situation of construction in astronomy was similar to that in other sciences, suffering bad effects. Not until the “Reform and Opening up” period after those events was construction able to continue, and various disciplines and international connections began to open. A “passage” had gradually developed. In this new circumstance, I kept pursuing the pioneers to explore a forward direction. Looking back today, this journey has been three periods of a four generation relay. This article is divided into three sections that describe my research work in these times that I recall: (1) Looking back at the beginning of the return and tracing the footprints of the founders. (2) Recalling my radio astronomy tour. (3) Retrospection and expectation of LAMOST.

  18. Recent Advances in Programmable Photonic-Assisted Ultrabroadband Radio-Frequency Arbitrary Waveform Generation

    CERN Document Server

    Rashidinejad, Amir; Weiner, Andrew M

    2015-01-01

    This paper reviews recent advances in photonic-assisted radio-frequency arbitrary waveform generation (RF-AWG), with emphasis on programmable ultrabroadband microwave and millimeter-wave waveforms. The key enabling components in these techniques are programmable optical pulse shaping, frequency-to-time mapping via dispersive propagation, and high-speed photodetection. The main advantages and challenges of several different photonic RF-AWG schemes are discussed. We further review some proof-of-concept demonstrations of ultrabroadband RF-AWG applications, including high-resolution ranging and ultrabroadband non-line-of-sight channel compensation. Finally, we present recent progress toward RF-AWG with increased time aperture and time-bandwidth product.

  19. Polyphase Multipath Circuits for Cognitive Radio and Flexible Multi-phase Clock Generation

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Gao, Xiang; Nauta, Bram

    2009-01-01

    Abstract: In this chapter we discuss flexible cognitive radio circuits for dynamic access of unused spectrum. Ideally, such circuits can work at an arbitrary radio frequency (RF). We review techniques to realize radios without resorting to frequency selective dedicated filters, in particular a recen

  20. ADDITIONAL OBSERVATIONS OF PLANETS AND QUASI-STELLAR RADIO SOURCES AT 3 MM,

    Science.gov (United States)

    MERCURY ( PLANET ), VENUS( PLANET ), PERIODIC VARIATIONS, RADIO ASTRONOMY, SPECTRUM SIGNATURES...EXTRATERRESTRIAL RADIO WAVES, SOURCES), GALAXIES, BLACKBODY RADIATION, BRIGHTNESS, TEMPERATURE, MARS( PLANET ), JUPITER( PLANET ), SATURN( PLANET

  1. South African Student Constructed Indlebe Radio Telescope

    Science.gov (United States)

    McGruder, Charles H.; MacPherson, Stuart; Janse Van Vuuren, Gary Peter

    2017-01-01

    The Indlebe Radio Telescope (IRT) is a small transit telescope with a 5 m diameter parabolic reflector working at 21 cm. It was completely constructed by South African (SA) students from the Durban University of Technology (DUT), where it is located. First light occurred on 28 July 2008, when the galactic center, Sagittarius A, was detected. As a contribution to the International Year of Astronomy in 2009, staff members in the Department of Electronic Engineering at DUT in 2006 decided to have their students create a fully functional radio telescope by 2009. The specific project aims are to provide a visible project that could generate interest in science and technology in high school students and to provide a real world system for research in radio astronomy in general and an optimization of low noise radio frequency receiver systems in particular. These aims must be understood in terms of the SA’s government interests in radio astronomy. SA is a partner in the Square Kilometer Array (SKA) project, has constructed the Karoo Array Telescope (KAT) and MeerKat, which is the largest and most sensitive radio telescope in the southern hemisphere. SA and its partners in Africa are investing in the construction of the African Very Long Baseline Interferometry Network (AVN), an array of radio telescopes throughout Africa as an extension of the existing global Very Long Baseline Interferometry Network (VLBI). These projects will allow SA to make significant contributions to astronomy and enable astronomy to contribute to the scientific education and development goals of the country. The IRT sees on a daily basis the transit of Sag A. The transit time is influenced by precession, nutation, polar motion, aberration, celestial pole offset, proper motion, length of the terrestrial day and variable ionospheric refraction. Of these eight factors six are either predictable or measureable. To date neither celestial pole offset nor variable ionospheric refraction are predicable

  2. Energy harvesting by dielectric elastomer generator and self-priming circuit: verification by radio transmission

    Science.gov (United States)

    Ikegame, Toru; Takagi, Kentaro; Ito, Takamasa; Kojima, Hiroki; Yoshikawa, Hitoshi

    2017-04-01

    This paper discusses energy harvesting and its application using dielectric elastomer and self-priming circuit. With the self-priming circuit attached to the dielectric elastomer, the generated voltage increases exponentially according to the variation of the capacitance caused by applied deformation to the elastomer. Two-stage self-priming circuit is selected for optimal harvesting. The self-priming harvesting technique is able to increase the voltage of the dielectric elastomer from a few volts to kV order, however in this paper the generated voltage is limited up to 1kV in order to avoid the destruction of the dielectric elastomer. The ability of energy harvesting using dielectric elastomer and self-priming circuit is confirmed by both numerical simulation and experiments. In the experiment, the dielectric elastomer is deformed by an electric motor, and the harvested energy is stored to a charging capacitor through Zener diodes. A low-power microcomputer which has a radio transmitter is connected to the charging capacitor for the application example. The experimental results show that the temperature data can be transmitted only by the harvested energy. In addition, the efficiency of the energy harvesting is calculated by comparing the generated power with the charged power.

  3. Possible Radio Interference Between Video Capsule Endoscopy and Second-Generation OmniPod Patch Pump.

    Science.gov (United States)

    Pitocco, Dario; Rizzi, Alessandro; Tortora, Annalisa; Manto, Andrea; Zaccardi, Francesco; Ghirlanda, Giovanni; Costamagna, Guido; Riccioni, Maria Elena

    2016-07-01

    Video capsule endoscopy (VCE) is a noninvasive diagnostic tool used to observe the small intestinal mucosa. We report a case of a 57-year-old woman with T2DM, treated with continuous subcutaneous insulin infusion using second-generation OmniPod patch pump, undergoing VCE (Given M2A; VCE Ltd, Yoqneam, Israel) for melena and anemia. During VCE, an abnormal interruption of communication between video capsule and its receiver occurred. Two hours after capsule ingestion, the patient activated the insulin pump infusion through the Personal Diabetes Manager (PDM) because she drank a sugary beverage for the first time after ingestion. Due to this, we decided to repeat VCE after the removal of the insulin pump and PDM: at this time, the capsule recorded for more than 10 h without any interruption. The video capsule and second-generation OmniPod patch pump use the same radio frequency and this may cause interference between these two devices. In patients using second-generation OmniPod patch pump undergoing VCE, we suggest to switch to intravenous insulin infusion or multiple daily injection or to use a different model of VCE, as MiRoCam (Intromedic, Seoul, Korea).

  4. Astronomy education in Thailand

    Science.gov (United States)

    Hutawarakorn, Busaba; Soonthornthum, B.; Kirdkao, T.

    Thailand is one of the developing countries which pursues the goal to advance economy, technology as well as science. Education in Astronomy is considered as a supporting factor, since it is one of the basic sciences which can teach the young generation to understand and conserve their mother nature and at the same time helps to develop analytical thinking. The poster reports the present developments in astronomical education in Thailand which includes (1) current astronomy education in school and university; (2) educational activities outside school; (3) development of programs for teaching astronomy in school (including teacher training); (4) the access of educational resources via internet. Proposals for future development and collaborations will be presented and discussed.

  5. Cognitive Radio and its Application for Next Generation Cellular and Wireless Networks

    CERN Document Server

    Muntean, Gabriel-Miro

    2012-01-01

    This book provides a broad introduction to Cognitive Radio, which attempts to mimic human cognition and reasoning applied to Software Defined Radio and reconfigurable radio over wireless networks.  It provides readers with significant technical and practical insights into different aspects of Cognitive Radio, starting from a basic background, the principle behind the technology, the inter-related technologies and application to cellular and vehicular networks, the technical challenges, implementation and future trends.  The discussion balances theoretical concepts and practical implementation. Wherever feasible, the different concepts explained are linked to application of the corresponding scheme in a particular wireless standard.     This book has two sections: the first section begins with an introduction to cognitive radio and discusses in detail various, inter-dependent technologies such as network coding, software-based radio, dirty RF, etc. and their relation to cognitive radio. The second section ...

  6. Multiverso: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.

    2012-05-01

    In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

  7. Minoan Astronomy

    Science.gov (United States)

    Blomberg, Mary; Henriksson, Göran

    Of the three great cultures of the ancient eastern Mediterranean — the Babylonian, Egyptian, and Minoan — we have considerable knowledge of the astronomy of the first two through their documents (see relevant sections of this Handbook). Very little written material, however, has survived from Minoan Crete, but the evidence of other impressive archaeological discoveries implies that the inhabitants were on a par with their neighbors and had made similar advances in astronomy. In lieu of written sources, we have used the methods of archaeoastronomy to recover as much as possible about Minoan astronomy. In short, these are measuring the orientations of walls and their opposite horizons at a representative selection of monuments, analyzing the measurements statistically, and comparing the results with digital reconstruction of the positions of significant celestial bodies for the time when the walls were built.

  8. Application of lightning discharge generated radio atmospherics/tweeks in lower ionospheric plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, A K; Singh, R; Veenadhari, B [Indian Institute of Geomagnetism, New Panvel, Navi Mumbai - 410 218 (India); Pant, P [Aryabhatta Research Institute of Observational Sciences (ARIES), Manora Peak, Nainital - 263129, Uttrakhand (India); Singh, A K, E-mail: ajeet.iig@gmail.co, E-mail: akmaurya@iigs.iigm.res.i [Physics Department, Banaras Hindu University, Varanasi - 221005 (India)

    2010-02-01

    Lightning discharges during thunderstorm are the significant natural source of electromagnetic waves. They generate electromagnetic pulses, which vary from few Hz to tens of MHz, but the maximum radiated energy is confined in extremely low (ELF: 3-3000Hz) and very low (VLF: 3-30 KHz) frequency band. These pulsed signals with frequency dispersion are known as radio atmospherics or tweeks. These waves propagate through the process of multiple reflections in the earth-ionosphere waveguide over long distances with very low attenuation (2-3 dB/1000km). Since these waves are reflected by lower boundary of ionosphere, these are used extensively for probing the D-region ionosphere. D-region is important to the space weather, as well as the submarine communication and navigational aid. In this perspective the measurement of electron density profiles of the D-region is undoubtedly of great interest to both the development of reliable models and radio wave propagation. Earlier work on the tweeks is mainly focused to the theoretical considerations related to polarization, waveform analysis, and occurrence time and propagation mechanism. In this study we investigate tweeks to determine the equivalent night time electron densities at reflection height of the D-region. Distance traveled by the VLF waves from the causative lightning discharges to the receiving station has also been calculated. Tweeks recorded at a low latitude ground station of Allahabad (Geomag. lat. 16.05{sup 0} N) during the night of 23 March 2007 have been used in the present analysis. Based on the analysis of the fundamental cut-off frequency of tweeks, the estimated equivalent electron density of the D-region has been found to be in the range of {approx}20 to 25 el/cm{sup 3} at ionospheric reflection height of {approx}80 to 95 km respectively. Propagation distance in Earth-Ionosphere wave guide (EIWG) from causative lightning source to experimental site varies from {approx}1500 to 8000 km.

  9. Astronomy Allies

    Science.gov (United States)

    Flewelling, Heather; Alatalo, Katherine A.

    2017-01-01

    Imagine you are a grad student, at your first conference, and a prominent senior scientist shows interest in your work, and he makes things get way too personal? What would you do? Would you report it? Or would you decide, after a few other instances of harassment, that maybe you shouldn't pursue astronomy? Harassment is under-reported, the policies can be difficult to understand or hard to find, and it can be very intimidating as a young scientist to report it to the proper individuals. The Astronomy Allies Program is designed to help you with these sorts of problems. We are a group of volunteers that will help by doing the following: provide safe walks home during the conference, someone to talk to confidentially, as an intervener, as a resource to report harassment. The Allies are a diverse group of scientists committed to acting as mentors, advocates, and liaisons. The Winter 2015 AAS meeting was the first meeting that had Astronomy Allies, and Astronomy Allies provided a website for information, as well as a twitter, email, and phone number for anyone who needs our help or would like more information. We posted about the Astronomy Allies on the Women In Astronomy blog, and this program resonates with many people: either they want to help, or they have experienced harassment in the past and don't want to see it in the future. Harassment may not happen to most conference participants, but it's wrong, it's against the AAS anti-harassment policy ( http://aas.org/policies/anti-harassment-policy ), it can be very damaging, and if it happens to even one person, that is unacceptable. We intend to improve the culture at conferences to make it so that harassers feel they can't get away with their unprofessional behavior.

  10. Highlighting the History of Astronomy in the Asia-Pacific Region

    CERN Document Server

    Nakamura, Tsuko; Strom, Richard G; ICOA-6 Conference

    2011-01-01

    This book provides readers with the results of recent research from some of the world's leading historians of astronomy on aspects of Arabic, Australian, Chinese, Japanese, and North and South American astronomy and astrophysics. It contains peer-reviewed papers gathered from the International Conferences on Oriental Astronomy 6 (ICO-6) with the chosen theme of "Highlighting the History of Astronomy in the Asia-Pacific Region." Of particular note are the sections on Arabic astronomy, Asian applied astronomy and the history of Australian radio astronomy, and the chapter on Peruvian astronomy. This title is a valuable complement for those with research interests in applied historical astronomy; archaeoastronomy; calendars, manuscripts, and star charts; historical instruments and observatories, and the history of radio astronomy.

  11. Astronomy essentials

    CERN Document Server

    Brass, Charles O

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Astronomy includes the historical perspective of astronomy, sky basics and the celestial coordinate systems, a model and the origin of the solar system, the sun, the planets, Kepler'

  12. Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes

    NARCIS (Netherlands)

    Sotomayor-Beltran, C.; Sobey, C.; Hessels, J.W.T.; Bruyn, de G.; Noutsos, A.; Alexov, A.; Anderson, J.; Asgekar, A.; Avruch, I.M.; Beck, R.; Bell, M.E.; Bell, M.R.; Bentum, M.J.; Bernardi, G.; Best, P.; Birzan, L.; Bonafede, A.; Breitling, F.; Broderick, J.; Brouw, W.N.; Brüggen, M.; Ciardi, B.; Gasperin, de F.; Dettmar, R.-J.; Duin, van A.; Duscha, S.; Eislöffel, J.; Falcke, H.; Fallows, R.A.; Fender, R.; Ferrari, C.; Frieswijk, W.; Garrett, M.A.; Griessmeier, J.; Grit, T.; Gunst, A.W.; Hassall, T.E.; Heald, G.; Hoeft, M.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Keane, E.; Kohler, J; Kramer, M.; Kondratiev, V.I.; Koopmans, L.V.E.; Kuniyoshi, M.; Kuper, G.; Leeuwen, van J.; Maat, P.; Macario, G.; Markoff, S.; McKean, J.P.; Mulcahy, D.D.; Munk, H.; Orrú, E.; Paas, H.; Pandey-Pommier, M.; Pilia, M.; Pizzo, R.; Polatidis, A.G.; Reich, W.; Röttgering, H.; Serylak, M.; Sluman, J.; Stappers, B.W.; Tagger, M.; Tang, Y.; Tasse, C.; Veen, ter S.; Vermeulen, R.; Weeren, van R.J.; Wijers, R.A.M.J.; Wijnholds, S.J.; Wise, M.W.; Wucknitz, O.; Yatawatta, S.; Zarka, P.

    2013-01-01

    Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires accurate removal of the time-variable ionospheric Faraday rotation

  13. Calibrating high-precision Faraday rotation measurements for LOFAR and the next generation of low-frequency radio telescopes

    NARCIS (Netherlands)

    Sotomayor-Beltran, C.; et al., [Unknown; Hessels, J.W.T.; Alexov, A.; van Leeuwen, J.; Markoff, S.; Wijers, R.A.M.J.; Wise, M.W.

    2013-01-01

    Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires accurate removal of the time-variable ionospheric Faraday rotation

  14. A bidirectional radio over fiber system with multiband-signal generation using one single-drive MZM.

    Science.gov (United States)

    Zhang, Liang; Hu, Xiaofeng; Cao, Pan; Wang, Tao; Su, Yikai

    2011-03-14

    We propose and experimentally demonstrate a simple and cost-effective bidirectional radio-over-fiber (RoF) system for transmission of downstream multiband signals and upstream data. At the central station (CS), the multiband data consisting of baseband, micro-wave (MW) and millimeter-wave (MMW) signals are generated using only one single-drive x-cut Mach-Zehnder modulator (MZM), which is driven by a clock signal at radio frequency (RF) port and an electrical data at bias port. Upstream data transmission is realized by re-modulation of filtered frequency-shift-keying (FSK) signal, selected from the multiband signals.

  15. Self-consistent modeling of radio-frequency plasma generation in stellarators

    Science.gov (United States)

    Moiseenko, V. E.; Stadnik, Yu. S.; Lysoivan, A. I.; Korovin, V. B.

    2013-11-01

    A self-consistent model of radio-frequency (RF) plasma generation in stellarators in the ion cyclotron frequency range is described. The model includes equations for the particle and energy balance and boundary conditions for Maxwell's equations. The equation of charged particle balance takes into account the influx of particles due to ionization and their loss via diffusion and convection. The equation of electron energy balance takes into account the RF heating power source, as well as energy losses due to the excitation and electron-impact ionization of gas atoms, energy exchange via Coulomb collisions, and plasma heat conduction. The deposited RF power is calculated by solving the boundary problem for Maxwell's equations. When describing the dissipation of the energy of the RF field, collisional absorption and Landau damping are taken into account. At each time step, Maxwell's equations are solved for the current profiles of the plasma density and plasma temperature. The calculations are performed for a cylindrical plasma. The plasma is assumed to be axisymmetric and homogeneous along the plasma column. The system of balance equations is solved using the Crank-Nicholson scheme. Maxwell's equations are solved in a one-dimensional approximation by using the Fourier transformation along the azimuthal and longitudinal coordinates. Results of simulations of RF plasma generation in the Uragan-2M stellarator by using a frame antenna operating at frequencies lower than the ion cyclotron frequency are presented. The calculations show that the slow wave generated by the antenna is efficiently absorbed at the periphery of the plasma column, due to which only a small fraction of the input power reaches the confinement region. As a result, the temperature on the axis of the plasma column remains low, whereas at the periphery it is substantially higher. This leads to strong absorption of the RF field at the periphery via the Landau mechanism.

  16. The history of early low frequency radio astronomy in Australia. 8: Grote Reber and the 'Square Kilometre Array' near Bothwell, Tasmania, in the 1960s and 1970s

    Science.gov (United States)

    George, Martin; Orchiston, Wayne; Wielebinski, Richard

    2017-08-01

    In the 1960s, Grote Reber (1911‒2002) established and used an antenna array near Bothwell in Tasmania. Working independently, he produced a radio map of the southern sky at a frequency of 2.085 MHz (a wavelength of 144 metres). Encouraged by this success, he modified the array in the 1970s to work at 1.155 MHz, but this second endeavour failed to produce any usable results.

  17. FeltRadio – Experiencing Community-generated WiFi Activities

    DEFF Research Database (Denmark)

    Fritsch, Jonas; Gronvall, Erik

    2016-01-01

    FeltRadio is a portable technology for sensing WiFi through sensorial augmentation and Electric Muscle Stimulation (EMS). The technology enables its wearer to sensorially engage with the radio waves and WiFi activities that have become an integrated part of our everyday lives. The sensorial...... engagement changes people’s experience of WiFi activities, and allows them to participate in wireless communication infrastructures in novel ways. This is both an immediately embodied activity as it is a new form of social awareness. In this paper, we briefly present the FeltRadio technology and show how...

  18. Chaco astronomies

    Science.gov (United States)

    Martín López, Alejandro

    2015-08-01

    This presentation discusses the result of 18 years of ethnographic and ethnohistorical studies on Chaco astronomies. The main features of the systems of astronomical knowledge of the Chaco Aboriginal groups will be discussed. In particular we will discuss the relevance of the Milky Way, the role of the visibility of the Pleiades, the ways in which the celestial space is represented, the constitution of astronomical orientations in geographic space, etc. We also address a key feature of their vision of the cosmos: the universe is seen by these groups as a socio-cosmos, where humans and non-humans are related. These are therefore actually socio-cosmologies. We will link this to the theories of Chaco Aboriginal groups about power and political relations.We will discuss how the study of Aboriginal astronomies must be performed along with the studies about astronomies of Creole people and European migrants, as well as anthropological studies about the science teaching in the formal education system and by the mass media. In this form we will discuss the relevance of a very complex system of interethnic relations for the conformation of these astronomical representations and practices.We will also discuss the general methodological implications of this case for the ethnoastronomy studies. In particular we will talk about the advantages of a study of regional scope and about the key importance of put in contact the ethnoastronomy with contemporary issues in social sciences.We also analyze the importance of ethnoastronomy studies in relation to studies of sociology of science, especially astronomy. We also study the potential impact on improving formal and informal science curricula and in shaping effective policies to protect the tangible and intangible astronomical heritage in a context of respect for the rights of Aboriginal groups.

  19. Fundamental astronomy

    CERN Document Server

    Kröger, Pekka; Oja, Heikki; Poutanen, Markku; Donner, Karl

    2017-01-01

    Now in its sixth edition this successful undergraduate textbook gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The chapters on galactic and extragalactic astronomy as well as cosmology were extensively modernized in the previous edition. In this new edition they have been further revised to include more recent results. The long chapter on the solar system has been split into two parts: the first one deals with the general properties, and the other one describes individual objects. A new chapter on exoplanets has been added to the end of the book next to the chapter on astrobiology. In response to the fact that astronomy has evolved enormously over the last few years, only a few chapters of this book have been left unmodified. Long considered a standard text for physical science maj...

  20. Generation of Acoustic Gravity Waves by Periodic Radio Transmissions from a High-Power Ionospheric Heater

    Science.gov (United States)

    Frolov, Vladimir; Chernogor, Leonid; Rozumenko, Victor

    The Radiophysical Research Institute (Nizhny Novgorod, Russia) and Kharkiv V. N. Karazin National University (Kharkiv, Ukraine) have studied opportunities for the effective generation of acoustic gravity waves (AGWs) in 3 - 180-min period range. The excitation of such waves was conducted for the last several years using the SURA heating facility (Nizhny Novgorod). The detection of the HF-induced AGWs was carried out in the Radiophysical Observatory located near Kharkiv City at a distance of about 960 km from the SURA. A coherent radar for vertical sounding, an ionosonde, and magnetometer chains were used in our measurements. The main results are the following (see [1-5]): 1. Infrasound oscillation trains with a period of 6 min are detected during periodic SURA heater turn-on and -off. Similar oscillation trains are detected after long time pumping, during periodic transmissions with a period of 20 s, as well as after pumping turn-off. The train recordings begin 28 - 54 min after the heater turn-on or -off, and the train propagation speeds are about 300 - 570 m/s, the value of which is close to the sound speed at upper atmospheric altitudes. The amplitude of the Doppler shift frequency is of 10 - 40 mHz, which fits to the 0.1 - 0.3% electron density disturbances at ionospheric altitudes. The amplitude of the infrasound oscillations depends on the SURA mode of operation and the state of the upper atmosphere and ionosphere. 2. High-power radio transmissions stimulate the generation (or enhancement) of waves at ionospheric altitudes in the range of internal gravity wave periods. The HF-induced waves propagate with speeds of 360 - 460 m/s and produce changes in electron density with amplitudes of 2 - 3%. The generation of such periodic perturbations is more preferable with periods of 10 - 60 minutes. Their features depend significantly on the heater mode of operation. It should be stressed that perturbation intensity increases when a pumping wave frequency approaches

  1. Effects of exomoon’s magnetic field on generation of radio emissions

    Science.gov (United States)

    Griffith, John; Noyola, Joaquin; Satyal, Suman; Musielak, Zdzislaw E.

    2017-01-01

    In the recent work by Noyola et al. (2014, 2016), a novel technique of detection of exomoons through the radio emissions produced by the magnetic field interactions between exoplanet-exomoon pair is emulated based upon the processes occurring in the Jupiter-Io system. Their calculations have shown that the radio signal from the distant extra-solar planetary systems is detectable by current technology provided that the systems emanating the radio waves are relatively closer, have some form of atmosphere, and have larger exomoons. In this work, we explore the effect of exomoon’s magnetic field on the radio emission processes by considering a hypothetical magnetic exomoon and re-calculating the resulting radio flux. Then, a limit to the exomoon’s magnetic field is proposed based on the signal amplification versus the dampening effect the magnetic field induces on the secondary conditions such as the containment of ions within the exomoon’s magnetic field and the effect of the plasma torus density that co-orbits with the moon. The energy from the exomoon’s magnetic field is expected to amplify the radio signal, hence increasing the probability of detection of the first exomoons.

  2. Load-Aware Radio Access Selection in Future Generation Satellite-Terrestrial Wireless Networks

    Directory of Open Access Journals (Sweden)

    M. Ali

    2012-03-01

    Full Text Available In the telecommunication networks the introduction of Next Generation Wireless Networks (NGWN has been described as the most significant change in wireless communication. The convergence of different access networks in NGWN allows generalized mobility, consistency and ubiquitous provision of services to mobile users. The general target of NGWN is to transport different types of information like voice,data, and other media like video in packets form like IP. The NGWNs offer significant savings in costs to the operators along with new and interesting services to the consumers. Major challenges in NGWN are efficient resource utilization, maintaining service quality, reliability and the security. This paper proposes a solution for seamless load aware Radio Access Technology (RAT selection based on interworking of different RATs in NGWN. In this paper novel load balancing algorithms have been proposed which have been simulated on the target network architecture for TCP data services. The IEEE 802.21 Media Independent Handover (MIH is utilized in load balancing specifically for mobility management, which enable low handover latency by reducing the target network detection time. The proposed method considers the network type, signal strength, data rate and network load as primary decision parameters for RAT selection process and consists of two different algorithms, one located inthe mobile terminal and the other at the network side. The network architecture, the proposed load balancing framework and RAT selection algorithms were simulated using NS2. Different attributes like load distribution in the wireless networks and average throughput to evaluate the effects of load balancing in considered scenarios.

  3. Everyday Radio Telescope

    CERN Document Server

    Mandal, Pranshu; Kumar, Pratik; Yelikar, Anjali; Soni, Kanchan; T, Vineeth Krishna

    2016-01-01

    We have developed an affordable, portable college level radio telescope for amateur radio astronomy which can be used to provide hands-on experience with the fundamentals of a radio telescope and an insight into the realm of radio astronomy. With our set-up one can measure brightness temperature and flux of the Sun at 11.2 GHz and calculate the beam width of the antenna. The set-up uses commercially available satellite television receiving system and parabolic dish antenna. We report the detection of point sources like Saturn and extended sources like the galactic arm of the Milky way. We have also developed python pipeline, which are available for free download, for data acquisition and visualization.

  4. Matching Radio Catalogs with Realistic Geometry: Application to SWIRE and ATLAS

    CERN Document Server

    Fan, Dongwei; Norris, Ray P; Hopkins, Andrew M

    2015-01-01

    Crossmatching catalogs at different wavelengths is a difficult problem in astronomy, especially when the objects are not point-like. At radio wavelengths an object can have several components corresponding, for example, to a core and lobes. {Considering not all radio detections correspond to visible or infrared sources, matching these catalogs can be challenging.} Traditionally this is done by eye for better quality, which does not scale to the large data volumes expected from the next-generation of radio telescopes. We present a novel automated procedure, using Bayesian hypothesis testing, to achieve reliable associations by explicit modelling of a particular class of radio-source morphology. {The new algorithm not only assesses the likelihood of an association between data at two different wavelengths, but also tries to assess whether different radio sources are physically associated, are double-lobed radio galaxies, or just distinct nearby objects.} Application to the SWIRE and ATLAS CDF-S catalogs shows t...

  5. Strategic Plan for Astronomy in the Netherlands 2011-2020

    CERN Document Server

    Groot, P J; Stark, R

    2012-01-01

    Strategic Plan for Astronomy in the Netherlands 2011 - 2020, written by the Netherlands Committee for Astronomy (NCA), on behalf of the excellence research school in astronomy NOVA, (combining the university astronomy institutes of the universities of Amsterdam, Groningen, Leiden and Nijmegen), the NWO division of Physical Sciences, the Netherlands Institute for Radio Astronomy ASTRON and the Netherlands Institute for Space Research SRON. The Strategic plan outlines the scientific priorities for Dutch astronomy in the next decade; the instrumentation effort required to address these priorities, and the connection between astronomical instrumentation and technology development and fundamental technological R&D; the financial contours needed to realise the priorities; and the role of Dutch astronomy in education and outreach. The Strategic Plan also includes a retrospective on the achievements since the last Strategic Plan (2000) and a forward look beyond 2020.

  6. Astronomy research in China

    Science.gov (United States)

    Wang, Jingxiu

    Decades of efforts made by Chinese astronomers have established some basic facilities for astronomy observations, such as the 2.16-m optical telescope, the solar magnetic-field telescope, the 13.7-m millimeter-wave radio telescope etc. One mega-science project, the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), intended for astronomical and astrophysical studies requiring wide fields and large samples, has been initiated and funded. To concentrate the efforts on mega-science projects, to operate and open the national astronomical facilities in a more effective way, and to foster the best astronomers and research groups, the National Astronomical Observatories (NAOs) has been coordinated and organizated. Four research centers, jointly sponsored by observatories of the Chinese Academy of Sciences and universities, have been established. Nine principal research fields have received enhanced support at NAOs. They are: large-scale structure of universe, formation and evolution of galaxies, high-energy and cataclysmic processes in astrophysics, star formation and evolution, solar magnetic activity and heliogeospace environment, astrogeodynamics, dynamics of celestial bodies in the solar system and artificial bodies, space-astronomy technology, and new astronomical techniques and methods.

  7. Calibrating High-Precision Faraday Rotation Measurements for LOFAR and the Next Generation of Low-Frequency Radio Telescopes

    CERN Document Server

    Sotomayor-Beltran, C; Hessels, J W T; de Bruyn, G; Noutsos, A; Alexov, A; Anderson, J; Asgekar, A; Avruch, I M; Beck, R; Bell, M E; Bell, M R; Bentum, M J; Bernardi, G; Best, P; Birzan, L; Bonafede, A; Breitling, F; Broderick, J; Brouw, W N; Brueggen, M; Ciardi, B; de Gasperin, F; Dettmar, R -J; van Duin, A; Duscha, S; Eisloeffel, J; Falcke, H; Fallows, R A; Fender, R; Ferrari, C; Frieswijk, W; Garrett, M A; Griessmeier, J; Grit, T; Gunst, A W; Hassall, T E; Heald, G; Hoeft, M; Horneffer, A; Iacobelli, M; Juette, E; Karastergiou, A; Keane, E; Kohler, J; Kramer, M; Kondratiev, V I; Koopmans, L V E; Kuniyoshi, M; Kuper, G; van Leeuwen, J; Maat, P; Macario, G; Markoff, S; McKean, J P; Mulcahy, D D; Munk, H; Orru, E; Paas, H; Pandey-Pommier, M; Pilia, M; Pizzo, R; Polatidis, A G; Reich, W; Roettgering, H; Serylak, M; Sluman, J; Stappers, B W; Tagger, M; Tang, Y; Tasse, C; ter Veen, S; Vermeulen, R; van Weeren, R J; Wijers, R A M J; Wijnholds, S J; Wise, M W; Wucknitz, O; Yatawatta, S; Zarka, P; 10.1051/0004-6361/201220728

    2013-01-01

    Faraday rotation measurements using the current and next generation of low-frequency radio telescopes will provide a powerful probe of astronomical magnetic fields. However, achieving the full potential of these measurements requires accurate removal of the time-variable ionospheric Faraday rotation contribution. We present ionFR, a code that calculates the amount of ionospheric Faraday rotation for a specific epoch, geographic location, and line-of-sight. ionFR uses a number of publicly available, GPS-derived total electron content maps and the most recent release of the International Geomagnetic Reference Field. We describe applications of this code for the calibration of radio polarimetric observations, and demonstrate the high accuracy of its modeled ionospheric Faraday rotations using LOFAR pulsar observations. These show that we can accurately determine some of the highest-precision pulsar rotation measures ever achieved. Precision rotation measures can be used to monitor rotation measure variations - e...

  8. Fast radio flashes observed with LOFAR prototypes

    NARCIS (Netherlands)

    Nigl, A.

    2008-01-01

    This thesis consists of a detailed analysis of several observations with prototype stations of the Low Frequency Array (LOFAR). Chapter 1 introduces the field of radio astronomy, briefly describes the radio telescopes which were used and discusses radio frequency interference (RFI) and important too

  9. Using IP as Transport Technology in Third Generation and Beyond Radio Access Networks

    NARCIS (Netherlands)

    Bader, Attila; Westberg, Lars; Karagiannis, Georgios; de Meer, H; Bhatti, N.T.

    This paper discusses the motivation for developing a new QoS signaling protocol for IP-based Radio Access Networks. It describes the main characteristics of these networks and the special requirements imposed by these characteristics on QoS signaling solutions.

  10. A Simple Demonstration for Exploring the Radio Waves Generated by a Mobile Phone

    Science.gov (United States)

    Hare, Jonathan

    2010-01-01

    Described is a simple low cost home-made device that converts the radio wave energy from a mobile phone signal into electricity for lighting an LED. No battery or complex circuitry is required. The device can form the basis of a range of interesting experiments on the physics and technology of mobile phones. (Contains 5 figures.)

  11. Next Generation Radio over Fiber Network Management for a Distributed Antenna System

    DEFF Research Database (Denmark)

    Santiago, Carlos; Gangopadhyay, Bodhisattwa; arsenio, Artur

    2009-01-01

    Dette dokument beskriver funktioner og procedurer i futon Radio Over Fiber Manager til at operere med det øvre (net) og nederste (fysiske) lag, der anvendes til transport af trådløse signaler mellem en central enhed (CU) og Remote Antenna Units. Også, det giver nogle mekanismer og procedurer, der...

  12. A Proposed Method of FSK Generation and Demodulation for the DREO Radio Test Bed

    Science.gov (United States)

    1990-03-01

    34, Addison Wesley Publishing Company, Reading, Massachusetts, 1982 [3] Wilson, M. J. (editor), "The 1987 ARRL Handbook For The Radio Amateur", American...Hughes, Frederick W., "Op-Amp Handbook ", Prentice-Hall Publications, Englewood Cliffs, New Jersey, 1986 [11] EXAR Corporation Databook [12] Bendix

  13. A Simple Demonstration for Exploring the Radio Waves Generated by a Mobile Phone

    Science.gov (United States)

    Hare, Jonathan

    2010-01-01

    Described is a simple low cost home-made device that converts the radio wave energy from a mobile phone signal into electricity for lighting an LED. No battery or complex circuitry is required. The device can form the basis of a range of interesting experiments on the physics and technology of mobile phones. (Contains 5 figures.)

  14. A simple demonstration for exploring the radio waves generated by a mobile phone

    Science.gov (United States)

    Hare, Jonathan

    2010-09-01

    Described is a simple low cost home-made device that converts the radio wave energy from a mobile phone signal into electricity for lighting an LED. No battery or complex circuitry is required. The device can form the basis of a range of interesting experiments on the physics and technology of mobile phones.

  15. System Wide Implementation of Photonically Generated Impulse Radio Ultra-Wideband for Gigabit Fiber-Wireless Access

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Rodes Lopez, Roberto

    2013-01-01

    radio ultra-wideband (IR-UWB) signals at 781.25 Mbps with on-off keying (OOK) and binary phase shift keying (BPSK) modulation formats. We further advance the state-of-the-art to include multi-Gigabit IR-UWB signal generation. Both OOK and BPSK signals comply with the Federal Communications Commission......-of-the-art electronic generation method in terms of transmission bit-error rate performance. Moreover, photonic IR-UWB generation is shown to be capable of longer wireless reach due to its lower bandwidth limitation. Finally, we experimentally demonstrate the integration of a relaxation oscillations-based UWB photonic...... generation system into existing wavelength division multiplexing passive optical networks (WDM-PON) infrastructure. This provides converged Gigabit indoor wireless and wireline access services....

  16. Simultaneous transmission of 256-QAM WIMAX at 5.7GHz and optically generated impulse radio UWB over fiber for indoor wireless multi-services

    DEFF Research Database (Denmark)

    Yu, Xianbin; Yin, Xiaoli; Gibbon, Timothy Braidwood;

    2010-01-01

    Fiber transmission of simultaneous optically generated FCC compliant 625Mbps impulse radio UWB and 80Mbps 256-QAM IEEE 802.16 WIMAX signals is experimentally demonstrated by using a single directly modulated light source.......Fiber transmission of simultaneous optically generated FCC compliant 625Mbps impulse radio UWB and 80Mbps 256-QAM IEEE 802.16 WIMAX signals is experimentally demonstrated by using a single directly modulated light source....

  17. All optical up-converted signal generation with high dispersion tolerance using frequency quadrupling technique for radio over fiber system

    Science.gov (United States)

    Gu, Yiying; Zhao, Jiayi; Hu, Jingjing; Kang, Zijian; Zhu, Wenwu; Fan, Feng; Han, Xiuyou; Zhao, Mingshan

    2016-05-01

    A novel all optical up-converted signal generation scheme with optical single-sideband (OSSB) technique for radio over fiber (RoF) application is presented and experimentally demonstrated using low-bandwidth devices. The OSSB signal is generated by one low-bandwidth intensity LiNbO3 Mach-Zehnder modulator (LN-MZM) under frequency quadrupling modulation scheme and one low-bandwidth LN-MZM under double sideband carrier suppressed modulation (DSB-CS) scheme. The proposed all OSSB generation scheme is capable of high tolerance of fiber chromatic dispersion induced power fading (DIPF) effect. Benefiting from this novel OSSB generation scheme, a 26 GHz radio frequency (RF) signal up-conversion is realized successfully when one sideband of the optical LO signal is reused as the optical carrier for intermediate frequency (IF) signal modulation. The received vector signal transmission over long distance single-mode fiber (SMF) shows negligible DIPF effect with the error vector magnitude (EVM) of 15.7% rms. In addition, a spurious free dynamic range (SFDR) of the OSSB up-converting system is measured up to 81 dB Hz2/3. The experiment results indicate that the proposed system may find potential applications in future wireless communication networks, especially in microcellular personal communication system (MPCS).

  18. Astronomy Education Challenges in Egypt

    Science.gov (United States)

    El Fady Beshara Morcos, Abd

    2015-08-01

    One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

  19. TeachAstronomy.com - Digitizing Astronomy Resources

    Science.gov (United States)

    Hardegree-Ullman, Kevin; Impey, C. D.; Austin, C.; Patikkal, A.; Paul, M.; Ganesan, N.

    2013-06-01

    Teach Astronomy—a new, free online resource—can be used as a teaching tool in non-science major introductory college level astronomy courses, and as a reference guide for casual learners and hobbyists. Digital content available on Teach Astronomy includes: a comprehensive introductory astronomy textbook by Chris Impey, Wikipedia astronomy articles, images from Astronomy Picture of the Day archives and (new) AstroPix database, two to three minute topical video clips by Chris Impey, podcasts from 365 Days of Astronomy archives, and an RSS feed of astronomy news from Science Daily. Teach Astronomy features an original technology called the Wikimap to cluster, display, and navigate site search results. Development of Teach Astronomy was motivated by steep increases in textbook prices, the rapid adoption of digital resources by students and the public, and the modern capabilities of digital technology. This past spring semester Teach Astronomy was used as content supplement to lectures in a massive, open, online course (MOOC) taught by Chris Impey. Usage of Teach Astronomy has been steadily growing since its initial release in August of 2012. The site has users in all corners of the country and is being used as a primary teaching tool in at least four states.

  20. Candidates for detecting exoplanetary radio emissions generated by magnetosphere-ionosphere coupling

    CERN Document Server

    Nichols, J D

    2012-01-01

    In this paper we consider the magnetosphere-ionosphere (M-I) coupling at Jupiter-like exoplanets with internal plasma sources such as volcanic moons, and we have determined the best candidates for detection of these radio emissions by estimating the maximum spectral flux density expected from planets orbiting stars within 25 pc using data listed in the NASA/IPAC/NExScI Star and Exoplanet Database (NStED). In total we identify 91 potential targets, of which 40 already host planets and 51 have stellar X-ray luminosity 100 times the solar value. In general, we find that stronger planetary field strength, combined with faster rotation rate, higher stellar XUV luminosity, and lower stellar wind dynamic pressure results in higher radio power. The top two targets for each category are $\\epsilon$ Eri and HIP 85523, and CPD-28 332 and FF And.

  1. RECONFIGURABLE RADIO SYSTEMS FOR PUBLIC SAFETY: NEW GENERATION OF PUBLIC SAFETY ICT

    OpenAIRE

    Baldini, Gianmarco; VERGARI Fabrizio

    2011-01-01

    Reconfigurable Radio Systems (RRS) is a subject which is becoming more and more interesting in that represents an affordable and effective solution to integrate the applications for first responders on Public Protection and Disaster Relief (PPDR). These End Users are more and more involved in operations of protection to people environment and properties and they address a large number of threats both natural and man-made, acts of terrorism, technological, radiological or environmental acciden...

  2. Multiwavelength astronomy and big data

    Science.gov (United States)

    Mickaelian, A. M.

    2016-09-01

    Two major characteristics of modern astronomy are multiwavelength (MW) studies (fromγ-ray to radio) and big data (data acquisition, storage and analysis). Present astronomical databases and archives contain billions of objects observed at various wavelengths, both galactic and extragalactic, and the vast amount of data on them allows new studies and discoveries. Astronomers deal with big numbers. Surveys are the main source for discovery of astronomical objects and accumulation of observational data for further analysis, interpretation, and achieving scientific results. We review the main characteristics of astronomical surveys, compare photographic and digital eras of astronomical studies (including the development of wide-field observations), describe the present state of MW surveys, and discuss the Big Data in astronomy and related topics of Virtual Observatories and Computational Astrophysics. The review includes many numbers and data that can be compared to have a possibly overall understanding on the Universe, cosmic numbers and their relationship to modern computational facilities.

  3. First Demonstration of Electron Beam Generation and Characterization with an All Superconducting Radio-frequency (SRF) Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Kamps, T; Barday, R; Jankowiak, A; Knobloch, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Volkov, V; Weinberg, G

    2011-09-01

    In preparation for a high brightness, high average current electron source for the energy-recovery linac BERLinPro an all superconducting radio-frequency photoinjector is now in operation at Helmholtz-Zentrum Berlin. The aim of this experiment is beam demonstration with a high brightness electron source able to generate sub-ps pulse length electron bunches from a superconducting (SC) cathode film made of Pb coated on the backwall of a Nb SRF cavity. This paper describes the setup of the experiment and first results from beam measurements.

  4. Compact FPGA-based pulse-sequencer and radio-frequency generator for experiments with trapped atoms

    CERN Document Server

    Pruttivarasin, Thaned

    2015-01-01

    We present a compact FPGA-based pulse sequencer and radio-frequency (RF) generator suitable for experiments with cold trapped ions and atoms. The unit is capable of outputting a pulse sequence with at least 32 TTL channels with a timing resolution of 40 ns and contains a built-in 100 MHz frequency counter for counting electrical pulses from a photo-multiplier tube (PMT). There are 16 independent direct-digital-synthesizers (DDS) RF sources with fast (rise-time of ~60 ns) amplitude switching and sub-mHz frequency tuning from 0 to 800 MHz.

  5. Next Generation Summer School

    Science.gov (United States)

    Eugenia, Marcu

    2013-04-01

    On 21.06.2010 the "Next Generation" Summer School has opened the doors for its first students. They were introduced in the astronomy world by astronomical observations, astronomy and radio-astronomy lectures, laboratory projects meant to initiate them into modern radio astronomy and radio communications. The didactic programme was structure as fallowing: 1) Astronomical elements from the visible spectrum (lectures + practical projects) 2) Radio astronomy elements (lectures + practical projects) 3) Radio communication base (didactic- recreative games) The students and professors accommodation was at the Agroturistic Pension "Popasul Iancului" situated at 800m from the Marisel Observatory. First day (summer solstice day) began with a practical activity: determination of the meridian by measurements of the shadow (the direction of one vertical alignment, when it has the smallest length). The experiment is very instructive and interesting because combines notions of physics, spatial geometry and basic astronomy elements. Next day the activities took place in four stages: the students processed the experimental data obtained on first day (on sheets of millimetre paper they represented the length of the shadow alignments according the time), each team realised its own sun quadrant, point were given considering the design and functionality of these quadrant, the four teams had to mimic important constellations on carton boards with phosphorescent sticky stars and the students, accompanied by the professors took a hiking trip to the surroundings, marking the interest point coordinates, using a GPS to establish the geographical coronations and at the end of the day the students realised a small map of central Marisel area based on the GPS data. On the third day, the students were introduced to basic notions of radio astronomy, the principal categories of artificial Earth satellites: low orbit satellites (LEO), Medium orbit satellites (MEO) and geostationary satellites (GEO

  6. SKA antenna systems; outlook for non-astronomy applications

    NARCIS (Netherlands)

    Ardenne, van A.; Bentum, M.J.; Boonstra, A.J.

    2011-01-01

    The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a frequ

  7. SKA antenna systems; Outlook for non-astronomy applications

    NARCIS (Netherlands)

    Ardenne, van A.; Bentum, M.J.; Boonstra, A.J.

    2012-01-01

    The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a frequ

  8. SKA antenna systems; Outlook for non-astronomy applications

    NARCIS (Netherlands)

    van Ardenne, A.; Bentum, Marinus Jan; Boonstra, A.J.

    2012-01-01

    The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a

  9. SKA antenna systems; outlook for non-astronomy applications

    NARCIS (Netherlands)

    van Ardenne, A.; Bentum, Marinus Jan; Boonstra, A.J.

    2011-01-01

    The globally endorsed Square Kilometre Array project primarily aims to advance high sensitivity radio astronomy using a distributed collection of radio telescope stations spiraling outward from the core along three to five arms out to 3000km. This planned highly sensitive instrument covering a

  10. Highlights of Astronomy, Vol. 16

    Science.gov (United States)

    Montmerle, Thierry

    2015-04-01

    Part I. Invited Discourses: 1. The Herschel view of star formation; 2. Past, present and future of Chinese astronomy; 3. The zoo of galaxies; 4. Supernovae, the accelerating cosmos, and dark energy; Part II. Joint Discussion: 5. Very massive stars in the local universe; 6. 3-D views of the cycling Sun in stellar context; 7. Ultraviolet emission in early-type galaxies; 8. From meteors and meteorites to their parent bodies: current status and future developments; 9. The connection between radio properties and high-energy emission in AGNs; 10. Space-time reference systems for future research; Part III. Special Sessions: 11. Origin and complexity of massive star clusters; 12. Cosmic evolution of groups and clusters of galaxies; 13. Galaxy evolution through secular processes; 14. New era for studying interstellar and intergalactic magnetic fields; 15. The IR view of massive stars: the main sequence and beyond; 16. Science with large solar telescopes; 17. The impact hazard: current activities and future plans; 18. Calibration of star-formation rate measurements across the electromagnetic spectrum; 19. Future large scale facilities; 20. Dynamics of the star-planet relations strategic plan and the Global Office of Astronomy for Development; 21. Strategic plan and the Global Office of Astronomy for Development; 22. Modern views of the interstellar medium; 23. High-precision tests of stellar physics from high-precision photometry; 24. Communicating astronomy with the public for scientists; 25. Data intensive astronomy; 26. Unexplained spectral phenomena in the interstellar medium; 27. Light pollution: protecting astronomical sites and increasing global awareness through education.

  11. Highlights of Astronomy

    Science.gov (United States)

    van der Hucht, Karel

    2008-02-01

    Preface Karel A. van der Hucht; Part I. Invited Discourses: Part II. Joint Discussions: 1. Particle acceleration - from Solar System to AGN Marian Karlicky and John C. Brown; 2. Pulsar emission and related phenomena Werner Becker, Janusz A. Gil and Bronislaw Rudak; 3. Solar activity regions and magnetic structure Debi Prasad Choudhary and Michal Sobotka; 4. The ultraviolet universe: Stars from birth to death Ana I. Gomez de Castro and Martin A. Barstow; 5. Calibrating the top of the stellar M-L relationship Claus Leitherer, Anthony F. J. Moat and Joachim Puls; 6. Neutron stars and black holes in star clusters Frederic A. Rasio; 7. The Universe at z > 6 Daniel Schaerer and Andrea Ferrara; 8. Solar and stellar activity cycles Klaus G. Strassmeier and Alexander Kosovichev; 9. Supernovae: One millennium after SN 1006 P. Frank Winkler, Wolfgang Hillebrandt and Brian P. Schmidt; 10. Progress in planetary exploration missions Guy J. Consolmagno; 11. Pre-solar grains as astrophysical tools Anja C. Andersen and John C. Lattanzio; 12. Long wavelength astrophysics T. Joseph W. Lazio and Namir E. Kassim; 13. Exploiting large surveys for galactic astronomy Christopher J. Corbally, Coryn A. L. Bailer-Jones, Sunetra Giridhar and Thomas H. Lloyd Evans; 14. Modeling dense stellar systems Alison I. Sills, Ladislav Subr and Simon F. Portegies Zwart; 15. New cosmology results from the Spitzer Space Telescope George Helou and David T. Frayer; 16. Nomenclature, precession and new models in fundamental astronomy Nicole Capitaine, Jan Vondrak & James L. Hilton; 17. Highlights of recent progress in seismology of the Sun and Sun-like stars John W. Leibacher and Michael J. Thompson; Part III. Special Sessions: SpS 1. Large astronomical facilities of the next decade Gerard F. Gilmore and Richard T. Schilizzi; SpS 2. Innovation in teaching and learning astronomy methods Rosa M. Ros and Jay M. Pasachoff; SpS 3. The Virtual Observatory in action: New science, new technology and next-generation

  12. Goldstone Apple Valley Radio Telescope Project.

    Science.gov (United States)

    Ibe, Mary; MacLaren, Dave

    2003-01-01

    Describes the Goldstone Apple Valley Radio Telescope (GAVRT) project as a way of teaching astronomy concepts to middle school students. The project provides students opportunities to work with professional scientists. (SOE)

  13. Teaching and Learning Astronomy

    Science.gov (United States)

    Pasachoff, Jay; Percy, John

    2009-07-01

    Preface; Part I. Astronomy in the Curriculum Around the World: Preface; 1. Why astronomy is useful and should be included in the school curriculum John R. Percy; 2. Astronomy and mathematics education Rosa M. Ros; 3. Astronomy in the curriculum around the world; 4. Engaging gifted science students through astronomy Robert Hollow; 5. Poster highlights: astronomy in the curriculum around the world; Part II. Astronomy Education Research: Preface; 6. Astronomy education research down under John M. Broadfoot and Ian S. Ginns; 7. A contemporary review of K-16 astronomy education research Janelle M. Bailey and Timothy F. Slater; 8. Implementing astronomy education research Leonarda Fucili; 9. The Astronomy Education Review: report on a new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights: astronomy education research; Part III. Educating Students: Preface; 11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet astronomy education David H. McKinnon; 13. Educating students with robotic telescopes - open discussion; 14. Poster highlights - educating students; Part IV. Educating teachers: Preface; 15. Pre-service astronomy education of teachers Mary Kay Hemenway; 16. In-service education of teachers Michèle Gerbaldi; 17. Poster highlights: educating teachers; Part V. Astronomy and Pseudoscience: Preface; 18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar; 19. Astronomical pseudosciences in North America John R. Percy and Jay M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster highlights: astronomy and culture; Part VII. Astronomy in Developing Countries: Preface; 22. Astronomy Curriculum for developing countries Case Rijsdijk; 23. Science education resources for the developing countries James C. White II; Part VIII. Public Outreach in Astronomy: Preface; 24. What makes informal education programs successful? Nahide Craig and Isabel

  14. A method for mechanical generation of radio frequency fields in nuclear magnetic resonance force microscopy

    CERN Document Server

    Wagenaar, J J T; Donkersloot, R J; Marsman, F; de Wit, M; Bossoni, L; Oosterkamp, T H

    2016-01-01

    We present an innovative method for magnetic resonance force microscopy (MRFM) with ultra-low dissipation, by using the higher modes of the mechanical detector as radio frequency (rf) source. This method allows MRFM on samples without the need to be close to an rf source. Furthermore, since rf sources require currents that give dissipation, our method enables nuclear magnetic resonance experiments at ultra-low temperatures. Removing the need for an on-chip rf source is an important step towards a MRFM which can be widely used in condensed matter physics.

  15. Binocular astronomy

    CERN Document Server

    Tonkin, Stephen

    2014-01-01

    Binoculars have, for many, long been regarded as an “entry level” observational tool, and relatively few have used them as a serious observing instrument. This is changing! Many people appreciate the relative comfort of two-eyed observing, but those who use binoculars come to realize that they offer more than comfort. The view of the stars is more aesthetically pleasing and therefore binocular observers tend to observe more frequently and for longer periods. Binocular Astronomy, 2nd Edition, extends its coverage of small and medium binoculars to large and giant (i.e., up to 300mm aperture) binoculars and also binoviewers, which brings the work into the realm of serious observing instruments. Additionally, it goes far deeper into the varying optical characteristics of binoculars, giving newcomers and advanced astronomers the information needed to make informed choices on purchasing a pair. It also covers relevant aspects of the physiology of binocular (as in “both eyes”) observation. The first edition ...

  16. Monitoring System for Atmospheric Water Vapor with a Ground-Based Multi-Band Radiometer: Meteorological Application of Radio Astronomy Technologies

    Science.gov (United States)

    Nagasaki, T.; Araki, K.; Ishimoto, H.; Kominami, K.; Tajima, O.

    2016-08-01

    High-resolution estimation of thermodynamic properties in the atmosphere can help to predict and mitigate meteorological disasters, such as local heavy rainfall and tornadic storms. For the purposes of short-term forecasting and nowcasting of severe storms, we propose a novel ground-based measurement system, which observes the intensity of atmospheric radiation in the microwave range. Our multi-band receiver system is designed to identify a rapid increase in water vapor before clouds are generated. At frequencies between 20 and 30 GHz, our system simultaneously measures water vapor as a broad absorption peak at 22 GHz as well as cloud liquid water. Another band at 50-60 GHz provides supplementary information from oxygen radiation to give vertical profiles of physical temperature. For the construction of this cold receiver system, novel technologies originally developed for observations of cosmic microwave background radiation were applied. The input atmospheric signal is amplified by a cold low-noise amplifier maintained below 10 K, while the spectrum of this amplified signal is measured using a signal analyzer under ambient conditions. The cryostat also contains a cold black body at 40 K to act as a calibration signal. This calibration signal is transported to each of the receivers via a wire grid. We can select either the atmospheric signal or the calibration signal by changing the orientation of this wire. Each receiver can be calibrated using this setup. Our system is designed to be compact (<1 m3), with low power consumption (˜ 1.5 kW). Therefore, it is easy to deploy on top of high buildings, mountains, and ship decks.

  17. The systematic spectral analysis of radio surveys

    CERN Document Server

    Harwood, Jeremy J

    2016-01-01

    Current and future continuum surveys being undertaken by the new generation of radio telescopes are now poised to address many important science questions, ranging from the earliest galaxies, to the physics of nearby AGN, as well as potentially providing new and unexpected discoveries. However, how to efficiently analyse the large quantities of data collected by these studies in order to maximise their scientific output remains an open question. In these proceedings we present details of the surveys module for the Broadband Radio Astronomy Tools (BRATS) software package which will combine new observations with existing multi-frequency data in order to automatically analyse and select sources based on their spectrum. We show how these methods can been applied to investigate objects observed on a variety of spatial scales, and suggest a pathway for how this can be used in the wider context of surveys and large samples.

  18. Astronomy for teachers: A South African Perspective

    Science.gov (United States)

    de Witt, Aletha; West, Marion; Leeuw, Lerothodi; Gouws, Eldrie

    2015-08-01

    South Africa has nominated Astronomy as a “flagship science” and aims to be an international Astronomy hub through projects such as the Square Kilometre Array (SKA) and the South African Large Telescope (SALT). These projects open up career opportunities in maths, science and engineering and therefore offers a very real door for learners to enter into careers in science and technology through Astronomy. However, the Trends in International Mathematics and Science Survey (TIMSS), the Global Competitiveness Report (GCR) and Annual National Assessment (ANA) have highlighted that South Africa’s Science and Mathematics education is in a critical condition and that South African learners score amongst the worst in the world in both these subjects. In South Africa Astronomy is generally regarded as the worst taught and most avoided Natural Science knowledge strand, and most teachers that specialised in Natural Sciences, never covered Astronomy in their training.In order to address these issues a collaborative project between the University of South Africa (UNISA) and the Hartebeesthoek Radio Astronomy Observatory (HartRAO) was initiated, which aims to assist teachers to gain more knowledge and skills so that they can teach Astronomy with confidence. By collaborating we aim to ensure that the level of astronomy development will be raised in both South Africa and the rest of Africa.With the focus on Teaching and Learning, the research was conducted within a quantitative paradigm and 600 structured questionnaires were administered to Natural Science teachers in Public primary schools in Gauteng, South Africa. This paper reports the findings of this research and makes recommendations on how to assist teachers to teach Astronomy with confidence.

  19. Encyclopedia of the History of Astronomy and Astrophysics

    Science.gov (United States)

    Leverington, David

    2013-06-01

    Preface; Part I. General Astronomy: 1. Ancient (pre-telescopy) astronomy; 2. Period overviews; 3. International Astronomical Union; Part II. The Solar System: 4. Overview - the Solar System; 5. Sun, Earth, and Moon; 6. Inner Solar System; 7. Giant planets; 8. Smaller objects; 9. Exoplanets; Part III. Stars: 10. Stars considered individually; 11. Stars considered as a group; 12. Types of stars; Part IV. Galaxies and Cosmology: 13. Milky Way; 14. Other galaxies and cosmology; Part V. General Astronomical Tools and Techniques (After 1600); Part VI. Optical Telescopes and Observatories: 15. Overview - optical telescopes and observatories; 16. Optical observatories; Part VII. Radio Telescopes, Observatories and Radar: 17. Overview - radio telescopes and observatories; 18. Early radio astronomy and observatories; 19. Later radio observatories; Part VIII. Other Ground-Based Observatories; Part IX. Solar System Exploration Spacecraft: 20. Overview - Solar System exploration spacecraft; 21. Individual Solar System spacecraft; Part X. Selected Observatory Spacecraft: 22. Overview - spacecraft observatories; 23. Individual spacecraft observatories; Name index; Subject index.

  20. Astronomy in the City for Astronomy Education

    Science.gov (United States)

    Ros, Rosa M.; Garc, Beatriz

    2016-10-01

    Astronomy is part of our culture. Astronomy cannot be isolated in a classroom, it has to be integrated in the normal life of teachers and students. ``Astronomy in the city'' is an important part of NASE (Network for Astronomy School Education) (Ros & Hemenway 2012). In each NASE course we introduce a ``working group session'' chaired by a local expert in cultural astronomy. The chair introduces several examples of astronomy in their city and after that, the participants have the opportunity to discuss and mention several similar examples. After this session all participants visit one or two sites proposed and introduced by the chair. After more than 5 years using this method we visited and discovered several examples of astronomy in the city: •Astronomy in ancient typical clothes. •Archaeological temples oriented according to the sunrise or set. •Petroglyphs with astronomical meaning. •Astronomy in monuments. •Sundials. •Oriented Colonial churches. •Astronomy in Souvenirs. In any case, teachers and students discover that Astronomy is part of their everyday life. They can take into account the Sun's path when they park their car or when they take a bus ``what is the best part in order to be seat in the shadow during the journey?'' The result is motivation to go with ``open eyes'' when they are in the street and they try to get more and more information about their surroundings. In summary, one of the main activities is to introduce local cultural aspects in NASE astronomy courses. The participants can discover a new approach to local culture from an astronomical point of view.

  1. Experimental Analysis of 60-GHz VCSEL and ECL Photonic Generation and Transmission of Impulse-Radio Ultra-Wideband Signals

    DEFF Research Database (Denmark)

    Beltran, Marta; Jensen, Jesper Bevensee; Llorente, Roberto

    2011-01-01

    Optical generation of impulse-radio ultra-wideband (UWB) signals in the 60-GHz band is proposed and experimentally demonstrated. External-cavity laser (ECL) and vertical-cavity surface-emitting laser (VCSEL) is employed for frequency up-conversion by heterodyne mixing with a UWB optical signal...... for comparison purposes. Real-time bit-error-rate (BER) performance of generated signals at 3.125 Gb/s is evaluated combining fiber and 2-m wireless transmission. Different optical fiber types including 1-km bend-insensitive single-mode fiber and 20-km nonzero dispersion-shifted fiber is evaluated. $\\hbox......{BER} for the ECL and $\\hbox{BER} for the VCSEL requiring higher received optical power than the ECL is demonstrated employing electrical power detection....

  2. Identifying the first generation of radio powerful AGN in the Universe with the SKA

    CERN Document Server

    Afonso, Jose; Prandoni, Isabella; Jarvis, Matt; Lorenzoni, Silvio; Magliocchetti, Manuela; Seymour, Nick

    2014-01-01

    One of the most challenging and exciting subjects in modern astrophysics is that of galaxy formation at the epoch of reionisation. The SKA, with its revolutionary capabilities in terms of frequency range, resolution and sensitivity, will allow to explore the first Gyr of structure formation in the Universe, in particular, with the detection and study of the earliest manifestations of the AGN phenomenon. The tens of QSOs that are currently known out to the highest redshifts (z~7), many of them exhibiting powerful radio emission, imply that super-massive black holes can be grown on a very short timescale and support the existence of very high redshift (z > 7) radio loud sources - sources that have so far escaped detection. Not only would such detections be paramount to the understanding of the earliest stages of galaxy evolution, they are necessary for the direct study of neutral hydrogen in the Epoch of Reionisation, through observations of the HI 21cm forest against such background sources. In order to unders...

  3. Innovation in Astronomy Education

    Science.gov (United States)

    Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi

    2013-01-01

    Preface; Part I. General Strategies for Effective Teaching: Introduction; 1. Main objectives of SpS2; 2. Learning astronomy by doing astronomy; 3. Hands-on Universe-Europe; 4. Life on Earth in the atmosphere of the Sun; 5. A model of teaching astronomy to pre-service teachers; 6. How to teach, learn about, and enjoy astronomy; 7. Clickers: a new teaching tool of exceptional promise; 8. Educational opportunities in pro-am collaboration; 9. Teaching history of astronomy to second-year engineering students; 10. Teaching the evolution of stellar and Milky Way concepts through the ages; 11. Educational efforts of the International Astronomical Union; 12. Astronomy in culture; 13. Light pollution: a tool for astronomy education; 14. Astronomy by distance learning; 15. Edible astronomy demonstrations; 16. Amateur astronomers as public outreach partners; 17. Does the Sun rotate around Earth or Earth rotate around the Sun?; 18. Using sounds and sonifications for astronomy outreach; 19. Teaching astronomy and the crisis in science education; 20. Astronomy for all as part of a general education; Poster abstracts; Part II. Connecting Astronomy with the Public: Introduction; 21. A status report from the Division XII working group; 22. Outreach using media; 23. Astronomy podcasting; 24. IAU's communication strategy, hands-on science communication, and the communication of the planet definition discussion; 25. Getting a word in edgeways: the survival of discourse in audiovisual astronomy; 26. Critical evaluation of the new Hall of Astronomy; 27. Revitalizing astronomy teaching through research on student understanding; Poster abstracts; Part III. Effective Use of Instruction and Information Technology: Introduction; 28. ESO's astronomy education program; 29. U.S. student astronomy research and remote observing projects; 30. Global network of autonomous observatories dedicated to student research; 31. Remote telescopes in education: report of an Australian study; 32. Visualizing

  4. The Development and Validation of the Test Of Astronomy STandards (TOAST)

    Science.gov (United States)

    Slater, Stephanie J.

    2014-01-01

    The Test Of Astronomy STandards (TOAST) is a comprehensive assessment instrument designed to measure students' general astronomy content knowledge. Built upon the research embedded within a generation of astronomy assessments designed to measure single concepts, the TOAST is appropriate to measure across an entire astronomy course. The TOAST's…

  5. Advances in astronomy and astrophysics 7

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

    Advances in Astronomy and Astrophysics, Volume 7 covers reviews about the advances in astronomy and astrophysics. The book presents reviews on the scattering of electrons by diatomic molecules and on Babcock's theory of the 22-year solar cycle and the latitude drift of the sunspot zone. The text then describes reviews on the structures of the terrestrial planets (Earth, Venus, Mars, Mercury) and on type III solar radio bursts. The compact and dispersed cosmic matter is also considered with regard to the search for new cosmic objects and phenomena and on the nature of the ref shift from compact

  6. Enabling technologies for millimeter-wave radio-over-fiber systems in next generation heterogeneous mobile access networks

    Science.gov (United States)

    Zhang, Junwen; Yu, Jianjun; Wang, Jing; Xu, Mu; Cheng, Lin; Lu, Feng; Shen, Shuyi; Yan, Yan; Cho, Hyunwoo; Guidotti, Daniel; Chang, Gee-kung

    2017-01-01

    Fifth-generation (5G) wireless access network promises to support higher access data rate with more than 1,000 times capacity with respect to current long-term evolution (LTE) systems. New radio-access-technologies (RATs) based on higher carrier frequencies to millimeter-wave (MMW) radio-over-fiber, and carrier-aggregation (CA) using multi-band resources are intensively studied to support the high data rate access and effectively use of frequency resources in heterogeneous mobile network (Het-Net). In this paper, we investigate several enabling technologies for MMW RoF systems in 5G Het-Net. Efficient mobile fronthaul (MFH) solutions for 5G centralized radio access network (C-RAN) and beyond are proposed, analyzed and experimentally demonstrated based on the analog scheme. Digital predistortion based on memory polynomial for analog MFH linearization are presented with improved EVM performances and receiver sensitivity. We also propose and experimentally demonstrate a novel inter-/intra- RAT CA scheme for 5G Het- Net. The real-time standard 4G-LTE signal is carrier-aggregated with three broadband 60GHz MMW signals based on proposed optical-domain band-mapping method. RATs based on new waveforms have also been studied here to achieve higher spectral-efficiency (SE) in asynchronous environments. Full-duplex asynchronous quasi-gapless carrier aggregation scheme for MMW ROF inter-/intra-RAT based on the FBMC is also presented with 4G-LTE signals. Compared with OFDM-based signals with large guard-bands, FBMC achieves higher spectral-efficiency with better EVM performance at less received power and smaller guard-bands.

  7. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    CERN Document Server

    Thyagarajan, Nithyanandan; Bowman, Judd D; Morales, Miguel F

    2015-01-01

    Modern radio telescopes are favoring densely packed array layouts consisting of large numbers of antennas ($N_\\textrm{a}\\gtrsim 1000$). Since the complexity of traditional correlators scales as $\\mathcal{O}(N_\\textrm{a}^2)$, there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (EPIC), we present the first software demonstration of a generalized direct imaging algorithm known as the Modular Optimal Frequency Fourier (MOFF) imager. It takes advantage of the multiplication-convolution theorem of Fourier transforms. Not only does it bring down the cost for dense layouts to $\\mathcal{O}(N_\\textrm{a}\\log_2 N_\\textrm{a})$ but can also image from irregularly arranged heterogeneous antenna arrays. EPIC is highly modular and parallelizable, implemented in object oriented Python, and publicly available. We have verified the images produced to be equivalent to those produced using traditional techniques. We...

  8. PURIFY: a new algorithmic framework for next-generation radio-interferometric imaging

    CERN Document Server

    Carrillo, Rafael E; Wiaux, Yves

    2014-01-01

    In recent works, compressed sensing (CS) and convex optimization techniques have been applied to radio-interferometric imaging showing the potential to outperform state-of-the-art imaging algorithms in the field. We review our latest contributions, which leverage the versatility of convex optimization to both handle realistic continuous visibilities and offer a highly parallelizable structure paving the way to significant acceleration of the reconstruction and high-dimensional data scalability. The new algorithmic structure promoted in a new software PURIFY (beta version) relies on the simultaneous-direction method of multipliers (SDMM). The performance of various sparsity priors is evaluated through simulations in the continuous visibility setting, confirming the superiority of our recent average sparsity approach SARA.

  9. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Flight Test Report

    Science.gov (United States)

    Ishac, Joseph A.; Iannicca, Dennis C.; Shalkhauser, Kurt A.; Kachmar, Brian A.

    2014-01-01

    NASA Glenn Research Center conducted a series of flight tests for the purpose of evaluating air-to-ground communications links for future unmanned aircraft systems (UAS). The primary objective of the test effort was to evaluate the transition of the aircraft communications from one ground station to the next, and to monitor data flow during the "hand-off" event. To facilitate the testing, ground stations were installed at locations in Cleveland, Ohio and Albany, Ohio that each provides line-of-sight radio communications with an overflying aircraft. This report describes results from the flight tests including flight parameters, received signal strength measurements, data latency times, and performance observations for the air-to-ground channel.

  10. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    Science.gov (United States)

    Thyagarajan, Nithyanandan; Beardsley, Adam P.; Bowman, Judd D.; Morales, Miguel F.

    2017-05-01

    Modern radio telescopes are favouring densely packed array layouts with large numbers of antennas (NA ≳ 1000). Since the complexity of traditional correlators scales as O(N_A^2), there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (epic), we present the first software demonstration of a generalized direct imaging algorithm, namely the Modular Optimal Frequency Fourier imager. Not only does it bring down the cost for dense layouts to O(N_A log _2N_A) but can also image from irregular layouts and heterogeneous arrays of antennas. epic is highly modular, parallelizable, implemented in object-oriented python, and publicly available. We have verified the images produced to be equivalent to those from traditional techniques to within a precision set by gridding coarseness. We have also validated our implementation on data observed with the Long Wavelength Array (LWA1). We provide a detailed framework for imaging with heterogeneous arrays and show that epic robustly estimates the input sky model for such arrays. Antenna layouts with dense filling factors consisting of a large number of antennas such as LWA, the Square Kilometre Array, Hydrogen Epoch of Reionization Array, and Canadian Hydrogen Intensity Mapping Experiment will gain significant computational advantage by deploying an optimized version of epic. The algorithm is a strong candidate for instruments targeting transient searches of fast radio bursts as well as planetary and exoplanetary phenomena due to the availability of high-speed calibrated time-domain images and low output bandwidth relative to visibility-based systems.

  11. A Generic and Efficient E-field Parallel Imaging Correlator for Next-Generation Radio Telescopes

    Science.gov (United States)

    Thyagarajan, Nithyanandan; Beardsley, Adam P.; Bowman, Judd D.; Morales, Miguel F.

    2017-01-01

    Modern radio telescopes are favouring densely packed array layouts with large numbers of antennas (NA ≳ 1000). Since the complexity of traditional correlators scales as O(N_{A}^2), there will be a steep cost for realizing the full imaging potential of these powerful instruments. Through our generic and efficient E-field Parallel Imaging Correlator (EPIC), we present the first software demonstration of a generalized direct imaging algorithm, namely, the Modular Optimal Frequency Fourier (MOFF) imager. Not only does it bring down the cost for dense layouts to O(N_{A} log _2N_{A}) but can also image from irregular layouts and heterogeneous arrays of antennas. EPIC is highly modular, parallelizable, implemented in object-oriented Python, and publicly available. We have verified the images produced to be equivalent to those from traditional techniques to within a precision set by gridding coarseness. We have also validated our implementation on data observed with the Long Wavelength Array (LWA1). We provide a detailed framework for imaging with heterogeneous arrays and show that EPIC robustly estimates the input sky model for such arrays. Antenna layouts with dense filling factors consisting of a large number of antennas such as LWA, the Square Kilometre Array, Hydrogen Epoch of Reionization Array, and Canadian Hydrogen Intensity Mapping Experiment will gain significant computational advantage by deploying an optimized version of EPIC. The algorithm is a strong candidate for instruments targeting transient searches of Fast Radio Bursts (FRB) as well as planetary and exoplanetary phenomena due to the availability of high-speed calibrated time-domain images and low output bandwidth relative to visibility-based systems.

  12. Characteristics in the jet region of helium radio-frequency atmospheric-pressure glow discharge with array generators

    Directory of Open Access Journals (Sweden)

    Zhi-Bin Wang

    2015-09-01

    Full Text Available The two-dimensional spatially extended atmospheric plasma arrays by many parallel radio-frequency glow discharge plasma jets packed densely, represent a feature option of large-scale low-temperature atmospheric plasma technologies with distinct capability of directed delivery of reactive species and good insusceptibility to sample variations. However, it is still a challenge to form plasma jet with large area of uniform active species on a downstream substrate due to the complex interactions between individual jets. This paper proposes to numerically study the strategy and mechanism of control/modulation for the array discharge to produce two-dimensional plasma uniformity in the downstream working area. In this work, a two dimensional fluid model is employed to investigate the characteristics in the jet region of helium radio-frequency atmospheric-pressure glow discharge (RF APGD with array generators. The influences of upstream discharge characteristics, gas flow and their cooperative effects on the distribution of species densities, gas temperatures and the uniformity of active species in the material treating area is studied, and the essential strategy for the modulation method is acquired. The results will be significant for deep understanding of coupling behaviors of multiple plasma plumes in the RF APGD array and applications of the technology.

  13. Tools of Radio Astronomy, 5th edition

    Science.gov (United States)

    Wilson, Thomas L.; Rohlfs, Kristian; Huttemeister, Susanne

    2012-12-01

    New 5th corrected edition of the book http://adsabs.harvard.edu/abs/2009tra..book.....W in Russian, translated by O. Verkhodanov and S. Trushkin, editing S.A. Trushkin from Special astrophysical observatory RAS. This edition contains the translation of the 5th Springer edition of 2009 and new additional chapter (wrote by authors) of Solutions of the problems.

  14. Acousto-optic spectrometer for radio astronomy

    Science.gov (United States)

    Chin, G.; Buhl, D.; Florez, J. M.

    1980-01-01

    A prototype acousto-optic spectrometer which uses a discrete bulk acoustic wave Itek Bragg cell, 5 mW Helium Neon laser, and a 1024 element Reticon charge coupled photodiode array is described. The analog signals from the photodiode array are digitized, added, and stored in a very high speed custom built multiplexer board which allows synchronous detection of weak signals to be performed. The experiment is controlled and the data are displayed and stored with an LSI-2 microcomputer system with dual floppy discs. The performance of the prototype acousto-optic spectrometer obtained from initial tests is reported.

  15. Radio Astronomy Antennas by the Thousands

    Science.gov (United States)

    Schultz, Roger

    2004-06-01

    Large number of microwave antennas of size and surface accuracy appropriate for the Square Kilometre Array (SKA) have not been manufactured previously. To minimize total cost, the design needs to be much more carefully considered and optimized than would be affordable for a small number of antennas. The required surface area requires new methods of manufacture and production-line type assembly to be considered. A blend of past antenna construction technology, creativity, and new technology is needed to provide the best possible telescope for the proposed SKA science goals. The following key concepts will be discussed with respect to reflector antennas and many supporting photographs, figures and drawings will be included. Surface and supporting structure comparison of panels with a one-piece shell as produced by hydroforming.

  16. HF Radio Astronomy from a Small Satellite

    Science.gov (United States)

    2016-06-15

    antenna as shown in Figure 4. Dual mode loop-dipole elements are described in [25,29,30]. The 10 MHz radiation patterns of the six modes are shown in... telemetry , GPS, and vector antenna modules. Robey 14 30th Annual AIAA/USU Conference on Small Satellites Alexander Morris. Thanks to Sara Klein for

  17. Astronomy in the City for Astronomy Education

    Science.gov (United States)

    Ros, Rosa Maria; García, Beatriz

    2015-08-01

    Astronomy is part of our culture. Astronomy cannot be isolated in a classroom, it has to be integrated in the normal life of teachers and students. “Astronomy in the city” is an important part of NASE (Network for Astronomy School Education). In each NASE course we introduce a “working group session” chaired by a local expert in cultural astronomy. The chair introduces several examples of astronomy in their city and after that, the participants have the opportunity to discuss and mention several similar examples. After this session all participants visit one or two sites proposed and introduced by the chair.After more than 5 years using this method we visited and discovered several examples of astronomy in the city:• Astronomy in ancient typical cloths• Archeological temples oriented according the Sun rise or set.• Petroglyphs with astronomical meaning.• Astronomy in monuments.• Sundials.• Oriented Colonial churches• Astronomy in SouvenirsIn any case, teachers and students discover that Astronomy is part of their everyday life. They can take into account the Sun's path when they park their car or when they take a bus "what is the best part in order to be seat in the shadow during the journey?" The result is motivation to go with “open eyes” when they are in the street and they try to get more and more information about their surroundings.The most significant characteristic of NASE is that the ”Local NASE Working Group” (LWG) in each country continues with astronomy activities using our materials and new materials created by them. These LWG are integrated by 6 to 8 teachers and professors that participated actively in NASE courses. They maintains alive the program and increases the number of students which can learn through our didactical proposal. There are more than 25 LWG that teach and organize activities on astronomy (education and/or communication) in about 20 countries.In summary, one of the main activities is to introduce local

  18. Statistical methods in astronomy

    OpenAIRE

    Long, James P.; de Souza, Rafael S.

    2017-01-01

    We present a review of data types and statistical methods often encountered in astronomy. The aim is to provide an introduction to statistical applications in astronomy for statisticians and computer scientists. We highlight the complex, often hierarchical, nature of many astronomy inference problems and advocate for cross-disciplinary collaborations to address these challenges.

  19. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Flight Test Report

    Science.gov (United States)

    Iannicca, Dennis C.; Ishac, Joseph A.; Shalkhauser, Kurt A.

    2015-01-01

    NASA Glenn Research Center (GRC), in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the Federal Aviation Administration (FAA) and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the GRC prototype CNPC architecture as a demonstration platform. The proposed security controls were integrated into the GRC flight test system aboard our S-3B Viking surrogate aircraft and several network tests were conducted during a flight on November 15th, 2014 to determine whether the controls were working properly within the flight environment. The flight test was also the first to integrate Robust Header Compression (ROHC) as a means of reducing the additional overhead introduced by the security controls and Mobile IPv6. The effort demonstrated the complete end-to-end secure CNPC link in a relevant flight environment.

  20. Hybrid Radio/Free-Space Optical Design for Next Generation Backhaul Systems

    KAUST Repository

    Douik, Ahmed

    2016-04-22

    The deluge of date rate in today\\'s networks imposes a cost burden on the backhaul network design. Developing cost-efficient backhaul solutions becomes an exciting, yet challenging, problem. Traditional technologies for backhaul networks, including either radio-frequency (RF) backhauls or optical fibers (OF). While RF is a cost-effective solution as compared with OF, it supports the lower data rate requirements. Another promising backhaul solution is the free-space optics (FSO) as it offers both a high data rate and a relatively low cost. The FSO, however, is sensitive to nature conditions, e.g., rain, fog, and line-of-sight. This paper combines both the RF and FSO advantages and proposes a hybrid RF/FSO backhaul solution. It considers the problem of minimizing the cost of the backhaul network by choosing either OF or hybrid RF/FSO backhaul links between the base stations, so as to satisfy data rate, connectivity, and reliability constraints. It shows that under a specified realistic assumption about the cost of OF and hybrid RF/FSO links, the problem is equivalent to a maximum weight clique problem, which can be solved with moderate complexity. Simulation results show that the proposed solution shows a close-to-optimal performance, especially for reasonable prices of the hybrid RF/FSO links. They further reveal that the hybrid RF/FSO is a cost-efficient solution and a good candidate for upgrading the existing backhaul networks. © 2016 IEEE.

  1. Multiband Radio Frequency Interconnect (MRFI) Technology For Next Generation Mobile/Airborne Computing Systems

    Science.gov (United States)

    2017-02-01

    25 4.1.11 Wide-Tuning-Range, Low-Jitter PLL Design...Figure 24: Blocks in the Layout of Carrier Generation ............................................................... 26 Figure 25: PLL Layout...27 Figure 26: PLL Block Diagram

  2. The Slacker Astronomy Podcast

    Science.gov (United States)

    Price, A.; Gay, P.; Searle, T.

    2005-05-01

    The Slacker Astronomy podcast is a weekly audio show about astronomy. Available in MP3 format, it is syndicated using RSS and XML feeds that make downloading snap. Each show presents a recent astronomical news item in an entertaining, humorous, and easy-to-understand manner that informs yet respects the intelligence of the listener. First launched on 05 Feb 14, the show has grown to over 5,000 weekly subscribers as of 05 April 01 without any formal publicity. Response has been over overwhelmingly positive, with strong reviews coming from other popular podcasts and coverage on the front page of the MSNBC.com science section. Our only consistent negative feedback is that the show is too short and too infrequent. This demonstrates a strong need to add content. We believe podcasting provides a unique mechanism to extend astronomical outreach to the younger generations and to those who lead busy lifestyles. Our formula is proving successful and we are looking for ways to quantify our impact and measure our demographic so that we can serve them better.

  3. Astronomy and Politics

    Science.gov (United States)

    Steele, John M.

    The relationship between astronomy and politics is a complex but important part of understanding the practice of astronomy throughout history. This chapter explores some of the ways that astronomy, astrology, and politics have interacted, placing particular focus on the way that astronomy and astrology have been used for political purposes by both people in power and people who wish to influence a ruler's policy. Also discussed are the effects that politics has had on the development of astronomy and, in particular, upon the recording and preservation of astronomical knowledge.

  4. Hot electron generation under large-signal radio frequency operation of GaN high-electron-mobility transistors

    Science.gov (United States)

    Latorre-Rey, Alvaro D.; Sabatti, Flavio F. M.; Albrecht, John D.; Saraniti, Marco

    2017-07-01

    In order to assess the underlying physical mechanisms of hot carrier-related degradation such as defect generation in millimeter-wave GaN power amplifiers, we have simulated the electron energy distribution function under large-signal radio frequency conditions in AlGaN/GaN high-electron-mobility transistors. Our results are obtained through a full band Monte Carlo particle-based simulator self-consistently coupled to a harmonic balance circuit solver. At lower frequency, simulations of a Class AB power amplifier at 10 GHz show that the peak hot electron generation is up to 43% lower under RF drive than it is under DC conditions, regardless of the input power or temperature of operation. However, at millimeter-wave operation up to 40 GHz, RF hot carrier generation reaches that from DC biasing and even exceeds it up to 75% as the amplifier is driven into compression. Increasing the temperature of operation also shows that degradation of DC and RF characteristics are tightly correlated and mainly caused by increased phonon scattering. The accurate determination of the electron energy mapping is demonstrated to be a powerful tool for the extraction of compact models used in lifetime and reliability analysis.

  5. Control and Non-Payload Communications (CNPC) Prototype Radio - Generation 2 Security Architecture Lab Test Report

    Science.gov (United States)

    Iannicca, Dennis C.; McKim, James H.; Stewart, David H.; Thadhani, Suresh K.; Young, Daniel P.

    2015-01-01

    NASA Glenn Research Center, in cooperation with Rockwell Collins, is working to develop a prototype Control and Non-Payload Communications (CNPC) radio platform as part of NASA Integrated Systems Research Program's (ISRP) Unmanned Aircraft Systems (UAS) Integration in the National Airspace System (NAS) project. A primary focus of the project is to work with the FAA and industry standards bodies to build and demonstrate a safe, secure, and efficient CNPC architecture that can be used by industry to evaluate the feasibility of deploying a system using these technologies in an operational capacity. GRC has been working in conjunction with these groups to assess threats, identify security requirements, and to develop a system of standards-based security controls that can be applied to the current GRC prototype CNPC architecture as a demonstration platform. The security controls were integrated into a lab test bed mock-up of the Mobile IPv6 architecture currently being used for NASA flight testing, and a series of network tests were conducted to evaluate the security overhead of the controls compared to the baseline CNPC link without any security. The aim of testing was to evaluate the performance impact of the additional security control overhead when added to the Mobile IPv6 architecture in various modes of operation. The statistics collected included packet captures at points along the path to gauge packet size as the sample data traversed the CNPC network, round trip latency, jitter, and throughput. The effort involved a series of tests of the baseline link, a link with Robust Header Compression (ROHC) and without security controls, a link with security controls and without ROHC, and finally a link with both ROHC and security controls enabled. The effort demonstrated that ROHC is both desirable and necessary to offset the additional expected overhead of applying security controls to the CNPC link.

  6. African Cultural Astronomy

    CERN Document Server

    Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa

    2008-01-01

    Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

  7. RECENT DEVELOPMENTS IN ULTRA-HIGH ENERGY NEUTRINO ASTRONOMY

    Directory of Open Access Journals (Sweden)

    Peter K. F. Grieder

    2013-12-01

    Full Text Available We outline the current situation in ultrahigh energy (UHE cosmic ray physics, pointing out the remaining problems, in particular the puzzle concerning the origin of the primary radiation and the role of neutrino astronomy for locating the sources. Various methods for the detection of UHE neutrinos are briefly described and their merits compared. We give an account of the achievements of the existing optical Cherenkov neutrino telescopes, outline the possibility of using air fluorescence and particle properties of air showers to identify neutrino induced events, and discuss various pioneering experiments employing radio and acoustic detection of extremely energetic neutrinos. The next generation of space, ground and sea based neutrino telescopes now under construction or in the planning phase are listed.

  8. Integration of Optically Generated Impulse Radio UWB Signals into Baseband WDM-PON

    DEFF Research Database (Denmark)

    Pham, Tien Thang; Yu, Xianbin; Dittmann, Lars

    2011-01-01

    We propose a compact integration system to simultaneously provide wireline and wireless (baseband and ultra-wide band (UWB)) services to end-users in a WDM-PON. A 1-Gbps UWB signal is optically generated and shares the same wavelength with the baseband signal. Error-free performance was achieved ...

  9. African Astronomy and the Square Kilometre Array

    Science.gov (United States)

    MacLeod, Gordon

    2010-02-01

    We highlight the growth of astronomy across Africa and the effect of hosting the Square Kilometer Array (SKA) will have on this growth. From the construction of a new 25m radio telescope in Nigeria, to new university astronomy programmes in Kenya, the HESS in Namibia and the Mauritian Radio Telescope, to the world class projects being developed in South Africa (Southern African Large Telescope and Karoo Array Telescope) astronomy is re-emerging across the continent. The SKA will represent the pinnacle of technological advancement in astronomy when constructed; requiring ultra high speed data transmission lines over 3000 km baselines and the World's fastest computer for correlation purposes. The investment alone to build the SKA on African soil will be of great economic benefit to its people, but the required network connectivity will significantly drive commercial expansion far beyond the initial value of the SKA investment. The most important consequence of hosting the SKA in Africa would be the impact on Human Capital Development (HCD) on the continent. Major HCD projects already underway producing excellent results will be presented. )

  10. Forthcoming mutual events of planets and astrometric radio sources

    CERN Document Server

    Malkin, Z; Tsekmejster, S

    2013-01-01

    Radio astronomy observations of close approaches of the Solar system planets to compact radio sources as well as radio source occultations by planets may be of large interest for planetary sciences, dynamical astronomy, and testing gravity theories. In this paper, we present extended lists of occultations of astrometric radio sources observed in the framework of various astrometric and geodetic VLBI programs by planets, and close approaches of planets to radio sources expected in the nearest years. Computations are made making use of the EPOS software package.

  11. Triple-Play and 60-GHz Radio-over-Fiber Techniques for Next-Generation Optical Access Networks

    DEFF Research Database (Denmark)

    Llorente, R.; Walker, S.; Tafur Monroy, Idelfonso

    2011-01-01

    Radio-over-fiber techniques apply to fiber-to-thehome distributions to reach the customer premises with the services to be received with full-standard low-cost equipment. Bi-directional coarse wavelength division multiplexing (CWDM) radio-over-fiber transmission of triple-format full-standard ort......Radio-over-fiber techniques apply to fiber-to-thehome distributions to reach the customer premises with the services to be received with full-standard low-cost equipment. Bi-directional coarse wavelength division multiplexing (CWDM) radio-over-fiber transmission of triple-format full...... performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitting lasers (VCSELs), and further wireless transmission, of standard OFDM UWB signals is reported when operating in the 60-GHz radio band. Performance is evaluated at 1.44 Gbit/s bitrate. PON transmission distance up...

  12. Radio-frequency ion source generating beams with an increased proton content

    Science.gov (United States)

    Ivanov, A. A.; Podyminogin, A. A.; Shikhovtsev, I. V.

    2007-01-01

    The results of experiments with an rf ion source generating a beam with an improved mass composition are reported. The proton content in the beam is increased by raising the rf power density in the discharge under the antenna and installing a magnetic filter near the plasma grid. Additional steps are taken to prevent the earlier observed degradation of the beam composition because of aluminum reduction on the inner surface of the ceramic discharge chamber and water release. Specifically, the chamber is lined with pyrolytic boron nitride sheets.

  13. Armenian Cultural Astronomy

    Science.gov (United States)

    Farmanyan, S. V.; Mickaelian, A. M.

    2015-07-01

    Cultural Astronomy is the reflection of sky events in various fields of nations' culture. In foreign literature this field is also called "Astronomy in Culture" or "Astronomy and Culture". Cultural astronomy is the set of interdisciplinary fields studying the astronomical systems of current or ancient societies and cultures. It is manifested in Religion, Mythology, Folklore, Poetry, Art, Linguistics and other fields. In recent years, considerable attention has been paid to this sphere, particularly international organizations were established, conferences are held and journals are published. Armenia is also rich in cultural astronomy. The present paper focuses on Armenian archaeoastronomy and cultural astronomy, including many creations related to astronomical knowledge; calendars, rock art, mythology, etc. On the other hand, this subject is rather poorly developed in Armenia; there are only individual studies on various related issues (especially many studies related to Anania Shirakatsi) but not coordinated actions to manage this important field of investigation.

  14. Astronomy in Argentina

    CERN Document Server

    Muriel, Hernán

    2013-01-01

    This article analyses the current state of Astronomy in Argentina and describes its origins. We briefly describe the institutions where astronomical research takes place, the observational facilities available, the training of staff and professionals, and the role of the institutions in scientific promotion. We also discuss the outreach of Astronomy towards the general public, as well as amateur activities. The article ends with an analysis of the future prospects of astronomy in Argentina.

  15. Why is Astronomy Important?

    OpenAIRE

    Rosenberg, Marissa; Russo, Pedro; Bladon, Georgia; Christensen, Lars Lindberg

    2013-01-01

    Astronomy and related fields are at the forefront of science and technology; answering fundamental questions and driving innovation. Although blue-skies research like astronomy rarely contributes directly with tangible outcomes on a short time scale, the pursuit of this research requires cutting-edge technology and methods that can on a longer time scale, through their broader application make a difference. A wealth of examples show how the study of astronomy contributes to technology, econom...

  16. Some innovative programmes in Astronomy education

    Science.gov (United States)

    Babu, G. S. D.; Sujatha, S.

    In order to inculcate a systematic scientific awareness of the subject of Astronomy among the students and to motivate them to pursue careers in Astronomy and Astrophysics, various innovative educational programmes have been designed at MPBIFR. Among them, the main programme is termed as the ``100-hour Certificate Course in Astronomy and Astrophysics'' which has been designed basically for the students of the undergraduate level of B.Sc. and B.E. streams. The time duration of the 100 hours in this course is partitioned as 36 hours of classroom lectures, 34 hours of practicals and field trips and the remaining 30 hours being dedicated to dissertation writing and seminar presentations by the students. In addition, after the 100-hour course, the students have the option to take up specialized advance courses in the topics of Astrobiology, Astrochemistry, Radio Astronomy, Solar Astronomy and Cosmology as week-end classes. These courses are at the post graduate level and are covered in a span of 18 to 20 hours spread over a period of 9 to 10 weeks. As a preparatory programme, short-term introductory courses in the same subject are conducted for the high school students during the summer vacation period. Along with this, a three-week programme in basic Astronomy is also designed as an educational package for the general public. The students of these courses have the opportunity of being taken on field trips to various astronomical centers as well as the Radio, Solar and the Optical Observatories as part of their curriculum. The guided trips to the ISRO’s Satellite Centre at Bangalore and the Satellite Launching Station at SHAR provide high degree of motivation apart from giving thrilling experiences to the students. Further, the motivated students are encouraged to involve themselves in regular research programmes in Astronomy at MPBIFR for publishing research papers in national and international journals. The teaching and mentoring faculty for all these programmes

  17. Radio Frequency Interference Mitigation at the WSRT

    CERN Document Server

    Fridman, P A; Millenaar, R P

    2010-01-01

    The sensitivity of radio astronomical stations is often limited by man-made radio frequency interference (RFI) due to a variety of terrestrial activities. An RFI mitigation subsystem (RFIMS) based on real-time digital signalprocessing is proposed here for the Westerbork Synthesis Radio Telescope based on a powerful field programmable gate array processor. In this system the radio astronomy signals polluted by RFI are "cleaned" with the RFIMS before routine back-end correlation processing takes place. The high temporal and frequency resolution of RFIMS allows the detection and excision of RFI better than do standard radio telescope back-end configurations.

  18. "Conference on communicating astronomy with the public":taking action

    Science.gov (United States)

    Billings, L.

    In October 2003, The National Radio Astronomy Observatories (NRAO) and the National Research Council (NRC) held a three-day conference in Washington, D.C., on communicating with the public about astronomy. The goals of this conference, intended to be a working meeting, were 'to develop a program to share outreach and education resources among the astronomical community [and] to find ways of communicating with underdeveloped constituencies.' Scientists, communication specialists and others active in public outreach and education about astronomy and space science deliberated on the current state of astronomy communications, the needs of the mass media and the entertainment media, the conduct of public outreach and education as an element of research astronomy, and best practices in astronomy outreach and education. Two important products of the meeting were: 1) A 'Washington charter for communicating astronomy with the public,' a position paper articulating principles of action for funding agencies, professional astronomical societies, individual researchers and universities, laboratories, research organizations and other institutions interested in communicating with the public about astronomy; 2) The appointment of a task force to to organize an electronic archive of informational resources about astronomy. Two options under consideration by the task force are creation of a Web site providing links, categorized and searchable, to astronomy public outreach and education resources; and creation of a Web site that would be a searchable database of astronomy information and imagery (either representative or comprehensive). This paper will highlight the proceedings of the conference, report outcomes, and provide a status report on post-conference actions.

  19. Random time series in Astronomy

    CERN Document Server

    Vaughan, Simon

    2013-01-01

    Progress in astronomy comes from interpreting the signals encoded in the light received from distant objects: the distribution of light over the sky (images), over photon wavelength (spectrum), over polarization angle, and over time (usually called light curves by astronomers). In the time domain we see transient events such as supernovae, gamma-ray bursts, and other powerful explosions; we see periodic phenomena such as the orbits of planets around nearby stars, radio pulsars, and pulsations of stars in nearby galaxies; and persistent aperiodic variations (`noise') from powerful systems like accreting black holes. I review just a few of the recent and future challenges in the burgeoning area of Time Domain Astrophysics, with particular attention to persistently variable sources, the recovery of reliable noise power spectra from sparsely sampled time series, higher-order properties of accreting black holes, and time delays and correlations in multivariate time series.

  20. Random time series in astronomy.

    Science.gov (United States)

    Vaughan, Simon

    2013-02-13

    Progress in astronomy comes from interpreting the signals encoded in the light received from distant objects: the distribution of light over the sky (images), over photon wavelength (spectrum), over polarization angle and over time (usually called light curves by astronomers). In the time domain, we see transient events such as supernovae, gamma-ray bursts and other powerful explosions; we see periodic phenomena such as the orbits of planets around nearby stars, radio pulsars and pulsations of stars in nearby galaxies; and we see persistent aperiodic variations ('noise') from powerful systems such as accreting black holes. I review just a few of the recent and future challenges in the burgeoning area of time domain astrophysics, with particular attention to persistently variable sources, the recovery of reliable noise power spectra from sparsely sampled time series, higher order properties of accreting black holes, and time delays and correlations in multi-variate time series.

  1. Multiversos: Rock'n'Astronomy

    Science.gov (United States)

    Caballero, J. A.; Arias, A.; García, N.

    2011-11-01

    Imagine that you can use your fingers only for typing target coordinates at thetelescope, reduce images and spectra with IRAF, or write papers for Astronomy &Astrophysics, but you would never be able to play an electric guitar.Imagine that you love music, work in front of the computer always withheadphones, and dream of playing with your favourite rock band in a tumultuousconcert.Imagine that you are an astronomer who, after a "cosmic fluke", share stagewith the band which themes you have always hummed since you were a teenager.Imagine that you were born for rock, played a main role in the best Spanishalbum of the 90s (Omega, with Enrique Morente), and your songs arerutinary played by Radio 3, but you would never be able to detect an exoplanetor a galaxy at a high redshift.Imagine that you love Astronomy, try to see the Moon craters and Andromeda withyour small telescope through the light pollution of your city, and explain yourdaughter that Pluto is not a planet any longer. Imagine that you are a musician who, after a "cosmic fluke", give a talk justafter a Nobel laureate that discovered the cosmic microwave backgroundradiation.Such "cosmic flukes" sometimes happen. If you were not at the dinner of the SEA meeting and do not believe us, visithttp://www.myspace.com/antonioariasmultiverso or open the proceedings DVD andlisten "El ordenador simula el nacimiento de las estrella...".

  2. Astronomy in School

    Science.gov (United States)

    Beet, E. A.

    1973-01-01

    Summarizes practical projects, science activities, and teaching aids usable in teaching of the astronomy section of physics courses at the pre-O, O and A-level stages. Indicates that the teacher interest is the decisive factor influencing introduction of astronomy into schools. (CC)

  3. Towards ``Astronomy for Development''

    Science.gov (United States)

    Govender, Kevin

    2016-10-01

    The ambition of the IAU's decadal strategic plan is to use astronomy to stimulate development globally. The Office of Astronomy for Development was established in 2011 to implement this visionary plan. This talk will reflect on the past, present and future activities of the office, and describe the status of implementation of the plan at this halfway point in the 2010- decade.

  4. Compendium of Practical Astronomy

    Science.gov (United States)

    Roth, Günter D.; Augensen, H. J.; Heintz, W. D.

    The Compendium of Practical Astronomy is a revised and enlarged English version of the fourth edition of G. Roth's famous handbook for stargazers. In three volumes 28 carefully edited articles aimed especially at amateur astronomers and students and teachers of astronomy in high schools and colleges cover the length and breadth of practical astronomy. Volume 1 contains information on modern instrumentation and reduction techniques, including spherical astronomy, error estimations, telescope mountings, astrophotography, and more. Volume 2 covers the planetary system, with contributions on artificial satellites, comets, the polar aurorae, and the effects of the atmophere on observational data. Volume 3 is devoted to stellar objects, variable stars and binary stars in particular, the Milky Way and Galaxies. An introduction to the astronomical literature and a comprehensive chapter on astronomy education and instructional aids make the Compendium a useful complement to any college library.

  5. Handbook of Practical Astronomy

    CERN Document Server

    Roth, Günter D

    2009-01-01

    With amateurs, students, and teachers of astronomy in high schools and colleges particularly in mind, the Handbook of Practical Astronomy is an essential source to demonstrate trends and variety of astronomical observations. The book presents the substance of celestial bodies for the amateur observer: the planets, the stars, and the galaxies. The sun is the local link to the other stars, the nexus of cosmic evolution. The solar system is made up by the sun and all the celestial bodies orbit it. This system is of special interest for the observing amateur. The Handbook of Practial Astronomy spans astronomy, education and computing. Like many other fields of science, astronomy has become digitized and data rich in recent years. Besides the references at the end of each chapter, there are the notes in the margins with astronomical news and observing highlights on the web.

  6. Joseph Henry and Astronomy

    Science.gov (United States)

    Rothenberg, Marc

    2016-01-01

    Joseph Henry (1797-1878) is best known for his work in electromagnetism and as the first secretary of the Smithsonian Institution. But he was also a pioneer solar physicist, an early advocate of US participation in astrophysics, and a facilitator of international cooperation in astronomy. This paper will briefly trace his role in the development of the US astronomical community from the time he taught astronomy at Princeton in the 1830s through his death, focusing on failed efforts to persuade US astronomers and patrons of astronomy that the best path for US astronomy should be astrophysics. He thought that the US could make a more significant contribution to astronomy science by striking out on a less travelled path rather than competing with the established European observatories.

  7. 40 Gb/s W-band (75-110 GHz) 16-QAM radio-over-fiber signal generation and its wireless transmission.

    Science.gov (United States)

    Kanno, Atsushi; Inagaki, Keizo; Morohashi, Isao; Sakamoto, Takahide; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

    2011-12-12

    The generation of a 40-Gb/s 16-QAM radio-over-fiber (RoF) signal and its demodulation of the wireless signal transmitted over free space of 30 mm in W-band (75-110 GHz) is demonstrated. The 16-QAM signal is generated by a coherent polarization synthesis method using a dual-polarization QPSK modulator. A combination of the simple RoF generation and the versatile digital receiver technique is suitable for the proposed coherent optical/wireless seamless network.

  8. Stratospheric Observatory for Infrared Astronomy

    CERN Document Server

    Hamidouche, M; Marcum, P; Krabbe, A

    2010-01-01

    We present one of the new generations of observatories, the Stratospheric Observatory For Infrared Astronomy (SOFIA). This is an airborne observatory consisting of a 2.7-m telescope mounted on a modified Boeing B747-SP airplane. Flying at an up to 45,000 ft (14 km) altitude, SOFIA will observe above more than 99 percent of the Earth's atmospheric water vapor allowing observations in the normally obscured far-infrared. We outline the observatory capabilities and goals. The first-generation science instruments flying on board SOFIA and their main astronomical goals are also presented.

  9. A Michelson-type Radio Interferometer for University Education

    CERN Document Server

    Koda, Jin; Hasegawa, Tetsuo; Hayashi, Masahiko; Shafto, Gene; Slechta, Jeff; Metchev, Stanimir

    2016-01-01

    We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the future generation of astronomers. This interferometer provides the hands-on experience needed to fully understand the basic concepts of interferometry. The design of this interferometer is based on the Michelson & Pease stellar optical interferometer, but operates at a radio wavelength (~11 GHz; ~2.7cm); thus the requirement for optical accuracy is much less stringent. We utilize a commercial broadcast satellite dish and feedhorn. Two flat side mirrors slide on a ladder, providing baseline coverage. This interferometer resolves and measures the diameter of the Sun, a nice daytime experiment which can be carried out even in marginal weather (i.e., partial cloud cover). Commercial broadcast satellites provide convenient point sources for comparison to the Su...

  10. Saturation Ion Current Densities in Inductively Coupled Hydrogen Plasma Produced by Large-Power Radio Frequency Generator

    Science.gov (United States)

    Wang, Songbai; Lei, Guangjiu; Bi, Zhenhua; Ghomi, H.; Yang, Size; Liu, Dongping

    2016-09-01

    An experimental investigation of the saturation ion current densities (Jions) in hydrogen inductively coupled plasma (ICP) produced by a large-power (2-32 kW) radio frequency (RF) generator is reported, then some reasonable explanations are given out. With the increase of RF power, the experimental results show three stages: in the first stage (2-14 kW), the electron temperature will rise with the increase of RF power in the ICP, thus, the Jions increases continually as the electron temperature rises in the ICP. In the second stage (14-20 kW), as some H- ions lead to the mutual neutralization (MN), the slope of Jions variation firstly decreases then increases. In the third stage (20-32 kW), both the electronic detachment (ED) and the associative detachment (AD) in the ICP result in the destruction of H- ions, therefore, the increased amplitude of the Jions in the third stage is weaker than the one in the first stage. In addition, with the equivalent transformer model, we successfully explain that the Jions at different radial locations in ICP has the same rule. Finally, it is found that the Jions has nothing to do with the outer/inner puffing gas pressure ratio, which is attributed to the high-speed movement of hydrogen molecules. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2011GB108011 and 2010GB103001), the Major International (Regional) Project Cooperation and Exchanges of China (No. 11320101005) and the Startup Fund from Fuzhou University (No. 510071)

  11. NASA IDEAS to Improve Instruction in Astronomy and Space Science

    Science.gov (United States)

    Malphrus, B.; Kidwell, K.

    1999-12-01

    The IDEAS to Improve Instructional Competencies in Astronomy and Space Science project is intended to develop and/or enhance teacher competencies in astronomy and space sciences of teacher participants (Grades 5-12) in Kentucky. The project is being implemented through a two-week summer workshop, a series of five follow-up meetings, and an academic year research project. The resources of Kentucky's only Radio Astronomy Observatory- the Morehead Radio Telescope (MRT), Goldstone Apple Valley Radio Telescope (GAVRT) (via remote observing using the Internet), and the Kentucky Department of Education regional service centers are combined to provide a unique educational experience. The project is designed to improve science teacher's instructional methodologies by providing pedagogical assistance, content training, involving the teachers and their students in research in radio astronomy, providing access to the facilities of the Morehead Astrophysical Observatory, and by working closely with a NASA-JOVE research astronomer. Participating teachers will ultimately produce curriculum units and research projects, the results of which will be published on the WWW. A major goal of this project is to share with teachers and ultimately students the excitement and importance of scientific research. The project represents a partnership of five agencies, each matching the commitment both financially and/or personnel. This project is funded by the NASA IDEAS initiative administered by the Space Telescope Science Institute and the National Air and Space Administration (NASA).

  12. Naming asteroids for the popularisation of astronomy

    Science.gov (United States)

    Naranjo, O. A.

    2008-06-01

    We give a detailed description of how the naming of asteroids was used as a prize in competitions run by educational institutions and museums. There were two events, one in Venezuela and one in Brazil, which used this as an attractive alternative method for the popularisation of astronomy. The first competition, named Bautizo Espacial (Space Baptism), consisted of scientific stories written by high school students. The second, called Grande Desafio (Big Challenge), was a competition where teams of students were challenged to design and build prototype equipment to fight forest fires. Nationally, both events received wide publicity through newspapers, radio, TV and web pages, reaching many people in both countries. As part of both the events, several activities promoting the public knowledge of astronomy were held. The asteroids that were named in these competitions are just some of the many discovered in a search programme developed by the Group of Theoretical Astrophysics of University of Los Andes in Mérida, Venezuela (Grupo de Astrofisica Teórica de la Universidad de Los Andes) as a mainstream research programme. Finally, Asteroids for the Popularisation of Astronomy has been formally proposed to the IAU as a worldwide programme during the celebration of the International Year of Astronomy in 2009 (IYA2009).

  13. The Network for Astronomy in Education in Southwest New Mexico

    Science.gov (United States)

    Neely, B.

    1998-12-01

    The Network for Astronomy in Education was organized to use astronomy as a motivational tool to teach science methods and principles in the public schools. NFO is a small private research observatory, associated with the local University, Western New Mexico. We started our program in 1996 with an IDEA grant by introducing local teachers to the Internet, funding a portable planetarium (Starlab) for the students, and upgrading our local radio linked computer network. Grant County is a rural mining and ranching county in Southwest New Mexico. It is ethnically diverse and has a large portion of the population below the poverty line. It's dryness and 6000' foot elevation, along with dark skies, suite it to the appreciation of astronomy. We now have 8 local schools involved in astronomy at some level. Our main programs are the Starlab and Project Astro, and we will soon install a Sidewalk Solar System in the center of Silver City.

  14. Teaching Astronomy with Technology

    Science.gov (United States)

    Austin, Carmen; Impey, Chris David; Wenger, Matthew

    2015-01-01

    Students today are expected to have access to computers and the Internet. Students young and old, in school and out of school, are interested in learning about astronomy, and have computers to use for this. Teach Astronomy is a website with a comprehensive digital astronomy textbook freely available to students and educators. In addition to the textbook, there are astronomy Wikipedia articles, image archives from Astronomy Picture of the Day and AstroPix, and video lectures covering all topics of astronomy. Teach Astronomy has a unique search tool called the wikimap that can be used to search through all of the resources on the site. Astronomy: State of the Art (ASOTA) is a massive, open, online course (MOOC). Over 18,000 students have enrolled over the past year and half. This MOOC has been presented in various forms. First, only to students on the web, with content released weekly on host site Udemy. Then to university students who met formally in the classroom for educational activities, but were also expected to watch lectures online on their own time. Presently, it is available online for students to go at their own pace. In the future it will be available in an extended format on a new host site, Coursera. ASOTA instructors use social media to interact with students. Students ask questions via the course host site, Udemy. Live question and answer sessions are conducted using Google Hangouts on Air, and interesting and relevant astronomy news, or supplementary educational content is shared via the ASOTA Facebook page. Teaching on the Internet may seem impersonal and impractical, but by learning to use all of these tools, instructors have the ability to interact with students, and keep them engaged.

  15. Highschool astronomy research workshop in Thailand and how it transforms Thai astronomy education

    Science.gov (United States)

    Tangmatitham, Matipon

    2017-01-01

    The National Astronomical Research Institute of Thailand (NARIT) have launched the program "Advance Teacher Training Workshop" that aims to introduce both the students and astronomy teacher alike to the nature of critical thinking in science via hands on experience in astronomy projects. Students and accompanying teachers are participated in 5 days workshop in which each of them must select an individual astronomy research project. The project is then carried out on their own for the next 6 months, after which their works are presented in a conference. Progress is monitored and extra aid is delivered as needed via the use of social media. Over a hundred projects have been completed under this program. Follow up study have suggests that this workshop has shown to be quite successful at improving critical thinking skills in participants. As the program became more popular, other schools began to follow. To support the growing interest, we have also launched the "Thai Astronomical Society: student session", a highschool astronomy conference for anyone who participated or interested in astronomy related projects. Via these stages we are able to secure a permanent foothold in Thai astronomy education and inspire new generations to participate in astronomy projects.

  16. Astronomy and culture

    CERN Document Server

    Hetherington, Edith

    2009-01-01

    While astronomy is a burgeoning science, with tremendous increases in knowledge every year, it also has a tremendous past, one that has altered humanity's understanding of our place in the universe. The impact of astronomy on culture - whether through myths and stories, or through challenges to the intellectual status quo - is incalculable. This volume in the Greenwood Guides to the Universe series examines how human cultures, in all regions and time periods, have tried to make sense of the wonders of the universe. Astronomy and Culture shows students how people throughout time have struggled

  17. Astronomy in Ukraine

    CERN Document Server

    Pavlenko, Ya V; Vavilova, I B; Pavlenko, Ya.V.

    2005-01-01

    The current and prospective status of astronomical research in Ukraine is discussed. A brief history of astronomical research in Ukraine is presented and the system organizing scientific activity is described, including astronomy education, institutions and staff, awarding higher degrees/titles, government involvement, budgetary investments and international cooperation. Individuals contributing significantly to the field of astronomy and their accomplishments are mentioned. Major astronomical facilities, their capabilities, and their instrumentation are described. In terms of the number of institutions and personnel engaged in astronomy, and of past accomplishments, Ukraine ranks among major nations of Europe. Current difficulties associated with political, economic and technological changes are addressed and goals for future research activities presented.

  18. Discovering Astronomy Through Poetry

    Science.gov (United States)

    Mannone, John C.

    2011-05-01

    The literature is replete with astronomical references. And much of that literature is poetry. Using this fact, not only can the teacher infuse a new appreciation of astronomy, but also, the student has the opportunity to rediscover history through astronomy. Poetry can be an effective icebreaker in the introduction of new topics in physics and astronomy, as well as a point of conclusion to a lecture. This presentation will give examples of these things from the ancient literature (sacred Hebraic texts), classical literature (Homer's Iliad and Odyssey), traditional poetry (Longfellow, Tennyson and Poe) and modern literature (Frost, Kooser, and others, including the contemporary work of this author).

  19. To See the Unseen: A History of Planetary Radar Astronomy

    Science.gov (United States)

    Butrica, Andrew J.

    1996-01-01

    This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground

  20. Large Databases in Astronomy

    Science.gov (United States)

    Szalay, Alexander S.; Gray, Jim; Kunszt, Peter; Thakar, Anirudha; Slutz, Don

    The next-generation astronomy digital archives will cover most of the sky at fine resolution in many wavelengths, from X-rays through ultraviolet, optical, and infrared. The archives will be stored at diverse geographical locations. The intensive use of advanced data archives will enable astronomers to explore their data interactively. Data access will be aided by multidimensional spatial and attribute indices. The data will be partitioned in many ways. Small tag indices consisting of the most popular attributes will accelerate frequent searches. Splitting the data among multiple servers will allow parallel, scalable I/O and parallel data analysis. Hashing techniques will allow efficient clustering, and pair-wise comparison algorithms that should parallelize nicely. Randomly sampled subsets will allow debugging otherwise large queries at the desktop. Central servers will operate a data pump to support sweep searches touching most of the data. The anticipated queries will require special operators related to angular distances and complex similarity tests of object properties, like shapes, colors, velocity vectors, or temporal behaviors. These issues pose interesting data management challenges.

  1. Tools and Methods of Low-Frequency Radio Recombination Lines Investigations

    Science.gov (United States)

    Konovalenko, A. A.; Stepkin, S. V.; Mukha, D. V.; Vasilkovskiy, E. V.

    In the report the tools and methods of observations of radio recombination lines which are carried out at Institute of Radio Astronomy of the National Academy of Sciences of Ukraine using the world's largest decameter radio telescope UTR-2 (arrays "South - North" and "East - West") are described. The low-frequency radio recombination lines can be used as effective means of the low-density partially ionized interstellar medium diagnostic. However, low intensities of the lines and high level of interferences makes such investigations very difficult and impose high requirements to equipment. Observations are carried out with the 4096-channel digital correlometer and new generation digital spectral processors with 8192 spectral channels. Currently, the systematic observations of radio recombination lines have been carried out in the directions of remnants of supernova stars, Galactic plane, nebulas and dust clouds. Experiments aimed to finding the redshifted line of neutral hydrogen HI which arises in the cosmological epochs of reionization in the range 8 - 32 MHz are carried out. The carbon radio recombination lines have been detected in the direction of Cassiopeia A in the broad range of frequencies from 20 to 32 MHz. The carbon radio recombination line, corresponding to the transitions to atomic level with number of 1009 (these corresponds to the Bohr size of atom near 0,1 mm) have been registered.

  2. Gravitational Waves and Time Domain Astronomy

    Science.gov (United States)

    Centrella, Joan; Nissanke, Samaya; Williams, Roy

    2012-01-01

    The gravitational wave window onto the universe will open in roughly five years, when Advanced LIGO and Virgo achieve the first detections of high frequency gravitational waves, most likely coming from compact binary mergers. Electromagnetic follow-up of these triggers, using radio, optical, and high energy telescopes, promises exciting opportunities in multi-messenger time domain astronomy. In the decade, space-based observations of low frequency gravitational waves from massive black hole mergers, and their electromagnetic counterparts, will open up further vistas for discovery. This two-part workshop featured brief presentations and stimulating discussions on the challenges and opportunities presented by gravitational wave astronomy. Highlights from the workshop, with the emphasis on strategies for electromagnetic follow-up, are presented in this report.

  3. Islands of Astronomy

    Directory of Open Access Journals (Sweden)

    Godfrey Baldacchino

    2009-05-01

    Full Text Available A global review of islands and their connections with astronomy throughout history up to the contemporary times suggests eight compelling, distinct yet interlocking reasons why islands have been and remain so important to astronomy and astronomers. Islands constitute favourable locations for various types of astronomy-related activities: from tracking satellites and monitoring significant celestial events, to providing exceptional locations to jurisdictions with mandated dark and unpolluted skies. They appeal for their favourable longitude and (especially southern latitude, as well as for their disposition towards the conditions that the scientific community may expect in an ideal world: relatively clear viewing conditions from a secure, self-contained platform that is, however, endowed with connectivity. This article is written as a contribution to the International Year of Astronomy (2009.

  4. Astronomy, Astrology, and Medicine

    Science.gov (United States)

    Greenbaum, Dorian Gieseler

    Astronomy and astrology were combined with medicine for thousands of years. Beginning in Mesopotamia in the second millennium BCE and continuing into the eighteenth century, medical practitioners used astronomy/astrology as an important part of diagnosis and prescription. Throughout this time frame, scientists cited the similarities between medicine and astrology, in addition to combining the two in practice. Hippocrates and Galen based medical theories on the relationship between heavenly bodies and human bodies. In an enduring cultural phenomenon, parts of the body as well as diseases were linked to zodiac signs and planets. In Renaissance universities, astronomy and astrology were studied by students of medicine. History records a long tradition of astrologer-physicians. This chapter covers the topic of astronomy, astrology, and medicine from the Old Babylonian period to the Enlightenment.

  5. Cultural Astronomy in Japan

    Science.gov (United States)

    Renshaw, Steven L.

    While Japan is known more for its contributions to modern astronomy than its archaeoastronomical sites, there is still much about the culture's heritage that is of interest in the study of cultural astronomy. This case study provides an overview of historical considerations necessary to understand the place of astronomy in Japanese society as well as methodological considerations that highlight traditional approaches that have at times been a barrier to interdisciplinary research. Some specific areas of study in the cultural astronomy of Japan are discussed including examples of contemporary research based on interdisciplinary approaches. Japan provides a fascinating background for scholars who are willing to go beyond their curiosity for sites of alignment and approach the culture with a desire to place astronomical iconography in social context.

  6. Astronomy @ Hale School

    Science.gov (United States)

    Cooper, William

    Earth in space is one of the teaching strands of the Western Australia science curriculum. I was able to beg some money from my school to set up an astronomy club and address some of the outcomes of the teaching statement. As a Pom, I thought teaching Astronomy here was going to be great. As a baby boomer mesmerized by the moon landings it came as a disappointment to find that my MTV students found Astronomy passé. Why aren?t students fascinated? Astronomy asks the fundamental life questions: * Where did everything come from? * How did it all get here? * Where is it all going to? * Why are all the science labs I've ever worked in hiding a dusty Tasco refractor or a half working Meade * How was I going to survive?

  7. Stamping through astronomy

    CERN Document Server

    Dicati, Renato

    2013-01-01

    Stamps and other postal documents are an attractive vehicle for presenting astronomy and its development. Written with expertise and great enthusiasm, this unique book offers a historical and philatelic survey of astronomy and some related topics on space exploration. It contains more than 1300 color reproductions of stamps relating to the history of astronomy, ranging from the earliest observations of the sky to modern research conducted with satellites and space probes. Featured are the astronomers and astrophysicists who contributed to this marvelous story – not only Ptolemy, Copernicus, Kepler, Newton, Herschel, and Einstein but also hundreds of other minor protagonists who played an important role in the development of this, the most ancient yet the most modern of all the sciences. The book also examines in depth the diverse areas which have contributed to the history of astronomy, including the instrumentation, the theories, and the observations. Many stamps illustrate the beauty and the mystery of ce...

  8. A Machine Learning Classifier for Fast Radio Burst Detection at the VLBA

    CERN Document Server

    Wagstaff, Kiri L; Thompson, David R; Khudikyan, Shakeh; Wyngaard, Jane; Deller, Adam T; Palaniswamy, Divya; Tingay, Steven J; Wayth, Randall B

    2016-01-01

    Time domain radio astronomy observing campaigns frequently generate large volumes of data. Our goal is to develop automated methods that can identify events of interest buried within the larger data stream. The V-FASTR fast transient system was designed to detect rare fast radio bursts (FRBs) within data collected by the Very Long Baseline Array. The resulting event candidates constitute a significant burden in terms of subsequent human reviewing time. We have trained and deployed a machine learning classifier that marks each candidate detection as a pulse from a known pulsar, an artifact due to radio frequency interference, or a potential new discovery. The classifier maintains high reliability by restricting its predictions to those with at least 90% confidence. We have also implemented several efficiency and usability improvements to the V-FASTR web-based candidate review system. Overall, we found that time spent reviewing decreased and the fraction of interesting candidates increased. The classifier now c...

  9. A randomised primal-dual algorithm for distributed radio-interferometric imaging

    CERN Document Server

    Onose, Alexandru; McEwen, Jason D; Wiaux, Yves

    2016-01-01

    Next generation radio telescopes, like the Square Kilometre Array, will acquire an unprecedented amount of data for radio astronomy. The development of fast, parallelisable or distributed algorithms for handling such large-scale data sets is of prime importance. Motivated by this, we investigate herein a convex optimisation algorithmic structure, based on primal-dual forward-backward iterations, for solving the radio interferometric imaging problem. It can encompass any convex prior of interest. It allows for the distributed processing of the measured data and introduces further flexibility by employing a probabilistic approach for the selection of the data blocks used at a given iteration. We study the reconstruction performance with respect to the data distribution and we propose the use of nonuniform probabilities for the randomised updates. Our simulations show the feasibility of the randomisation given a limited computing infrastructure as well as important computational advantages when compared to state...

  10. AMIsurvey, chimenea and other tools: Automated imaging for transient surveys with existing radio-observatories

    CERN Document Server

    Staley, Tim D

    2015-01-01

    In preparing the way for the Square Kilometre Array and its pathfinders, there is a pressing need to begin probing the transient sky in a fully robotic fashion using the current generation of radio telescopes. Effective exploitation of such surveys requires a largely automated data-reduction process. This paper introduces an end-to-end automated reduction pipeline, AMIsurvey, used for calibrating and imaging data from the Arcminute Microkelvin Imager Large Array. AMIsurvey makes use of several component libraries which have been packaged separately for open-source release. The most scientifically significant of these is chimenea, which implements a telescope agnostic algorithm for automated imaging of pre-calibrated multi-epoch radio-synthesis data, making use of CASA subroutines for the underlying image-synthesis operations. At a lower level, AMIsurvey relies upon two libraries, drive-ami and drive-casa, built to allow use of mature radio-astronomy software packages from within Python scripts. These packages...

  11. NASA thesaurus: Astronomy vocabulary

    Science.gov (United States)

    1988-01-01

    A terminology of descriptors used by the NASA Scientific and Technical information effort to index documents in the area of astronomy is presented. The terms are listed in hierarchical format derived from the 1988 edition of the NASA Thesaurus Volume 1 -- Hierarchical Listing. Over 1600 terms are included. In addition to astronomy, space sciences covered include astrophysics, cosmology, lunar flight and exploration, meteors and meteorites, celestial mechanics, planetary flight and exploration, and planetary science.

  12. Radio sky and the right to observe it

    CERN Document Server

    Gulyaev, Sergei

    2012-01-01

    It was decided in May 2012 that the Square Kilometre Array (SKA) will be built in Africa and Australia, two Southern Hemisphere continents. Here we discuss the plan for SKA design and construction, and how New Zealand radio astronomers can participate in this project and contribute to astronomy and astrophysics research. Geodesy and the study of tectonic plate motion is another important area of research for New Zealand radio astronomy to contribute to. As New Zealand is located at the boundary between two colliding tectonic plates (Australian and Pacific) and most of geological activity in New Zealand originates from their motion, it is important to monitor the relative plate motion with high precision using both GPS and radio astronomical techniques. We discuss radio frequency interference (RFI) as a limiting factor for radio astronomy, and provide results of RFI measurements in different locations in New Zealand.

  13. Cosmological measurements with forthcoming radio continuum surveys

    CSIR Research Space (South Africa)

    Raccanelli

    2012-08-01

    Full Text Available –819 (2012) doi:10.1111/j.1365-2966.2012.20634.x Cosmological measurements with forthcoming radio continuum surveys Alvise Raccanelli,1� Gong-Bo Zhao,1 David J. Bacon,1 Matt J. Jarvis,2,3 Will J. Percival,1 Ray P. Norris,4 Huub Ro¨ttgering,5 Filipe B. Abdalla... of Universe – radio continuum: galaxies. 1 IN T RO D U C T I O N Radio surveys for cosmology are entering a new phase with the construction of the Low Frequency Array (LOFAR) for radio �E-mail: alvise.raccanelli@port.ac.uk astronomy (Ro¨ttgering 2003...

  14. Radio emission of the sun and planets

    CERN Document Server

    Zheleznyakov, V V

    1970-01-01

    International Series of Monographs in Natural Philosophy, Volume 25: Radio Emission of the Sun and Planets presents the origin of the radio emission of the planets. This book examines the outstanding triumphs achieved by radio astronomy of the solar system. Comprised of 10 chapters, this volume begins with an overview of the physical conditions in the upper layers of the Sun, the Moon, and the planets. This text then examines the three characteristics of radio emission, namely, the frequency spectrum, the polarization, and the angular spectrum. Other chapters consider the measurements of the i

  15. Conceptual frameworks in astronomy

    Science.gov (United States)

    Pundak, David

    2016-06-01

    How to evaluate students' astronomy understanding is still an open question. Even though some methods and tools to help students have already been developed, the sources of students' difficulties and misunderstanding in astronomy is still unclear. This paper presents an investigation of the development of conceptual systems in astronomy by 50 engineering students, as a result of learning a general course on astronomy. A special tool called Conceptual Frameworks in Astronomy (CFA) that was initially used in 1989, was adapted to gather data for the present research. In its new version, the tool included 23 questions, and five to six optional answers were given for each question. Each of the answers was characterized by one of the four conceptual astronomical frameworks: pre-scientific, geocentric, heliocentric and sidereal or scientific. The paper describes the development of the tool and discusses its validity and reliability. Using the CFA we were able to identify the conceptual frameworks of the students at the beginning of the course and at its end. CFA enabled us to evaluate the paradigmatic change of students following the course and also the extent of the general improvement in astronomical knowledge. It was found that the measure of the students’ improvement (gain index) was g = 0.37. Approximately 45% of the students in the course improved their understanding of conceptual frameworks in astronomy and 26% deepened their understanding of the heliocentric or sidereal conceptual frameworks.

  16. Bad Astronomy Goes Hollywood

    Science.gov (United States)

    Plait, P.

    2003-05-01

    It can be argued that astronomy is the oldest of all the sciences, so you'd think that after all this time people would have a pretty good understanding of it. In reality, however, misconceptions about astronomy abound, and even basic concepts are misunderstood. There are many sources of these cosmic misconceptions, including incorrect textbooks, parents and/or teachers who don't understand astronomy and therefore spread misinformation, urban legends, and so on. Perhaps the most pervasive source of bad astronomy is Hollywood. Science fiction movies are enormously popular, but are commonly written and directed by people who don't have even a passing familiarity with astronomy. The smash hit "Armageddon" (the number one box office movie of 1998), for example, used vast quantities of incorrect astronomy in the plot. It reinforced such popular misconceptions as huge asteroids impacting the Earth with little warning, small meteorites being hot when they impact, air existing in space, and that a simple bomb can blow up an asteroid the size of a small moon (even when the bomb is buried only 800 feet deep!). However, movie scenes can be used as a hook that engages the student, helping them learn and remember the correct science. In this talk, I will light-heartedly discuss specific examples of common misinformation, using movie clips, diagrams, and a splash of common sense to show just where Hollywood gets it wrong, and what you can do to help students and the public get it right.

  17. Astronomy and Mathematics Education

    Science.gov (United States)

    Ros, Rosa M.

    There are many European countries where Astronomy does not appear as a specific course on the secondary school. In these cases Astronomy content can be introduced by means of other subjects. There are some astronomical topics within the subject of Physics but this talk concerns introducing Astronomy in Mathematics classes. Teaching Astronomy through Mathematics would result in more exposure than through Physics as Mathematics is more prevalent in the curriculum. Generally it is not easy to motivate students in Mathematics but they are motivated to find out more about the universe and Astronomy current events than appears in the media. This situation can be an excellent introduction to several mathematics topics. The teachers in secondary and high school can use this idea in order to present more attractive mathematics courses. In particular some different examples will be offered regarding * Angles and spherical coordinates considering star traces * Logarithms and visual magnitudes * Plane trigonometry related orbital movements * Spherical trigonometry in connection with ecliptic obliquity * Conic curves related to sundial at several latitudes Some students do not enjoy studying Mathematics but they can be attracted by practical situations using Applied Mathematics: Astronomy is always very attractive to teenagers.

  18. Galactic gamma ray astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Schoenfelder, V.

    1982-05-01

    During the last decade the exploration of the sky in the light of gamma rays has begun by means of satellite-and balloon-borne instruments. Like in other ranges of the electromagnetic spectrum the Milky Way clearly stands out against the rest of the sphere. Part of the galactic ..gamma..-ray emission is due to discrete sources, part is diffuse in origin and is produced in interstellar space. Some of the discrete ..gamma..-ray sources are radio pulsars, the nature of the other sources is still unknown. The intensity distribution of the diffuse galactic ..gamma..-ray component is consistent with a decrease of the cosmic-ray intensity towards the outer part of the galaxy. The identification of the cosmic-ray sources will be one of the main objectives of the next generation of ..gamma..-ray telescopes.

  19. Launching Astronomy: Standards and STEM Integration (LASSI)

    Science.gov (United States)

    French, Debbie; Burrows, Andrea C.; Myers, Adam D.

    2015-01-01

    While astronomy is prevalent in the Next Generation Science Standards, it is often relegated to the '4th nine-weeks' in middle and high school curricula. I.e., it is taught at the end of the year, if time permits. However, astronomy ties in many core ideas from chemistry, earth science, physics, and even biology (with astrobiology being an up-and-coming specialization) and mathematics. Recent missions to Mars have captured students' attention and have added excitement to the fields of engineering and technology. Using astronomy as a vehicle to teach science, technology, engineering, and mathematics (STEM) connects these disciplines in an engaging way. The workshop entitled, 'Launching Astronomy: Standards and STEM Integration,' (LASSI) is a year-long professional development (PD) opportunity for teachers in grades K-12 to use astronomy as a vehicle to teach STEM and implement science standards through astronomy. Eight teachers participated in a two-week summer workshop and six follow-up sessions are scheduled during the 2014-2015 school year. Additional teachers plan to participate in the upcoming follow-up sessions. We evaluate the effectiveness of the LASSI PD to identify and confront teachers' misconceptions in astronomy, and discuss whether teachers identified topics for which astronomy can be used as a vehicle for standards-based STEM curricula. Teachers from around Wyoming were invited to participate. Participating teachers were surveyed on the quality of the workshop, their astronomy content knowledge before and after listening to talks given by experts in the field, conducting standards-based inquiry activities, developing their own lessons, and their level of engagement throughout the workshop. Two-thirds of teachers planned to incorporate LASSI activities into their classrooms in this school year. Teachers' misconceptions and requests for astronomy-based curriculum were identified in the summer session. These will be addressed during the follow-up session

  20. Highlights of Astronomy, Volume 14

    Science.gov (United States)

    van der Hucht, Karel

    2007-08-01

    Preface Karel A. van der Hucht; Part I. Invited Discourses: Part II. Joint Discussions: 1. Particle acceleration - from Solar System to AGN Marian Karlicky and John C. Brown; 2. Pulsar emission and related phenomena Werner Becker, Janusz A. Gil and Bronislaw Rudak; 3. Solar activity regions and magnetic structure Debi Prasad Choudhary and Michal Sobotka; 4. The ultraviolet universe: Stars from birth to death Ana I. Gomez de Castro and Martin A. Barstow; 5. Calibrating the top of the stellar M-L relationship Claus Leitherer, Anthony F. J. Moat and Joachim Puls; 6. Neutron stars and black holes in star clusters Frederic A. Rasio; 7. The Universe at z > 6 Daniel Schaerer and Andrea Ferrara; 8. Solar and stellar activity cycles Klaus G. Strassmeier and Alexander Kosovichev; 9. Supernovae: One millennium after SN 1006 P. Frank Winkler, Wolfgang Hillebrandt and Brian P. Schmidt; 10. Progress in planetary exploration missions Guy J. Consolmagno; 11. Pre-solar grains as astrophysical tools Anja C. Andersen and John C. Lattanzio; 12. Long wavelength astrophysics T. Joseph W. Lazio and Namir E. Kassim; 13. Exploiting large surveys for galactic astronomy Christopher J. Corbally, Coryn A. L. Bailer-Jones, Sunetra Giridhar and Thomas H. Lloyd Evans; 14. Modeling dense stellar systems Alison I. Sills, Ladislav Subr and Simon F. Portegies Zwart; 15. New cosmology results from the Spitzer Space Telescope George Helou and David T. Frayer; 16. Nomenclature, precession and new models in fundamental astronomy Nicole Capitaine, Jan Vondrak & James L. Hilton; 17. Highlights of recent progress in seismology of the Sun and Sun-like stars John W. Leibacher and Michael J. Thompson; Part III. Special Sessions: SpS 1. Large astronomical facilities of the next decade Gerard F. Gilmore and Richard T. Schilizzi; SpS 2. Innovation in teaching and learning astronomy methods Rosa M. Ros and Jay M. Pasachoff; SpS 3. The Virtual Observatory in action: New science, new technology and next-generation

  1. A theory for narrow-banded radio bursts at Uranus - MHD surface waves as an energy driver

    Science.gov (United States)

    Farrell, W. M.; Curtis, S. A.; Desch, M. D.; Lepping, R. P.

    1992-01-01

    A possible scenario for the generation of the narrow-banded radio bursts detected at Uranus by the Voyager 2 planetary radio astronomy experiment is described. In order to account for the emission burstiness which occurs on time scales of hundreds of milliseconds, it is proposed that ULF magnetic surface turbulence generated at the frontside magnetopause propagates down the open/closed field line boundary and mode-converts to kinetic Alfven waves (KAW) deep within the polar cusp. The oscillating KAW potentials then drive a transient electron stream that creates the bursty radio emission. To substantiate these ideas, Voyager 2 magnetometer measurements of enhanced ULF magnetic activity at the frontside magnetopause are shown. It is demonstrated analytically that such magnetic turbulence should mode-convert deep in the cusp at a radial distance of 3 RU.

  2. Astronomy and Inclusion: resouces for disabled populations

    Science.gov (United States)

    García, Beatriz; Ortiz Gil, Amelia

    2015-08-01

    Commission 46 proposed, in 2012, the creation of an interdisciplinary WG in which astronomers work together with educators and disability specialists to develop new teaching and learning strategies devoted to generate resources of impact among disabled populations, which are usually away from astronomy. We present some of the achivements and new challenges.

  3. Senior radio listeners

    DEFF Research Database (Denmark)

    Blaakilde, Anne Leonora

    Radiobroadcasting and the hardware materialization of radio have during the 20th century changed significantly, which means that senior radio listeners have travelled along with this evolution from large, impressive radio furnitures to DAB and small, wireless, mobile devices, and from grave...... and solemn radio voices to lightharted, laughing and chatting speakers. Senior radio listerners have experienced the development and refinements of technique, content and genres. It is now expected of all media users that they are capable of crossing media, combining, juggling and jumping between various...... media platforms, not the least when listening to radio. The elder generation is no exception from this. Recently, for instance, the Danish public broadcast DR has carried out an exodus of programmes targeted for the senior segment. These programmes are removed from regular FM and sent to DAB receivers...

  4. Radio Astronomical Polarimetry and the Lorentz Group

    CERN Document Server

    Britton, M C

    1999-01-01

    In radio astronomy the polarimetric properties of radiation are often modified during propagation and reception. Effects such as Faraday rotation, receiver cross-talk, and differential amplification act to change the state of polarized radiation. A general description of such transformations is useful for the investigation of these effects and for the interpretation and calibration of polarimetric observations. Such a description is provided by the Lorentz group, which is intimately related to the transformation properties of polarized radiation. In this paper the transformations that commonly arise in radio astronomy are analyzed in the context of this group. This analysis is then used to construct a model for the propagation and reception of radio waves. The implications of this model for radio astronomical polarimetry are discussed.

  5. Astronomy in Georgia - Present Status and Perspectives

    Science.gov (United States)

    Todua, M.

    2016-09-01

    Astronomy in Georgia is generally represented in Abastumani Astrophysical Observatory found in 1932. It is one of the leading scientific institutes in the country. Main fields of research are solar system bodies (including near-Earth asteroids), various aspects of solar physics, stellar astronomy (including binary stars and open clusters), extragalactic objects (AGNs), theoretical astrophysics, cosmology, atmospheric and solar-terrestrial physics. Several telescopes are operational today, as well as the instruments for atmospheric studies. In 2007 the Observatory was integrated with Ilia State University, merging scientific research and education which facilitated the growth of a new generation of researchers. There are groups of astronomers and astrophysicists in other Georgian universities and institutions as well. Georgian scientists collaborate with research centers and universities worldwide. Research groups participate in various international scientific projects. The interest in astronomy in Georgia has been growing, which increases future perspectives of its development in the country.

  6. Scalable, Asynchronous, Distributed Eigen-Monitoring of Astronomy Data Streams

    Data.gov (United States)

    National Aeronautics and Space Administration — In this paper, we develop a distributed algorithm for monitoring the principal components (PCs) for next generation of astronomy petascale data pipelines such as the...

  7. Rescuing Middle School Astronomy

    Science.gov (United States)

    Mayo, L. A.; Janney, D.

    2010-12-01

    There is a crisis in education at the middle school level (Spellings, 2006). Recent studies point to large disparities in middle school performance in schools with high minority populations. The largest disparities exist in areas of math and science. Astronomy has a universal appeal for K-12 students but is rarely taught at the middle school level. When it is taught at all it is usually taught in isolation with few references in other classes such as other sciences (e.g. physics, biology, and chemistry), math, history, geography, music, art, or English. The problem is greatest in our most challenged school districts. With scores in reading and math below national averages in these schools and with most state achievement tests ignoring subjects like astronomy, there is little room in the school day to teach about the world outside our atmosphere. Add to this the exceedingly minimal training and education in astronomy that most middle school teachers have and it is a rare school that includes any astronomy teaching at all. In this presentation, we show how to develop and offer an astronomy education training program for middle school teachers encompassing a wide range of educational disciplines that are frequently taught at the middle school level. The prototype for this program was developed and launched in two of the most challenged and diverse school systems in the country; D.C. Public Schools, and Montgomery County (MD) Public Schools.

  8. Radio Journalism.

    Science.gov (United States)

    Bittner, John R.; Bittner, Denise A.

    This book, a how-to-do-it guide for the novice and the professional alike, deals with several aspects of radio journalism: producing documentaries, preparing and announcing radio news, ethics and responsibility, regulation of radio journalism, and careers. It traces the history and growth of radio news, shows its impact on the public, and…

  9. Radio Telescopes "Save the Day," Produce Data on Titan's Winds

    Science.gov (United States)

    2005-02-01

    In what some scientists termed "a surprising, almost miraculous turnabout," radio telescopes, including major facilities of the National Science Foundation's National Radio Astronomy Observatory (NRAO), have provided data needed to measure the winds encountered by the Huygens spacecraft as it descended through the atmosphere of Saturn's moon Titan last month -- measurements feared lost because of a communication error between Huygens and its "mother ship" Cassini. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) A global network of radio telescopes, including the NRAO's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia and eight of the ten antennas of the Very Long Baseline Array (VLBA), recorded the radio signal from Huygens during its descent on January 14. Measurements of the frequency shift caused by the craft's motion, called Doppler shift, are giving planetary scientists their first direct information about Titan's winds. "When we began working with our international partners on this project, we thought our telescopes would be adding to the wind data produced by the two spacecraft themselves. Now, with the ground-based telescopes providing the only information about Titan's winds, we are extremely proud that our facilities are making such a key contribution to our understanding of this fascinating planetary body," said Dr. Fred K.Y. Lo, Director of the National Radio Astronomy Observatory (NRAO). Early analysis of the radio-telescope data shows that Titan's wind flows from west to east, in the direction of the moon's rotation, at all altitudes. The highest wind speed, nearly 270 mph, was measured at an altitude of about 75 miles. Winds are weak near Titan's surface and increase in speed slowly up to an altitude of about 37 miles, where the spacecraft encountered highly-variable winds that scientists think indicate a region of vertical wind shear. The ground-based Doppler

  10. First Colombian Solar Radio Interferometer: current stage

    Science.gov (United States)

    Guevara Gómez, J. C.; Martínez Oliveros, J. C.; Calvo-Mozo, B.

    2017-10-01

    Solar radio astronomy is a fast developing research field in Colombia. Here, we present the scientific goals, specifications and current state of the First Colombian Solar Radio Interferometer consisting of two log-periodic antennas covering a frequency bandwidth op to 800 MHz. We describe the importance and benefits of its development to the radioastronomy in Latin America and its impact on the scientific community and general public.

  11. Status of Radio Ice Cherenkov Experiment (RICE)

    CERN Document Server

    Allen, C; Besson, D; Frichter, G; Kotov, S A; Kravchenko, I V; McKay, D; Miller, T; Piccirillo, L; Ralston, J P; Seckel, D; Seunarine, S; Spiczak, G M

    1997-01-01

    RICE is designed to detect ultrahigh energy (>100 TeV) neutrinos from astrophysical sources. It will consist of an array of compact radio (100 to 1000 MHz) receivers buried in ice at the South Pole. During the 1995-96 and 1996-97 austral summers, several receivers transmitters were deployed in bore holes drilled for the AMANDA project, at depths of 141 to 260 m. This was the first in situ test of radio receivers in deep ice for neutrino astronomy.

  12. The MeqTrees software system and its use for third-generation calibration of radio interferometers

    CERN Document Server

    Noordam, Jan E; 10.1051/0004-6361/201015013

    2011-01-01

    The formulation of the radio interferometer measurement equation (RIME) by Hamaker et al. has provided us with an elegant mathematical apparatus for better understanding, simulation and calibration of existing and future instruments. The calibration of the new radio telescopes (LOFAR, SKA) would be unthinkable without the RIME formalism, and new software to exploit it. MeqTrees is designed to implement numerical models such as the RIME, and to solve for arbitrary subsets of their parameters. The technical goal of MeqTrees is to provide a tool for rapid implementation of such models, while offering performance comparable to hand-written code. We are also pursuing the wider goal of increasing the rate of evolution of radio astronomical software, by offering a tool for rapid experimentation and exchange of ideas. MeqTrees is implemented as a Python-based front-end called the meqbrowser, and an efficient (C++-based) computational back-end called the meqserver. Numerical models are defined on the front-end via a P...

  13. Berkeley's Advanced Labs for Undergraduate Astronomy Majors

    Science.gov (United States)

    Heiles, C.

    1998-12-01

    We currently offer three advanced laboratory courses for undergraduate majors: optical, IR, and radio. These courses contain both intellectual and practical content; in this talk we focus on the radio lab as a representative example. The first half of the semester concentrates on fundamentals of microwave electronics and radio astronomy techniques in four formal laboratory exercises which emphasize hands-on use of microwave devices, laboratory instruments, and computer-controlled data taking. The second half of the course emphasizes astronomy, using a horn with ~ 1 m(2) aperture to map the HI in the Galaxy and a two-element interferometer composed of ~ 1 m diameter dishes on a ~ 10 m baseline to measure accurate positions of radio sources and accurate diameters for the Sun and Moon. These experiments and observations offer ideal opportunities for teaching coordinates, time, rotation matrices, data reduction techniques, least squares, signal processing, image processing, Fourier transforms, and laboratory and astronomical instrumentation. The students can't get along without using computers as actually used by astronomers. We stay away from packaged software such as IRAF, which are ``black boxes''; rather, students learn far more by writing their own software, usually for the first time. They use the IDL language to take and reduce data and prepare them for the lab reports. We insist on quality reports---including tables, postscript graphs and images, correct grammar, spelling, and all the rest---and we strongly urge (successfully!) the students to use LATEX. The other two lab courses have the same emphasis: the guiding spirit is to place the students in a real-life research-like situation. There is too much to do, so students perform the work in small groups of 3 or 4 and groups are encouraged to share their knowledge. Lab reports are written individually. These courses are very demanding, requiring an average of 20 hours per week from the students (and probably

  14. Proceedings of the 4th Workshop of Young Researchers in Astronomy & Astrophysics

    Science.gov (United States)

    Forgács-Dajka, E.

    2006-09-01

    Preface: It is a great pleasure for the Organizers to present the proceedings already the Fourth Workshop of Young Researchers in Astronomy & Astrophysics. Six years ago the Organizers of the first meeting of these conference series declared that their intention is to begin a long-lasting tradition of such biennial conference series where the young postgraduate scientists can meet each other as well as with senior scholars on the wide fields of astronomy & astrophysics, and they can present their results, getting important experiences in presentation oral lectures. And, of course, vice versa this is a great possibility for the senior astronomers and astrophysicists to know the new generation, and form new connections.I am glad to say that the idea became successful. On the present, fourth meeting almost 50 lectures -- which covers many areas of astrophysics and related topics from solar physics to cosmology -- was presented by the young researchers affiliated to all those Hungarian scientific institutes, where astronomy and/or astrophysics are studied. It is a new and happily sequel, that a lot of hungarian young researchers who are working abroad came back to Hungary for a while to present their science. Like a bridge between the generation, a significant part of the lecturers are already not PhD students. They are mainly postdoctoral researchers who attended on the first conferences as young scientists, but feel theirself young in their hearts, and return back from meetings to meetings due to their nice memories. They are highly welcomed in the future, too. Furthermore, last, but not least I mention, that as a manifestation of the great honour of the senior generations to the young scientists several leading Hungarian experts of the different fields kindly accepted our invitation to present invited lectures on their research topics. The above mentiond topics of the present conference were as follows: Solar physics, Space Physics, Celestial Mechanics

  15. Visualising Astronomy: "Other Worlds"

    Science.gov (United States)

    Wyatt, R.

    2009-02-01

    The infrastructures that are built and used for astronomical research are financed by - and therefore must be justified to - our society. Astronomy has an innate appeal for people of all ages, partly because it concerns the fascinating, great questions "of life, the Universe and everything" and partly because much of the data obtained with telescopes can be presented as objects of stunning beauty. These are key facts when considering communicating astronomy with the public. This native advantage that astronomy has over many other sciences does not, however, relieve us of the obligation to explain what we are doing to the public at large. There are many reasons for doing this. They range from attracting bright young people into the subject to fuel future research endeavours to convincing decision-takers to allocate large sums of money to finance increasingly expensive and ambitious projects.

  16. Python in Astronomy 2016

    Science.gov (United States)

    Jenness, Tim; Robitaille, Thomas; Tollerud, Erik; Mumford, Stuart; Cruz, Kelle

    2016-04-01

    The second Python in Astronomy conference will be held from 21-25 March 2016 at the University of Washington eScience Institute in Seattle, WA, USA. Similarly to the 2015 meeting (which was held at the Lorentz Center), we are aiming to bring together researchers, Python developers, users, and educators. The conference will include presentations, tutorials, unconference sessions, and coding sprints. In addition to sharing information about state-of-the art Python Astronomy packages, the workshop will focus on improving interoperability between astronomical Python packages, providing training for new open-source contributors, and developing educational materials for Python in Astronomy. The meeting is therefore not only aimed at current developers, but also users and educators who are interested in being involved in these efforts.

  17. Astronomy Librarian - Quo Vadis?

    Science.gov (United States)

    Lagerstrom, Jill; Grothkopf, Uta

    "You don't look like a librarian" is a phrase we often hear in the astronomy department or observatory library. Astronomy librarians are a breed apart, and are taking on new and non-traditional roles as information technology evolves. This talk will explore the future of librarians and librarianship through the lens of some of the recent talks given at the sixth "Libraries and Information Services in Astronomy" conference held in Pune, India in February 2010. We will explore the librarian's universe, illustrating how librarians use new technologies to perform such tasks as bibliometrics, how we are re-fashioning our library spaces in an increasingly digital world and how we are confronting the brave new world of Open Access, to name but a few topics.

  18. Astronomy Librarians - Quo Vadis?

    CERN Document Server

    Lagerstrom, Jill

    2011-01-01

    "You don't look like a librarian" is a phrase we often hear in the astronomy department or observatory library. Astronomy librarians are a breed apart, and are taking on new and non-traditional roles as information technology evolves. This talk will explore the future of librarians and librarianship through the lens of the recent talks given at the sixth "Libraries and Information Services in Astronomy" conference held in Pune, India in February 2010. We will explore the librarian's universe, illustrating how librarians use new technologies to perform such tasks as bibliometrics, how we are re-fashioning our library spaces in an increasingly digital world and how we are confronting the brave new world of open access, to name but a few topics.

  19. Statistics in astronomy

    CERN Document Server

    Feigelson, Eric D

    2009-01-01

    Perhaps more than other physical sciences, astronomy is frequently statistical in nature. The objects under study are inaccessible to direct manipulation in the laboratory, so the astronomer is restricted to observing a few external characteristics and inferring underlying properties and physics. Astronomy played a profound role in the historical development of statistics from the ancient Greeks through the 19th century. But the fields drifted apart in the 20th century as astronomy turned towards astrophysics and statistics towards human affairs. Today we see a resurgence in astrostatistical activity with the proliferation of survey mega-datasets and the need to link complicated data to nonlinear astrophysical models. Several contemporary astrostatistical challenges are outlined: heteroscedastic measurement errors, censoring and truncation in multivariate databases; time series analysis of variable objects including dynamical models of extrasolar planetary systems; treatments of faint sources and other Poisso...

  20. The LOFAR radio environment

    CERN Document Server

    Offringa, A R; Zaroubi, S; van Diepen, G; Martinez-Ruby, O; Labropoulos, P; Brentjens, M A; Ciardi, B; Daiboo, S; Harker, G; Jelic, V; Kazemi, S; Koopmans, L V E; Mellema, G; Pandey, V N; Pizzo, R F; Schaye, J; Vedantham, H; Veligatla, V; Wijnholds, S J; Yatawatta, S; Zarka, P; Alexov, A; Anderson, J; Asgekar, A; Avruch, M; Beck, R; Bell, M; Bell, M R; Bentum, M; Bernardi, G; Best, P; Birzan, L; Bonafede, A; Breitling, F; Broderick, J W; Bruggen, M; Butcher, H; Conway, J; de Vos, M; Dettmar, R J; Eisloeffel, J; Falcke, H; Fender, R; Frieswijk, W; Gerbers, M; Griessmeier, J M; Gunst, A W; Hassall, T E; Heald, G; Hessels, J; Hoeft, M; Horneffer, A; Karastergiou, A; Kondratiev, V; Koopman, Y; Kuniyoshi, M; Kuper, G; Maat, P; Mann, G; McKean, J; Meulman, H; Mevius, M; Mol, J D; Nijboer, R; Noordam, J; Norden, M; Paas, H; Pandey, M; Pizzo, R; Polatidis, A; Rafferty, D; Rawlings, S; Reich, W; Rottgering, H J A; Schoenmakers, A P; Sluman, J; Smirnov, O; Sobey, C; Stappers, B; Steinmetz, M; Swinbank, J; Tagger, M; Tang, Y; Tasse, C; van Ardenne, A; van Cappellen, W; van Duin, A P; van Haarlem, M; van Leeuwen, J; van Weeren, R J; Vermeulen, R; Vocks, C; Wijers, R A M J; Wise, M; Wucknitz, O

    2012-01-01

    Aims: This paper discusses the spectral occupancy for performing radio astronomy with the Low-Frequency Array (LOFAR), with a focus on imaging observations. Methods: We have analysed the radio-frequency interference (RFI) situation in two 24-h surveys with Dutch LOFAR stations, covering 30-78 MHz with low-band antennas and 115-163 MHz with high-band antennas. This is a subset of the full frequency range of LOFAR. The surveys have been observed with a 0.76 kHz / 1 s resolution. Results: We measured the RFI occupancy in the low and high frequency sets to be 1.8% and 3.2% respectively. These values are found to be representative values for the LOFAR radio environment. Between day and night, there is no significant difference in the radio environment. We find that lowering the current observational time and frequency resolutions of LOFAR results in a slight loss of flagging accuracy. At LOFAR's nominal resolution of 0.76 kHz and 1 s, the false-positives rate is about 0.5%. This rate increases approximately linear...

  1. Scalable Distributed Change Detection from Astronomy Data Streams using Local, Asynchronous Eigen Monitoring Algorithms

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper considers the problem of change detection using local distributed eigen monitoring algorithms for next generation of astronomy petascale data pipelines...

  2. Exploring Systems Engineering (and the Universe) Through the RadioJOVE telescope

    Science.gov (United States)

    Aditi Raj, Anya

    2017-01-01

    Amateur projects in radio astronomy are popular methods to engage in what often seems to be an inaccessible field, and pre-made kits are becoming increasingly available to hobbyists and educators. One such kit is the RadioJOVE, which is attractive due to its simplicity, accessibility and its extensive support network and community of users. When coupled with an education in project management, building the RadioJOVE provides a perfect framework to learn about best practices in completing a project. We will primarily discuss the use of the RadioJOVE project to enhance study in project management and systems engineering. We also intend to discuss the importance of amateur projects such as the RadioJOVE in gaining a holistic understanding of radio astronomy and the project’s potential to spark interest in radio astronomy in students of various disciplines.

  3. Lessons from Mayan Astronomy

    CERN Document Server

    Loeb, Abraham

    2016-01-01

    The Mayan culture collected exquisite astronomical data for over a millennium. However, it failed to come up with the breakthrough ideas of modern astronomy because the data was analyzed within a mythological culture of astrology that rested upon false but mathematically sophisticated theories about the Universe. Have we learned the necessary lessons to prevent our current scientific culture from resembling Mayan Astronomy? Clearly, data collection by itself is not a guarantee for good science as commonly assumed by funding agencies. A vibrant scientific culture should cultivate multiple approaches to analyzing existing data and to collecting new data.

  4. Astronomy and Poetry (overview)

    Science.gov (United States)

    Samvelyan, David

    2016-12-01

    Through this work we have tried to show how astronomy penetrates into the poetry of different periods in time and in various poets' works all over the world. The following work has significant cognitive value, demonstrates and reveals the general nature of certain poets' astronomical ideas and provides a brief analysis in some cases. As a result, we have come to the conclusion that astronomy with all its components such as the sky, our solar system and phenomena such as these have always been a source of inspiration for those who create works of art, moreover some of them have even gained actual astronomical knowledge.

  5. Forthcoming Occultations of Astrometric Radio Sources by Planets

    Science.gov (United States)

    L'vov, Victor; Malkin, Zinovy; Tsekmeister, Svetlana

    2010-01-01

    Astrometric observations of radio source occultations by solar system bodies may be of large interest for testing gravity theories, dynamical astronomy, and planetary physics. In this paper, we present an updated list of the occultations of astrometric radio sources by planets expected in the coming years. Such events, like solar eclipses, generally speaking can only be observed in a limited region. A map of the shadow path is provided for the events that will occurr in regions with several VLBI stations and hence will be the most interesting for radio astronomy experiments.

  6. Quickly Creating Interactive Astronomy Illustrations

    Science.gov (United States)

    Slater, Timothy F.

    2015-01-01

    An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

  7. Teaching Astronomy in UK Schools

    Science.gov (United States)

    Roche, Paul; Roberts, Sarah; Newsam, Andy; Barclay, Charles

    2012-01-01

    This article attempts to summarise the good, bad and (occasionally) ugly aspects of teaching astronomy in UK schools. It covers the most common problems reported by teachers when asked about covering the astronomy/space topics in school. Particular focus is given to the GCSE Astronomy qualification offered by Edexcel (which is currently the…

  8. Quickly Creating Interactive Astronomy Illustrations

    Science.gov (United States)

    Slater, Timothy F.

    2015-01-01

    An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

  9. Teaching Astronomy in UK Schools

    Science.gov (United States)

    Roche, Paul; Roberts, Sarah; Newsam, Andy; Barclay, Charles

    2012-01-01

    This article attempts to summarise the good, bad and (occasionally) ugly aspects of teaching astronomy in UK schools. It covers the most common problems reported by teachers when asked about covering the astronomy/space topics in school. Particular focus is given to the GCSE Astronomy qualification offered by Edexcel (which is currently the…

  10. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  11. PERFORMANCE ANALYSIS OF CLUSTERED RADIO INTERFEROMETRIC CALIBRATION

    NARCIS (Netherlands)

    Kazemi, S.; Yatawatta, S.; Zaroubi, S.

    2012-01-01

    Subtraction of compact, bright sources is essential to produce high quality images in radio astronomy. It is recently proposed that 'clustered' calibration can perform better in subtracting fainter background sources. This is due to the fact that the effective power of a source cluster is greater th

  12. Radio Synthesis Imaging - A High Performance Computing and Communications Project

    Science.gov (United States)

    Crutcher, Richard M.

    The National Science Foundation has funded a five-year High Performance Computing and Communications project at the National Center for Supercomputing Applications (NCSA) for the direct implementation of several of the computing recommendations of the Astronomy and Astrophysics Survey Committee (the "Bahcall report"). This paper is a summary of the project goals and a progress report. The project will implement a prototype of the next generation of astronomical telescope systems - remotely located telescopes connected by high-speed networks to very high performance, scalable architecture computers and on-line data archives, which are accessed by astronomers over Gbit/sec networks. Specifically, a data link has been installed between the BIMA millimeter-wave synthesis array at Hat Creek, California and NCSA at Urbana, Illinois for real-time transmission of data to NCSA. Data are automatically archived, and may be browsed and retrieved by astronomers using the NCSA Mosaic software. In addition, an on-line digital library of processed images will be established. BIMA data will be processed on a very high performance distributed computing system, with I/O, user interface, and most of the software system running on the NCSA Convex C3880 supercomputer or Silicon Graphics Onyx workstations connected by HiPPI to the high performance, massively parallel Thinking Machines Corporation CM-5. The very computationally intensive algorithms for calibration and imaging of radio synthesis array observations will be optimized for the CM-5 and new algorithms which utilize the massively parallel architecture will be developed. Code running simultaneously on the distributed computers will communicate using the Data Transport Mechanism developed by NCSA. The project will also use the BLANCA Gbit/s testbed network between Urbana and Madison, Wisconsin to connect an Onyx workstation in the University of Wisconsin Astronomy Department to the NCSA CM-5, for development of long

  13. Astronomy Education and Popularization Facilities at Guanajuato University in Mexico

    Science.gov (United States)

    Bravo-Alfaro, H.; Schroeder, K.-P.; Ramirez, L.

    2006-08-01

    At the Astronomy Department of Universidad de Guanajuato, 400 km NW of Mexico City, nine professional astronomers do research and teaching at both graduate and undergraduate level. In addition, in the last few years, this group has carried out astronomy popularization activities at three different sites. First, a rudimentary observatory named "La Azotea" (the roof) on the top of the main building of the University (at Guanajuato centre), which includes a 16-cm refractor in a dome, a couple of XIXth century astronomical instruments, and a classroom with capacity for 50 people. The refractor was out of use for about twelve years but will be fully operational before summer 2006. Second, the "Observatorio de La Luz", 20 kms away from Guanajuato centre, includes a professional 0.6m Cassegrain and a 2m radio telescope, with a 21cm receiver. Finally, on the roof of the Astronomy Department headquarters, an optical 0.4m Dobsonian is available. We also dispose of internet connection everywhere and 6 portable 8-inch telescopes (two at each site), devoted to regular astronomical observations for the general public, specially for scholars. Numerous repair works are currently carried out on the building of "La Azotea", and recently a project to establish there a Centre for Popularization of Astronomy has been approved by the Regional Science Council. The main activities, some of them currently developed at these sites are: (1) A permanent program of astronomical observations for a wide audience. (2) Training in Observational Astronomy for physics undergraduate students. (3) Regular talks on astronomy and other science domains. (4) Summer schools in Astronomy for elementary and high-school teachers. (5) In the near future, the foundation of an amateur society of astronomy.

  14. Generation of constant-amplitude radio-frequency sweeps at a tunnel junction for spin resonance STM

    Science.gov (United States)

    Paul, William; Baumann, Susanne; Lutz, Christopher P.; Heinrich, Andreas J.

    2016-07-01

    We describe the measurement and successful compensation of the radio-frequency transfer function of a scanning tunneling microscope over a wide frequency range (15.5-35.5 GHz) and with high dynamic range (>50 dB). The precise compensation of cabling resonances and attenuations is critical for the production of constant-voltage frequency sweeps for electric-field driven electron spin resonance (ESR) experiments. We also demonstrate that a well-calibrated tunnel junction voltage is necessary to avoid spurious ESR peaks that can arise due to a non-flat transfer function.

  15. Highlights of Astronomy, Vol. 15

    Science.gov (United States)

    Corbett, Ian

    2010-11-01

    Preface; Part I. Gruber Cosmology Prize Lecture; Part II. Invited Discourses; Part III. Joint Discussions: 1. Dark matter in early-type galaxies Léon V. E. Koopmans and Tommaso Treu; 2. Diffuse light in galaxy clusters Magda Arnaboldi and Ortwin Gerhard; 3. Neutron stars - timing in extreme environments Tomaso Belloni, Mariano Méndez and Chengmin Zhang; 4. Progress in understanding the physics of Ap and related stars Margarida Cunha; 5. Modelling the Milky Way in the age of Gaia Annie C. Robin; 6. Time and astronomy Pascale Defraigne; 7. Astrophysical outflows and associated accretion phenomena Elisabete M. de Gouveia Dal Pino and Alex C. Raga; 8. Hot interstellar matter in elliptical galaxies Dong-Woo Kim and Silvia Pellegrini; 9. Are the fundamental constants varying with time? Paolo Molaro and Elisabeth Vangioni; 10. 3D views on cool stellar atmospheres - theory meets observation K. N. Nagendra, P. Bonifacio and H. G. Ludwig; 11. New advances in helio- and astero-seismology; 12. The first galaxies - theoretical predictions and observational clues; 13. Eta Carinae in the context of the most massive stars Theodore R. Gull and Augusto Damineli; 14. The ISM of galaxies in the far-infrared and sub-millimetre; 15. Magnetic fields in diffuse media Elisabete M. de Gouveia Dal Pino and Alex Lazarian; 16. IHY global campaign - whole heliosphere interval; Part IV. Special Sessions: SpS 1. IR and sub-mm spectroscopy - a new tool for studying stellar evolution Glenn Wahlgren, Hans Käufl and Florian Kerber; SpS 2. The international year of astronomy Pedro Russo, Catherine Cesarsky and Lars Lindberg Christensen; SpS 3. Astronomy in Antarctica in 2009 Michael G. Burton; SpS 4. Astronomy education between past and future J. P. De Greve; SpS 5. Accelerating the rate of astronomical discovery Ray P. Norris; SpS 6. Planetary systems as potential sites for life Régis Courtin, Alan Boss and Michel Mayor; SpS 7. Young stars, brown dwarfs, and protoplanetary disks Jane Gregorio

  16. Session 21.3 - Radio and Optical Site Protection

    Science.gov (United States)

    Sefako, Ramotholo

    2016-10-01

    Advancement in radio technology means that radio astronomy has to share the radio spectrum with many other non-astronomical activities, majority of which increase radio frequency interference (RFI), and therefore detrimentally affecting the radio observations at the observatory sites. Major radio facilities such as the SKA, in both South Africa and Australia, and the Five-hundred-meter Aperture Spherical radio Telescope (FAST) in China will be very sensitive, and therefore require protection against RFI. In the case of optical astronomy, the growing urbanisation and industrialisation led to optical astronomy becoming impossible near major cities due to light and dust pollution. Major optical and IR observatories are forced to be far away in remote areas, where light pollution is not yet extreme. The same is true for radio observatories, which have to be sited away from highly RFI affected areas near populated regions and major cities. In this review, based on the Focus Meeting 21 (FM21) oral presentations at the IAU General Assembly on 11 August 2015, we give an overview of the mechanisms that have evolved to provide statutory protection for radio astronomy observing, successes (e.g at 21 cm HI line), defeats and challenges at other parts of the spectrum. We discuss the available legislative initiatives to protect the radio astronomy sites for large projects like SKA (in Australia and South Africa), and FAST against the RFI. For optical protection, we look at light pollution with examples of its effect at Xinglong observing station of the National Astronomical Observatories of China (NAOC), Ali Observatory in Tibet, and Asiago Observatory in Italy, as well as the effect of conversion from low pressure sodium lighting to LEDs in the County of Hawaii.

  17. Colonial American Astronomy

    Science.gov (United States)

    Yeomans, Donald K.

    2007-12-01

    While a foundation of German scientific methods enabled the rapid growth of North American Astronomy in the nineteenth century, during the seventeenth and most of the eighteenth centuries, the colonial men of science looked only to the English mother country for scientific patronage and guidance. An essay on fundamental astronomy appeared in one of the annual colonial almanacs as early as 1656, telescopic observations were made about 1660 and the first original colonial astronomical work was published by Thomas Danforth on the comet of 1664. By 1671 the Copernican ideas were so espoused at Harvard College that a physics class refused to read a Ptolemaic textbook when it was assigned to them by a senior instructor. At least in the Cambridge-Boston area, contemporary colonialist had access to the most recent scientific publications from the mother country. Observations of the great comet of 1680 by the Almanac maker, John Foster, reached Isaac Newton and were used and gratefully acknowledged in his Principia. During the seventeenth century the colonial interest in astronomy was more intense than it was for other sciences but colonists still occupied a position in the scientific backwater when compared with contemporary European scientists. Nevertheless, the science of astronomy was successfully transplanted from England to North America in the seventeenth century.

  18. Physics and astronomy

    CSIR Research Space (South Africa)

    Moraal, H

    2009-01-01

    Full Text Available The chapter is about physics and astronomy. The chapter gives a background about the origins of physics in South Africa. After the CSIR was founded in 1945, physics emerged as a nationwide and unified discipline. The authors show how physics...

  19. Resources for Teaching Astronomy.

    Science.gov (United States)

    Grafton, Teresa; Suggett, Martin

    1991-01-01

    Resources that are available for teachers presenting astronomy in the National Curriculum are listed. Included are societies and organizations, resource centers and places to visit, planetaria, telescopes and binoculars, planispheres, star charts, night sky diaries, equipment, audiovisual materials, computer software, books, and magazines. (KR)

  20. Teaching Astronomy Using Tracker

    Science.gov (United States)

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas

    2013-01-01

    A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

  1. Astronomy on the Walls

    Science.gov (United States)

    Santascoy, J.

    2016-01-01

    Many of us are interested in increasing youth and minority involvement in the sciences. Using art that integrates images of space exploration with ethnic astronomical mythology may increase participation in astronomy in general, while also forming a bridge to underrepresented communities. This paper describes a freely available presentation of Carlos Callejo's Discover the Secrets of the Universe Through the Library for outreach.

  2. Teaching Astronomy Using Tracker

    Science.gov (United States)

    Belloni, Mario; Christian, Wolfgang; Brown, Douglas

    2013-01-01

    A recent paper in this journal presented a set of innovative uses of video analysis for introductory physics using Tracker. In addition, numerous other papers have described how video analysis can be a meaningful part of introductory courses. Yet despite this, there are few resources for using video analysis in introductory astronomy classes. In…

  3. Novel wavelength division multiplex-radio over fiber-passive optical network architecture for multiple access points based on multitone generation and triple sextupling frequency

    Science.gov (United States)

    Cheng, Guangming; Guo, Banghong; Liu, Songhao; Huang, Xuguang

    2014-01-01

    An innovative wavelength division multiplex-radio over fiber-passive optical network architecture for multiple access points (AP) based on multitone generation and triple sextupling frequency is proposed and demonstrated. A dual-drive Mach-Zehnder modulator (DD-MZM) is utilized to realize the multitone generation. Even sidebands are suppressed to make the adjacent frequency separation twice the frequency of the local oscillator by adjusting the modulation voltage of the DD-MZM. Due to adopting three fiber Bragg gratings to reflect the unmodulated sidebands for uplink communications source free at optical network unit (ONU), is achieved. The system can support at least three APs at one ONU simultaneously with a 30 km single-mode fiber (SMF) transmission and 5 Gb/s data rate both for uplink and downlink communications. The theoretical analysis and simulation results show the architecture has an excellent performance and will be a promising candidate in future hybrid access networks.

  4. Powerful Radio Burst Indicates New Astronomical Phenomenon

    Science.gov (United States)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant

  5. Strategies for Teaching Astronomy

    Science.gov (United States)

    Bennett, J.

    2000-12-01

    No matter whether you are teaching school children, undergraduates, or colleagues, a few key strategies are always useful. I will present and give examples for the following five key strategies for teaching astronomy. 1. Provide a Contextual Framework: It is much easier to learn new facts or concepts if they can be ``binned" into some kind of pre-existing mental framework. Unless your listeners are already familiar with the basic ideas of modern astronomy (such as the hierarchy of structure in the universe, the scale of the universe, and the origin of the universe), you must provide this before going into the details of how we've developed this modern picture through history. 2. Create Conditions for Conceptual Change: Many people hold misconceptions about astronomical ideas. Therefore we cannot teach them the correct ideas unless we first help them unlearn their prior misconceptions. 3. Make the Material Relevant: It's human nature to be more interested in subjects that seem relevant to our lives. Therefore we must always show students the many connections between astronomy and their personal concerns, such as emphasizing how we are ``star stuff" (in the words of Carl Sagan), how studying other planets helps us understand our own, and so on. 4. Limit Use of Jargon: The number of new terms in many introductory astronomy books is larger than the number of words taught in many first courses in foreign language. This means the books are essentially teaching astronomy in a foreign language, which is a clear recipe for failure. We must find ways to replace jargon with plain language. 5. Challenge Your Students: Don't dumb your teaching down; by and large, students will rise to meet your expectations, as long as you follow the other strategies and practice good teaching.

  6. Precision engineering for astronomy: historical origins and the future revolution in ground-based astronomy.

    Science.gov (United States)

    Cunningham, Colin; Russell, Adrian

    2012-08-28

    Since the dawn of civilization, the human race has pushed technology to the limit to study the heavens in ever-increasing detail. As astronomical instruments have evolved from those built by Tycho Brahe in the sixteenth century, through Galileo and Newton in the seventeenth, to the present day, astronomers have made ever more precise measurements. To do this, they have pushed the art and science of precision engineering to extremes. Some of the critical steps are described in the evolution of precision engineering from the first telescopes to the modern generation telescopes and ultra-sensitive instruments that need a combination of precision manufacturing, metrology and accurate positioning systems. In the future, precision-engineered technologies such as those emerging from the photonics industries may enable future progress in enhancing the capabilities of instruments, while potentially reducing the size and cost. In the modern era, there has been a revolution in astronomy leading to ever-increasing light-gathering capability. Today, the European Southern Observatory (ESO) is at the forefront of this revolution, building observatories on the ground that are set to transform our view of the universe. At an elevation of 5000 m in the Atacama Desert of northern Chile, the Atacama Large Millimetre/submillimetre Array (ALMA) is nearing completion. The ALMA is the most powerful radio observatory ever and is being built by a global partnership from Europe, North America and East Asia. In the optical/infrared part of the spectrum, the latest project for ESO is even more ambitious: the European Extremely Large Telescope, a giant 40 m class telescope that will also be located in Chile and which will give the most detailed view of the universe so far.

  7. From radio signals to cosmic rays; Des signaux radio aux rayons cosmiques

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, C.

    2009-12-15

    Radio detection of high energy cosmic rays is currently being reinvested, both on the experimental and theoretical sides. The question is to know whether radio-detection is a competitive technique compared or in addition to usual detection techniques; in order to increase statistics at the highest energies (around 10{sup 20} eV - where particle astronomy should be possible) or to characterize precisely the cosmic rays at lower energies (some 10{sup 18} eV). During this work, we tried to progress towards the answer, using radio emission models, experimental data analysis and preparing the next generation of detectors. On the theoretical side, geo-synchrotron emission of the particles of the showers has been computed analytically using a simplified shower model as well as using the Monte Carlo simulation AIRES to have a realistic shower development. Various dependencies of the electric field have been extracted, among which a proportionality of the field with the -v{sup {yields}} * B{sup {yields}} vector under certain conditions. Experimentally, the analysis of CODALEMA data enabled to characterise more precisely the electric field produced by air showers, in particular the topology of the field at ground level, the energy dependency and the coherence with a -v{sup {yields}} * B{sup {yields}} proportionality. These results are summarised in an overall parametrization of the electric field. More data are probably required in order to give a definitive statement on the interest of the radio-detection technique. The CODALEMA parametrization has finally been used to extrapolate CODALEMA's results to a future larger array, extrapolation applied in particular to the AERA detector of the Pierre Auger Observatory. (author)

  8. PARTNeR: A Tool for Outreach and Teaching Astronomy

    Science.gov (United States)

    Gallego, Juan Ángel Vaquerizo; Fuertes, Carmen Blasco

    PARTNeR is an acronym for Proyecto Académico con el Radio Telescopio de NASA en Robledo (Academic Project with the NASA Radio Telescope at Robledo). It is intended for general Astronomy outreach and, in particular, radioastronomy, throughout Spanish educational centres. To satisfy this target, a new educational material has been developed in 2007 to help not only teachers but also students. This material supports cross curricular programs and provides with the possibility of including Astronomy in related subjects like Physics, Chemistry, Technology, Mathematics or even English language. In this paper, the material that has been developed will be shown in detail and how it can be adapted to the disciplines from 4th year ESO (Enseñanza Secundaria Obligatoria-Compulsory Secondary Education) to High School. The pedagogic results obtained for the first year it has been implemented with students in classrooms will also be presented.

  9. Successes and challenges in Space Science/Astronomy Development in West Africa

    Science.gov (United States)

    EKEOMA Opara, Fidelis

    2015-08-01

    The increasing number of Astronomers in Nigeria has challenged Space Scientists and Engineers on the popularization of Space Science and Astronomy.The aothor presents in this work many successes recorded at the Centre for Basic Space Science and Astronomy (CBSS), National Space Research and Development Agency, Nigeria in terms of local fabrications of instruments in both radio and optical frequencies with its attendant challenges.Professor F.E. Opara is the Director/ CEO NASRDA Centre for Basic Space Science and Astronomy (CBSS), Nsukka, Nigeria.

  10. Astronomy Olympiad: An Initiative To Promote Astronomy Education In Nepal

    Science.gov (United States)

    Bhattarai, Suresh

    2015-08-01

    This paper presents National Astronomy Olympiad Program as a new initiative towards the development of astronomy education in Nepal by Nepal Astronomical Society (NASO).Innovoative components of the olympiad programs designed by NASO to engage both scince and non-science backgound people will be discussed in detail. It will discuss the first National Astronomy Olympiad 2014 and Second National Astronomy Olympiad 2015 in details. It will also present crowd funding, its effectiveness to outreach as well as collecting funds from around the world will be presented in brief. Proposed module of astronomy olympiad to promote astronnomy in the countries without formal astronomy education in high school like Nepal,will be presented in dedail. Possible strategry to strengthen such programs in developing nations and role of IAU to promote such educational program will be explored in detail.

  11. Lessons from our Own Solar System: Generation Mechanisms of Radio Emissions from Earth, Saturn and Jupiter and Atmospheric Loss from Magnetized versus non-magnetized planets

    Science.gov (United States)

    Brandt, Pontus

    2017-05-01

    The understanding of the engines and mechanisms behind kilometric and decametric radio emissions from the planets in our own solar system have taken great leaps with missions such as the NASA/Cassini, IMAGE and Galileo missions. The periodic Saturn Kilometric Radiation (SKR), the Auroral Kilometric Radiation (AKR) at Earth and the periodic decametric radio emissions from Jupiter all point to the same generation mechanisms: very large-scale explosive plasma heating events in the magnetotail of each of the planets. The character and periodicity of the associated radio emissions not only tells us about the presence of a magnetic field but also about the plasma content and size of the planetary magnetosphere, and the nature of the interaction with the solar wind.The presence of a planetary magnetic field, as could be established for exoplanets by the positive detection of low-frequency exoplanetary radio emissions, has been thought to shield a planet from atmospheric loss to space. However, recent data from Mars Express, MAVEN, and Venus Express, together with the wealth of terrestrial measurements of atmospheric escape to space has brought a surprising question in to light: Does a planetary magnetic field suppress or enhance atmospheric loss? While at the non-magnetized planets such as Mars and Venus, the solar wind has a more direct access to the ionized upper atmosphere, these planets do set up self shielding currents that do limit escape. Furthermore, it is not clear if Mars have lost the majority of its atmosphere by condensation in to surface and sub-surface frost, or through atmospheric escape. At Earth, the geomagnetic field sets up a relatively large cross section to the solar wind, that allows the induced solar-wind electric field to transfer substantial energy to the upper ionosphere and atmosphere resulting in substantial loss. It is therefore not clear how a planetary magnetic field correlates to the atmospheric loss, or if it does at all.In this

  12. Astronomy and astrology

    Science.gov (United States)

    Zarka, Philippe

    2011-06-01

    Astrology meets a large success in our societies, from the private to the political sphere as well as in the media, in spite of the demonstrated inaccuracy of its psychological as well as operational predictions. We analyse here the relations between astrology and astronomy, as well as the criticisms opposed by the latter to the former. We show that most of these criticisms are weak. Much stronger ones emerge from the analysis of the astrological practice compared to the scientific method, leading us to conclude to the non-scientificity of astrology. Then we return to the success of astrology, and from its analysis we propose a renewed (and prophylactic) rôle for astronomy in society.

  13. Bringing Students To Astronomy

    Science.gov (United States)

    Clark, Gilbert

    2013-05-01

    The Telescopes In Education (TIE) Program was the pioneer in robotic astronomy. The first users came online in the spring of 1993. The TIE program was dedicated to K-14 students with the hope of inspiring them to develop a greater appreciation for math, science, and engineering through their participation in astronomy. The program was very successful through 2005 when NASA felt there were enough robotic telescopes in the community to support the students into the future. During the 12 years of supported operations, TIE had over one hundred thousand student operations. TIE then started working with Universities in Australia to help move their students towards careers in the sciences and engineering. We discovered that students in the middle schools were the ones that should be focused on, to successfully bring them into the sciences and engineering. We have crafted a system that should be very successful in this endeavor.

  14. Thread Safe Astronomy

    CERN Document Server

    Seaman, Robert

    2008-01-01

    Observational astronomy is the beneficiary of an ancient chain of apprenticeship. Kepler's laws required Tycho's data. As the pace of discoveries has increased over the centuries, so has the cadence of tutelage (literally, "watching over"). Naked eye astronomy is thousands of years old, the telescope hundreds, digital imaging a few decades, but today's undergraduates will use instrumentation yet unbuilt - and thus, unfamiliar to their professors - to complete their doctoral dissertations. Not only has the quickening cadence of astronomical data-taking overrun the apprehension of the science within, but the contingent pace of experimental design threatens our capacity to learn new techniques and apply them productively. Virtual technologies are necessary to accelerate our human processes of perception and comprehension to keep up with astronomical instrumentation and pipelined dataflows. Necessary, but not sufficient. Computers can confuse us as efficiently as they illuminate. Rather, as with neural pathways e...

  15. e-POP Radio Science Using Amateur Radio Transmissions

    Science.gov (United States)

    Frissell, N. A.; Perry, G. W.; Miller, E. S.; Shovkoplyas, A.; Moses, M. L.; James, H. G.; Yau, A. W.

    2015-12-01

    A major component of the enhanced Polar Outflow Probe (e-POP) Radio Receiver Instrument (RRI) mission is to utilize artificially generated radio emissions to study High Frequency (HF) radio wave propagation in the ionosphere. In the North American and European sectors, communications between amateur radio operators are a persistent and abundant source source of HF transmissions. We present the results of HF radio wave propagation experiments using amateur radio transmissions as an HF source for e-POP RRI. We detail how a distributed and autonomously operated amateur radio network can be leveraged to study HF radio wave propagation as well as the structuring and dynamics of the ionosphere over a large geographic region. In one case, the sudden disappearance of nearly two-dozen amateur radio HF sources located in the midwestern United States was used to detect a enhancement in foF2 in that same region. We compare our results to those from other more conventional radio instruments and models of the ionosphere to demonstrate the scientific merit of incorporating amateur radio networks for radio science at HF.

  16. Software systems for astronomy

    CERN Document Server

    Conrad, Albert R

    2014-01-01

    This book covers the use and development of software for astronomy. It describes the control systems used to point the telescope and operate its cameras and spectrographs, as well as the web-based tools used to plan those observations. In addition, the book also covers the analysis and archiving of astronomical data once it has been acquired. Readers will learn about existing software tools and packages, develop their own software tools, and analyze real data sets.

  17. Astronomy on a Landfill

    Science.gov (United States)

    Venner, Laura

    2008-09-01

    Engaging "K-to-Gray” audiences (children, families, and older adults) in astronomical activities is one of the main goals of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will assist in bringing the goals of IYA 2009 to the approximately 25,000 students and 15,000 adults that visit our site from the NY/NJ region each year. Diversifying our traditional environmental science offerings, we have incorporated astronomy into our repertoire with "The Sun Through Time” module, which includes storytelling, cultural astronomy, telescope anatomy, and other activities that are based on the electromagnetic spectrum and our current knowledge of the sun. These lessons have also been modified to bring astronomy to underserved communities, specifically those individuals that have dexterity or cognitive ability differences. The program is conducted in a classroom setting and is designed to meet New Jersey Core Curriculum Content Standards. With the installation of our new 20” telescope, students and amateur astronomers will be given the opportunity to perform rudimentary research. In addition, a program is in development that will allow individuals to measure local sky brightness and understand the effects of light pollution on astronomical viewing. Teaching astronomy in an urban setting presents many challenges. All individuals, regardless of ability level or location, should be given the opportunity to be exposed to the wonders of the universe and the MEC/CESE has been successful in providing those opportunities.

  18. TEAM Experience in Astronomy

    Science.gov (United States)

    McGruder, C. H., III; Tyson, N.; Williams, B.; Hackney, K.; Hackney, R.; Rudloff, M.; Scott, R.; Tyler, R.

    1996-05-01

    The purpose of the project was to increase minority interest and appreciation of science using astronomy as a tool. This goal was achieved by inviting high school minority students and their teachers to the campus of Western Kentucky University to participate along with minority role models in team based learning experiences. All participants worked together in many hands-on activities and events centered around the exploration of space.

  19. Infrared spectroscopy in astronomy

    Science.gov (United States)

    Houck, J. R.

    1981-01-01

    The use of infrared spectroscopy in astronomy has increased dramatically in the past ten years. The broad design considerations are discussed in terms of wavelength coverage and resolution. Three rough resolution ranges, lambda/Delta lambda of approximately 100, 1000 and 10,000, are identified in which various types of astronomical problems can be studied. Numerous existing systems are briefly discussed and references are given to more complete descriptions.

  20. Astronomy in the streets

    Science.gov (United States)

    Kebe, Fatoumata

    2015-08-01

    The Ephemerides Association was founded last year by a PhD student in Astronomy. The association is devoted to the promotion and advancement of knowledge of the universe through research and education.The main activities of the association are scientific meetings, the planning and realization of scientific projects, the support of the scientific activities of its members, and the dissemination of related information among members and other interested persons.The association targets the disadvantaged zones of the Paris suburbs.The main issue was how to bring astronomy in those places. In the suburbs, since most of the youth are poor, most leisure activities like cinema are out of your reach. Thus, mostly of them will play football or basketball outside.We decided to go to meet young people who find themselves together in the evening. We prepare the telescope as well as the fasicules to start the observation of the planets. The discussion finally lead to their career plans and aspirations. Astronomy has become a tool to address societal issues. We present our results after one year of activity.

  1. Probing Atmospheric Electric Fields through Radio Emission from Cosmic-Ray-Induced Air Showers

    Science.gov (United States)

    Scholten, Olaf; Trinh, Gia; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Hoerandel, Joerg; Nelles, Anna; Schellart, Pim; Rachen, Joerg; Rutjes, Casper; ter Veen, Sander; Rossetto, Laura; Thoudam, Satyendra

    2016-04-01

    Energetic cosmic rays impinging on the atmosphere create a particle avalanche called an extensive air shower. In the leading plasma of this shower electric currents are induced that generate coherent radio wave emission that has been detected with LOFAR, a large and dense array of simple radio antennas primarily developed for radio-astronomy observations. Our measurements are performed in the 30-80 MHz frequency band. For fair weather conditions the observations are in excellent agreement with model calculations. However, for air showers measured under thunderstorm conditions we observe large differences in the intensity and polarization patterns from the predictions of fair weather models. We will show that the linear as well as the circular polarization of the radio waves carry clear information on the magnitude and orientation of the electric fields at different heights in the thunderstorm clouds. We will show that from the measured data at LOFAR the thunderstorm electric fields can be reconstructed. We thus have established the measurement of radio emission from extensive air showers induced by cosmic rays as a new tool to probe the atmospheric electric fields present in thunderclouds in a non-intrusive way. In part this presentation is based on the work: P. Schellart et al., Phys. Rev. Lett. 114, 165001 (2015).

  2. Indigenous Astronomies and Progress in Modern Astronomy

    CERN Document Server

    Ruggles, Clive

    2010-01-01

    From an anthropological point of view, the whole concept of a "path of progress" in astronomical discovery is anathema, since it implicitly downgrades other cultural perspectives, such as the many "indigenous cosmologies" that still exist in the modern world. By doing so, one risks provoking those who hold them and-as is most obvious in places such as Hawaii where the two "world-views" come into direct contact-reating avoidable resistance to that very progress. The problem is complicated by the existence of "fringe" and "new-age" views that are increasingly confused with, and even passed off as, indigenous perceptions. In a modern world where widespread public perceptions include many that are unscientific in the broadest sense of the term, I shall argue that there are actually a range of positive benefits for progress in scientific astronomy to be derived from the mutual awareness and comprehension of "genuine" cultural world-views whose goals-in common with those of modern science-are to make sense of the c...

  3. Student comprehension of mathematics through astronomy

    Science.gov (United States)

    Search, Robert

    The purpose of this study is to examine how knowledge of astronomy can enhance college-level learning situations involving mathematics. The fundamental symbiosis between mathematics and astronomy was established early in the 17th century when Johannes Kepler deduced the 3 basic laws of planetary motion. This mutually harmonious relationship between these sciences has been reinforced repeatedly in history. In the early 20th century, for example, astronomer Arthur Eddington used photographic evidence from a 1919 solar eclipse to verify Einstein's mathematical theory of relativity. This study was conducted in 5 undergraduate mathematics classes over the course of 2 years. An introductory course in ordinary differential equations, taught in Spring Semester 2013, involved 4 students. A similar course in Spring Semester 2014 involved 6 students, a Summer Semester 2014 Calculus II course involved 2 students, and a Summer 2015 Astronomy course involved 8 students. The students were asked to use Kepler's astronomical evidence to deduce mathematical laws normally encountered on an undergraduate level. They were also asked to examine the elementary mathematical aspects involved in a theoretical trajectory to the planet Neptune. The summer astronomy class was asked to draw mathematical conclusions about large numbers from the recent discoveries concerning the dwarf planet Pluto. The evidence consists primarily of videotaped PowerPoint presentations conducted by the students in both differential equations classes, along with interviews and tests given in all the classes. All presentations were transcribed and examined to determine the effect of astronomy as a generator of student understanding of mathematics. An analysis of the data indicated two findings: definite student interest in a subject previously unknown to most of them and a desire to make the mathematical connection to celestial phenomena.

  4. Astronomy Education for Physics Students

    Indian Academy of Sciences (India)

    J. H. Fan; J. S. Zhang; J. Y. Zhang; Y. Liu; H. G. Wang

    2011-03-01

    Astronomy is a very interesting subject for undergraduate students studying physics. In this paper, we report astronomy education for undergraduate students in the Physics Department of Guangzhou University, and how we are teaching astronomy to the students. Astrophysics has been rapidly developing since 1994, when the center for astrophysics was founded. Now, astrophysics has become a key subject in Guangdong Province, and the Astronomy Science and Technology Research Laboratory one of the key laboratories of the Department of Education of the Guangdong Province. Many undergraduate students, working under the tutorship of faculty members completed their thesis at the Center for Astrophysics in Guangzhou.

  5. Transmission of Babylonian Astronomy to Other Cultures

    Science.gov (United States)

    Jones, Alexander

    Babylonian astronomy and astrology were extensively transmitted to other civilizations in the second and first millennia BC. Greek astronomy in particular was largely shaped by knowledge of Babylonian observations and mathematical astronomy.

  6. Cascaded neural networks for sequenced propagation estimation, multiuser detection, and adaptive radio resource control of third-generation wireless networks for multimedia services

    Science.gov (United States)

    Hortos, William S.

    1999-03-01

    A hybrid neural network approach is presented to estimate radio propagation characteristics and multiuser interference and to evaluate their combined impact on throughput, latency and information loss in third-generation (3G) wireless networks. The latter three performance parameters influence the quality of service (QoS) for multimedia services under consideration for 3G networks. These networks, based on a hierarchical architecture of overlaying macrocells on top of micro- and picocells, are planned to operate in mobile urban and indoor environments with service demands emanating from circuit-switched, packet-switched and satellite-based traffic sources. Candidate radio interfaces for these networks employ a form of wideband CDMA in 5-MHz and wider-bandwidth channels, with possible asynchronous operation of the mobile subscribers. The proposed neural network (NN) architecture allocates network resources to optimize QoS metrics. Parameters of the radio propagation channel are estimated, followed by control of an adaptive antenna array at the base station to minimize interference, and then joint multiuser detection is performed at the base station receiver. These adaptive processing stages are implemented as a sequence of NN techniques that provide their estimates as inputs to a final- stage Kohonen self-organizing feature map (SOFM). The SOFM optimizes the allocation of available network resources to satisfy QoS requirements for variable-rate voice, data and video services. As the first stage of the sequence, a modified feed-forward multilayer perceptron NN is trained on the pilot signals of the mobile subscribers to estimate the parameters of shadowing, multipath fading and delays on the uplinks. A recurrent NN (RNN) forms the second stage to control base stations' adaptive antenna arrays to minimize intra-cell interference. The third stage is based on a Hopfield NN (HNN), modified to detect multiple users on the uplink radio channels to mitigate multiaccess

  7. Astronomy Camp = IYA x 22: 22 Years of International Astronomy Education

    Science.gov (United States)

    Hooper, Eric Jon; McCarthy, D. W.; Camp Staff, Astronomy

    2010-01-01

    Do you remember childhood dreams of being an astronomer, or the ravenous desire for ever larger glass and better equipment as an amateur astronomer? What if your child or the person down the street could live that dream for a weekend or a week? The University of Arizona Astronomy Camp continues to substantiate those dreams after more than two decades in existence. Astronomy Camp is an immersion hands-on field experience in astronomy, ranging from two to eight nights, occurring a few times per year. Participants span an age range from elementary students to octogenarians. The three basic offerings include adult camps, a beginning Camp for teenagers, and an advanced teen Camp. Several variants of the basic Camp model have evolved, including an ongoing decade long series of specialized Camps for Girl Scout leaders from across the country, funded by the NIRCam instrument development program for the James Webb Space Telescope. The advanced teen Camp is a microcosm of the entire research arc: the participants propose projects, spend the week collecting and analyzing data using research grade CCDs, infrared arrays, and radio/sub-millimeter telescopes, and finish with a presentation of the results. This past summer the Camps moved to Kitt Peak National Observatory for the first time, providing access to a vast and diverse collection of research instruments, including the 0.9-meter WIYN and 2.3-meter Bok telescopes, the McMath-Pierce Solar Telescope, and the 12-meter ARO radio telescope. Education research into the Camp's impact indicates that reasons for its appeal to youth include a learner-centered and personal approach with a fun attitude toward learning, authentic scientific inquiry led by mentors who are real scientists, a peer group with common interests in science and engineering, and the emotional appeal of spending time on a dark "sky island" devoted to the exploration of nature.

  8. Radio archive

    OpenAIRE

    Street, Sean

    2008-01-01

    The Centre for Broadcasting History Research, in association with the\\ud British Universities Film and Video Council, is developing an online\\ud audio archive of UK commercial radio, from 1973 to 1992. Work produced\\ud before the Broadcasting Act 1990 represents a different ethos to the role\\ud commercial radio played, and subsequently,continues to play, in the UK.\\ud The change in commercial radio since this period is extraordinary. It is\\ud impossible for the young student of radio, born si...

  9. Astronomy across cultures the history of non-Western astronomy

    CERN Document Server

    Xiaochun, Sun

    2000-01-01

    Astronomy Across Cultures: A History of Non-Western Astronomy consists of essays dealing with the astronomical knowledge and beliefs of cultures outside the United States and Europe. In addition to articles surveying Islamic, Chinese, Native American, Aboriginal Australian, Polynesian, Egyptian and Tibetan astronomy, among others, the book includes essays on Sky Tales and Why We Tell Them and Astronomy and Prehistory, and Astronomy and Astrology. The essays address the connections between science and culture and relate astronomical practices to the cultures which produced them. Each essay is well illustrated and contains an extensive bibliography. Because the geographic range is global, the book fills a gap in both the history of science and in cultural studies. It should find a place on the bookshelves of advanced undergraduate students, graduate students, and scholars, as well as in libraries serving those groups.

  10. Dyslexia and Astronomy

    Science.gov (United States)

    Schneps, Matthew H.; Greenhill, L. J.; Rose, L. T.

    2007-12-01

    Dyslexia is a hereditary neurological disability that impairs reading. It is believed that anywhere from 5% to 20% of all people in the US may have dyslexia to a greater or lesser degree. Though dyslexia is common, it is a "silent disability" in the sense that it is not easy to tell which individuals suffer from dyslexia and which do not. There is a substantial body of evidence to suggest that people with dyslexia tend to do well in science. For example, Baruj Benacerraf, a Nobel laureate in medicine, is among those whose impairments have been documented and studied. Given that dyslexia was not diagnosed in schools prior to the late 1970's, many established science researchers may have dyslexia and be unaware of their impairment. Therefore, it would not be surprising to find that substantial numbers of scientists working in the fields of astronomy and astrophysics have dyslexia, and yet be unaware of the effects this disability has had on their research. A recently proposed theory by the authors suggests that there may be specific neurological reasons why those with dyslexia may be predisposed to science, and predicts that dyslexia may be associated with enhanced abilities for certain types of visual processing, with special implications for image processing. Our study, funded by the NSF, investigates this hypothesis in the context of astronomy and astrophysics. We expect this work will uncover and document challenges faced by scientists with dyslexia, but perhaps more importantly, lead to an understanding of the strengths these scientists bring to research. The program will serve as a clearing-house of information for scientists and students with dyslexia, and begin to provide mentoring for young people with dyslexia interested in astronomy. Scientists who have reason to believe they may have dyslexia are encouraged to contact the authors.

  11. Astrology as Cultural Astronomy

    Science.gov (United States)

    Campion, Nicholas

    The practice of astrology can be traced in most if not all human societies, in most time periods. Astrology has prehistoric origins and flourishes in the modern world, where it may be understood as a form of ethnoastronomy - astronomy practiced by the people. The Western tradition, which originated in Mesopotamia and was developed in the Greek world, has been most studied by academics. However, India is also home to a tradition which has survived in a continuous lineage for 2,000 years. Complex systems of astrology also developed in China and Mesoamerica, while all other human societies appear to seek social and religious meaning in the stars.

  12. Applied Astronomy: Asteroid Prospecting

    Science.gov (United States)

    Elvis, M.

    2013-09-01

    In the age of asteroid mining the ability to find promising ore-bearing bodies will be valuable. This will give rise to a new discipline- "Applied Astronomy". Just as most geologists work in industry, not in academia, the same will be true of astronomers. Just how rare or common ore-rich asteroids are likely to be, and the skills needed to assay their value, are discussed here, with an emphasis on remote - telescopic - methods. Also considered are the resources needed to conduct extensive surveys of asteroids for prospecting purposes, and the cost and timescale involved. The longer-term need for applied astronomers is also covered.

  13. Robots in astronomy

    Science.gov (United States)

    Baruch, John E. F.

    A development history and a development trends evaluation are presented for the growth of automation and robotics in industry and in observational astronomy, with a view to the distinctive problems of each field of application. Recent concepts concerning the astronomical use of robots as personal assistants are noted, and an effort is made to discern ways in which technology guides both methods and perceptions. Current programs for robotic and automated telescope development are noted, and it is argued that international standards should soon be formulated for this technology.

  14. Gravitational-Wave Astronomy

    Science.gov (United States)

    Kelly, Bernard J.

    2010-01-01

    Einstein's General Theory of Relativity is our best classical description of gravity, and informs modern astronomy and astrophysics at all scales: stellar, galactic, and cosmological. Among its surprising predictions is the existence of gravitational waves -- ripples in space-time that carry energy and momentum away from strongly interacting gravitating sources. In my talk, I will give an overview of the properties of this radiation, recent breakthroughs in computational physics allowing us to calculate the waveforms from galactic mergers, and the prospect of direct observation with interferometric detectors such as LIGO and LISA.

  15. Astronomy in Iran

    Science.gov (United States)

    Sobouti, Y.

    2006-08-01

    Institute for Advanced Studies in Basic Sciences, Zanjan, Iran In spite of her renowned pivotal role in the advancement of astronomy on the world scale during 9th to 15th centuries, Iran's rekindled interest in modern astronomy is a recent happening. Serious attempts to introduce astronomy into university curricula and to develop it into a respectable and worthwhile field of research began in the mid 60's. The pioneer was Shiraz University. It should be credited for the first few dozens of astronomy- and astrophysics- related research papers in international journals, for training the first half a dozen of professional astronomers and for creating the Biruni Observatory. Here, I take this opportunity to acknowledge the valuable advice of Bob Koch and Ed Guinan, then of the University of Pennsylvania, in the course of the establishment of this observatory. At present the astronomical community of Iran consists of about 65 professionals, half university faculty members and half MS and PhD students. The yearly scientific contribution of its members has, in the past three years, averaged to about 15 papers in reputable international journals, and presently has a healthy growth rate. Among the existing observational facilities, Biruni Observatory with its 51 cm Cassegrain, CCD cameras, photometers and other smaller educational telescopes, is by far the most active place. Tusi Observatory of Tabriz University has 60 and 40 cm Cassegrains, and a small solar telescope. A number of smaller observing facilities exist in Meshed, Zanjan, Tehran, Babol and other places. The Astronomical Society of Iran (ASI), though some 30 years old, has expanded and institutionalized its activities since early 1990's. ASI sets up seasonal schools for novices, organizes annual colloquia and seminars for professionals and supports a huge body of amateur astronomers from among high school and university students. Over twenty of ASI members are also members of IAU and take active part in its

  16. Astronomy in the classroom

    Science.gov (United States)

    Moiteiro, Bárbara; Rodrigues, Berta

    2016-04-01

    The motivation of young students to science is much higher when the theoretical teaching is accompanied by practice and these are engaged in activities that involve real problems of their society and requiring a scientific basis for its discussion. Several activities such as collaboration on current scientific experiments, direct contact with scientists, participation in science competitions, visits to Science Museums, artistic and craft activities, the use of simulators and virtual laboratories, increase the degree of student satisfaction and motivate them in their learning processes. This poster shows some of Astronomy activities with students of schools Agrupamento de Escolas José Belchior Viegas within the Physics and Chemistry classes.

  17. Islamic Mathematical Astronomy

    Science.gov (United States)

    Montelle, Clemency

    A short survey on Islamic mathematical astronomy practiced during the period running from the eight century until the fifteenth is presented. Various pertinent themes, such as the translation of foreign scientific works and their impact on the tradition; the introduction, assimilation, and critique of the Ptolemaic model; and the role of observations, will be covered. In addition, the zīj, the dominant format for astronomical works, will be briefly explained as well as the legacy of the Islamic tradition of astral sciences to other cultures.

  18. High-power radio frequency pulse generation and extration based on wakefield excited by an intense charged particle beam in dielectric-loaded waveguides.

    Energy Technology Data Exchange (ETDEWEB)

    Gao, F.; High Energy Physics; Illinois Inst. of Tech

    2009-07-24

    Power extraction using a dielectric-loaded (DL) waveguide is a way to generate high-power radio frequency (RF) waves for future particle accelerators, especially for two-beam-acceleration. In a two-beam-acceleration scheme, a low-energy, high-current particle beam is passed through a deceleration section of waveguide (decelerator), where the power from the beam is partially transferred to trailing electromagnetic waves (wakefields); then with a properly designed RF output coupler, the power generated in the decelerator is extracted to an output waveguide, where finally the power can be transmitted and used to accelerate another usually high-energy low-current beam. The decelerator, together with the RF output coupler, is called a power extractor. At Argonne Wakefield Accelerator (AWA), we designed a 7.8GHz power extractor with a circular DL waveguide and tested it with single electron bunches and bunch trains. The output RF frequency (7.8GHz) is the sixth harmonic of the operational frequency (1.3GHz) of the electron gun and the linac at AWA. In single bunch excitation, a 1.7ns RF pulse with 30MW of power was generated by a single 66nC electron bunch passing through the decelerator. In subsequent experiments, by employing different splitting-recombining optics for the photoinjector laser, electron bunch trains were generated and thus longer RF pulses could be successfully generated and extracted. In 16-bunch experiments, 10ns and 22ns RF pulses have been generated and extracted; and in 4-bunch experiments, the maximum power generated was 44MW with 40MW extracted. A 26GHz DL power extractor has also been designed to test this technique in the millimeter-wave range. A power level of 148MW is expected to be generated by a bunch train with a bunch spacing of 769ps and bunch charges of 20nC each. The arrangement for the experiment is illustrated in a diagram. Higher-order-mode (HOM) power extraction has also been explored in a dual-frequency design. By using a bunch

  19. Gravitational wave astronomy: the current status

    CERN Document Server

    Blair, David; Zhao, Chunnong; Wen, Linqing; Chu, Qi; Fang, Qi; Cai, RongGen; Gao, JiangRui; Lin, XueChun; Liu, Dong; Wu, Ling-An; Zhu, ZongHong; Reitze, David H; Arai, Koji; Zhang, Fan; Flaminio, Raffaele; Zhu, Xingjiang; Hobbs, George; Manchester, Richard N; Shannon, Ryan M; Baccigalupi, Carlo; Xu, Peng; Bian, Xing; Cao, Zhoujian; Chang, ZiJing; Dong, Peng; Gong, XueFei; Huang, ShuangLin; Ju, Peng; Luo, ZiRen; Qiang, Li'E; Tang, WenLin; Wan, XiaoYun; Wang, Yue; Xu, ShengNian; Zhang, YunLong; Zhang, HaiPeng; Lau, Yun-Kau; Ni, Wei-Tou

    2016-01-01

    In the centenary year of Einstein's General Theory of Relativity, this paper reviews the current status of gravitational wave astronomy across a spectrum which stretches from attohertz to kilohertz frequencies. Sect. 1 of this paper reviews the historical development of gravitational wave astronomy from Einstein's first prediction to our current understanding the spectrum. It is shown that detection of signals in the audio frequency spectrum can be expected very soon, and that a north-south pair of next generation detectors would provide large scientific benefits. Sect. 2 reviews the theory of gravitational waves and the principles of detection using laser interferometry. The state of the art Advanced LIGO detectors are then described. These detectors have a high chance of detecting the first events in the near future. Sect. 3 reviews the KAGRA detector currently under development in Japan, which will be the first laser interferometer detector to use cryogenic test masses. Sect. 4 of this paper reviews gravit...

  20. Science and Mathematics in Astronomy

    Science.gov (United States)

    Woolack, Edward

    2009-01-01

    A brief historical introduction to the development of observational astronomy will be presented. The close historical relationship between the successful application of mathematical concepts and advances in astronomy will be presented. A variety of simple physical demonstrations, hands-on group activities, and puzzles will be used to understand how the properties of light can be used to understand the contents of our universe.

  1. Science and Mathematics in Astronomy

    Science.gov (United States)

    Woolack, Edward

    2009-01-01

    A brief historical introduction to the development of observational astronomy will be presented. The close historical relationship between the successful application of mathematical concepts and advances in astronomy will be presented. A variety of simple physical demonstrations, hands-on group activities, and puzzles will be used to understand how the properties of light can be used to understand the contents of our universe.

  2. How Create an Astronomy Outreach Program to Bring Astronomy to Thousands of People at Outdoor Concerts Astronomy Festivals, or Tourist Sites

    Science.gov (United States)

    Lubowich, Donald

    2015-08-01

    I describe how to create an astronomy program for thousands of people at outdoor concerts based on my $308,000 NASA-funded Music and Astronomy Under the Stars (MAUS) program (60 events 2009 - 2013), and the Astronomy Festival on the National Mall (AFNM, 10,000 people/yr).MAUS reached 50,000 music lovers at local parks and at the Central Park Jazz, Newport Folk, Ravinia, or Tanglewood Music Festivals with classical, folk, pop/rock, opera, Caribbean, or county-western concerts assisted by astronomy clubs. Yo-Yo-Ma, the Chicago and Boston Symphony Orchestras, Ravi Coltrane, Esperanza Spalding, Phish, Blood Sweat and Tears, Deep Purple, Tony Orlando, and Wilco performed at these events. AFNM was started in 2010 with co-sponsorship by the White House Office of Science and Technology Policy. MAUS and AFMN combine solar, optical, and radio telescope observations; large posters/banners; hands-on activities, imaging with a cell phone mount; citizen science activities; hand-outs; and teacher info packet. Representatives from scientific institutions participated. Tyco Brahe, Johannes Kepler, and Caroline Herschel made guest appearances.MAUS reached underserved groups and attracted large crowds. Young kids participated in this family learning experience-often the first time they looked through a telescope. While < 50% of the participants took part in a science activity in the past year, they found MAUS enjoyable and understandable; learned about astronomy; wanted to learn more; and increased their interest in science (ave. rating 3.6/4). MAUS is effective in promoting science education!Lessons learned: plan early; create partnerships with parks, concert organizers, and astronomy clubs; test equipment; have backup equipment; create professional displays; select the best location to obtain a largest number of participants; use social media/www sites to promote the events; use many telescopes for multiple targets; project a live image or video; select equipment that is easy to

  3. How Will Astronomy Archives Survive The Data Tsunami?

    CERN Document Server

    Berriman, G Bruce

    2011-01-01

    The field of astronomy is starting to generate more data than can be managed, served and processed by current techniques. This paper has outlined practices for developing next-generation tools and techniques for surviving this data tsunami, including rigorous evaluation of new technologies, partnerships between astronomers and computer scientists, and training of scientists in high-end software engineering engineering skills.

  4. Harmonization based on regulatory science between scientific and commercial radio uses in a case of ultrawideband radio

    Science.gov (United States)

    Kohno, Ryuji; Iinatti, Jari; Sameshima, Keiko

    2016-12-01

    Harmonization for scientific and commercial radio uses is one of the unsolved problems in academia, industry, and regulatory bodies. The demands for commercial radio, mobile communications, and broadcasting have significantly increased over the past few decades; therefore, interference has become a major concern. There is an increasing need to prevent such interferences, for example, between commercial radio systems and other potentially sensitive radio systems such as those used for radio astronomy or studies. When discussing the fairness in resolving such conflicts, regulatory science may be a useful multidisciplinary approach as it scientifically investigates the advantages and disadvantages of a new application or technology for conflicts between different stakeholders through a mathematical analysis of risks versus benefits of the given technology. Such an analysis enables fair rules or regulations to be made. In this study, we apply the above-mentioned concept to harmonize the scientific and commercial uses of radio. After a brief introduction to regulatory science, a case study about the coexistence between ultrawideband commercial radio systems and radio astronomy is considered. Finally, a proposal by International Union of Radio Science, Japan, to the Science Council of Japan in the Cabinet Office to establish a "Center for Coexistence and Harmonization of Scientific and Commercial Uses of Radio Waves" is explained.

  5. Astronomy in Syria

    Science.gov (United States)

    Al-Mousli, A. T.

    2006-11-01

    Syria has been involved in the field of astronomy since 1997, when Prof. F.R. QUERCI, France, visited Syria and made a presentation on the International NORT project; (NORT: the Network of Oriental Robotic Telescope), which was a selected project of the sixth United Nations/ European Space Agency Workshop on Basic Space Science (document no. A/AC.105/657 dated 13/12/1996). NORT aims to establish a robotic telescope network on high mountain peaks around the Tropic of Cancer, from Morocco in the west to the desert of China in the east. The purposes for establishing this network are technical and educational. The General Organization of Remote Sensing (GORS) has carried out a pilot study using remote sensing techniques and has selected four sites in order to determine the best location for the astronomical observatory the within NORT programme. Following this project, GORS decided to establish an office for astronomical studies, one of the earliest works of GORS in astronomy was an initiative to establish a planetarium within the GORS campus, to accommodate approximately 120 observers. A contest to choose the best planetarium design, for the Arab World, took place at GORS.

  6. Active Astronomy Roadshow Haiti

    Science.gov (United States)

    Laycock, Silas; Oram, Kathleen; Alabre, Dayana; Douyon, Ralph; UMass Lowell Haiti Development Studies Center

    2016-01-01

    College-age Haitian students working with advisors and volunteers from UMass Lowell in 2015 developed and tested an activity-based K-8 curriculum in astronomy, space, and earth science. Our partner school is located in Les Cayes, Haiti a city where only 65% of children attend school, and only half of those will complete 6th grade. Astronomy provides an accessible and non-intimidating entry into science, and activity-based learning contrasts with the predominant traditional teaching techniques in use in Haiti, to reach and inspire a different cohort of learners. Teachers are predominantly women in Haiti, so part of the effort involves connecting them with scientists, engineers and teacher peers in the US. As a developing nation, it is vital for Haitian (as for all) children to grow up viewing women as leaders in science. Meanwhile in the US, few are aware of the reality of getting an education in a 3rd world nation (i.e. most of the world), so we also joined with teachers in Massachusetts to give US school children a peek at what daily life is like for their peers living in our vibrant but impoverished neighbor. Our Haitian partners are committed to helping their sister-schools with curriculum and educator workshops, so that the overall quality of education can rise, and not be limited to the very few schools with access to resources. We will describe the activites, motivation, and and the lessons learned from our first year of the project.

  7. Astronomy in Antarctica

    CERN Document Server

    Burton, Michael G

    2010-01-01

    Antarctica provides a unique environment for astronomy. The cold, dry and stable air found above the high plateau, as well as the pure ice below, offers new opportunities across the photon & particle spectrum. The summits of the plateau provide the best seeing conditions, the darkest skies and the most transparent atmosphere of any earth-based observing site. Astronomical activities are now underway at four plateau sites: the Amundsen-Scott South Pole Station, Concordia Station at Dome C, Kunlun Station at Dome A and Fuji Station at Dome F, in addition to long duration ballooning from the coastal station of McMurdo. Astronomy conducted includes optical, IR, THz & sub-mm, measurements of the CMBR, solar, as well as high energy astrophysics involving measurement of cosmic rays, gamma rays and neutrinos. Antarctica is also the richest source of meteorites on our planet. An extensive range of site testing measurements have been made over the high plateau. We summarise the facets of Antarctica that are dri...

  8. Astronomy books in Spanish

    Science.gov (United States)

    Fierro, Julieta

    Great cultures have created language. They have discovered its strength among other reasons for education. For a long time the Bible was one of the few books available in western culture, its influence is beyond any doubt. Many developing nations have no science books in their mother tongue. They might carry a few translations but these do not convey the local culture so it is harder for students to grasp the concepts and to build on what they know. Books, even if they are extremely simple, should be written in local languages because that will facilitate the conveying of knowledge and the creation of scientific culture. In the books examples that pertain to every day local life must be given, in particular examples that have to do with women. Women play a central role in developing nations by child bearing; if they become literate they will influence enormously the quality of their children's education, in particular their science comprehension. In Mexico a collection that includes astronomy books has recently been edited by the National Council for Culture and Arts. The books are small and light, which encourages middle-school students to carry them around and read them while traveling in public transportation, such as the subway. Every other page is a new subject, that carries illustrations, abstracts and conclusions. The astronomy books are on search for extraterrestrial life, the stars and the universe. These books are distributed nation-wide and are inexpensive. They have been written by Mexican astronomers.

  9. The Astronomy Genealogy Project

    Science.gov (United States)

    Tenn, Joseph S.

    2014-01-01

    The Astronomy Genealogy Project, to be known as AstroGen, will list as many as possible of the world's astronomers with their academic parents (aka thesis advisors) and enable the reader to trace both academic ancestors and descendants. It will be very similar to the highly successful Mathematics Genealogy Project (MGP), available at http://genealogy.math.ndsu.nodak.edu. The MGP, which has been in operation since 1996, now contains the names of about 170,000 "mathematicians." These include many physicists and astronomers, as well as practitioners of related sciences. Mitchel Keller, the director of the MGP, has generously shared the software used in that project, and the American Astronomical Society (AAS) will host AstroGen, a project of the Historical Astronomy Division, on its website. We expect to start seeking entries soon, depending on the availability of computational assistance from the AAS IT department. We are seeking volunteers to help run the project. If you are interested, please contact me at joe.tenn@sonoma.edu.

  10. Women in Italian astronomy

    CERN Document Server

    Matteucci, Francesca

    2014-01-01

    This document gives some quantitative facts about the role of women in Italian astronomy. More than 26% of Italian IAU members are women: this is the largest fraction among the world leading countries in astronomy. Most of this high fraction is due to their presence in INAF, where women make up 32% of the research staff (289 out of 908) and 40% of the technical/administrative staff (173 out of 433); the percentage is slightly lower among permanent research staff (180 out of 599, about 30%). The presence of women is lower in the Universities (27 out of 161, about 17%, among staff). In spite of these (mildly) positive facts, we notice that similarly to other countries (e.g. USA and Germany) career prospects for Italian astronomers are clearly worse for women than for men. Within INAF, the fraction of women is about 35-40% among non-permanent position, 36% for Investigators, 17% for Associato/Primo Ricercatore, and only 13% among Ordinario/Dirigente di Ricerca. The situation is even worse at University (only 6% ...

  11. Challenges in Astronomy Education

    Science.gov (United States)

    De Greve, Jean-Pierre

    2010-11-01

    Astronomy is an attractive subject for education. It deals with fascination of the unknown and the unreachable, yet is uses tools, concepts and insights from various fundamental sciences such as mathematics, physics, chemistry, biology. Because of this it can be well used for introducing sciences to young people and to raise their interest in further studies in that direction. It is also an interesting subject for teaching as its different aspects (observation techniques, theory, data sampling and analysis, modelling,?) offer various didactical approaches towards different levels of pupils, students and different backgrounds. And it gives great opportunities to teach and demonstrate the essence of scientific research, through tutorials and projects. In this paper we discuss some of the challenges education in general, and astronomy in particular, faces in the coming decades, given the major geophysical and technological changes that can be deducted from our present knowledge. This defines a general, but very important background in terms of educational needs at various levels, and in geographical distribution of future efforts of the astronomical community. Special emphasis will be given to creative approaches to teaching, to strategies that are successful (such as the use of tutorials with element from computer games), and to initiatives complementary to the regular educational system. The programs developed by the IAU will be briefly highlighted.

  12. Ancient Astronomy in Armenia

    Science.gov (United States)

    Parsamian, Elma S.

    2007-08-01

    The most important discovery, which enriched our knowledge of ancient astronomy in Armenia, was the complex of platforms for astronomical observations on the Small Hill of Metzamor, which may be called an ancient “observatory”. Investigations on that Hill show that the ancient inhabitants of the Armenian Highlands have left us not only pictures of celestial bodies, but a very ancient complex of platforms for observing the sky. Among the ancient monuments in Armenia there is a megalithic monument, probably, being connected with astronomy. 250km South-East of Yerevan there is a structure Zorats Kar (Karahunge) dating back to II millennium B.C. Vertical megaliths many of which are more than two meters high form stone rings resembling ancient stone monuments - henges in Great Britain and Brittany. Medieval observations of comets and novas by data in ancient Armenian manuscripts are found. In the collection of ancient Armenian manuscripts (Matenadaran) in Yerevan there are many manuscripts with information about observations of astronomical events as: solar and lunar eclipses, comets and novas, bolides and meteorites etc. in medieval Armenia.

  13. Making Astronomy Accessible

    Science.gov (United States)

    Grice, Noreen A.

    2011-05-01

    A new semester begins, and your students enter the classroom for the first time. You notice a student sitting in a wheelchair or walking with assistance from a cane. Maybe you see a student with a guide dog or carrying a Braille computer. Another student gestures "hello” but then continues hand motions, and you realize the person is actually signing. You wonder why another student is using an electronic device to speak. Think this can't happen in your class? According to the U.S. Census, one out of every five Americans has a disability. And some disabilities, such as autism, dyslexia and arthritis, are considered "invisible” disabilities. This means you have a high probability that one of your students will have a disability. As an astronomy instructor, you have the opportunity to reach a wide variety of learners by using creative teaching strategies. I will share some suggestions on how to make astronomy and your part of the universe more accessible for everyone.

  14. Evaluation of the 2. generation radio-receptional assay for anti-TSH receptor antibodies (TRAb) in autoimmune thyroid diseases. Comparison with 1. generation and anti-thyroperoxidae antibodies (AbTPO)

    Energy Technology Data Exchange (ETDEWEB)

    Giovanella, L.; Ceriani, L.; Garacini, S. [University Hospital Ospedale di Circolo e Fondazione Macchi, Dept. of Nuclear Medicine, Lab. of Endocrinology and Thyroid Unit, Varese (Italy)

    2001-03-01

    The detection of autoantibodies to the TSH-receptor (TRAb) by radio-receptor assays (RRA) is widely requested in clinical practice for the diagnostic work-up of Graves' disease and its differentiation from diffuse thyroid autonomy. Additionally, TRAb measurement can be useful during antithyroid drug treatment of Graves' disease to evaluate the risk of relapse after therapy discontinuation. Nevertheless, some patients affected by Graves' disease are TRAb-negative when 1. generation assay is used. In this study the diagnostic performance of a newly developed 2. generation TRAb assay (TRAK human DYNOtest(R), BRAHMS Diagnostica GmbH, Berlin, Germany) was evaluated in 74 untreated patients affected by Graves' disease, in 53 untreated patients affected by Hashimoto's thyroiditis and in 88 patients affected by euthyroid nodular goiter. It was also compared the new TRAb assay with the 1. generation test (TRAK(R) Assay, BRAHMS Diagnostica GmbH, Berlin, Germany) and anti-thyroperoxidase assay (AbTPO DYNOtest(R), BRAHMS GmbH, Berlin). The 2. generation TRAb assay showed the better diagnostic sensitivity in Graves' disease (97%) with respect to the 1. generation assay (85%) and AbTPO assay (64%). The AbTPO assay was positive in 50 of 53 (94%) patients affected by autoimmune thyroiditis. The 1. and 2. generation TRAb assays were positive in 4 (7%) and 7 (13%) of 53 patients affected by autoimmune thyroiditis, respectively. No patients affected by nodular goiter showed positive 1. and 2. generation TRAb assay while AbTPO levels were positive in 8 of 88 patients (specificity 91%). In conclusion, the 2. generation TRAb assay is clearly more sensitive than the 1. generation test and should be used in clinical practice to minimize the incidence of TRAb-negative Graves' disease. Long term prospective studies are needed to evaluate the prognostic role of 2. generation TRAb assay in Graves' disease. The assay of AbTPO is the best marker for

  15. Preservice elementary teachers learning of astronomy

    Science.gov (United States)

    Fidler, Chuck Gary

    The dissertation presents a new approach for the study of preservice elementary teacher astronomy education. The approach suggests that learning astronomical concepts are facilitated by greater sophistication in scale perception and spatial-aptitude. This dissertation is underscored by the national call for elementary science education reform efforts and suggests certain strategies shown more effective for the development of accurate astronomical comprehension. The present research study describes how preservice elementary teachers conceptualize and communicate ideas about Space. Instead of assuming a universal mental conception of cosmic orientations and relationships, the dissertation claims that the perception of Space related dimensions vary among preservice elementary teachers. Furthermore, the dissertation suggests individual perceptions of the scale sizes and orientations of celestial systems have direct influences on mental models used to organize and communicate astronomical information. The development of inaccurate mental models of the scaled dimensions of Space may perpetuate the teacher-student cycle of misconception and naive-theory generation among children in elementary education settings. The ability to conceptualize the vast cosmos is facilitated by the minds ability to think about vast scales and orientations of celestial objects. The Earth-based perspective of astronomy education compels the learner to think about astronomical principles within imaginary frames of reference and across unfamiliar scaled dimensions. Therefore, mental astronomical model building is underscored by the perception of scale and cosmic spatiality. This study suggests these cognitive skill sets are interconnected and facilitate the learning of accurate astronomy principles; as well as play an important role when designing an astronomy education program for preservice elementary teachers. This research study is comprised of three separate standalone articles designed and

  16. An efficient feedback calibration algorithm for direct imaging radio telescopes

    Science.gov (United States)

    Beardsley, Adam P.; Thyagarajan, Nithyanandan; Bowman, Judd D.; Morales, Miguel F.

    2017-10-01

    We present the E-field Parallel Imaging Calibration (EPICal) algorithm, which addresses the need for a fast calibration method for direct imaging radio astronomy correlators. Direct imaging involves a spatial fast Fourier transform of antenna signals, alleviating an O(Na ^2) computational bottleneck typical in radio correlators, and yielding a more gentle O(Ng log _2 Ng) scaling, where Na is the number of antennas in the array and Ng is the number of gridpoints in the imaging analysis. This can save orders of magnitude in computation cost for next generation arrays consisting of hundreds or thousands of antennas. However, because antenna signals are mixed in the imaging correlator without creating visibilities, gain correction must be applied prior to imaging, rather than on visibilities post-correlation. We develop the EPICal algorithm to form gain solutions quickly and without ever forming visibilities. This method scales as the number of antennas, and produces results comparable to those from visibilities. We use simulations to demonstrate the EPICal technique and study the noise properties of our gain solutions, showing they are similar to visibility-based solutions in realistic situations. By applying EPICal to 2 s of Long Wavelength Array data, we achieve a 65 per cent dynamic range improvement compared to uncalibrated images, showing this algorithm is a promising solution for next generation instruments.

  17. Dual-frequency Brillouin fiber laser for optical generation of tunable low-noise radio frequency/microwave frequency.

    Science.gov (United States)

    Geng, Jihong; Staines, Sean; Jiang, Shibin

    2008-01-01

    We demonstrate a new approach, i.e., a cw dual-frequency Brillouin fiber laser pumped by two independent single-frequency Er-doped fiber lasers, for the generation of tunable low-noise rf/microwave optical signals. Its inherent features of both linewidth narrowing effect in a Brillouin fiber cavity and common mode noise cancellation between two laser modes sharing a common cavity allow us to achieve high frequency stability without using a supercavity. Beat frequency of the dual-frequency Brillouin fiber laser can be tuned from tens of megahertz up to 100 GHz by thermally tuning the wavelengths of the two pump lasers with tuning sensitivity of approximately 1.4 GHz/ degrees C. Allan variance measurements show the beat signals have the hertz-level frequency stability.

  18. Integrating Research into the BYU Undergraduate Astronomy Major and Descriptive Astronomy Classes

    Science.gov (United States)

    Hintz, Eric G.; Moody, J. W.; Joner, M. D.; Stephens, D. C.

    2009-01-01

    We have designed an undergraduate astronomy major at BYU which makes astronomical research the focus of the program. The major requires a research focused class (Phscs 329) which teaches students how to take data at the telescope, reduce the data, and present the data. The students must present their results in the format used to submit manuscripts to journals (AASTeX) and as a meeting poster. Finally the class works together to prepare a real telescope proposal that is actually submitted. Majors must then take part in faculty mentored research leading to a senior thesis. At all levels the data produced is of such quality as to generate referred publications in astronomy journals. As an extention of our major we have designed observing projects for our descriptive astronomy class that allow the non-majors a chance to see how astronomers learn the concepts that are taught. The projects range from taking data to create a 3-color image to working with astronomy majors to acquire research quality data.

  19. Test Of Astronomy STandards TOAST Survey of K-12 Teachers

    Science.gov (United States)

    Slater, Timothy F.; Slater, Stephanie; Stork, Debra J.

    2015-01-01

    Discipline-based education research in astronomy is focused on understanding the underlying mental mechanisms used by students when learning astronomy and teachers when teaching astronomy. Systematic surveys of K-12 teacher' knowledge in the domain of astronomy are conducted periodically in order to better focus and improve professional development. These surveys are most often done when doing contemporary needs assessments or when new assessment instruments are readily available. Designed by Stephanie J. Slater of the CAPER Center for Astronomy & Physics Education Research, the 29-item multiple-choice format Test Of Astronomy STandards - TOAST is a carefully constructed, criterion-referenced instrument constructed upon a solid list of clearly articulated and widely agreed upon learning objectives. The targeted learning concepts tightly align with the consensus learning goals stated by the American Astronomical Society - Chair's Conference on ASTRO 101, the American Association of the Advancement of Science's Project 2061 Benchmarks, and the National Research Council's 1996 National Science Education Standards. Without modification, the TOAST is also aligned with the significantly less ambitious 2013 Next Generation Science Standards created by Achieve, Inc., under the auspices of the National Research Council. This latest survey reveals that K-12 teachers still hold many of the same fundamental misconceptions uncovered by earlier surveys. This includes misconceptions about the size, scale, and structure of the cosmos as well as misconceptions about the nature of physical processes at work in astronomy. This suggests that professional development in astronomy is still needed and that modern curriculum materials are best served if they provide substantial support for implementation.

  20. Radio Eska Lodz, Commercial Radio As a Local Radio

    OpenAIRE

    Szews, Przemysław

    2015-01-01

    The article discusses aspects of network-based local radio using the example of Radio Eska Lodz. The author responds to questions about whether a commercial network radio station can fulfill the functions of local radio and on what this locality is actually based. In this respect, Radio Eska Lodz is characterized as part of the most popular commercial radio network in Poland. The introduction focuses on the process of transformation that local radio stations are undergoing, along with its gen...