47 CFR 73.1030 - Notifications concerning interference to radio astronomy, research and receiving installations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... astronomy, research and receiving installations. 73.1030 Section 73.1030 Telecommunication FEDERAL... Broadcast Stations § 73.1030 Notifications concerning interference to radio astronomy, research and receiving installations. (a)(1) Radio astronomy and radio research installations. In order to minimize...

47 CFR 2.1 - Terms and definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... radiocommunication services or the radio astronomy service under specified conditions. This term shall also be... or the spacecraft above the Earth's surface or another surface. (RR) Radio Astronomy. Astronomy based on the reception of radio waves of cosmic origin. (RR) Radio Astronomy Service. A service involving...

47 CFR 2.1 - Terms and definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... radiocommunication services or the radio astronomy service under specified conditions. This term shall also be... or the spacecraft above the Earth's surface or another surface. (RR) Radio Astronomy. Astronomy based on the reception of radio waves of cosmic origin. (RR) Radio Astronomy Service. A service involving...

47 CFR 2.1 - Terms and definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... radiocommunication services or the radio astronomy service under specified conditions. This term shall also be... or the spacecraft above the Earth's surface or another surface. (RR) Radio Astronomy. Astronomy based on the reception of radio waves of cosmic origin. (RR) Radio Astronomy Service. A service involving...

78 FR 59844 - Operation in the 57-64 GHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-30

.... With regard to the radio astronomy service and National Radio Astronomy Observatory (NRAO) concerns... analysis of potential harmful interference from 60 GHz devices to radio astronomy service. 20. Consistent with this experience, the Commission finds that interference to Radio Astronomy Service (RAS) stations...

47 CFR 73.1030 - Notifications concerning interference to radio astronomy, research and receiving installations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... astronomy, research and receiving installations. 73.1030 Section 73.1030 Telecommunication FEDERAL... Broadcast Stations § 73.1030 Notifications concerning interference to radio astronomy, research and receiving installations. (a)(1) Radio astronomy and radio research installations. In order to minimize...

47 CFR 73.1030 - Notifications concerning interference to radio astronomy, research and receiving installations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... astronomy, research and receiving installations. 73.1030 Section 73.1030 Telecommunication FEDERAL... Broadcast Stations § 73.1030 Notifications concerning interference to radio astronomy, research and receiving installations. (a)(1) Radio astronomy and radio research installations. In order to minimize...

47 CFR 73.1030 - Notifications concerning interference to radio astronomy, research and receiving installations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... astronomy, research and receiving installations. 73.1030 Section 73.1030 Telecommunication FEDERAL... Broadcast Stations § 73.1030 Notifications concerning interference to radio astronomy, research and receiving installations. (a)(1) Radio astronomy and radio research installations. In order to minimize...

47 CFR 5.91 - Notification to the National Radio Astronomy Observatory.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 1 2014-10-01 2014-10-01 false Notification to the National Radio Astronomy... SERVICE Applications and Licenses § 5.91 Notification to the National Radio Astronomy Observatory. In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located...

47 CFR 5.91 - Notification to the National Radio Astronomy Observatory.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 1 2013-10-01 2013-10-01 false Notification to the National Radio Astronomy... SERVICE Applications and Licenses § 5.91 Notification to the National Radio Astronomy Observatory. In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located...

"Radio Astronomy, Whatever That May Be." The Marginalization of Early Radio Astronomy

NASA Astrophysics Data System (ADS)

Jarrell, Richard

2005-01-01

Today we see radio astronomy as a fully-integrated part of astronomy; it is now just one of several available wavelength regimes and many astrophysicists who use radio data are not radio astronomers themselves. At the beginning, it was very different. Between 1946 and 1960, radio astronomy emerged as an important speciality but it was an area little understood by mainstream astronomers. Radio astronomers rarely published in astronomical journals, gave papers at astronomical conferences or were accorded much notice. The pioneers in the field were not astronomers themselves and had little in common with astronomers. In this paper I note the various ways in which radio astronomy was alienated from the mainstream in its first decade and some of the reasons this alienation occurred. I will also speculate on when and how the integration began to occur.

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 1 2012-10-01 2012-10-01 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...

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

Code of Federal Regulations, 2010 CFR

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...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 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...

Learning radio astronomy by doing radio astronomy

NASA Astrophysics Data System (ADS)

Vaquerizo Gallego, J. A.

2011-11-01

PARTNeR (Proyecto Académico con el Radio Telescopio de NASA en Robledo, Academic Project with the NASA Radio Telescope at Robledo) is an educational program that allows high school and undergraduate students to control a 34 meter radio telescope and conduct radio astronomical observations via the internet. High-school teachers who join the project take a course to learn about the science of radio astronomy and how to use the antenna as an educational resource. Also, teachers are provided with learning activities they can do with their students and focused on the classroom implementation of the project within an interdisciplinary framework. PARTNeR provides students with firsthand experience in radio astronomy science. Thus, remote radio astronomical observations allow students to learn with a first rate scientific equipment the basics of radio astronomy research, aiming to arouse scientific careers and positive attitudes toward science. In this contribution we show the current observational programs and some recent results.

Early years of Radio Astronomy in the U.S.

NASA Astrophysics Data System (ADS)

Burke, B. F.

Radio Astronomy in the U.S. went through two distinct phases, the pioneering phase before the Second World War, when Karl Jansky and Grote Reber were the only two radio astronomers in the world, and the post-WWII era, when the subject blossomed throughout the world, especially in England and Australia, while U.S. radio astronomy languished at a relatively low level, until its resurgence a decade later. Here in Budapest we are celebrating the 70th anniversary of Jansky's discovery, and I shall start with a review of his work, and the subsequent work of Grote Reber, who died, regrettably, in December 2002. Two historical references will be cited frequently: Serendipitous Discoveries in Radio Astronomy (Kellermann & Sheets, eds. 1983, referred to as Paper 1) and the two historical collections edited by W.T. Sullivan, Classics in Radio Astronomy (1982, referred to as Paper 2) and The Early Years of Radio Astronomy (1984, Paper 3).

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. [69 FR 69331, Nov. 29, 2004] ...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. [69 FR 69331, Nov. 29, 2004] ...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. [69 FR 69331, Nov. 29, 2004] ...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. [69 FR 69331, Nov. 29, 2004] ...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... interference to radio astronomy, research and receiving installations. 73.6027 Section 73.6027... radio astronomy, research and receiving installations. An applicant for digital operation of an existing... astronomy, research and receiving installations. [69 FR 69331, Nov. 29, 2004] ...

A Voyage through the Radio Universe

ERIC Educational Resources Information Center

Spuck, Timothy

2004-01-01

Each year, professionals and amateurs alike make significant contributions to the field of astronomy. High school students can also conduct astronomy research. Since 1992, the Radio Astronomy Research Team from Oil City Area Senior High School (OCHS) in Oil City, Pennsylvania, has traveled each year to the National Radio Astronomy Observatory…

47 CFR 25.203 - Choice of sites and frequencies.

Code of Federal Regulations, 2014 CFR

2014-10-01

... National Radio Astronomy Observatory: In order to minimize possible harmful interference at the National Radio Astronomy Observatory site at Green Bank, Pocahontas County, W. Va., and at the Naval Radio..., simultaneously notify the Director, National Radio Astronomy Observatory, P.O. Box No. 2, Green Bank, W. Va...

Highlighting the History of French Radio Astronomy. 7: The Genesis of the Institute of Astronomy at Millimeter Wavelengths (IRAM)

NASA Astrophysics Data System (ADS)

Encrenaz, Pierre; Gómez González, Jesús; Lequeux, James; Orchiston, Wayne

2011-07-01

Radio astronomy in France and in Germany started around 1950. France was then building interferometers and Germany large single dishes, so it was not unexpected that their first projects involving millimetre radio astronomy were respectively with an interferometer and a single dish. In this paper, we explain in detail how these two projects finally merged in 1979 with the formation of the Institute of Radio Astronomy at Millimetre Wavelengths (IRAM), after a long process with many ups and downs. We also describe how Spain started radio astronomy by joining IRAM. Presently, IRAM is the most powerful facility worldwide for millimetre radio astronomy. We wish to dedicate our paper to the memory of Émile-Jacques Blum (1923-2009), who played a major role in the construction of IRAM but died before he could participate in the writing of this paper. An interview made one month before his death was very useful in the preparation of this paper.

A Radio Astronomy Curriculum for STARLAB

NASA Astrophysics Data System (ADS)

Boltuch, D.; Hund, L.; Buck, S.; Fultz, C.; Smith, T.; Harris, R.; Castelaz, M. W.; Moffett, D.; LaFratta, M.; Walsh, L.

2005-12-01

We present elements of a curriculum that will accompany the STARLAB module "Sensing the Radio Sky" a portable planetarium program and projection of the radio sky. The curriculum will serve to familiarize high school students to a set of topics in radio astronomy. The curriculum includes lessons and activities addressing several topics related to radio astronomy and the Milky Way that consists of two main resources: a manual and a multimedia website. It is designed to accommodate a wide variety of possible uses and time constraints. The manufacturer of STARLAB, Learning Technologies, Inc. produces a short manual to accompany each presentation for the STARLAB. The "Sensing the Radio Sky" manual we have created includes the mandatory, minimum background information that students need to understand radio astronomy. It briefly discusses waves and electromagnetic radiation, similarities and differences between optical and radio astronomy, probable misconceptions about radio astronomy, how radio images are produced, synchrotron radiation in the Milky Way, and galactic coordinates. It also includes a script that presenters can choose to follow inside the STARLAB, a lesson plan for teachers, and activities for students to complete before and after the STARLAB experience that mirror the scientific method. The multimedia website includes more detailed information about electromagnetic radiation and a more detailed comparison of optical and radio astronomy. It also discusses the life cycles of stars, radiation from a variety of specific sources, and pulsars, as each relates to radio astronomy. The five highly detailed lessons are pulled together in sixth "overview lesson", intended for use by teachers who want to present more than the basic material in the manual, but do not have the classroom time to teach all five of the in-depth lessons. . We acknowledge support from the NSF Internship in Public Science Education Program grant number 0324729.

NRAO Image Gallery

Science.gov Websites

Go Home NRAO: National Radio Astronomy Observatory Search NRAO... Go Home About NRAO Research Facilities Contact Us Careers Director's Office Maps & Directions Learn & Explore Radio Astronomy Brochures & Posters Presentations Essential Radio Astronomy Ask an Astronomer Astronomers Home >

47 CFR 25.203 - Choice of sites and frequencies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... National Radio Astronomy Observatory: In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the Naval... such application with the Commission, simultaneously notify the Director, National Radio Astronomy...

47 CFR 1.924 - Quiet zones.

Code of Federal Regulations, 2012 CFR

2012-10-01

... to minimize possible impact on the operations of radio astronomy or other facilities that are highly..., radio astronomy, research, and receiving installation entity. The areas involved and procedures required... interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West...

47 CFR 1.924 - Quiet zones.

Code of Federal Regulations, 2010 CFR

2010-10-01

... impact on the operations of radio astronomy or other facilities that are highly sensitive to interference. Consent throughout this paragraph means written consent from the quiet zone, radio astronomy, research... Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West Virginia, and at the...

47 CFR 1.924 - Quiet zones.

Code of Federal Regulations, 2011 CFR

2011-10-01

... impact on the operations of radio astronomy or other facilities that are highly sensitive to interference. Consent throughout this paragraph means written consent from the quiet zone, radio astronomy, research... Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West Virginia, and at the...

47 CFR 25.203 - Choice of sites and frequencies.

Code of Federal Regulations, 2011 CFR

2011-10-01

... National Radio Astronomy Observatory: In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the Naval... such application with the Commission, simultaneously notify the Director, National Radio Astronomy...

47 CFR 1.924 - Quiet zones.

Code of Federal Regulations, 2014 CFR

2014-10-01

... to minimize possible impact on the operations of radio astronomy or other facilities that are highly..., radio astronomy, research, and receiving installation entity. The areas involved and procedures required... interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West...

47 CFR 25.203 - Choice of sites and frequencies.

Code of Federal Regulations, 2013 CFR

2013-10-01

... National Radio Astronomy Observatory: In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the Naval... such application with the Commission, simultaneously notify the Director, National Radio Astronomy...

47 CFR 1.924 - Quiet zones.

Code of Federal Regulations, 2013 CFR

2013-10-01

... to minimize possible impact on the operations of radio astronomy or other facilities that are highly..., radio astronomy, research, and receiving installation entity. The areas involved and procedures required... interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, West...

47 CFR 25.203 - Choice of sites and frequencies.

Code of Federal Regulations, 2012 CFR

2012-10-01

... National Radio Astronomy Observatory: In order to minimize possible harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the Naval... such application with the Commission, simultaneously notify the Director, National Radio Astronomy...

The Spectrum Landscape: Prospects for Terrestrial Radio Astronomy

NASA Astrophysics Data System (ADS)

Liszt, Harvey Steven

2018-01-01

Radio astronomers work within broad constraints imposed by commercial and other non-astronomical uses of the radio spectrum, somewhat modified to accommodate astronomy’s particular needs through the provision of radio quiet zones, radio frequency allocations, coordination agreements and other devices of spectrum management. As radio astronomers increase the instantaneous bandwidth, frequency coverage and sensitivity of their instruments, these external constraints, and not the limitations of their own instruments, will increasingly be the greatest obstacles to radio astronomy’s ability to observe the cosmos from the surface of the Earth. Therefore, prospects for future radio astronomy operations are contingent on situational awareness and planning for the impact of non-astronomical uses of the radio frequency spectrum. New radio astronomy instruments will have to incorporate adaptive reactions to external developments, and radio astronomers should be encouraged to think in untraditional ways. Increased attention to spectrum management is one of these. In this talk I’ll recap some recent developments such as the proliferation of 76 – 81 GHz car radar and orbiting earth-mapping radars, either of which can burn out a radio astronomy receiver. I’ll summarize present trends for non-astronomical radio spectrum use that will be coming to fruition in the next decade or so, categorized into terrestrial fixed and mobile, airborne and space-borne uses, sub-divided by waveband from the cm to the sub-mm. I’ll discuss how they will impact terrestrial radio astronomy and the various ways in which radio astronomy should be prepared to react. Protective developments must occur both within radio astronomy’s own domain – designing, siting and constructing its instruments and mitigating unavoidable RFI – and facing outward toward the community of other spectrum users. Engagement with spectrum management is no panacea but it is an important means, and perhaps the only means, by which radio astronomy can take an active role in shaping its terrestrial environment.

47 CFR 78.19 - Interference.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the... Astronomy Observatory, Post Office Box No. 2, Green Bank, WV 24944, in writing, of the technical particulars...

47 CFR 78.19 - Interference.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the... Astronomy Observatory, Post Office Box No. 2, Green Bank, WV 24944, in writing, of the technical particulars...

47 CFR 78.19 - Interference.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the... Astronomy Observatory, Post Office Box No. 2, Green Bank, WV 24944, in writing, of the technical particulars...

47 CFR 78.19 - Interference.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the... Astronomy Observatory, Post Office Box No. 2, Green Bank, WV 24944, in writing, of the technical particulars...

47 CFR 78.19 - Interference.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Radio Astronomy and Radio Research Installations. In order to minimize harmful interference at the National Radio Astronomy Observatory site located at Green Bank, Pocahontas County, W. Va., and at the... Astronomy Observatory, Post Office Box No. 2, Green Bank, WV 24944, in writing, of the technical particulars...

Radio astronomy

NASA Technical Reports Server (NTRS)

Taylor, R. M.; Manchester, R. N.

1980-01-01

The activities of the Deep Space Network in support of radio and radar astronomy operations during July and August 1980 are reported. A brief update on the OSS-sponsored planetary radio astronomy experiment is provided. Also included are two updates, one each from Spain and Australia on current host country activities.

C-BASS: The C-Band All Sky Survey

NASA Astrophysics Data System (ADS)

Pearson, Timothy J.; C-BASS Collaboration

2016-06-01

The C-Band All Sky Survey (C-BASS) is a project to image the whole sky at a wavelength of 6 cm (frequency 5 GHz), measuring both the brightness and the polarization of the sky. Correlation polarimeters are mounted on two separate telescopes, one at the Owens Valley Observatory (OVRO) in California and another in South Africa, allowing C-BASS to map the whole sky. The OVRO instrument has completed observations for the northern part of the survey. We are working on final calibration of intensity and polarization. The southern instrument has recently started observations for the southern part of the survey from its site at Klerefontein near Carnarvon in South Africa. The principal aim of C-BASS is to allow the subtraction of polarized Galactic synchrotron emission from the data produced by CMB polarization experiments, such as WMAP, Planck, and dedicated B-mode polarization experiments. In addition it will contribute to studies of: (1) the local (< 1 kpc) Galactic magnetic field and cosmic-ray propagation; (2) the distribution of the anomalous dust emission, its origin and the physical processes that affect it; (3) modeling of Galactic total intensity emission, which may allow CMB experiments access to the currently inaccessible region close to the Galactic plane. Observations at many wavelengths from radio to infrared are needed to fully understand the foregrounds. At 5 GHz, C-BASS maps synchrotron polarization with minimal corruption by Faraday rotation, and complements the full-sky maps from WMAP and Planck. I will present the project status, show results of component separation in selected sky regions, and describe the northern survey data products.C-BASS (http://www.astro.caltech.edu/cbass/) is a collaborative project between the Universities of Oxford and Manchester in the UK, the California Institute of Technology (supported by the National Science Foundation and NASA) in the USA, the Hartebeesthoek Radio Astronomy Observatory (supported by the Square Kilometre Array project) in South Africa, and the King Abdulaziz City for Science and Technology (KACST) in Saudi Arabia.

MASER: A Tool Box for Solar System Low Frequency Radio Astronomy

NASA Astrophysics Data System (ADS)

Cecconi, B.; Le Sidaner, P.; Savalle, R.; Bonnin, X.; Zarka, P.; Louis, C.; Coffre, A.; Lamy, L.; Denis, L.; Griessmeier, J.-M.; Faden, J.; Piker, C.; André, N.; Génot, V.; Erard, S.; King, T. A.; Mafi, J. N.; Sharlow, M.; Sky, J.; Demleitner, M.

2018-04-01

MASER (Measuring, Analysing, and Simulating Radio Emissions) is a toolbox for solar system radio astronomy. It provides tools for reading, displaying, finding, and modeling low frequency radio datasets.

Highlighting the History of Japanese Radio Astronomy: 1: An Introduction

NASA Astrophysics Data System (ADS)

Ishiguro, Masato; Orchiston, Wayne; Akabane, Kenji; Kaifu, Norio; Hayashi, Masa; Nakamura, Tsuko; Stewart, Ronald; Yokoo, Hiromitsu

2012-11-01

Japan was one of a number of nations that made important contributions in the fledgling field of radio astronomy in the years immediately following WWII. In this paper we discuss the invention of the Yagi-Uda antenna and the detection of solar radio emission in 1938, before reviewing radio astronomical developments that occurred between 1948 and 1961 in Osaka, Nagoya, Tokyo and Hiraiso. In order to place these early Japanese experiments in a national and international context we briefly review the world-wide development of radio astronomy in the immediate post-War years before discussing the growth of optical astronomy in Japan at this time.

75 FR 33620 - Notice of Public Information Collections Being Reviewed by the Federal Communications Commission...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-14

..., Notifications Concerning Interference to Radio Astronomy, Research and Receiving Installations. Form Number: N/A... Astronomy Observatory site located at Green, Pocahontas County, West Virginia, and at the Naval Radio... the west, shall notify the Interference Office, National Radio Astronomy Observatory, P.O. Box 2...

47 CFR 2.106 - Table of Frequency Allocations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... radio astronomy service from harmful interference. Emissions from spaceborne or airborne stations can be particularly serious sources of interference to the radio astronomy service (see Nos. 4.5 and 4.6 and Article...-401 MHz, administrations shall take all practicable steps to protect the radio astronomy service in...

47 CFR 2.106 - Table of Frequency Allocations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... radio astronomy service from harmful interference. Emissions from spaceborne or airborne stations can be particularly serious sources of interference to the radio astronomy service (see Nos. 4.5 and 4.6 and Article...-401 MHz, administrations shall take all practicable steps to protect the radio astronomy service in...

78 FR 17664 - Information Collections Being Reviewed by the Federal Communications Commission Under Delegated...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-22

..., Notifications Concerning Interference to Radio Astronomy, Research and Receiving Installations. Form Number: N/A... Astronomy Observatory site located at Green, Pocahontas County, West Virginia, and at the Naval Radio... Interference Office, National Radio Astronomy Observatory, P.O. Box 2, Green Bank, West Virginia 24944...

47 CFR 2.106 - Table of Frequency Allocations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... radio astronomy service from harmful interference. Emissions from spaceborne or airborne stations can be particularly serious sources of interference to the radio astronomy service (see Nos. 4.5 and 4.6 and Article...-401 MHz, administrations shall take all practicable steps to protect the radio astronomy service in...

Multi-Beam Radio Frequency (RF) Aperture Arrays Using Multiplierless Approximate Fast Fourier Transform (FFT)

DTIC Science & Technology

2017-08-01

filtering, correlation and radio- astronomy . In this report approximate transforms that closely follow the DFT have been studied and found. The approximate...communications, data networks, sensor networks, cognitive radio, radar and beamforming, imaging, filtering, correlation and radio- astronomy . FFTs efficiently...public release; distribution is unlimited. 4.3 Digital Hardware and Design Architectures Collaboration for Astronomy Signal Processing and Electronics

Preface

NASA Astrophysics Data System (ADS)

Gurvits, L. I.; Frey, S.; Rawlings, S.

Three quarters of the century has passed since the synergy between scientific discovery and technological advances enabled Karl Jansky to open a new window on the Universe, marking the birth of radio astronomy. Since then, radio astronomy has become one of the major tools for studying the Universe. Radio galaxies with their enormously energetic clouds of relativistic electrons and cosmic jets that extend up to millions of light years into space, a broad variety of atoms and molecules, from neutral hydrogen to complex organic conglomerates, cosmic microwave masers, the cosmic microwave background radiation, quasars, pulsars, gravitational lenses and extra-solar planetary systems were all discovered in radio domain. Radio telescopes have also been used to measure the relativistic bending of electromagnetic waves which pass near the limb of the Sun, to establish the existence of gravitational radiation and measure continental drift. The progress of radio astronomy is driven by the needs of fundamental science and is based on the state-of-the-art developments in technology. Since its first steps, radio astronomy has made huge progress, resulting in the improvement of sensitivity by many orders of magnitude and approaching micro-arcsecond angular resolution. This progress will continue in the XXI century with the advent of new radio astronomy facilities on the ground (LOFAR, ALMA, SKA) and in space (Planck, next generation space VLBI systems). In this book, the current state of radio astronomy is framed by several retrospective reviews and introductions to the next generation facilities. Views at radio astronomy from other domains, optical astronomy and high energy astrophysics, are also presented. Advances of modern radio astronomy were in the focus of the symposium “Radio Astronomy at 70: from Karl Jansky to microjansky”, which was held under the auspices of the annual Joint European National Astronomy Meeting (JENAM) in Budapest, Hungary, 27-30 August 2003. More than 30 contributed papers from that symposium have been published recently in Baltic Astronomy (2005, Vol. 14, No. 3). This book contains a set of invited review presentations given at the symposium. They cover a range of scientific topics in extragalactic and galactic radio astronomy studies as well as recent developments in radio astronomy techniques aimed at the next generation radio astronomy facilities. On behalf of the organisers and participants of the symposium, we express our gratitude to the sponsors of the event and this publication: the European Astronomical Society, Hungarian Academy of Sciences, Eötvös Loránd University, Konkoly Observatory, Eötvös Loránd Physical Society, Netherlands Foundation for Research in Astronomy (ASTRON), Joint Institute for VLBI in Europe, Hungarian Scientific Research Fund, EC FP5 Infrastructure Cooperation Network RadioNET and EC FP6 Integrated Infrastructure Initiative RadioNet. We are grateful to the members of the Scientific Organising Committee of the Symposium. Ken Kellermann made very useful remarks on several papers. Ellen Bouton and Pat Smiley helped to include in this book several photos from the AUI-NRAO archive. Mark Bentum designed the cover picture of the book, visual components for which were kindly supplied by W.A. Baan, M.F. Bietenholz, R. Boomsma, R. Braun, N. Bartel, M.A. Garrett, J.M. van der Hulst, H.R. Klockner, NASA/WMAP Science Team, T.A. Oosterloo, M.P. Rupen, R. Sancisi, B. Stappers, R.G. Strom, D.A. Thilker, and R.A.M. Walterbos. Most of all, we are grateful to all the authors of this book for their efforts in the increasingly old-fashioned art of writing papers for a real “paper” publication as opposed to putting powerpoint files on a web site. We do hope that their nice work will be appreciated by the readers. Leonid Gurvits, Dwingeloo, The Netherlands Sándor Frey, Budapest, Hungary Steve Rawlings, Oxford, UK

Teaching radio astronomy with Affordable Small Radio Telescope (ASRT)

NASA Astrophysics Data System (ADS)

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.

75 FR 9850 - Tank Level Probing Radars in the Frequency Band 77-81 GHz

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-04

... National Radio Astronomy Observatory (NRAO) states that it would not object to the Ohmart/VEGA waiver if it Frequency Band of Operation. Authorized operations in the 77-81 GHz band currently include radio astronomy... operations in this band would have on authorized services. Regarding radio astronomy, the Commission observes...

77 FR 29236 - Unlicensed Operation in the TV Broadcast Band

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-17

... under the Administrative Procedure Act (APA). Protection of Radio Astronomy 39. Section 15.712(h) of the rules prohibits the operation of TV bands devices within 2.4 kilometers of certain radio astronomy and... coordinates for several radio astronomy receive sites and filed a request with the Commission to correct these...

47 CFR 2.106 - Table of Frequency Allocations.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., administrations are urged to take all practicable steps to protect the radio astronomy service from harmful... interference to the radio astronomy service (see Nos. 4.5 and 4.6 and Article 29). (WRC-07) 5.150The following...-401 MHz, administrations shall take all practicable steps to protect the radio astronomy service in...

The Deep Space Network: An instrument for radio astronomy research

NASA Technical Reports Server (NTRS)

Renzetti, N. A.; Levy, G. S.; Kuiper, T. B. H.; Walken, P. R.; Chandlee, R. C.

1988-01-01

The NASA Deep Space Network operates and maintains the Earth-based two-way communications link for unmanned spacecraft exploring the solar system. It is NASA's policy to also make the Network's facilities available for radio astronomy observations. The Network's microwave communication systems and facilities are being continually upgraded. This revised document, first published in 1982, describes the Network's current radio astronomy capabilities and future capabilities that will be made available by the ongoing Network upgrade. The Bibliography, which includes published papers and articles resulting from radio astronomy observations conducted with Network facilities, has been updated to include papers to May 1987.

77 FR 76250 - WRC-07 Implementation

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-27

... to list the radio astronomy stations that observe in the 4800-4940 MHz and 14.47-14.5 GHz bands... transmission on a primary basis. Update the list of radio astronomy stations in US388 that observe in the...- 111.8, 114.25-116, 148.5-151.5, 164-167, 200-209, and 250-252 GHz, the radio astronomy service shall...

78 FR 41343 - Expanding Access to Broadband and Encouraging Innovation Through Establishment of an Air-Ground...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... Space Research Service users in the 14.0-14.5 GHz band, and to coordinate with the Radio Astronomy Service to avoid interference to radio astronomy observations. The Commission also proposes to license air... Administration's Tracking and Data Relay Satellite Service and with radio astronomy observatories. Further, the...

77 FR 76234 - WRC-07 Implementation Order

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-27

... that non- Federal use of the 406.1-410 MHz band is limited to the radio astronomy service and as... allocation status of the radio astronomy service in the 2655-2690 MHz band that is shown in the U.S. Table... Commission correct the elevations of nearly all of the radio astronomy observatories specified in US355. It...

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

NASA Astrophysics Data System (ADS)

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.

HF Radio Astronomy from a Small Satellite

DTIC Science & Technology

2016-06-15

SSC16-XI-03 HF Radio Astronomy from a Small Satellite Frank C. Robey1, Mary Knapp2, Alan J. Fenn1, Mark Silver1, Kerry Johnson1 Frank J. Lind3...frequency end of the electromagnetic spectrum (below 15 MHz) is one of the least explored windows in observational astronomy . Observations at these...pdf. [Accessed: 17-Oct-2015]. 3. G. Hallinan, “The Owens Valley LWA,” in Exascale Radio Astronomy , 2014, vol. 2. 4. C. J. Lonsdale, R. J. Cappallo

Vector Antenna and Maximum Likelihood Imaging for Radio Astronomy

DTIC Science & Technology

2016-03-05

Maximum Likelihood Imaging for Radio Astronomy Mary Knapp1, Frank Robey2, Ryan Volz3, Frank Lind3, Alan Fenn2, Alex Morris2, Mark Silver2, Sarah Klein2...haystack.mit.edu Abstract1— Radio astronomy using frequencies less than ~100 MHz provides a window into non-thermal processes in objects ranging from planets...observational astronomy . Ground-based observatories including LOFAR [1], LWA [2], [3], MWA [4], and the proposed SKA-Low [5], [6] are improving access to

Radio astronomy

NASA Technical Reports Server (NTRS)

Kellermann, Kenneth I.; Heeschen, David; Backer, Donald C.; Cohen, Marshall H.; Davis, Michael; Depater, Imke; Deyoung, David; Dulk, George A.; Fisher, J. R.; Goss, W. Miller

1991-01-01

The following subject areas are covered: (1) scientific opportunities (millimeter and sub-millimeter wavelength astronomy; meter to hectometer astronomy; the Sun, stars, pulsars, interstellar masers, and extrasolar planets; the planets, asteroids, and comets; radio galaxies, quasars, and cosmology; and challenges for radio astronomy in the 1990's); (2) recommendations for new facilities (the millimeter arrays, medium scale instruments, and small-scale projects); (3) continuing activities and maintenance, upgrading of telescopes and instrumentation; (4) long range programs and technology development; and (5) social, political, and organizational considerations.

Postwar Radio Astronomy and the US Military

NASA Astrophysics Data System (ADS)

Sullivan, W. T., III

1993-12-01

The course of radio astronomy in the United States during the period 1945-60 was greatly influenced by the funding and requirements of the US military. The scientific researchers and their military patrons continued the intimate relationship that had been so successful for the development of radar and communications during World War II. The result was a very high level of funding that led to large-scale projects, a concentration on the microwave portion of the radio spectrum, and primary interest in the sun, moon, and planets. These effects, however, ironically significantly contributed to the lag in US radio astronomy relative to that in Australia and England. Unlike the American approach, the strategy of the groups in Sydney, Cambridge and Jodrell Bank, reasoned that the most fruitful way to approach the radio sky at the time was with relatively simple equipment (largely revamped war surplus) operating at the lower frequencies. Other factors, such as the strength of optical astronomy in the US, also played important roles. By the mid-1960s, the microwave expertise that had been developed in the US finally paid off such that US radio astronomy was at last able to assume a position of more parity. Some similarities in the development of postwar Soviet radio astronomy will also be discussed.

Charles Townes, the Maser, and the Laser

Science.gov Websites

electronics, radio astronomy and infrared astronomy. He holds the original patent for the maser [microwave research and teaching and pursued new interests in astrophysics. His work there in radio astronomy resulted

47 CFR 27.19 - Requirements for operation of base and fixed stations in the 600 MHz downlink band in close...

Code of Federal Regulations, 2014 CFR

2014-10-01

... stations in the 600 MHz downlink band in close proximity to Radio Astronomy Observatories. 27.19 Section 27... base and fixed stations in the 600 MHz downlink band in close proximity to Radio Astronomy Observatories. (a) Licensees must make reasonable efforts to protect the radio astronomy observatory at Green...

The Radio JOVE Project - Shoestring Radio Astronomy

NASA Technical Reports Server (NTRS)

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

A Radio Astronomy Curriculum for the Middle School Classroom

NASA Astrophysics Data System (ADS)

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.

I. S. Shklovsky and Low-Frequency Radio Astronomy

NASA Astrophysics Data System (ADS)

Konovalenko, A. A.

2017-03-01

Purpose: Proving of the high astrophysical significance of the low-frequency radio astronomy (decameter and adjacent hectometer and meter wavelengths), demonstration of the priority results of the Ukrainian low-frequency radio astronomy as well as significant contribution of I. S. Shklovsky to its development. Design/methodology/approach: The requirements to characteristics of high efficiency radio telescopes UTR-2, URAN, GURT and to sensitive and interference immune observational methods at low frequencies are formulated by using the theoretical analysis and astrophysical predictions including those I. S. Shklovsky’s. Findings: New generation radio telescopes UTR-2, URAN, GURT are created and modernized. New observational methods at low frequencies are introduced. Large-scale investigations of the Solar system, Galaxy and Methagalaxy are carried out. They have allowed to detect new objects and phenomena for the continuum, monochromatic, pulse and sporadic cosmic radio emission. The role of I. S. Shklovsky in the development of many low-frequency radio astronomy directions is noted, too. Conclusions: The unique possibilities of the low-frequency radio astronomy which gives new information about the Universe, inaccessible with the other astrophysical methods, are shown. The progress of the low-frequency radio astronomy opens the impressive possibilities for the future. It includes modernization of the largest radio telescopes UTR-2, URAN, NDA and creation of new instruments GURT, NenuFAR, LOFAR, LWA, MWA, SKA as well as making multi-antenna and ground-space experiments. The contribution of outstanding astrophysicist of the XX century I. S. Shklovsky to this part of actual astronomical science is evident, claiming for attention and will never be forgotten.

Signals from the Cosmos.

ERIC Educational Resources Information Center

Lichtman, Jeffrey M.

1991-01-01

Introduces the basics of radio astronomy and describes how to assemble several simple systems for receiving radio signals from the cosmos. Includes schematics, parts lists, working drawings, and contact information for radio astronomy suppliers. (11 references) (Author/JJK)

47 CFR 25.226 - Blanket Licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Code of Federal Regulations, 2013 CFR

2013-10-01

... vicinity of radio astronomy service (RAS) observatories observing in the 14.47-14.5 GHz band are subject to... RAS site, its location, and the applicable coordination zone. Table 1—Applicable Radio Astronomy... Radio Astronomy Observatory, Stinchfield Woods, MI 42°23′56″ 83°56′11″ 160. Very Long Baseline Array...

Historic Radio Astronomy Working Group

NASA Astrophysics Data System (ADS)

2007-06-01

This special issue of Astronomische Nachrichten contains the proceedings of a session of the Historic Radio Astronomy Working Group of the International Astronomical Union that took place during the 26th General Assembly of the IAU in Prague on 17th August 2006. In addition to the talks presented in Prague some contributions were solicited to give a more complete overview of `The Early History of European Radio Astronomy'.

Grote Reber, Radio Astronomy Pioneer, Dies

NASA Astrophysics Data System (ADS)

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 something of a minor tourist attraction, he later recalled. Using electronics he designed and built that pushed the technical capabilities of the era, Reber succeeded in detecting "cosmic static" in 1939. In 1941, Reber produced the first radio map of the sky, based on a series of systematic observations. His radio-astronomy work continued over the next several years. Though not a professional scientist, his research results were published in a number of prestigious technical journals, including Nature, the Astrophysical Journal, the Proceedings of the Institute of Radio Engineers and the Journal of Geophysical Research. Reber also received a number of honors normally reserved for scientists professionally trained in astronomy, including the American Astronomical Society's Henry Norris Russell Lectureship and the Astronomical Society of the Pacific's Bruce Medal in 1962, the National Radio Astronomy Observatory's Jansky Lectureship in 1975, and the Royal Astronomical Society's Jackson-Gwilt Medal in 1983. Reber's original dish antenna now is on display at the National Radio Astronomy Observatory's site in Green Bank, West Virginia, where Reber worked in the late 1950s. All of his scientific papers and records as well as his personal and scientific correspondence are held by the NRAO, and will be exhibited in the observatory's planned new library in Charlottesville, Virginia. Reber's amateur-radio callsign, W9GFZ, is held by the NRAO Amateur Radio Club. This callsign was used on the air for the first time since the 1930s on August 25, 2000, to mark the dedication of the Robert C. Byrd Green Bank Telescope. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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

NASA Astrophysics Data System (ADS)

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.

Cosmic Noise: The Pioneers of Early Radio Astronomy and Their Discoveries

NASA Astrophysics Data System (ADS)

Sullivan, Woodruff T., III

2012-01-01

Extraterrestrial radio waves (the galactic background), often referred to as "cosmic noise", were first detected accidentally by Karl Jansky at a frequency of 20 MHz in 1932, with significant followup by Grote Reber. Yet after World War II it was England and Australia that dominated the field. An entirely different sky from that of visual astronomy was revealed by the discoveries of solar noise, "radio stars” (discrete sources such as Cas A, Tau A, Cyg A, Cen A and Vir A), galactic noise, lunar and meteor radar experiments, the detection of the 21 cm hydrogen line, and eventually optical identifications such as the Crab Nebula and M87. Key players included wartime radar experts such as Stanley Hey (the British Army's Operational Research Group), Martin Ryle (Cambridge University), Bernard Lovell (Jodrell Bank) and Joe Pawsey (Radiophysics Lab, Sydney). Younger leaders also emerged such as Graham Smith, Tony Hewish, John Davies, "Chris" Christiansen, Bernie Mills, Paul Wild, and John Bolton. Some optical astronomers (Jan Oort, Henk van de Hulst, Jesse Greenstein, Rudolph Minkowski, and Walter Baade) were also extremely supportive. By the end of the postwar decade, radio astronomy was firmly established within the gamut of astronomy, although very few of its practitioners had been trained as astronomers. I will also trace the technical and social aspects of this wholly new type of astronomy, with special attention on military and national influences. I argue that radio astronomy represents one of the key developments in twentieth century astronomy not only because of its own discoveries, but also its pathfinding for the further opening the electromagnetic spectrum. This study is based on exhaustive archival research and over one hundred interviews with pioneering radio astronomers. Full details are available in the book "Cosmic Noise: A History of Early Radio Astronomy" (Cambridge Univ. Pr.).

47 CFR 25.226 - Blanket licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Code of Federal Regulations, 2010 CFR

2010-10-01

... of VMESs in the 14.47-14.5 GHz (Earth-to-space) frequency band in the vicinity of radio astronomy... location, and the applicable coordination zone. Table 1—Applicable Radio Astronomy Service (RAS) Facilities... Astronomical Research Institute, Rosman, NC 35°11′59″ 82°52′19″ 160. U of Michigan Radio Astronomy Observatory...

Electromagnetics and Antenna Technology, Chapters 4 and 5

DTIC Science & Technology

2017-03-07

potential future application is for performing radio astronomy missions [9–16]. The antenna technology described here could be applied to other platforms...vector sensor antenna for radio astronomy [11] is depicted in the photograph shown in Figure 5.1. This electromagnetic vector Figure 5.1 Photograph of...for performing radio astronomy missions. The antenna technology described here could be applied to other platforms such as airborne vehicles, towers

47 CFR 25.226 - Blanket licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Code of Federal Regulations, 2012 CFR

2012-10-01

... of VMESs in the 14.47-14.5 GHz (Earth-to-space) frequency band in the vicinity of radio astronomy... location, and the applicable coordination zone. Table 1—Applicable Radio Astronomy Service (RAS) Facilities... Astronomical Research Institute, Rosman, NC 35°11′59″ 82°52′19″ 160. U of Michigan Radio Astronomy Observatory...

47 CFR 25.226 - Blanket Licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Code of Federal Regulations, 2014 CFR

2014-10-01

... in the 14.47-14.5 GHz (Earth-to-space) frequency band in the vicinity of radio astronomy service (RAS... coordination zone. Table 1—Applicable Radio Astronomy Service (RAS) Facilities and Associated Coordination..., Rosman, NC 35°11′59″ 82°52′19″ 160. U of Michigan Radio Astronomy Observatory, Stinchfield Woods, MI 42...

47 CFR 25.226 - Blanket licensing provisions for domestic, U.S. Vehicle-Mounted Earth Stations (VMESs) receiving...

Code of Federal Regulations, 2011 CFR

2011-10-01

... of VMESs in the 14.47-14.5 GHz (Earth-to-space) frequency band in the vicinity of radio astronomy... location, and the applicable coordination zone. Table 1—Applicable Radio Astronomy Service (RAS) Facilities... Astronomical Research Institute, Rosman, NC 35°11′59″ 82°52′19″ 160. U of Michigan Radio Astronomy Observatory...

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

NASA Astrophysics Data System (ADS)

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.

Exploring Systems Engineering (and the Universe) Through the RadioJOVE telescope

NASA Astrophysics Data System (ADS)

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.

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz Mobile-Satellite Service.

Code of Federal Regulations, 2013 CFR

2013-10-01

... radio astronomy service in the 1610.6-1613.8 MHz band against interference from 1.6/2.4 GHz Mobile... System. (i) In the band 1610.6-1613.8 MHz, within a 160 km radius of the following radio astronomy sites... attenuated so that the power flux density it produces in the 1610.6-1613.8 MHz band at any radio astronomy...

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz Mobile-Satellite Service.

Code of Federal Regulations, 2014 CFR

2014-10-01

... radio astronomy service in the 1610.6-1613.8 MHz band against interference from 1.6/2.4 GHz Mobile... System. (i) In the band 1610.6-1613.8 MHz, within a 160 km radius of the following radio astronomy sites... attenuated so that the power flux density it produces in the 1610.6-1613.8 MHz band at any radio astronomy...

76 FR 5521 - Innovation in the Broadcast Television Bands

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

... raise the possibility of interference to radio astronomy operations on channel 37 or to services... interference to radio astronomy operations on channel 37 or to operations of other services above channel 51... astronomy that are at 608-614 MHz (at channel 37). The Commission requests comments on this proposed plan...

77 FR 48097 - Operation of Radar Systems in the 76-77 GHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... general public. 3. The 76-77 GHz band, which is allocated to the Radio Astronomy service (RAS) and the... astronomy observatories typically have control over access to a distance of one kilometer from the... radio astronomy community and several vehicular radar manufacturers. The measurements performed using...

A masing event in NGC 6334I: contemporaneous flaring of hydroxyl, methanol, and water masers

NASA Astrophysics Data System (ADS)

MacLeod, G. C.; Smits, D. P.; Goedhart, S.; Hunter, T. R.; Brogan, C. L.; Chibueze, J. O.; van den Heever, S. P.; Thesner, C. J.; Banda, P. J.; Paulsen, J. D.

2018-07-01

As a product of the maser monitoring program with the 26 m telescope of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), we present an unprecedented, contemporaneous flaring event of 10 maser transitions in hydroxyl, methanol, and water that began in 2015 January in the massive star-forming region NGC 6334I in the velocity range -10 to -2 km s-1. The 6.7 GHz methanol and 22.2 GHz water masers began flaring within 22 d of each other, while the 12.2 GHz methanol and 1665 MHz hydroxyl masers flared 80 and 113 d later, respectively. The 1665 MHz, 6.7 GHz, and 22.2 GHz masers have all remained in their flared state for nearly 3 yr. The brightest flaring components increased by factors of 66, 21, 26, and 20 in the 12.2 and 6.7 GHz methanol, 1665 MHz hydroxyl, and 22.2 GHz water maser transitions, respectively; some weaker components increased by up to a factor of 145. We also report new maser emission in the 1720, 6031, and 6035 MHz OH lines and the 23.1 GHz methanol line, along with the detection of only the fifth 4660 MHz OH maser. We note the correlation of this event with the extraordinary (sub)millimetre continuum outburst from the massive protostellar system NGC 6334I-MM1 and discuss the implications of the observed time lags between different maser velocity components on the nature of the outburst. Finally, we identify two earlier epoch maser flaring events likely associated with this object, which suggest a recurring accretive phenomenon that generates powerful radiative outbursts.

A Masing Event in NGC 6334I: Contemporaneous Flaring of Hydroxyl, Methanol and Water Masers

NASA Astrophysics Data System (ADS)

MacLeod, G. C.; Smits, D. P.; Goedhart, S.; Hunter, T. R.; Brogan, C. L.; Chibueze, J. O.; van den Heever, S. P.; Thesner, C. J.; Banda, P. J.; Paulsen, J. D.

2018-04-01

As a product of the maser monitoring program with the 26 m telescope of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), we present an unprecedented, contemporaneous flaring event of 10 maser transitions in hydroxyl, methanol, and water that began in 2015 January in the massive star-forming region NGC 6334I in the velocity range -10 to -2 km s-1. The 6.7 GHz methanol and 22.2 GHz water masers began flaring within 22 days of each other, while the 12.2 GHz methanol and 1665 MHz hydroxyl masers flared 80 and 113 days later respectively. The 1665 MHz, 6.7 GHz, and 22.2 GHz masers have all remained in their flared state for nearly 3 years. The brightest flaring components increased by factors of 66, 21, 26, and 20 in the 12.2 and 6.7 GHz methanol, 1665 MHz hydroxyl and 22.2 GHz water maser transitions respectively; some weaker components increased by up to a factor of 145. We also report new maser emission in the 1720, 6031, and 6035 MHz OH lines and the 23.1 GHz methanol line, along with the detection of only the fifth 4660 MHz OH maser. We note the correlation of this event with the extraordinary (sub)millimeter continuum outburst from the massive protostellar system NGC 6334I-MM1 and discuss the implications of the observed time lags between different maser velocity components on the nature of the outburst. Finally, we identify two earlier epoch maser flaring events likely associated with this object, which suggest a recurring accretive phenomenon that generates powerful radiative outbursts.

World War II Radar and Early Radio Astronomy

NASA Astrophysics Data System (ADS)

Smith, G.

2005-08-01

The pattern of radio astronomy which developed in Europe and Australia followed closely the development of metre wave radar in World War II. The leading pioneers, Ryle, Lovell, Hey and Pawsey, were all in radar research establishments in the UK and Australia. They returned to universities, recruited their colleagues into research groups and immediately started on some basic observations of solar radio waves, meteor echoes, and the galactic background. There was at first little contact with conventional astronomers. This paper traces the influence of the radar scientists and of several types of radar equipment developed during WW II, notably the German Wurzburg, which was adapted for radio research in several countries. The techniques of phased arrays and antenna switching were used in radar and aircraft installations. The influence of WW II radar can be traced at least up to 10 years after the War, when radio astronomy became accepted as a natural discipline within astronomy.

NAC/NINE Program Building Radio Jove's and Brining Radio Astronomy to the Community

NASA Astrophysics Data System (ADS)

Ramona Gallego, Angelina; Paul Gueye, Al Amin Kabir,

2018-01-01

During the course of the 8-week program, (NINE, National and International Non-Traditional Exchange Program), the summer was spent in Socorro, New Mexico, working on building a Radio Jove, and making observations with the Radio Jove as well as working on learning project management practices in order to take the CAPM PMI Exam. The NINE built the Radio Jove’s at the same time and in doing so learned to replicate it to teach it to others. The final portion of the program that was worked on was to create a NINE hub and do outreach with the community teaching them about radio astronomy and teaching students how to build their own Radio Jove’s and make observations. An important aspect of the summer program was to bring back the knowledge received about radio astronomy and teach it to high school students with the help of the institution each NINE participants came from.

Investigation on the Frequency Allocation for Radio Astronomy at the L Band

NASA Astrophysics Data System (ADS)

Abidin, Z. Z.; Umar, R.; Ibrahim, Z. A.; Rosli, Z.; Asanok, K.; Gasiprong, N.

2013-09-01

In this paper, the frequency allocation reserved for radio astronomy in the L band set by the International Telecommunication Union (ITU), which is between 1400 and 1427 MHz, is reviewed. We argue that the nearby frequencies are still very important for radio astronomers on the ground by investigating radio objects (H i sources) around 1300-1500 MHz. The L-band window is separated into a group of four windows, namely 1400-1427 MHz (window A), 1380-1400 MHz (window B), 1350-1380 MHz (window C), and 1300-1350 MHz (window D). These windows are selected according to their redshifts from a rest frequency for hydrogen spectral line at 1420.4057 MHz. Radio objects up to z ≈ 0.1 or frequency down to 1300 MHz are examined. We argue that since window B has important radio objects within the four windows, this window should also be given to radio astronomy. They are galaxies, spiral galaxies, and galaxy clusters. This underlines the significance of window B for radio astronomers on the ground. By investigating the severeness of radio frequency interference (RFI) within these windows, we have determined that window B still has significant, consistent RFI. The main RFI sources in the four windows have also been identified. We also found that the Department of Civil Aviation of Malaysia is assigned a frequency range of 1215-1427 MHz, which is transmitted within the four windows and inside the protected frequency for radio astronomy. We also investigated the RFI in the four windows on proposed sites of future radio astronomy observatories in Malaysia and Thailand and found the two best sites as Universiti Pendidikan Sultan Idris (UPSI) and Ubon Ratchathani, respectively. It has also been determined that RFI in window B increases with population density.

Session 21.3 - Radio and Optical Site Protection

NASA Astrophysics Data System (ADS)

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.

47 CFR 97.203 - Beacon station.

Code of Federal Regulations, 2013 CFR

2013-10-01

... written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2... the proposed operation is received by the FCC from the National Radio Astronomy Observatory at Green...

47 CFR 97.203 - Beacon station.

Code of Federal Regulations, 2011 CFR

2011-10-01

... written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2... the proposed operation is received by the FCC from the National Radio Astronomy Observatory at Green...

47 CFR 97.203 - Beacon station.

Code of Federal Regulations, 2014 CFR

2014-10-01

... written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2... the proposed operation is received by the FCC from the National Radio Astronomy Observatory at Green...

47 CFR 97.203 - Beacon station.

Code of Federal Regulations, 2012 CFR

2012-10-01

... written notification thereof to the Interference Office, National Radio Astronomy Observatory, P.O. Box 2... the proposed operation is received by the FCC from the National Radio Astronomy Observatory at Green...

The Radio JOVE Project: Inexpensive Radio Astronomy for the Classroom

NASA Astrophysics Data System (ADS)

Thieman, J. R.; Higgins, C. A.; Pine, W.

2000-12-01

Radio JOVE is an interactive, hands-on educational activity for learning the scientific method through the medium of radio astronomy observations of Jupiter and the sun. Students build a radio telescope from a relatively inexpensive non-profit kit (about \\$125) and use it to record data, analyze the data, and share the results with others. Alternatively, for no cost, the students can record and analyze data from remote radio telescopes connected to the Web. The project is a useful adjunct to activities in optical astronomy since students should recognize that we learn about the Universe through more than just the optical spectrum. In addition to supplementing knowledge of Jupiter and the sun, the project teaches about charged particles and magnetic fields. Building of the kit is also a mini-course in electronics. The Radio JOVE website (http://radiojove.gsfc.nasa.gov) contains science information, instruction manuals, observing guides, software, and education resources for students and teachers.

Division x: Radio Astronomy

NASA Astrophysics Data System (ADS)

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.

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio astronomy...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Code of Federal Regulations, 2011 CFR

2011-10-01

... frequency range 608-614 MHz and that will be located near the radio astronomy observatories listed below..., and obtain the written concurrence of, the director of the affected radio astronomy observatory before the equipment can be installed or operated (a) Within 80 kilometers of: (1) National Astronomy and...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Code of Federal Regulations, 2014 CFR

2014-10-01

... frequency range 608-614 MHz and that will be located near the radio astronomy observatories listed below..., and obtain the written concurrence of, the director of the affected radio astronomy observatory before the equipment can be installed or operated (a) Within 80 kilometers of: (1) National Astronomy and...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Code of Federal Regulations, 2013 CFR

2013-10-01

... frequency range 608-614 MHz and that will be located near the radio astronomy observatories listed below..., and obtain the written concurrence of, the director of the affected radio astronomy observatory before the equipment can be installed or operated (a) Within 80 kilometers of: (1) National Astronomy and...

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of any of the other radio astronomy observatories noted in footnote US385 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio astronomy...

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Code of Federal Regulations, 2012 CFR

2012-10-01

... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio astronomy...

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of any of the other radio astronomy observatories noted in footnote US385 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio astronomy...

47 CFR 15.242 - Operation in the bands 174-216 MHz and 470-668 MHz.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of any of the other radio astronomy observatories noted in footnote US 311 of Section 2.106 of this... astronomy observatory before the equipment can be installed or operated. The National Science Foundation... mobile stations operating under part 90 of this chapter in the 470-512 MHz band, and radio astronomy...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Code of Federal Regulations, 2010 CFR

2010-10-01

... frequency range 608-614 MHz and that will be located near the radio astronomy observatories listed below..., and obtain the written concurrence of, the director of the affected radio astronomy observatory before the equipment can be installed or operated (a) Within 80 kilometers of: (1) National Astronomy and...

47 CFR 95.1119 - Specific requirements for wireless medical telemetry devices operating in the 608-614 MHz band.

Code of Federal Regulations, 2012 CFR

2012-10-01

... frequency range 608-614 MHz and that will be located near the radio astronomy observatories listed below..., and obtain the written concurrence of, the director of the affected radio astronomy observatory before the equipment can be installed or operated (a) Within 80 kilometers of: (1) National Astronomy and...

77 FR 55715 - Medical Area Body Network

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-11

... operating in accordance with the rules. 13. The 2370-2390 MHz band is used for radio astronomy operations in... to ensure protection of radio astronomy operations at the Arecibo site. 14. Lastly, the Commission...

47 CFR 97.203 - Beacon station.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944. (1) The notification must include the... Radio Astronomy Observatory at Green Bank, Pocahontas County, WV, for itself or on behalf of the Naval...

The history of radio telescopes, 1945-1990

NASA Astrophysics Data System (ADS)

Sullivan, Woodruff T.

2009-08-01

Forged by the development of radar during World War II, radio astronomy revolutionized astronomy during the decade after the war. A new universe was revealed, centered not on stars and planets, but on the gas between the stars, on explosive sources of unprecedented luminosity, and on hundreds of mysterious discrete sources with no optical identifications. Using “radio telescopes” that looked nothing like traditional (optical) telescopes, radio astronomers were a very different breed from traditional (optical) astronomers. This pathbreaking of radio astronomy also made it much easier for later “astronomies” and their “telescopes” (X-ray, ultraviolet, infrared, gamma-ray) to become integrated into astronomy after the launch of the space age in the 1960s. This paper traces the history of radio telescopes from 1945 through about 1990, from the era of converted small-sized, military radar antennas to that of large interferometric arrays connected by complex electronics and computers; from the era of strip-chart recordings measured by rulers to powerful computers and display graphics; from the era of individuals and small groups building their own equipment to that of Big Science, large collaborations and national observatories.

Research Projects and Undergraduate Retention at the University of Arizona

NASA Astrophysics Data System (ADS)

Walker-LaFollette, Amanda; Hardegree-Ullman, K.; Towner, A. P.; McGraw, A. M.; Biddle, L. I.; Robertson, A.; Turner, J.; Smith, C.

2013-06-01

The University of Arizona’s Astronomy Club utilizes its access to the many telescopes in and around Tucson, Arizona, to allow students to fully participate in a variety of research projects. Three current projects - the exoplanet project, the radio astronomy project, and the Kepler project - all work to give undergraduates who are interested in astronomy the opportunity to explore practical astronomy outside the classroom and in a peer-supported environment. The exoplanet project strives to teach students about the research process, including observing exoplanet transits on the Steward Observatory 61” Kuiper telescope on Mt. Bigelow in Tucson, AZ, reducing the data into lightcurves with the Image Reduction and Analysis Facility (IRAF), modeling the lightcurves using the Interactive Data Language (IDL), and writing and publishing a professional paper, and does it all with no faculty involvement. The radio astronomy project is designed to provide students with an opportunity to work with a professor on a radio astronomy research project, and to learn about the research process, including observing molecules in molecular clouds using the Arizona Radio Observatory 12-meter radio telescope on Kitt Peak in Arizona. The Kepler project is a new project designed in part to facilitate graduate-undergraduate interaction in the Astronomy Department, and in part to allow students (both graduate and undergraduate) to participate in star-spot cycle research using data from the Kepler Mission. All of these research projects and structures provide students with unique access to telescopes, peer mentoring, networking, and understanding the entire process of astronomical research.

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz mobile-satellite service.

Code of Federal Regulations, 2012 CFR

2012-10-01

... radio astronomy service in the 1610.6-1613.8 MHz band against interference from 1.6/2.4 GHz Mobile... System. During periods of radio astronomy observations, land mobile earth stations shall not operate when... astronomy sites: Observatory Latitude (DMS) Longitude (DMS) Arecibo, PR 18 20 46 66 45 11 Green Bank...

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz mobile-satellite service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... radio astronomy service in the 1610.6-1613.8 MHz band against interference from 1.6/2.4 GHz Mobile... System. During periods of radio astronomy observations, land mobile earth stations shall not operate when... astronomy sites: Observatory Latitude (DMS) Longitude (DMS) Arecibo, PR 18 20 46 66 45 11 Green Bank...

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz mobile-satellite service.

Code of Federal Regulations, 2011 CFR

2011-10-01

... radio astronomy service in the 1610.6-1613.8 MHz band against interference from 1.6/2.4 GHz Mobile... System. During periods of radio astronomy observations, land mobile earth stations shall not operate when... astronomy sites: Observatory Latitude (DMS) Longitude (DMS) Arecibo, PR 18 20 46 66 45 11 Green Bank...

47 CFR 15.615 - General administrative requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

...-2190.5 kHz. Within the exclusion zone for the Very Large Array radio astronomy observatory, Access BPL... facilities located at the coordinates specified for radio astronomy facilities in 47 CFR 2.106, Note U.S. 311...

47 CFR 15.615 - General administrative requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-2190.5 kHz. Within the exclusion zone for the Very Large Array radio astronomy observatory, Access BPL... facilities located at the coordinates specified for radio astronomy facilities in 47 CFR 2.106, Note U.S. 311...

47 CFR 15.615 - General administrative requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

...-2190.5 kHz. Within the exclusion zone for the Very Large Array radio astronomy observatory, Access BPL... facilities located at the coordinates specified for radio astronomy facilities in 47 CFR 2.106, Note U.S. 311...

47 CFR 15.615 - General administrative requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

...-2190.5 kHz. Within the exclusion zone for the Very Large Array radio astronomy observatory, Access BPL... facilities located at the coordinates specified for radio astronomy facilities in 47 CFR 2.106, Note U.S. 311...

47 CFR 15.615 - General administrative requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-2190.5 kHz. Within the exclusion zone for the Very Large Array radio astronomy observatory, Access BPL... facilities located at the coordinates specified for radio astronomy facilities in 47 CFR 2.106, Note U.S. 311...

The future of Canada's radio astronomy

NASA Astrophysics Data System (ADS)

Gaensler, Bryan M.

2017-11-01

Through involvement in CHIME, ALMA, the Jansky VLA and the Murchison Widefield Array, Canada is well placed in current radio astronomy facilities and the future looks even brighter, with strategic interest in the SKA and the Next Generation VLA.

Radio astronomy aspects of the NASA SETI Sky Survey

NASA Technical Reports Server (NTRS)

Klein, Michael J.

1986-01-01

The application of SETI data to radio astronomy is studied. The number of continuum radio sources in the 1-10 GHz region to be counted and cataloged is predicted. The radio luminosity functions for steep and flat spectrum sources at 2, 8, and 22 GHz are derived using the model of Peacock and Gull (1981). The relation between source number and flux density is analyzed and the sensitivity of the system is evaluated.

Teaching radio astrophysics the hand-on way

NASA Astrophysics Data System (ADS)

Joshi, Bhal Chandra

Astronomy and space sciences have always been instrumental in attracting young students to physical sciences. While the lectures/demonstrations and exhibitions pertaining to space sci-ences capture the imagination of young students, these alone are not sufficient to induce them to join scientific research. In countries like India, where a large number of students take to physical sciences for under-graduate education, complex sociological factors are key issues in translating this large body of students to potential researchers. While lectures and exhibition lead to an increase in scientific awareness for these students, these do not give a feel for scien-tific research and bridge the gap between high school/college science education and high end research. In this context, a hands-on approach to astronomy education, in science research environments or closely connected to scientific institutions, offers a promising alternative. This approach has been used in optical astronomy, where inexpensive small telescopes are available, often coupling a vast network of amateur astronomy clubs to leading astronomy institutes. The non-visual and relatively more technical nature of radio astronomy has limited a similar approach in past for connecting students to space sciences using radio waveband. The tech-nological explosion in communication industry and radio connectivity in the last decade along with an expansion in engineering education makes this possible now using a hands-on approach in teaching radio astrophysics. In this presentation, the sociological factors affecting the student choice are discussed followed by a review of the efforts to bridge the above mentioned gap by various groups in the world in the last decade with a view to enumerate the best practices in a hands-on approach. A program using this approach at National Center for Radio Astrophysics is described, where the students are exposed to simple hands-on radio astronomy experiments such as spectral line observations of neutral hydrogen from Milky Way and solar flux moni-toring. Such experiments are also useful to familiarize the students with astronomy jargon, which many times becomes an impediment in connecting them with research. This program also aims to develop low cost radio telescopes with involvement of engineering students and the presentation aims at sharing the experience in this program. Future possibilities bridging the gap between the research institutions, such as ours, and the student population at large are also discussed.

Dr Elizabeth Alexander: First Female Radio Astronomer

NASA Astrophysics Data System (ADS)

Orchiston, Wayne

2005-01-01

During March-April 1945, solar radio emission was detected at 200 MHz by operators of a Royal New Zealand Air Force radar unit located on Norfolk Island. Initially dubbed the `Norfolk Island Effect', this anomalous radiation was investigated throughout 1945 by British-born Elizabeth Alexander, head of the Operational Research Section of the Radio Development Laboratory in New Zealand. Alexander prepared a number of reports on this work, and in early 1946 she published a short paper in the newly-launched journal, Radio & Electronics. A geologist by training, Elizabeth Alexander happened to be in the right place at the right time, and unwittingly became the first woman in the world to work in the field that would later become known as radio astronomy. Her research also led to further solar radio astronomy projects in New Zealand in the immediate post-war year, and in part was responsible for the launch of the radio astronomy program at the Division of Radiophysics, CSIRO, in Sydney.

A Virtual Tour of the Radio Astronomy Process

NASA Astrophysics Data System (ADS)

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.

The Beginnings of Australian Radio Astronomy

NASA Astrophysics Data System (ADS)

Sullivan, Woodruff T.

The early stages of Australian radio astronomy, especially the first decade after World War II, are described in detail. These include the transition of the CSIRO Radiophysics Laboratory, under the leadership of Joseph Pawsey and Taffy Bowen, from a wartime laboratory in 1945 to, by 1950, the largest and one of the two most important radio astronomy groups in the world (with the Cavendish Laboratory at Cambridge University). The initial solar investigations are described, including discovery of the hot corona and development of the sea-cliff interferometer. During this same period painstaking `radio star' observations by John Bolton and colleagues led to the first suggested optical identifications of Taurus-A (the Crab Nebula), Centaurus-A (NGC 5128), and Virgo-A (M87). The factors that led to the extraordinary early success of the Radiophysics Laboratory are analyzed in detail, followed by discussion of how the situation changed significantly in the second decade of 1955-1965. Finally, the development of major Australian instruments, from the Parkes Radio Telescope (1961) to the Australia Telescope (1988), is briefly presented. This chapter is a direct reprint of the following research paper: Sullivan, W., 2005. The beginnings of Australian radio astronomy. Journal of Astronomical History and Heritage, 8, 11-32.

MPS Internships in Public Science Education: Sensing the Radio Sky

NASA Astrophysics Data System (ADS)

Blake, Melvin; Castelaz, M. W.; Moffett, D.; Walsh, L.; LaFratta, M.

2006-12-01

The intent of the “Sensing the Radio Sky” program is to teach high school students the concepts and relevance of radio astronomy through presentations in STARLAB portable planetariums. The two year program began in the summer of 2004 and was completed in December 2006. The program involved a team of 12 undergraduate physics and multimedia majors and four faculty mentors from Furman University, University of North Carolina-Asheville and Pisgah Astronomical Research Institute (PARI). One component of the program is the development and production of a projection cylinder for the portable STARLAB planetariums. The cylinder gives a thorough view of the Milky Way and of several other celestial sources in radio wavelengths, yet these images are difficult to perceive without prior knowledge of radio astronomy. Consequently, the Radio Sky team created a multimedia presentation to accompany the cylinder. This multimedia component contains six informative lessons on radio astronomy assembled by the physics interns and numerous illustrations and animations created by the multimedia interns. The cylinder and multimedia components complement each other and provide a unique, thorough, and highly intelligible perspective on radio astronomy. The final draft is complete and will be sent to Learning Technologies, Inc., for marketing to owners of STARLAB planetariums throughout the world. We acknowledge support from the NSF Internship in Public Science Education Program grant number 0324729.

76 FR 61655 - Definition of Part 15 Auditory Assistance Device

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-05

... allocated on a primary basis for radio astronomy, and the 74.8-75.2 MHz band is allocated on a primary basis... radiodetermination, radio astronomy, and TV broadcast services are in bands adjacent to the part 15 auditory...

PARTNeR for Teaching and Learning Radio Astronomy Basics

NASA Astrophysics Data System (ADS)

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 radio astronomical remote observations have been performed with users. Until now, more than 2,000 students have been involved in radio astronomical observations.

75 FR 57792 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-22

...: Sections 25.203(i) and 73.1030(a)(2), Radio Astronomy Coordination Zone in Puerto Rico. Form No.: N/A. Type... notification procedures enable the Arecibo Radio Astronomy Observatory to receive information needed to assess...

Radio Astronomy Working Group for SEAAN and RFI Survey in INSTUN, Perak

NASA Astrophysics Data System (ADS)

Abidin, Zamri Zainal; Ibrahim, Zainol Abidin; Rosli, Zulfazli; Malim, Siti Fatin Fathinah; Anim, Norsuzian Mohd

2010-07-01

The South East Asia Astronomy Network (SEAAN) was established in 2006 at the Special Session of Astronomy for Developing World during the IAU General Assembly in Prague. It held its first meeting in 2007 at the Thai National Astronomy Meeting in Bangkok, Thailand. It aims to establish effective mechanisms for nurturing and sharing the development and experiences in astronomy research and education among SEA countries. This working group has a main objective of putting South East Asia on the map of the global radio astronomy community. This paper will discuss the working group's short-term and long-term goals. This paper will also discuss the results of the latest Radio Frequency Interference (RFI) study in Malaysia, particularly the survey at Institut Tanah dan Ukur Negara (INSTUN) in Perak. The RFI level at that site is measured at -94.312 (+/-0.999) dBm or 11.065 (+/-1.505) μV on average, which is considered quite well when compared to the best site in Malaysia, which is Langkawi (-100.352 +/-0.036) dBm or 2.192 lp+/-0.019) μV on average).

A low frequency RFI monitoring system

NASA Astrophysics Data System (ADS)

Amiri, Shahram; Shankar, N. Udaya; Girish, B. S.; Somashekar, R.

Radio frequency interference (RFI) is a growing problem for research in radio astronomy particularly at wavelengths longer than 2m. For satisfactory operation of a radio telescope, several bands have been protected for radio astronomy observations by the International Telecommunication Union. Since the radiation from cosmic sources are typically 40 to 100 dB below the emission from services operating in unprotected bands, often the out-of-band emission limits the sensitivity of astronomical observations. Moreover, several radio spectral emissions from cosmic sources are present in the frequency range outside the allocated band for radio astronomy. Thus monitoring of RFI is essential before building a receiver system for low frequency radio astronomy. We describe the design and development of an RFI monitoring system operating in the frequency band 30 to 100 MHz. This was designed keeping in view our proposal to extend the frequency of operation of GMRT down to 40 MHz. The monitor is a PC based spectrometer recording the voltage output of a receiver connected to an antenna, capable of digitizing the low frequency RF directly with an 8 bit ADC and sampling bandwidths up to 16 MHz. The system can operate continuously in almost real-time with a loss of only 2% of data. Here we will present the systems design aspects and the results of RFI monitoring carried out at the Raman Research Institute, Bangalore and at the GMRT site in Khodad.

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

NASA Astrophysics Data System (ADS)

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.

Astronomy research at the Aerospace Corporation. [research projects - NASA programs

NASA Technical Reports Server (NTRS)

Paulikas, G. A.

1974-01-01

This report reviews the astronomy research carried out at The Aerospace Corporation during 1974. The report describes the activities of the San Fernando Observatory, the research in millimeter wave radio astronomy as well as the space astronomy research.

HERO: a space based low frequency interferometric observatory for heliophysicsenabled by novel vector sensor technology

DTIC Science & Technology

2017-04-07

considerations. Experimental Astronomy , 2015.304 Dicke, R. H. The Measurement of Thermal Radiation at Microwave Frequencies. Review305 of Scientific Instruments...17, 7, 268, 1946.306 12 M. Knapp et al. Ellingson, S. W. Sensitivity of Antenna Arrays for Long-Wavelength Radio Astronomy .307 IEEE Transactions on...Morris, M. Silver, S. Klein, and314 S. Seager. Vector antenna and maximum likelihood imaging for radio astronomy . In315 IEEE Aerospace Conference

Development of a Mechanically Mediated RF to Optical Transducer

DTIC Science & Technology

2017-05-22

in radio astronomy receivers could be replaced by this noise- tolerant transducer, thus dramatically reducing the system’s size and cost [7]. Such a...conversion between microwave and optical light. Nat. Phys. 10, 321-326 (2014). [7] Kraus, J.D., Radio Astronomy (McGraw, 1966). [8] DARPA Optical Radiation

NSF Internships in Public Science Education: Sensing the Radio Sky

NASA Astrophysics Data System (ADS)

Hund, L.; Boltuch, D.; Fultz, C.; Buck, S.; Smith, T.; Harris, R.; Moffett, D.; LaFratta, M.; Walsh, L.; Castelaz, M. W.

2005-12-01

The intent of the "Sensing the Radio Sky" project is to teach high school students the concepts and relevance of radio astronomy through presentations in STARLAB portable planetariums. The two year project began in the summer of 2004. A total of twelve interns and four faculty mentors from Furman University and UNCA have participated at the Pisgah Astronomical Research Institute to develop the Radio Sky project. The project united physics and multimedia majors and allowed these students to apply their knowledge of different disciplines to a common goal. One component of the project is the development and production of a cylinder to be displayed in portable STARLAB planetariums. The cylinder gives a thorough view of the Milky Way and of several other celestial sources in radio wavelengths, yet these images are difficult to perceive without prior knowledge of radio astronomy. Consequently, the Radio Sky team created a multimedia presentation to accompany the cylinder. This multimedia component contains six informative lessons on radio astronomy assembled by the physics interns and numerous illustrations and animations created by the multimedia interns. The cylinder and multimedia components complement each other and provide a unique, thorough, and highly intelligible perspective on radio astronomy. The project is near completion and the final draft will be sent to Learning Technologies, Inc., for marketing to owners of STARLAB planetariums throughout the world. The development of the Radio Sky project has also provided a template for potential similar projects that examine our universe in different wavelengths, such as gamma ray, x-ray, and infrared. We acknowledge support from the NSF Internship in Public Science Education Program grant number 0324729.

Forthcoming Occultations of Astrometric Radio Sources by Planets

NASA Technical Reports Server (NTRS)

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.

Space astronomy and upper atmospheric sounding

NASA Technical Reports Server (NTRS)

Friedman, H.

1971-01-01

The discoveries and activities of the Space Science Program are reported. Results of studies are presented for the following areas: gamma and x-ray astronomy, optical geophysics and solar wind, infrared astronomy, radio astronomy, and rocket spectroscopy. Lists of publications, talks, and conferences are included.

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

NASA Astrophysics Data System (ADS)

Mena, J.; Bandura, K.; Cliche, J.-F.; Dobbs, M.; Gilbert, A.; Tang, Q. Y.

2013-10-01

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.

Bernard Yarnton Mills AC FAA. 8 August 1920 - 25 April 2011

NASA Astrophysics Data System (ADS)

Frater, R. H.; Goss, W. M.; Wendt, H. W.

2013-12-01

Bernie Mills is remembered globally as an influential pioneer in the evolving field of radio astronomy. His contributions with the 'Mills Cross' at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) Division of Radiophysics and later at the University of Sydney's School of Physics and the development of the Molonglo Observatory Synthesis Telescope (MOST) were widely recognized as astronomy evolved in the years 1948-85 and radio astronomy changed the viewpoint of the astronomer as a host of new objects were discovered.

Covariance estimation in Terms of Stokes Parameters with Application to Vector Sensor Imaging

DTIC Science & Technology

2016-12-15

S. Klein, “HF Vector Sensor for Radio Astronomy : Ground Testing Results,” in AIAA SPACE 2016, ser. AIAA SPACE Forum, American Institute of... astronomy ,” in 2016 IEEE Aerospace Conference, Mar. 2016, pp. 1–17. doi: 10.1109/ AERO.2016.7500688. [4] K.-C. Ho, K.-C. Tan, and B. T. G. Tan, “Estimation of...Statistical Imaging in Radio Astronomy via an Expectation-Maximization Algorithm for Structured Covariance Estimation,” in Statistical Methods in Imaging: IN

The Effectiveness of Internet-Controlled Astronomical Research Instrumentation for Education

ERIC Educational Resources Information Center

Pratap, Preethi; Salah, Joseph

2004-01-01

Over the last decade, remote instruments have become widely used in astronomy. Educational applications are more recent. This paper describes a program to bring radio astronomy into the undergraduate classroom through the use of a remote research-grade radio telescope, the MIT Haystack Observatory 37 m telescope. We examine the effectiveness of…

Teaching Astronomy at Columbus State University using Small Radio Telescopes

NASA Astrophysics Data System (ADS)

Webster, Zodiac T.

2006-12-01

Astronomy is inherently fascinating to students but dark skies and good weather are not often scheduled during the school day. Radio telescopes provide an all-weather, all-day opportunity for astronomical observations. Columbus State University (CSU) has installed two “Small Radio Telescopes” for use by undergraduate students to pursue extra-curricular research in introductory astronomy. These telescopes are relatively affordable and are designed to be remotely operated through a Windows, Linux, or Macintosh environment. They are capable of diffraction-limited observations of the Sun and galactic Hydrogen in the ‘L-band’. A comprehensive website of projects suitable for high-school students and undergraduates is maintained by a group at MIT. This website ensures users are not left to explore the telescope’s abilities blindly. Students with varied interests learn about the nature of science by using an instrument that doesn’t lend itself to pretty pictures. Radio telescopes also provide a slight engineering flavor drawing in students who might not otherwise be interested in astronomy. This poster will provide a summary of installation, calibration, and future plans, and will share some observations by undergraduates at CSU.

Advanced Technologies For Heterodyne Radio Astronomy Instrumentation - Part1 By A. Pavolotsky, And Advanced Technologies For Heterodyne Radio Astronomy Instrumentation - Part2 By V. Desmaris

NASA Astrophysics Data System (ADS)

Pavolotsky, Alexey

2018-01-01

Modern and future heterodyne radio astronomy instrumentation critically depends on availability of advanced fabrication technologies and components. In Part1 of the Poster, we present the thin film fabrication process for SIS mixer receivers, utilizing either AlOx, or AlN barrier superconducting tunnel junctions developed and supported by GARD. The summary of the process design rules is presented. It is well known that performance of waveguide mixer components critically depends on accuracy of their geometrical dimensions. At GARD, all critical mechanical parts are 3D-mapped with a sub-um accuracy. Further progress of heterodyne instrumentation requires new efficient and compact sources of LO signal. We present SIS-based frequency multiplier, which could become a new option for LO source. Future radio astronomy THz receivers will need waveguide components, which fabricating due to their tiny dimensions is not feasible by traditional mechanical machining. We present the alternative micromachining technique for fabricating waveguide component for up 5 THz band and probably beyond.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1984-01-01

Developments in space communications, radio navigation, radio science, ground-base radio astronomy, reports on the Deep Space Network (DSN) and its Ground Communications Facility (GCF), and applications of radio interferometry at microwave frequencies are discussed.

From the Beginning: Archiving the History of NRAO and US Radio Astronomy

NASA Astrophysics Data System (ADS)

Bouton, E. N.

2005-12-01

In 2006 the National Radio Astronomy Observatory will celebrate its 50th anniversary. Before 2003, there were neither archives nor a formal archiving program at NRAO; institutional records were located at any of the four NRAO sites in four different states, and there was no record of the materials that we had. In mid-2003, the long-time NRAO librarian retired and began part time work as NRAO's first archivist. With the completion of an addition to the headquarters building in Charlottesville in spring 2005, the fledgling NRAO Archives moved into a new 1400 sq ft space. In addition to NRAO materials, the Archives also collects papers of individuals. Grote Reber, who built the first radio telescope in his backyard in Wheaton IL in 1937, had in 1995, donated many of his personal papers to NRAO, and these papers have been indexed and are available to researchers. We continue to receive additional materials from his estate in Tasmania. The complete papers of John Kraus, author, researcher, and professor in radio astronomy and engineering at Ohio State University for many years, were donated to the NRAO Archives by his son and estate executor in spring 2005. The NRAO Archives has also mounted Web resources with texts written by Nan Dieter Conklin and by Doc Ewen describing their work in the developing years of US radio astronomy. This talk will present the highlights of how, on a limited budget but with broad support of NRAO staff, the NRAO Archives has begun a program to gather and organize materials on institutional history as well as the personal papers and recollections of contributors to US radio astronomy history.

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

NASA Astrophysics Data System (ADS)

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.

Astronomy Looks Different When You Listen to It.

ERIC Educational Resources Information Center

Jones, Richard C.

1994-01-01

Describes the use of a radio telescope to arouse new interest among students. The article partitions into the following sections: (1) Radio Astronomy--Which Level; (2) First Steps: The Site--The Antenna; (3) The Electronics: Do It Yourself, or Store Bought; (4) Field Test: Music of the Spheres; (5) Getting Started: Entry Level Projects; and (6)…

Observatory Sponsoring Astronomical Image Contest

NASA Astrophysics Data System (ADS)

2005-05-01

Forget the headphones you saw in the Warner Brothers thriller Contact, as well as the guttural throbs emanating from loudspeakers at the Very Large Array in that 1997 movie. In real life, radio telescopes aren't used for "listening" to anything - just like visible-light telescopes, they are used primarily to make images of astronomical objects. Now, the National Radio Astronomy Observatory (NRAO) wants to encourage astronomers to use radio-telescope data to make truly compelling images, and is offering cash prizes to winners of a new image contest. Radio Galaxy Fornax A Radio Galaxy Fornax A Radio-optical composite image of giant elliptical galaxy NGC 1316, showing the galaxy (center), a smaller companion galaxy being cannibalized by NGC 1316, and the resulting "lobes" (orange) of radio emission caused by jets of particles spewed from the core of the giant galaxy Click on image for more detail and images CREDIT: Fomalont et al., NRAO/AUI/NSF "Astronomy is a very visual science, and our radio telescopes are capable of producing excellent images. We're sponsoring this contest to encourage astronomers to make the extra effort to turn good images into truly spectacular ones," said NRAO Director Fred K.Y. Lo. The contest, offering a grand prize of $1,000, was announced at the American Astronomical Society's meeting in Minneapolis, Minnesota. The image contest is part of a broader NRAO effort to make radio astronomical data and images easily accessible and widely available to scientists, students, teachers, the general public, news media and science-education professionals. That effort includes an expanded image gallery on the observatory's Web site. "We're not only adding new radio-astronomy images to our online gallery, but we're also improving the organization and accessibility of the images," said Mark Adams, head of education and public outreach (EPO) at NRAO. "Our long-term goal is to make the NRAO Image Gallery an international resource for radio astronomy imagery and to provide a showcase for a broad range of astronomical research and celestial objects," Adams added. In addition, NRAO is developing enhanced data visualization techniques and data-processing recipes to assist radio astronomers in making quality images and in combining radio data with data collected at other wavelengths, such as visible-light or infrared, to make composite images. "We encourage all our telescope users to take advantage of these techniques to showcase their research," said Juan Uson, a member of the NRAO scientific staff and the observatory's EPO scientist. "All these efforts should demonstrate the vital and exciting roles that radio telescopes, radio observers, and the NRAO play in modern astronomy," Lo said. "While we want to encourage images that capture the imagination, we also want to emphasize that extra effort invested in enhanced imagery also will certainly pay off scientifically, by revealing subtleties and details that may have great significance for our understanding of astronomical objects," he added. Details of the NRAO Image Contest, which will become an annual event, are on the observatory's Web site. The observatory will announce winners on October 15. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Building a pipeline of talent for operating radio observatories

NASA Astrophysics Data System (ADS)

Wingate, Lory M.

2016-07-01

The National Radio Astronomy Observatory's (NRAO) National and International Non-Traditional Exchange (NINE) Program teaches concepts of project management and systems engineering in a focused, nine-week, continuous effort that includes a hands-on build project with the objective of constructing and verifying the performance of a student-level basic radio instrument. The combination of using a project management (PM)/systems engineering (SE) methodical approach based on internationally recognized standards in completing this build is to demonstrate clearly to the learner the positive net effects of following methodical approaches to achieving optimal results. It also exposes the learner to basic radio science theory. An additional simple research project is used to impress upon the learner both the methodical approach, and to provide a basic understanding of the functional area of interest to the learner. This program is designed to teach sustainable skills throughout the full spectrum of activities associated with constructing, operating and maintaining radio astronomy observatories. NINE Program learners thereby 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-represented1 groups of learners, thereby developing a strong pipeline of global talent to construct, operate and maintain radio astronomy observatories.

Vision for Astronomy in South Africa and partnership with the US

NASA Astrophysics Data System (ADS)

Nemaungani, Takalani

2014-01-01

The 2002 National Research and Development Strategy identified astronomy as a national geographic advantage. This identification was based on the historical investments in optical and, to a lesser extent, radio astronomy up to that point and the realisation that the conditions prevailing in Sutherland were among the best in the world. Since then a number of astronomy initiatives have burgeoned in the Southern African region and these include the HESS, SKA and the AVN. Currently, investments in astronomy are by far the biggest investments being made by the Department of Science and Technology (DST). South Africa’s involvement in modern astronomy dates back to 1685 when a French Astronomer, Guy Tachard, setup an observatory at the southern tip of Africa to decipher the star charts of the extreme southern sky. In 1820, a permanent observatory - the Royal Observatory - was established outside of Cape Town and astronomy has been practised continuously since then. By the late 1980s, it became clear that for South African astronomers and astrophysicists to continue conducting first class research, the acquisition of a much larger, powerful and sophisticated telescope would be necessary. This provided the impetus for a new vision to construct the largest single optical telescope in the Southern Hemisphere, eventually known as the Southern African Large Telescope (SALT). Within the last decade, the African appetite for radio astronomy initiatives has increased exponentially. This has largely been spurred by the African bid to host the SKA project and the need for African countries to work in close partnership that consequently resulted in a successful bid to co-host the SKA project and the subsequent need to ensure its effective implementation. This partnership, and the interactions related thereto, has effectively enhanced awareness around the requirements for hosting radio astronomy instrumentation and the associated benefits that could be derived in making such commitments. Consequently, there have been concerted efforts in support of various radio astronomy initiatives that sit at the cusp of the continents ambitions for the hosting of the SKA.

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

NASA Astrophysics Data System (ADS)

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 built a prototype adaptive canceler that consists of two receivers: the primary channel (input from the main beam of the telescope) and a separate reference channel. The primary channel receives the desired astronomical signal corrupted by RFI (radio-frequency interference) coming in the sidelobes of the main beam. A separate reference antenna is designed to receive only the RFI. The reference channel input is processed using a digital adaptive filter and then subtracted from the primary channel input, producing the system output. The weighting coefficients of the digital filter are adjusted by way of an algorithm that minimizes, in a least-squares sense, the power output of the system. Through an adaptive-iterative process, the canceler locks onto the RFI, and the filter adjusts itself to minimize the effect of the RFI at the system output. We have designed the adaptive canceler with an intermediate frequency (IF) of 40 MHz. This prototype system will ultimately be functional with a variety of radio astronomy receivers in the microwave band. We have also built a prototype receiver centered at 100 MHz (in the FM broadcast band) to test the adaptive canceler with actual interferers, which are well characterized. The initial laboratory tests of the adaptive canceler are encouraging, with attenuation of strong frequency-modulated (FM) interference to 72 dB (a factor of more than 10 million), which is at the performance limit of our measurements. We also consider requirements of the system and the RFI environment for effective adaptive canceling.

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

NASA Astrophysics Data System (ADS)

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.

The origin and development of extragalactic radio astronomy: the role of CSIRO's Division of Radiophysics Dover Heights Field Station in Sydney

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Robertson, Peter

2017-12-01

Initial post-war developments in non-solar radio astronomy were inspired by Hey, Phillips and Parson’s report in 1946 of an intense source of radio emission in Cygnus. This so-called ‘radio star’ was unique, and questions immediately were raised about its true nature. But it did not remain unique for long. Observing from Sydney, John Bolton, Gordon Stanley and Bruce Slee followed up the Cygnus discovery with more radio star detections, beginning what would evolve into a long-term multi-faceted research program and one of the mainstays of the CSIRO’s Division of Radiophysics. But more than this, these early discoveries in England and in Sydney opened up a whole new field of investigation, extragalactic radio astronomy, which has remained a major area of investigation through to the present day. This paper focusses on the early years of this program when the observations were carried out at Dover Heights Field Station in Sydney, and the ways in which new developments in instrumentation that allowed a major expansion of the program eventually led to the closure of Dover Heights and the founding of the Fleurs Field Station.

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

NASA Astrophysics Data System (ADS)

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.

South African Student Constructed Indlebe Radio Telescope

NASA Astrophysics Data System (ADS)

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. Currently, we are comparing the observed transit times of Sag A with the calculable predications in order to obtain information over these two factors, with a view to better understanding them.

Radio interference in the near-earth environment

NASA Technical Reports Server (NTRS)

Erickson, W. C.

1988-01-01

Natural and man-made radio frequency interference (RFI) are potentially serious obstacles to the successful operation of an array of spacecraft used for low frequency (1 to 30 MHz) radio interferometry in the near-earth environment. Several satellites and planetary probes have carried radio astronomy experiments, and the moderate data base that they provide are examined to help understand the near-earth RFI environment. The general conclusion is that the region of space within 100 earth-radii of the earth is a hostile environment for any radio astronomy experiment. If a low frequency array in earth orbit is to yield useful astronomical results, severe interference problems must be anticipated and overcome. A number of recommendations are made to further examine the feasibility of such an array.

Monitoring Radio Frequency Interference in Southwest Virginia

NASA Astrophysics Data System (ADS)

Rapp, Steve

2010-01-01

The radio signals received from astronomical objects are extremely weak. Because of this, radio sources are easily shrouded by interference from devices such as satellites and cell phone towers. Radio astronomy is very susceptible to this radio frequency interference (RFI). Possibly even worse than complete veiling, weaker interfering signals can contaminate the data collected by radio telescopes, possibly leading astronomers to mistaken interpretations. To help promote student awareness of the connection between radio astronomy and RFI, an inquiry-based science curriculum was developed to allow high school students to determine RFI levels in their communities. The Quiet Skies Project_the result of a collaboration between the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), and the National Radio Astronomy Observatory (NRAO)_encourages students to collect and analyze RFI data and develop conclusions as a team. Because the project focuses on electromagnetic radiation, it is appropriate for physics, physical science, chemistry, or general science classes. My class-about 50 students from 15 southwest Virginia high schools-participated in the Quiet Skies Project and were pioneers in the use of the beta version of the Quiet Skies Detector (QSD), which is used to detect RFI. Students have been involved with the project since 2005 and have collected and shared data with NRAO. In analyzing the data they have noted some trends in RFI in Southwest Virginia.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1989-01-01

Archival reports on developments in programs managed by the Jet Propulsion Laboratory's Office of Telecommunications and Data Acquisition are provided. Space communications, radio navigation, radio science, and ground based radio and radio astronomy are discussed. Deep Space Network projects are also discussed.

Astronomy in Australia

NASA Astrophysics Data System (ADS)

Watson, F.; Couch, W.

2017-12-01

Australians have watched the sky for tens of thousands of years. The nineteenth century saw the foundation of government observatories in capital cities such as Sydney and Melbourne. While early twentieth-century astronomy focused largely on solar physics, the advent of radio astronomy at the end of the Second World War enabled Australia to take a leading role in the new science, with particular emphasis on low-frequency studies. Today, the radio quietness of its outback interior provides an excellent location for the Australian core of the Square Kilometre Array. Australian optical astronomy has flourished since the 1960s, with the 3.9-metre Anglo-Australian Telescope becoming the principal national facility in 1974. Access to ESO’s facilities at the La Silla Paranal Observatory is warmly welcomed by all Australian astronomers.

47 CFR Alphabetical Index - Part 73

Code of Federal Regulations, 2014 CFR

2014-10-01

... 73.509 TV 73.612 Interference to Astronomy, Research and Receiving installations, Notifications... interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical designation of FM...

47 CFR Alphabetical Index - Part 73

Code of Federal Regulations, 2012 CFR

2012-10-01

... 73.509 TV 73.612 Interference to Astronomy, Research and Receiving installations, Notifications... interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical designation of FM...

47 CFR Alphabetical Index - Part 73

Code of Federal Regulations, 2013 CFR

2013-10-01

... 73.509 TV 73.612 Interference to Astronomy, Research and Receiving installations, Notifications... interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical designation of FM...

U.S.-Canadian Partnership in Radio Astronomy Valuable for Science, NRAO Director Says

NASA Astrophysics Data System (ADS)

2001-10-01

The United States and Canada intend to collaborate on two of the most important radio astronomy projects of the new century - the Atacama Large Millimeter Array (ALMA) and the Expanded Very Large Array (EVLA), astronomers from both countries announced today. "This cooperative program - the North American Partnership in Radio Astronomy - involves the key projects that will dominate radio astronomy world-wide," said Paul Vanden Bout, director of the National Radio Astronomy Observatory (NRAO). "This partnership will multiply the efforts of both nations' astronomers for the benefit of science. It builds on a long tradition of cooperative efforts in radio astronomy, and will ensure that we continue that tradition into the new millennium," Vanden Bout said. The U.S.-Canada radio astronomy partnership is outlined in two letters of intent signed recently. The first, between the U.S. National Science Foundation (NSF) and Canada's National Research Council (NRC), states that both agencies will use their best efforts to obtain the necessary funding for construction and operation of ALMA. The second, between the National Radio Astronomy Observatory, funded by the NSF, and the Herzberg Institute of Astrophysics, funded by the NRC, forms a partnership in the EVLA. The VLA Expansion Project is a two-phase program designed to improve the scientific capabilities of the VLA tenfold by replacing 1970s-vintage equipment with modern technologies and adding new radio-telescope antennas to the existing 27-antenna array. Dedicated in 1980, the VLA has been used for more than 10,000 observing projects covering nearly every area of astrophysics. It is the most powerful, flexible and widely-used radio telescope in the world. The Expanded VLA will provide the improved observational capabilities needed to meet the research challenges of the coming years. In addition to the participation by Canada, funds have been pledged by Mexico. Both Mexico and Germany have funded VLA improvements in the past. A proposal to the NSF requesting U.S. funds for the EVLA is currently under review by the National Science Foundation. The agreement between the NRAO and the Herzberg Institute of Astrophysics (HIA) calls for HIA to build a new correlator - the digital "heart" that combines the received signals from multiple antennas to make those antennas work as a single, powerful telescope - for the EVLA. The new correlator will represent a contribution of 10 million (US). The full EVLA project will cost about 150 million, to be done in two phases, the first costing 75 million. "Canada has a strong program of radio astronomy, and in particular a skilled team of specialists in designing correlators, and we are pleased to have their talents directed toward building a new machine for the VLA," Vanden Bout said. ALMA will consist of 64 12-meter-diameter dish antennas comprising a single imaging telescope to study the universe at millimeter and submillimeter wavelengths - the region between radio waves and infrared waves. An international project being designed and developed by the U.S. and European nations, ALMA will be located on a high-altitude site in the Atacama desert of Chile. "ALMA will give scientists an unprecedented look at the structure of the early universe and revolutionary insights on how stars and planets form, among many other contributions," Vanden Bout said. "The EVLA will bring unmatched power and versatility to the study of objects as close as the Sun and planets and as far as primeval galaxies at the edge of the observable universe. Together, these two instruments will be at the forefront of 21st Century astrophysics," he added. "ALMA has been a bilateral project involving the United States and Europe. These new agreements with Canada turn ALMA into a partnership between Europe and North America," Vanden Bout said. Design and development work on ALMA has been ongoing since 1998, funded by the NSF and European organizations. Canadians already have participated in this work. ALMA is planned for completion this decade. The new partnership calls for Canada to seek funding for a 20 million (US) contribution toward construction of ALMA. The total construction cost of ALMA is 552 million (2000 US), to be shared equally between Europe and North America. Under both letters of intent, applications for observing time on ALMA and NRAO radio telescopes, including the VLA, the Very Long Baseline Array (VLBA), and the Green Bank Telescope (GBT), from Canadian scientists will be treated the same as applications from U.S. scientists. Also, Canadian scientists will be appointed to NRAO advisory and oversight committees, and U.S. scientists will be appointed to similar Canadian committees. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

47 CFR 73.8000 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 73.509 TV 73.612 Interference to Astronomy, Research and Receiving installations, Notifications... interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical designation of FM...

SArdinia Roach2-based Digital Architecture for Radio Astronomy (SARDARA)

NASA Astrophysics Data System (ADS)

Melis, A.; Concu, R.; Trois, A.; Possenti, A.; Bocchinu, A.; Bolli, P.; Burgay, M.; Carretti, E.; Castangia, P.; Casu, S.; Pestellini, C. Cecchi; Corongiu, A.; D’Amico, N.; Egron, E.; Govoni, F.; Iacolina, M. N.; Murgia, M.; Pellizzoni, A.; Perrodin, D.; Pilia, M.; Pisanu, T.; Poddighe, A.; Poppi, S.; Porceddu, I.; Tarchi, A.; Vacca, V.; Aresu, G.; Bachetti, M.; Barbaro, M.; Casula, A.; Ladu, A.; Leurini, S.; Loi, F.; Loru, S.; Marongiu, P.; Maxia, P.; Mazzarella, G.; Migoni, C.; Montisci, G.; Valente, G.; Vargiu, G.

The Sardinia Radio Telescope (SRT) is a 64-m, fully-steerable single-dish radio telescope that was recently commissioned both technically and scientifically with regard to the basic observing modes. In order to improve the scientific capability and cover all the requirements for an advanced single-dish radio telescope, we developed the SArdinia Roach2-based Digital Architecture for Radio Astronomy (SARDARA), a wide-band, multi-feed, general-purpose, and reconfigurable digital platform, whose preliminary setup was used in the early science program of the SRT in 2016. In this paper, we describe the backend both in terms of its scientific motivation and technical design, how it has been interfaced with the telescope environment during its development and, finally, its scientific commissioning in different observing modes with single-feed receivers.

47 CFR 73.7005 - Holding period.

Code of Federal Regulations, 2011 CFR

2011-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

47 CFR Alphabetical Index - Part 73

Code of Federal Regulations, 2011 CFR

2011-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

47 CFR Alphabetical Index - Part 73

Code of Federal Regulations, 2010 CFR

2010-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

Technique to determine location of radio sources from measurements taken on spinning spacecraft

NASA Technical Reports Server (NTRS)

Fainberg, J.

1979-01-01

The procedure developed to extract average source direction and average source size from spin-modulated radio astronomy data measured on the IMP-6 spacecraft is described. Because all measurements are used, rather than just finding maxima or minima in the data, the method is very sensitive, even in the presence of large amounts of noise. The technique is applicable to all experiments with directivity characteristics. It is suitable for onboard processing on satellites to reduce the data flow to Earth. The application to spin-modulated nonpolarized radio astronomy data is made and includes the effects of noise, background, and second source interference. The analysis was tested with computer simulated data and the results agree with analytic predictions. Applications of this method with IMP-6 radio data have led to: (1) determination of source positions of traveling solar radio bursts at large distances from the Sun; (2) mapping of magnetospheric radio emissions by radio triangulation; and (3) detection of low frequency radio emissions from Jupiter and Saturn.

Radio astronomy Explorer B antenna aspect processor

NASA Technical Reports Server (NTRS)

Miller, W. H.; Novello, J.; Reeves, C. C.

1972-01-01

The antenna aspect system used on the Radio Astronomy Explorer B spacecraft is described. This system consists of two facsimile cameras, a data encoder, and a data processor. Emphasis is placed on the discussion of the data processor, which contains a data compressor and a source encoder. With this compression scheme a compression ratio of 8 is achieved on a typical line of camera data. These compressed data are then convolutionally encoded.

Working Papers: Astronomy and Astrophysics Panel Reports

NASA Technical Reports Server (NTRS)

Bahcall, John N.; Beichman, Charles A.; Canizares, Claude; Cronin, James; Heeschen, David; Houck, James; Hunten, Donald; Mckee, Christopher F.; Noyes, Robert; Ostriker, Jeremiah P.

1991-01-01

The papers of the panels appointed by the Astronomy and Astrophysics survey Committee are compiled. These papers were advisory to the survey committee and represent the opinions of the members of each panel in the context of their individual charges. The following subject areas are covered: radio astronomy, infrared astronomy, optical/IR from ground, UV-optical from space, interferometry, high energy from space, particle astrophysics, theory and laboratory astrophysics, solar astronomy, planetary astronomy, computing and data processing, policy opportunities, benefits to the nation from astronomy and astrophysics, status of the profession, and science opportunities.

Astronomers Win Protection for Key Part of Radio Spectrum

NASA Astrophysics Data System (ADS)

2000-06-01

Astronomers using the millimeter-wave region of the radio spectrum have won crucial protection for their science. Dedicated allocations for radio astronomy have been given final approval by the 2,500 delegates to the World Radiocommunication Conference (WRC-00), which recently concluded a month of deliberations in Istanbul, Turkey. Radio services can transmit in these parts of the spectrum as long as they don't hinder astronomers' attempts to catch faint signals from the cosmos. The new allocations represent the culmination of more than three years of cooperative planning by radio astronomers in many countries. Millimeter waves -- high-frequency radio waves -- have come of age as an astronomical tool in the last ten years. They are one of the last technological frontiers for astronomers. WRC-00 has protected for science all the frequencies between 71 and 275 Gigahertz (GHz) that radio astronomers currently use, adding more than 90 GHz of spectrum to the 44 GHz already set aside in this frequency range. As a result, radio astronomy is now allocated most of the frequencies between 71 and 275 GHz that can get through the Earth's atmosphere. "We have formal access to all three atmospheric 'windows', apart from their very edges," said Dr. Tom Gergely of the National Science Foundation, one of the U.S. delegates to WRC-00. The WRC also changed most of the frequencies allocated to satellite downlinks within the 71-275 GHz range to frequencies not used for science. Since no satellites yet operate at these high frequencies, no equipment needs to be altered. "Commercial technologies are just starting to develop above 50 GHz," said Dr. Klaus Ruf, Chairman of the Inter-Union Commission for the Allocation of Frequencies. "The WRC's actions mean that, when they are, radio astronomers should be able to share this part of the spectrum with most terrestrial services." The World Radiocommunication Conference is held every two or three years. Here member countries of the International Telecommunication Union meet to painstakingly parcel out the radio frequency spectrum between radio-based applications such as personal communications, satellite broadcasting, GPS and amateur radio, and the sciences of radio astronomy, earth exploration and deep space research. The WRC also coordinates sharing between services in the same radio bands. WRC decisions are incorporated into the Radio Regulations that govern radio services worldwide. The new spectrum allocations for radio astronomy are the first since 1979. Millimeter-wave astronomy was then in its infancy and many of its needs were not yet known. As astronomers began to explore this region of the spectrum they found spectral lines from many interesting molecules in space. Many of those lines had not fallen into the areas originally set aside for astronomy, but most will be under the new allocations. "It's a win for millimeter-wave science," said Dr. John Whiteoak of the Australia Telescope National Facility, Australian delegate to WRC-00. "This secures its future." The protection is a significant step for both existing millimeter-wave telescopes and new ones such as the Atacama Large Millimeter Array (ALMA) now being planned by a U.S.-European consortium. Even at its isolated site in Chile's Atacama desert, ALMA would be vulnerable to interference from satellite emissions. Sensitive radio astronomy receivers are blinded by these emissions, just as an optical telescope would be by a searchlight. "There is more energy at millimeter and sub-millimeter wavelengths washing through the Universe than there is of light or any other kind of radiation," said ALMA Project Scientist, Dr. Al Wootten of the National Radio Astronomy Observatory. "Imaging the sources of this energy can tell us a great deal about the formation of stars and galaxies, and even planets." "But the Earth's atmosphere isn't very kind to us - it has only a few windows at these frequencies, and not very transparent ones at that. They are easily clogged up. It's very important that we keep them as free as possible from interference." The new spectrum allocations were welcomed by Dr Johannes Andersen, General Secretary of the International Astronomical Union, which represents astronomers worldwide. "Protecting our ability to observe the Universe is the top priority for the International Astronomical Union," he said. "This action shows that international bodies accept the need for environmental emission standards in space as well as on Earth, for the benefit of all."

47 CFR 73.8000 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

47 CFR 73.8000 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

47 CFR 73.9009 - Manufacture for exportation.

Code of Federal Regulations, 2010 CFR

2010-10-01

....318 Interference, Protection from— FM 73.209 NCE-FM 73.509 TV 73.612 Interference to Astronomy... concerning interference to Radio Astronomy, Research and Receiving installations 73.1030 Numerical...

Radio Astronomy at the Centre for High Performance Computing in South Africa

NASA Astrophysics Data System (ADS)

Catherine Cress; UWC Simulation Team

2014-04-01

I will present results on galaxy evolution and cosmology which we obtained using the supercomputing facilities at the CHPC. These include cosmological-scale N-body simulations modelling neutral hydrogen as well as the study of the clustering of radio galaxies to probe the relationship between dark and luminous matter in the universe. I will also discuss the various roles that the CHPC is playing in Astronomy in SA, including the provision of HPC for a variety of Astronomical applications, the provision of storage for radio data, our educational programs and our participation in planning for the SKA.

Radio Frequency Interference: Radio Astronomy's Biggest Enemy

NASA Astrophysics Data System (ADS)

Acevedo, F.; Ghosh, Tapasi

1997-12-01

As technology progresses, the demand for the usage of the electromagnetic spectrum increases with it. The development is so fast and prolific that clean band space for passive users such as Radio Astronomy is becoming ever so scarce. Even though, several spectral bands have been protected for Radio Astronomy by Federal Communication Commission (in the USA) under the recommendations of the International Telecommunication Union (ITU), pressure for making more spectral space commercially usable is extreme. Although these commercial usages make our modern living at all possible, often the extreme vulnerability of passive users are are not fully appreciated, resulting in unwanted emissions (RFI) in the Radio Astronomy Bands. Another source of RFI is the fact that many of the electronic devices used in the observatories themselves generate radio waves. If proper precautions are not taken, these can be received back through the Radio Telescope itself. This problem is referred to as internal RFI. The focus of this paper is the search and diminution of internal RFI in the Arecibo Observatory in Arecibo, Puerto Rico. Using a simple setup of a log-periodic antenna and a Spectrum Analyzer, spectra spanning a frequency range of 100 - 1800 MHZ were recorded in some areas of the Observatory and the new Visitor Center (AOVEF). The measurements disclosed sources of radio emission among some of the digital electronic equipment in the Equipment room and a few displays in the AOVEF. Most prominent of these was a 2.5 MHz comb spanning the entire range of the measurements emitted from the SRENDIP and AOFTM machines. The respective groups were informed and corrective shielding & isolations were implemented immediately. In AOVEF, three displays, some audio-visual equipment, and video/digital cameras used by the visitors were found to be "leaky". In future, the use of such cameras will be prohibited and the exhibits will be screened appropriately.

Antenna design and implementation for the future space Ultra-Long wavelength radio telescope

NASA Astrophysics Data System (ADS)

Chen, Linjie; Aminaei, Amin; Gurvits, Leonid I.; Wolt, Marc Klein; Pourshaghaghi, Hamid Reza; Yan, Yihua; Falcke, Heino

2018-04-01

In radio astronomy, the Ultra-Long Wavelengths (ULW) regime of longer than 10 m (frequencies below 30 MHz), remains the last virtually unexplored window of the celestial electromagnetic spectrum. The strength of the science case for extending radio astronomy into the ULW window is growing. However, the opaqueness of the Earth's ionosphere makes ULW observations by ground-based facilities practically impossible. Furthermore, the ULW spectrum is full of anthropogenic radio frequency interference (RFI). The only radical solution for both problems is in placing an ULW astronomy facility in space. We present a concept of a key element of a space-borne ULW array facility, an antenna that addresses radio astronomical specifications. A tripole-type antenna and amplifier are analysed as a solution for ULW implementation. A receiver system with a low power dissipation is discussed as well. The active antenna is optimized to operate at the noise level defined by the celestial emission in the frequency band 1 - 30 MHz. Field experiments with a prototype tripole antenna enabled estimates of the system noise temperature. They indicated that the proposed concept meets the requirements of a space-borne ULW array facility.

The NRAO Observing for University Classes Program

NASA Astrophysics Data System (ADS)

Cannon, John M.; Van Moorsel, Gustaaf A.

2017-01-01

The NRAO "Observing for University Classes" program is a tremendous resource for instructors of courses in observational astronomy. As a service to the astronomical and educational communities, the NRAO offers small amounts of observing time on the Very Large Array (VLA) and the Very Long Baseline Array to such instructors. The data can be used by students and faculty to demonstrate radio astronomy theory with modern data products. Further, the results may lead to publication; this is a unique opportunity for faculty members to integrate research into the classroom. Previous experience with NRAO facilities is required for instructors; individuals without radio astronomy experience can take advantage of other NRAO educational opportunities (e.g., the Synthesis Imaging Workshop) prior to using the program. No previous experience with radio astronomy data is required for students; this is the primary target audience of the program. To demonstrate concept, this poster describes three different VLA observing programs that have been completed using the "Observing for University Classes" resource at Macalester College; undergraduate students have published the results of all three of these programs. Other recent "Observing for University Classes" programs are also described.

The Radio JOVE Project - An Inexpensive Introduction to Radio Astronomy

NASA Astrophysics Data System (ADS)

Thieman, J. R.; Higgins, C.

2004-12-01

The Radio JOVE project began over six years ago as an education-centered program to inspire secondary school students' interest in space science through hands-on radio astronomy. The project was begun on small grants from the Goddard Space Flight Center Director's Discretionary Fund, the Initiative to Develop Education through Astronomy and Space Science (IDEAS) program, and the American Astronomical Society. Students build a radio receiver and antenna kit capable of receiving Jovian, solar, and galactic emissions at a frequency of 20.1 MHz. More than 600 of these kits have been distributed to students and interested observers (ages 10 through adult) in over 30 countries. For those who are not comfortable building their own kit, the Radio JOVE project has made it possible to monitor real-time data and streaming audio online from professional radio telescopes in Florida (http://jupiter.kochi-ct.jp) and Hawaii http://jupiter.wcc.hawaii.edu/newradiojove/main.html). Freely downloadable software called Radio-Skypipe (http://radiosky.com) emulates a chart recorder to monitor ones own radio telescope or the telescopes of other observers worldwide who send out their data over the Internet. Inexpensive spectrographs have been developed for the professional telescopes in Hawaii and Florida and freely downloadable spectrograph display software is available to receive this research-quality data. We believe the amateur network data to be of value to the research community and would like to have students more directly connected to ongoing research projects to enhance their interest in participating. Results of the project and plans for the future will be highlighted.

Information Content in Radio Waves: Student Investigations in Radio Science

NASA Astrophysics Data System (ADS)

Jacobs, K.; Scaduto, T.

2013-12-01

We describe an inquiry-based instructional unit on information content in radio waves, created in the summer of 2013 as part of a MIT Haystack Observatory (Westford, MA) NSF Research Experiences for Teachers (RET) program. This topic is current and highly relevant, addressing science and technical aspects from radio astronomy, geodesy, and atmospheric research areas as well as Next Generation Science Standards (NGSS). Projects and activities range from simple classroom demonstrations and group investigations, to long term research projects incorporating data acquisition from both student-built instrumentation as well as online databases. Each of the core lessons is applied to one of the primary research centers at Haystack through an inquiry project that builds on previously developed units through the MIT Haystack RET program. In radio astronomy, students investigate the application of a simple and inexpensive software defined radio chip (RTL-SDR) for use in systems implementing a small and very small radio telescope (SRT and VSRT). Both of these systems allow students to explore fundamental principles of radio waves and interferometry as applied to radio astronomy. In ionospheric research, students track solar storms from the initial coronal mass ejection (using Solar Dynamics Observatory images) to the resulting variability in total electron density concentrations using data from the community standard Madrigal distributed database system maintained by MIT Haystack. Finally, students get to explore very long-baseline interferometry as it is used in geodetic studies by measuring crustal plate displacements over time. Alignment to NextGen standards is provided for each lesson and activity with emphasis on HS-PS4 'Waves and Their Applications in Technologies for Information Transfer'.

Development of Telecommunications of Prao ASC Lpi RAS

NASA Astrophysics Data System (ADS)

Isaev, E. A.; Dumskiy, D. V.; Likhachev, S. F.; Shatskaya, M. V.; Pugachev, V. D.; Samodurov, V. A.

The new modern and reliable data storage system was acquired in 2010 in order to develop internal telecommunication resources of the Observatory. The system is designed for store large amounts of observation data obtained from the three radio-astronomy complexes (PT-22, DKR-1000 and BSA). The digital switching system - "Elcom" is installed in the Pushchino Radio Astronomy Observatory to ensure the observatory by phone communications. The phone communication between buildings of the observatory carried out over fiber-optic data links by using the ip-telephony. The direct optical channel from tracking station RT-22 in Pushchino to Moscow processing center has been created and put into operation to transfer large amounts of data at the final stage of the establishment of ground infrastructure for the international space project "Radioastron". A separate backup system for processing and storing data is organized in Pushchino Radio Astronomy Observatory to eliminate data loss during communication sessions with the Space Telescope.

Goldstone-Apple Valley Radio Telescope System Theory of Operation

NASA Technical Reports Server (NTRS)

Stephan, George R.

1997-01-01

The purpose of this learning module is to enable learners to describe how the Goldstone-Apple Valley Radio Telescope (GAVRT) system functions in support of Apple Valley Science and Technology Center's (AVSTC) client schools' radio astronomy activities.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1985-01-01

Reports on developments in space communications, radio navigation, radio science, and ground-based radio astronomy are presented. Activities of the Deep Space Network (DSN) are reported in the areas of planning, supporting research and technology, implementation and operations. The application of radio interferometry at microwave frequencies for geodynamic measurements is also discussed.

Future Trends in Solar Radio Astronomy and Coronal Magnetic-Field Measurements

NASA Astrophysics Data System (ADS)

Fleishman, Gregory; Nita, Gelu; Gary, Dale

Solar radio astronomy has an amazingly rich, but yet largely unexploited, potential for probing the solar corona and chromosphere. Radio emission offers multiple ways of detecting and tracking electron beams, studying chromospheric and coronal thermal structure, plasma processes, particle acceleration, and measuring magnetic fields. To turn the mentioned potential into real routine diagnostics, two major components are needed: (1) well-calibrated observations with high spatial, spectral, and temporal resolutions and (2) accurate and reliable theoretical models and fast numerical tools capable of recovering the emission source parameters from the radio data. This report gives a brief overview of the new, expanded, and planned radio facilities, such as Expanded Owens Valley Solar Array (EOVSA), Jansky Very Large Array (JVLA), Chinese Solar Radio Heliograph (CSRH), Upgraded Siberian Solar Radio Telescope (USSRT), and Frequency Agile Solar Radiotelescope (FASR) with the emphasis on their ability to measure the coronal magnetic fields in active regions and flares. In particular, we emphasize the new tools for 3D modeling of the radio emission and forward fitting tools in development needed to derive the magnetic field data from the radio measurements.

The new 64m Sardinia Radio Telescope and VLBI facilities in Italy

NASA Astrophysics Data System (ADS)

Giovannini, Gabriele; Feretti, Luigina; Prandoni, Isabella; Giroletti, Marcello

2015-08-01

The Sardinia Radio Telescope (SRT) is a new major radio astronomical facility available in Italy for single dish and interferometric observations. It represents a flexible instrument for Radio Astronomy, Geodynamical studies and Space Science, either in single dish or VLBI mode. The SRT combines a 64m steerable collecting area, one of the largest all over the World with state-of-the-art technology (including an active surface) to enable high efficiency observations up to the 3-mm band.This new radio telescope together with the two 32m antennas in Noto and Medicina can be used for VLBI observations on a national basis (VLBIT). Data can be correlated in a short time (in real time soon) thanks to fiber-optics connection among the radio telescopes and the software correlator installed at the Radio Astronomy Institute in Bologna (IRA/INAF). In the poster I will present capabilities of the SRT telescope as well as the VLBIT project and I will shortly discuss the scientific prospects of the VLBIT.

Investigation of radio astronomy image processing techniques for use in the passive millimetre-wave security screening environment

NASA Astrophysics Data System (ADS)

Taylor, Christopher T.; Hutchinson, Simon; Salmon, Neil A.; Wilkinson, Peter N.; Cameron, Colin D.

2014-06-01

Image processing techniques can be used to improve the cost-effectiveness of future interferometric Passive MilliMetre Wave (PMMW) imagers. The implementation of such techniques will allow for a reduction in the number of collecting elements whilst ensuring adequate image fidelity is maintained. Various techniques have been developed by the radio astronomy community to enhance the imaging capability of sparse interferometric arrays. The most prominent are Multi- Frequency Synthesis (MFS) and non-linear deconvolution algorithms, such as the Maximum Entropy Method (MEM) and variations of the CLEAN algorithm. This investigation focuses on the implementation of these methods in the defacto standard for radio astronomy image processing, the Common Astronomy Software Applications (CASA) package, building upon the discussion presented in Taylor et al., SPIE 8362-0F. We describe the image conversion process into a CASA suitable format, followed by a series of simulations that exploit the highlighted deconvolution and MFS algorithms assuming far-field imagery. The primary target application used for this investigation is an outdoor security scanner for soft-sided Heavy Goods Vehicles. A quantitative analysis of the effectiveness of the aforementioned image processing techniques is presented, with thoughts on the potential cost-savings such an approach could yield. Consideration is also given to how the implementation of these techniques in CASA might be adapted to operate in a near-field target environment. This may enable a much wider usability by the imaging community outside of radio astronomy and thus would be directly relevant to portal screening security systems in the microwave and millimetre wave bands.

47 CFR 2.106 - Table of Frequency Allocations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... astronomy service from harmful interference. Emissions from spaceborne or airborne stations can be particularly serious sources of interference to the radio astronomy service (see Nos. 4.5 and 4.6 and Article...

47 CFR 95.1113 - Frequency coordinator.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1113 Frequency coordinator. (a... with radio astronomy observatories and Federal Government radar systems as specified in §§ 95.1119 and...

47 CFR 95.1113 - Frequency coordinator.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PERSONAL RADIO SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1113 Frequency coordinator. (a... with radio astronomy observatories and Federal Government radar systems as specified in §§ 95.1119 and...

Radio astronomy Explorer-B postlaunch attitude operations analysis

NASA Technical Reports Server (NTRS)

Werking, R. D.; Berg, R.; Brokke, K.; Hattox, T.; Lerner, G.; Stewart, D.; Williams, R.

1974-01-01

The attitude support activities of the Radio Astronomy Explorer-B are reported. The performance of the spacecraft hardware and software are discussed along with details of the mission events, from launch through main boom deployment. Reproductions of displays are presented which were used during support activities. The interactive graphics proved the support function by providing the quality control necessary to ensure mission success in an environment where flight simulated ground testing of spacecraft hardware cannot be performed.

Kinds of Astronomy-5

NASA Technical Reports Server (NTRS)

Ennico, Kimberly; DeVincenzi, D. (Technical Monitor)

2001-01-01

Astronomers study light and basically, almost everything we know about the universe has been figured out through the study of light gathered by telescopes on the earth, in the earth's atmosphere, and in space. This light comes in many different colors, the sum of which comprises what is commonly I known as the electromagnetic (EM) spectrum. Unfortunately, the earth's atmosphere blocks almost all of wavelengths in the EM spectrum. Only the visible (400-700 mn) and radio (approx. 1-150 m) "windows" are accessible from the ground, and thus have the longest observational "history." These early restrictions on the observational astronomer also gave rise to classifying "kinds" of astronomy based on their respective EM portion, such as the term "radio astronomy."

Importance of a Low Radio Frequency Interference Environment for the DSG

NASA Astrophysics Data System (ADS)

MacDowall, R. J.; Farrell, W. M.; Burns, J. O.

2018-02-01

The Deep Space Gateway (DSG) can serve radio astronomy in a variety of ways. Thus, it is important that DSG electronics, transmitters, and the instruments located on the DSG avoid contaminating the radio-quiet environment of the lunar far-side.

Radio Jove: Citizen Science for Jupiter Radio Astronomy

NASA Astrophysics Data System (ADS)

Higgins, C. A.; Thieman, J.; Reyes, F. J.; Typinski, D.; Flagg, R. F.; Greenman, W.; Brown, J.; Ashcraft, T.; Sky, J.; Cecconi, B.; Garcia, L. N.

2016-12-01

The Radio Jove Project (http://radiojove.gsfc.nasa.gov) has been operating as an educational activity for 18 years to introduce radio astronomy activities to students, teachers, and the general public. Participants may build a simple radio telescope kit, make scientific observations, and interact with radio observatories in real-time over the Internet. Recently some of our dedicated citizen science observers have upgraded their systems to better study radio emission from Jupiter and the Sun by adding dual-polarization spectrographs and wide-band antennas in the frequency range of 15-30 MHz. Some of these observations are being used in conjunction with professional telescopes such as the Long Wavelength Array (LWA), the Nancay Decametric Array, and the Ukrainian URAN2 Radio Telescope. In particular, there is an effort to support the Juno Mission radio waves instrument at Jupiter by using citizen science ground-based data for comparison and polarization verification. These data will be archived through a Virtual European Solar and Planetary Access (VESPA) archive (https://voparis-radiojove.obspm.fr/radiojove/welcome) for use by the amateur and professional radio science community. We overview the program and display recent observations that will be of interest to the science community.

The Radio JOVE Project

NASA Astrophysics Data System (ADS)

Garcia, L.; Thieman, J.; Higgins, C.

1999-09-01

Radio JOVE is an interactive educational activity which brings the radio sounds of Jupiter and the Sun to students, teachers, and the general public. This is accomplished through the construction of a simple radio telescope kit and the use of a real-time radio observatory on the Internet. Our website (http://radiojove.gsfc.nasa.gov/) will contain science information, instruction manuals, observing guides, and education resources for students and teachers. Our target audience is high school science classes, but subjects can be tailored to college undergraduate physics and astronomy courses or even to middle school science classes. The goals of the project are: 1) Educate people about planetary and solar radio astronomy, space physics, and the scientific method 2) Provide teachers and students with a hands-on radio astronomy exercise as a science curriculum support activity by building and using a simple radio telescope receiver/antenna kit 3) Create the first ever online radio observatory which provides real-time data for those with internet access 4) Allow interactions among participating schools by facilitating exchanges of ideas, data, and observing experiences. Our current funding will allow us to impact 100 schools by partially subsidizing their participation in the program. We expect to expand well beyond this number as publicity and general interest increase. Additional schools are welcome to fully participate, but we will not be able to subsidize their kit purchases. We hope to make a wide impact among the schools by advertising through appropriate newsletters, space grant consortia, the INSPIRE project (http://image.gsfc.nasa.gov/poetry/inspire/), electronic links, and science and education meetings. We would like to acknoledge support from the NASA/GSFC Director's Discretionary Fund, the STScI IDEAS grant program and the NASA/GSFC Space Science Data Operations Office.

Summary of interference measurements at selected radio observatories

NASA Technical Reports Server (NTRS)

Tarter, Jill C.

1990-01-01

Results are presented from a series of RF interference (RFI) observations conducted during 1989 and 1990 at selected radio astronomy observatories in order to choose a site for the SETI, where the local and orbital RFI would be as benign as possible for observations of weak electromagnetic signals. These observatories included the DSS13 at Goldstone (California), the Arecibo Observatory (Puerto Rico), the Algonquin Radio Observatory in Ottawa (Canada), the Ohio State University Radio Observatory in Columbus (Ohio), and the NRAO in Green Bank (West Virginia). The observations characterize the RFI environment at these sites from 1 to 10 GHz, using radio astronomy antennas, feeds, and receivers; SETI signal processors; and stand-alone equipment built specifically for this purpose. The results served as part of the basis for the selection (by the NASA SETI Microwave Observing Project) of NRAO as the site of choice for SETI observations.

Transient Phenomena: Opportunities for New Discoveries

NASA Technical Reports Server (NTRS)

Lazio, T. Joseph W.

2010-01-01

Known classes of radio wavelength transients range from the nearby (stellar flares and radio pulsars) to the distant Universe (gamma-ray burst afterglows). Hypothesized classes of radio transients include analogs of known objects, such as extrasolar planets emitting Jovian-like radio bursts and giant-pulse emitting pulsars in other galaxies, to the exotic, such as prompt emission from gamma-ray bursts, evaporating black holes and transmitters from other civilizations. Time domain astronomy has been recognized internationally as a means of addressing key scientific questions in astronomy and physics, and pathfinders and Precursors to the Square Kilometre Array (SKA) are beginning to offer a combination of wider fields of view and more wavelength agility than has been possible in the past. These improvements will continue when the SKA itself becomes operational. I illustrate the range of transient phenomena and discuss how the detection and study of radio transients will improve immensely.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1991-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN). Also included is standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. In the search for extraterrestrial intelligence (SETI), 'The TDA Progress Report' reports on implementation and operations for searching the microwave spectrum. In solar system radar, it reports on the uses of the Goldstone Solar System Radar for scientific exploration of the planets, their rings and satellites, asteroids, and comets. In radio astronomy, the areas of support include spectroscopy, very long baseline interferometry, and astrometry.

Molonglo Observatory: Building the Cross and MOST

NASA Astrophysics Data System (ADS)

McAdam, Bruce

2008-03-01

When Bernard Mills left the GSIRO in 1960 to establish a radio astronomy group in the School of Physics, University of Sydney, he had not only invented the principle of cross-type radio telescopes but proved their great efficiency at surveying the positions, intensity and structure of radio sources. He had ambitious plans for a second generation Cross - a radio telescope with arms one mile long. This paper describes the circumstances of Mills' appointment as Professor of Astrophysics and the recruitment of an international Department that achieved his vision with the Molonglo Cross: The construction involved interaction with many colleagues - engineers in other university departments and government agencies, and with the contracting firms. Formal links were set up with the Electrical Engineering Department through The Radio Astronomy Centre in the University of Sydney and then with Arecibo Observatory through the Cornell-Sydney University Astronomy Center. When the Molonglo Cross completed its main survey in 1978 after eleven years, it was switched off and the EW arm was then converted to the Molonglo Observatory Synthesis Telescope. Many of the staff involved with the MOST are now challenged by SKAMP, testing systems for the Square Kilometre Array with cylindrical geometry in the Molonglo Prototype. These two later developments out of the original Cross telescope are described briefly.

Harmonization based on regulatory science between scientific and commercial radio uses in a case of ultrawideband radio

NASA Astrophysics Data System (ADS)

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.

Next Generation Summer School

NASA Astrophysics Data System (ADS)

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). The lecture was sustained by Physicist Paul Dolea, researcher at BITNET CCSS and PhD in Electronic Engineer and Telecommunications at Technical University from Cluj. There were presented several didactic-demonstrative prototypes of radio transmission of audio and video signals, with directive reception antenna. We benefited from the BITNET firm help which allowed the students to visit the equipments for C and Ku bands reception, with 4m diameter parabolic antenna and 14 tones foundation. The students were also presented the S band communication equipment with low altitude artificial satellites. The parabolic antenna with 3m in diameter is able to detect everywhere on the sky the extremely fast satellites situated at thousands of kilometres distance, which "are crossing" the sky in only several minutes. Most of the students climbed the platform under the cupola designated to the astronomical observations in visible spectrum and took pictures. The following days were lectured on topics of theoretical astronomy and astrophysics and during the nights were made astronomical observations. All the students received diplomas to certify their participation to the first "Next Generation" Summer School. This summer school will be organised from now on every summer, in Marisel area from Cluj. Since then the summer school has been held each year.

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Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-05

... Number: 3060-0698. Title: Section 25.203(i) and 73.1030(a)(2), Radio Astronomy Coordination Zone in... Astronomy Observatory to receive information needed to assess whether an applicant's proposed operations...

Astronomy from the Moon: A New Frontier for 21st Century Astrophysics

NASA Astrophysics Data System (ADS)

Durst, Steve

2018-06-01

The International Lunar Observatory Association of Hawai'i USA continues into its second decade with research and development of South Pole instruments for astronomy, observation and communication from the Moon. Since the pioneering first astronomy observations from the Moon by Apollo 16 Commander John Young (an ILOA founding-emeritus director until his recent passing), with China Lunar Ultraviolet Telescope LUT operations and current American and European considerations for far-side radio telescopes, today's climate is most promising for a diversity of lunar-based astronomy locations, instruments and technologies. ILOA is aiming to advance this frontier through its Galaxy First Light Imaging program, being developed through contracts with Moon Express and Canadensys Aerospace Corp.A wide variety of extreme and unique lunar conditions enable many astronomy activities and installations, on the Moon's near-side, far-side, north pole, and south pole: The extremely thin lunar exosphere favors observations in millimeter / submillimeter to optical, UV, X-ray, and gamma-ray wavelengths; the highly stable platform that is the Moon provides for long-duration observations; ultra cold, shaded areas for cryogenic infrared instruments; far-side radio-quiet environment for radio telescopes and VLF astronomy; 1/6-Earth gravity for production and utilization of new, very lightweight materials and instruments, including large refractors, 100-m class liquid mirror telescopes, and possibly 1,000-m class radio telescopes and interferometer antenna arrays vastly larger than Atacama LMA; North and especially South Pole sites, with high peaks and long solar power windows, offer perhaps the widest variety of lunar conditions and opportunities for astronomical innovation on the Moon: a veritable "condominium of observatories".21st century astrophysics seems likely to find Luna a very busy and productive new frontier, as American Astronomical Society and IAU members will validate, with astronomers providing rationale and direction for lunar outpost build-out, while offering Galaxy / Cosmos perspective on the human advance towards a multi world civilization.

Distinguished Astronomer Awarded Jansky Lectureship

NASA Astrophysics Data System (ADS)

2008-05-01

Associated Universities, Inc. (AUI), and the National Radio Astronomy Observatory (NRAO) have awarded the 2008 Karl G. Jansky Lectureship to Dr. Arthur M. Wolfe of the University of California, San Diego (UCSD). The Jansky Lectureship is an honor established by the trustees of AUI to recognize outstanding contributions to the advancement of radio astronomy. Dr. Arthur M. Wolfe Dr. Arthur M. Wolfe CREDIT: UCSD Click on image for high-resolution file Dr. Wolfe has made major contributions in several areas of astronomy. Along with Rainer Sachs, he predicted the Sachs-Wolfe Effect, a phenomenon which forms the basis for modern precision cosmology using the background radio emission left over from the Big Bang. In the 1970s, he discovered that light emitted by very distant galaxies is absorbed by hydrogen atoms in previously-undetected intervening gas clouds. From the 1980s until the present, he used optical light emitted by distant quasars to show that these clouds are the progenitors of stars found in modern galaxies. This phenomenon has since been used extensively to study the production of heavy elements and history of star formation in the Universe. He also did landmark research on whether the fundamental constants of nature, such as the charge of the electron and the masses of elementary particles, do, in fact, remain constant through cosmological time. Dr. Wolfe was the Director of the Center for Astrophysics and Space Sciences at UCSD from 1997 to 2007. He joined UCSD as a Professor of Physics and Astronomy in 1989, leaving the University of Pittsburgh, where he had taught since 1973. He holds the Chancellor's Associates Chair of Physics at UCSD. Dr. Wolfe received his Ph.D from the University of Texas at Austin. He is a Fellow of the American Academy of Arts and Sciences, and received the Sackler Fellowship of the Institute of Astronomy at the University of Cambridge, UK, in 2004. As Jansky Lecturer, Wolfe will give a presentation entitled, Finding the Gas that Makes Galaxies, at NRAO facilities in Charlottesville, Virginia, Green Bank, West Virginia, and Socorro, New Mexico. The dates of these scientific lectures, which are open to the public, will be announced later. This is the forty-third Jansky Lectureship. First awarded in 1966, it is named in honor of the man who, in 1932, first detected radio waves from a cosmic source. Karl Jansky's discovery of radio waves from the central region of the Milky Way started the science of radio astronomy. Other recipients of the Jansky award include five Nobel laureates (Drs. Subrahmanyan Chandrasekhar, Arno Penzias, Robert Wilson, William Fowler, and Joseph Taylor) as well as Jocelyn Bell-Burnell, discoverer of the first pulsar, and Vera Rubin, discoverer of dark matter in galaxies. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Deep Space Telecommunications

NASA Technical Reports Server (NTRS)

Kuiper, T. B. H.; Resch, G. M.

2000-01-01

The increasing load on NASA's deep Space Network, the new capabilities for deep space missions inherent in a next-generation radio telescope, and the potential of new telescope technology for reducing construction and operation costs suggest a natural marriage between radio astronomy and deep space telecommunications in developing advanced radio telescope concepts.

Radio Frequency Interference Site Survey for Thai Radio Telescopes

NASA Astrophysics Data System (ADS)

Jaroenjittichai, P.; Punyawarin, S.; Singwong, D.; Somboonpon, P.; Prasert, N.; Bandudej, K.; Kempet, P.; Leckngam, A.; Poshyachinda, S.; Soonthornthum, B.; Kramer, B.

2017-09-01

Radio astronomical observations have increasingly been threaten by the march of today telecommunication and wireless technology. Performance of radio telescopes lies within the fact that astronomical sources are extremely weak. National Astronomy Research Institute of Thailand (NARIT) has initiated a 5-year project, known as the Radio Astronomy Network and Geodesy for Development (RANGD), which includes the establishment of 40-meter and 13-meter radio telescopes. Possible locations have been narrowed down to three candidates, situated in the Northern part of Thailand, where the atmosphere is sufficiently dry and suitable for 22 and 43 GHz observations. The Radio Frequency Interference (RFI) measurements were carried out with a DC spectrum analyzer and directional antennas at 1.5 meter above ground, from 20 MHz to 6 GHz with full azimuth coverage. The data from a 3-minute pointing were recorded for both horizontal and vertical polarizations, in maxhold and average modes. The results, for which we used to make preliminary site selection, show signals from typical broadcast and telecommunication services and aeronautics applications. The signal intensity varies accordingly to the presence of nearby population and topography of the region.

The Great Astronomical Ear.

ERIC Educational Resources Information Center

Hiatt, Blanchard

1980-01-01

Presents a description of the world's largest radio/radar antenna, the Areciba Observatory in Puerto Rico. Activities at the observatory are discussed as well as the scientific research in the field of radio astronomy. (SA)

Radio Astronomy Software Defined Receiver Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vacaliuc, Bogdan; Leech, Marcus; Oxley, Paul

The paper describes a Radio Astronomy Software Defined Receiver (RASDR) that is currently under development. RASDR is targeted for use by amateurs and small institutions where cost is a primary consideration. The receiver will operate from HF thru 2.8 GHz. Front-end components such as preamps, block down-converters and pre-select bandpass filters are outside the scope of this development and will be provided by the user. The receiver includes RF amplifiers and attenuators, synthesized LOs, quadrature down converters, dual 8 bit ADCs and a Signal Processor that provides firmware processing of the digital bit stream. RASDR will interface to a usermore » s PC via a USB or higher speed Ethernet LAN connection. The PC will run software that provides processing of the bit stream, a graphical user interface, as well as data analysis and storage. Software should support MAC OS, Windows and Linux platforms and will focus on such radio astronomy applications as total power measurements, pulsar detection, and spectral line studies.« less

Ionospheric Modelling using GPS to Calibrate the MWA. II: Regional Ionospheric Modelling using GPS and GLONASS to Estimate Ionospheric Gradients

NASA Astrophysics Data System (ADS)

Arora, B. S.; Morgan, J.; Ord, S. M.; Tingay, S. J.; Bell, M.; Callingham, J. R.; Dwarakanath, K. S.; For, B.-Q.; Hancock, P.; Hindson, L.; Hurley-Walker, N.; Johnston-Hollitt, M.; Kapińska, A. D.; Lenc, E.; McKinley, B.; Offringa, A. R.; Procopio, P.; Staveley-Smith, L.; Wayth, R. B.; Wu, C.; Zheng, Q.

2016-07-01

We estimate spatial gradients in the ionosphere using the Global Positioning System and GLONASS (Russian global navigation system) observations, utilising data from multiple Global Positioning System stations in the vicinity of Murchison Radio-astronomy Observatory. In previous work, the ionosphere was characterised using a single-station to model the ionosphere as a single layer of fixed height and this was compared with ionospheric data derived from radio astronomy observations obtained from the Murchison Widefield Array. Having made improvements to our data quality (via cycle slip detection and repair) and incorporating data from the GLONASS system, we now present a multi-station approach. These two developments significantly improve our modelling of the ionosphere. We also explore the effects of a variable-height model. We conclude that modelling the small-scale features in the ionosphere that have been observed with the MWA will require a much denser network of Global Navigation Satellite System stations than is currently available at the Murchison Radio-astronomy Observatory.

75 FR 65016 - Notice of Public Information Collection(s) Being Reviewed by the Federal Communications...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

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Construction of a Radio-Telescope Prototype in the 12 GHz Band

NASA Astrophysics Data System (ADS)

Ordóñez, J.; Quijano, A.; Luna, A.

2017-07-01

Radio astronomy is important in the branch of the Astronomy that studies the celestial bodies through their emissions in the domain of the radio waves, to obtain information of these bodies, astronomers must design new types of telescopes that can capture radiation at different wavelengths, including radio telescopes. This paper presents the construction of a prototype of an educational radio telescope, which is made using materials that are easily accessible and inexpensive. The construction of a radio telescope, will allow to carry out research in the field of radio astronomy, since at present it has not been possible to penetrate this branch due to the lack of an adequate equipment in the University of Nariño. The issues that are addressed in the construction of this instrument, its use and the analysis of the data, are very varied and with a high content of multidiciplinariety, gathering basic topics in areas such as astrophysics, physics, electronics, computing, mechanics, which are necessary for Concrete the efficient use of this instrument. For the development of the project, it counts with the advice of the director and researcher of the astronomical observatory of the University of Nariño MSc. Alberto Quijano Vodniza and Dr. Abraham Luna Castellanos of the National Institute of Astrophysics, Optics and Electronics INAOE. In addition to the construction of radiotelescope the final phase consists of the storage and analysis of data obtained with the observation of some celestial bodies that comply with The range in the 12 GHz band for study.

The telecommunications and data acquisition report

NASA Technical Reports Server (NTRS)

1980-01-01

Progress in the development and operations of the Deep Space Network is reported. Developments in Earth based radio technology as applied to geodynamics, astrophysics, and radio astronomy's use of the deep space stations for a radio search for extraterrestrial intelligence in the microwave region of the electromagnetic spectrum are reported.

Distribution of inhomogeneities in the interstellar plasma in the directions of three distant pulsars from observations with the RadioAstron ground-space interferometer

NASA Astrophysics Data System (ADS)

Popov, M. V.; Andrianov, A. S.; Bartel, N.; Gwinn, C.; Joshi, B. C.; Jauncey, D.; Kardashev, N. S.; Rudnitskii, A. G.; Smirnova, T. V.; Soglasnov, V. A.; Fadeev, E. N.; Shishov, V. I.

2016-09-01

The RadioAstron ground-space interferometer has been used to measure the angular sizes of the scattering disks of the three distant pulsars B1641-45, B1749-28, and B1933+16. The observations were carried out with the participation of the Westerbork Synthesis Radio Telescope; two 32-m telescopes at Torun, Poland and Svetloe, Russia (the latter being one antenna of the KVAZAR network); the Saint Croix VLBA antenna; the Arecibo radio telescope; the Parkes, Narrabri (ATCA), Mopra, Hobart, and Ceduna Australian radio telescopes; and the Hartebeesthoek radio telescope in South Africa. The full widths at half maximum of the scattering disks were 27 mas at 1668 MHz for B1641-45, 0.5 mas at 1668 MHz for B1749-28, and 12.3 at 316 MHz and 0.84 mas at 1668 MHz for B1933+16. The characteristic time scales for scatter-broadening of the pulses on inhomogeneities in the interstellar plasma τsc were also measured for these pulsars using various methods. Joint knowledge of the size of the scattering disk and the scatter-broadening time scale enables estimation of the distance to the effective scattering screen d. For B1641-45, d = 3.0 kpc for a distance to the pulsar D = 4.9 kpc, and for B1749-28, d = 0.95 kpc for D = 1.3 kpc. Observations of B1933+16 were carried out simultaneously at 316 and 1668 MHz. The positions of the screen derived using the measurements at the two frequencies agree: d 1 = 2.6 and d 2 = 2.7 kpc, for a distance to the pulsar of 3.7 kpc. Two screens were detected for this pulsar from an analysis of parabolic arcs in the secondary dynamic spectrum at 1668 MHz, at 1.3 and 3.1 kpc. The scattering screens for two of the pulsars are identified with real physical objects located along the lines of sight toward the pulsars: G339.1-04 (B1641-45) and G0.55-0.85 (B1749-28).

Ir A.H. de Voogt: life and career of a radio pioneer

NASA Astrophysics Data System (ADS)

Strom, R. G.

2007-06-01

There are probably few radio astronomers who would be able to recall A.H. de Voogt, which is unfortunate, but at the same time unsurprising: for he published no original astronomical research, never carried out pioneering observations, nor is his name linked to either theoretical or instrumental breakthroughs. Yet he was described by the man who first observed the 21 cm hydrogen line from the Netherlands as a radio astronomy pioneer, at the very birth of the Dutch effort. He was, moreover, a trail blazer at the cutting edge of radio, not once but twice in his career. Without him it is unlikely that the 21 cm line would have been observed in the Netherlands in 1951, and arguably the H I mapping of the Milky Way under Jan Oort's leadership would have taken place much later, if at all. Radio astronomy observing itself might well have been compromised by interference had it not been for De Voogt's foresight. \\ Anthonet Hugo de Voogt (1892-1969) built, while still a teenager, one of the very first amateur radio stations (call letters VO: *** -/- - -) in Holland, earned the radio-telegrapher's diploma during his student days, and was intimately involved in the foundation of the Dutch Society for Radio-Telegraphy in 1916. Until the 1920s, he was very active in amateur radio and astronomy circles. Trained in electrical engineering at Delft, he joined the PTT (Post Office) as a telegraph engineer in 1919, worked his way through the ranks to become head of the telephone district of Breda in 1939, and was promoted to head the PTT Radio Service just days after the end of the war. As his department was responsible for overseas radio communication, he initiated a research effort to study radio propagation in the ionosphere and the effects of solar activity. To this end, he rescued a number of Würzburg-Riese 7.5-m radar antennas abandoned at the end of the war, made one available for Jan Oort's H I work, and launched a series of radio astronomical initiatives. His group also built a number of antennas, monitored solar emission, and participated in the International Geophysical Year (1957-1958).

Application of Statistical Linear Time-Varying System Theory to Modeling of High Grazing Angle Sea Clutter

DTIC Science & Technology

2017-10-25

radar returns from a large object (such as a planet) in radio astronomy as a function of delay and Doppler shift using a so-called “scattering...from a planet in radar astronomy . Van Trees also briefly describes the scattering function in his 8 Corey D. Cooke most well-known book [7], as does... astronomy – communication via fluctuating multipath media,” rept. 234, MIT Lincoln Laboratory (October 1960). 6. P. E. Green, Jr., “Radar astronomy

The telecommunications and data acquisition

NASA Technical Reports Server (NTRS)

Renzetti, N. A. (Editor)

1980-01-01

Radio astronomy and radio interferometry at microwave frequencies are discussed. Other topics concerning the Deep Space Network include program planning, planetary and interplanetary mission support, tracking and ground based navigation, communications, and station control and system technology.

Discovering astronomy

NASA Technical Reports Server (NTRS)

Chapman, R. D.

1978-01-01

An overview of basic astronomical knowledge is presented with attention to the structure and dynamics of the stars and planets. Also dealt with are techniques of astronomical measurement, e.g., stellar spectrometry, radio astronomy, star catalogs, etc. Basic physical principles as they pertain to astronomy are reviewed, including the nature of light, gravitation, and electromagnetism. Finally, stellar evolution and cosmology are discussed with reference to the possibility of life elsewhere in the universe.

Advanced Technologies for Heterodyne Radio Astronomy Instrumentation - Part1 By A. Pavolotsky, and Advanced Technologies for Heterodyne Radio Astronomy Instrumentation - Part2 By V. Desmaris

NASA Astrophysics Data System (ADS)

Desmaris, Vincent

2018-01-01

We present the advanced micro/nano technological engineering at the atomic level producing state-of-the-art epitaxial NbN thin-films on GaN buffer layers. Furthermore, we report the outstanding performance of the hot electron bolometers fabricated on epitaxial NbN thin films on GaN buffer layers. Finally we present advanced passive devices such as waveguide hybrids, IF hybrids and combiners for the realization of heterodyne THz receivers.

Push for Cheese: A Metaphor for Software Usability

NASA Astrophysics Data System (ADS)

Radziwill, Nicole; Shelton, Amy

2005-12-01

At the National Radio Astronomy Observatory's (NRAO) Science Center in Green Bank, W. Va., visitors curious about radio astronomy and the observatory's history and operations will discover an educational, entertaining experience. Employees also visit the science center, but their thoughts are more on afternoon snacks rather than distant galaxies. The employees of NRAO's Software Development Division in Green Bank have gained tremendous insight on the topic of software usability from many visits to the Science Center Café by pontificating upon the wisdom inherent in the design and use of the liquid cheese dispenser there.

Contribution of the AN/TPS-3 Radar Antenna to Australian radio astronomy

NASA Astrophysics Data System (ADS)

Wendt, Harry; Orchiston, Wayne

2018-04-01

The CSIRO Division of Radiophysics used the WWII surplus AN/TPS-3 radar dishes for their early solar radio astronomy research and eclipse observations. These aerials were also used in a spaced (Michelson) interferometer configuration in the late 1940s to investigate solar limb brightening at 600 MHz. This work paralleled early solar observations at Cambridge. None of the Australian research results using the spaced interferometry technique appeared in publications, and the invention of the solar grating array in 1950 made further use of the method redundant.

The Value of Methodical Management: Optimizing Science Results

NASA Astrophysics Data System (ADS)

Saby, Linnea

2016-01-01

As science progresses, making new discoveries in radio astronomy becomes increasingly complex. Instrumentation must be incredibly fine-tuned and well-understood, scientists must consider the skills and schedules of large research teams, and inter-organizational projects sometimes require coordination between observatories around the globe. Structured and methodical management allows scientists to work more effectively in this environment and leads to optimal science output. This report outlines the principles of methodical project management in general, and describes how those principles are applied at the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia.

Explorers of the Southern Sky

NASA Astrophysics Data System (ADS)

Haynes, Raymond; Haynes, Roslynn D.; Malin, David; McGee, Richard

2010-08-01

Preface; Acknowledgements; 1. Dreaming the stars; 2. Sailing south for a new sky; 3. Astronomy in Sydney town; 4. The struggle for independence; 5. A bid for fame; 6. For love of the subject; 7. Astronomy on a national basis; 8. From swords to ploughshares; 9. Radio astronomy and the big telescopes; 10. Entrepreneurs in astronomy; 11. The advantage of latitude; 12. The high-energy frontier; 13. Diversity through innovation; 14. Optical astronomy goes high tech; 15. A telescope as wide as a continent; Glossary of abbreviations; Glossary of scientific and technical words; Bibliography; Index of names and dates; Subject index.

The Early Development of Australian Radio Astronomy: The Role of the CSIRO Division of Radiophysics Field Stations

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Slee, Bruce

During the period 1946-1961 Australia was one of the world's leading nations in radio astronomy and played a key role in its development. Much of the research was carried out at a number of different field stations and associated remote sites situated in or near Sydney which were maintained by the Commonwealth Scientific and Industrial Research Organisation's Division of Radiophysics. The best-known of these were Dover Heights, Dapto, Fleurs, Hornsby Valley and Potts Hill. At these and other field stations a succession of innovative radio telescopes was erected, and these were used by a band of young scientists—mainly men with engineering qualifications—to address a wide range of research issues, often with outstanding success.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1989-01-01

Developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. Activities of the Deep Space Network and its associated Ground Communications Facility in planning, in supporting research and technology, in implementation, and in operations are reported in space communications, radio navigation, radio science, and ground-based radio and radar astronomy.

The Telecommunications and Data Acquisition Progress Report 42-123

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1995-01-01

The progress of research programs monitored by the Jet Propulsion Laboratory's Telecommunications and Mission Operations Directorate (TMOD) are presented in this quarterly document. Areas monitored include space communications, radio navigation, radio science, ground-based radio and radar astronomy, information systems, and all other communication and research technology activities for the Deep Space Network (DSN).

Hey, James Stanley (1909-90)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

English radioastronomy pioneer, made three fundamental discoveries in radio astronomy. Working on radar during the second World War, he discovered radio interference from solar storms (at first thought to be enemy `jamming' of radar). It is surprising that he should have found this emission serendipitously, since solar radio emission had been sought without success by several scientists since ...

Need a Classroom Stimulus? Introduce Radio Astronomy

ERIC Educational Resources Information Center

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…

RASDR: Benchtop Demonstration of SDR for Radio Astronomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vacaliuc, Bogdan; Oxley, Paul; Fields, David

The Society of Amateur Radio Astronomers (SARA) members present the benchtop version of RASDR, a Software Defined Radio (SDR) that is optimized for Radio Astronomy. RASDR has the potential to be a common digital receiver interface useful to many SARA members. This document describes the RASDR 0.0 , which provides digitized radio data to a backend computer through a USB 2.0 interface. A primary component of RASDR is the Lime Microsystems Femtocell chip which tunes from a 0.4-4 GHz center frequency with several selectable bandwidths from 0.75 MHz to 14 MHz. A second component is a board with a Complexmore » Programmable Logic Device (CPLD) chip that connects to the Femtocell and provides two USB connections to the backend computer. A third component is an analog balanced mixer up conversion section. Together these three components enable RASDR to tune from 0.015 MHz thru 3.8GHz of the radio frequency (RF) spectrum. We will demonstrate and discuss capabilities of the breadboard system and SARA members will be able to operate the unit hands-on throughout the workshop.« less

Implementing the Second-Order Fermi Process in a Kinetic Monte-Carlo Simulation

NASA Technical Reports Server (NTRS)

Summerlin, Errol 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

DSMS science operations concept

NASA Technical Reports Server (NTRS)

Connally, M. J.; Kuiper, T. B.

2001-01-01

The Deep Space Mission System (DSMS) Science Operations Concept describes the vision for enabling the use of the DSMS, particularly the Deep Space Network (DSN) for direct science observations in the areas of radio astronomy, planetary radar, radio science and VLBI.

New Antennas and Methods for the Low Frequency Stellar and Planetary Radio Astronomy

NASA Astrophysics Data System (ADS)

Konovalenko, A. A.; Falkovich, I. S.; Rucker, H. O.; Lecacheux, A.; Zarka, Ph.; Koliadin, V. L.; Zakharenko, V. V.; Stanislavsky, A. A.; Melnik, V. N.; Litvinenko, G. V.; Gridin, A. A.; Bubnov, I. N.; Kalinichenko, N. N.; Reznik, A. P.; Sidorchuk, M. A.; Stepkin, S. V.; Mukha, D. V.; Nikolajenko, V. S.; Karlsson, R.; Thide, B.

According to the special Program of the National Academy of Sciences of Ukraine, creation of the new giant Ukrainian radio telescope (GURT) was started a few years ago on the UTR-2 radio telescope observatory. The main goal is to reach maximum band at the lowest frequencies (10-70 MHz), effective area (step-by-step up to 100,000 sq.m), and high interference immunity for resolving many astrophysical tasks when the sensitivity is less limited by the confusion effects. These tasks include stellar radio astronomy (the Sun, solar wind, flare stars, pulsars, transients) and planetary one (Jupiter, planetary lightnings, Earth ionosphere, the Moon, exoplanets). This array should be complementary to the LOFAR, E-LOFAR systems. The first stages of the GURT (6 x 25 cross dipole active elements) and broad-band digital registration of the impulsive and sporadic events were tested in comparison with the existing largest decameter array UTR-2.

The contribution of the Georges Heights Experimental Radar Antenna to Australian radio astronomy

NASA Astrophysics Data System (ADS)

Orchiston, Wayne; Wendt, Harry

2017-12-01

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 based in Sydney. The earliest celestial observations were made with former WWII radar antennas and simple Yagi aerials attached to recycled radar receivers, 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.

Thunderstorms and ground-based radio noise as observed by radio astronomy Explorer 1

NASA Technical Reports Server (NTRS)

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

1973-01-01

Radio Astronomy Explorer (RAE) data were analyzed to determine the frequency dependence of HF terrestrial radio noise power. RAE observations of individual thunderstorms, mid-ocean areas, and specific geographic regions for which concommitant ground based measurements are available indicate that noise power is a monotonically decreasing function of frequency which conforms to expectations over the geographic locations and time periods investigated. In all cases investigated, active thunderstorm regions emit slightly higher power as contrasted to RAE observations of the region during meteorologically quiet periods. Noise levels are some 15 db higher than predicted values over mid-ocean, while in locations where ground based measurements are available a maximum deviation of 5 db occurs. Worldwide contour mapping of the noise power at 6000 km for five individual months and four observing frequencies, examples of which are given, indicate high noise levels over continental land masses with corresponding lower levels over ocean regions.

A search for narrow band signals with SERENDIP II: a progress report

NASA Technical Reports Server (NTRS)

Werthimer, D.; Brady, R.; Berezin, A.; Bowyer, S.

1988-01-01

Commensal programs for the Search for Extraterrestrial Intelligence (SETI), carried out concurrently with conventional radio astronomical observing programs, can be an attractive and cost-effective means of exploring the large multidimensional search space intrinsic to this effort. Our automated commensal system, SERENDIP II, is a high resolution 131,072 channel spectrometer. It searches for 0.49 Hz signals in sequential 64,700 Hz bands of the IF signal from a radio telescope being used for an astronomical observation. Upon detection of a narrow band signal with power above a preset threshold, the frequency, power, time, and telescope direction are recorded for later study. The system has been tested at the Hat Creek Radio Astronomy Observatory 85 ft telescope and the NASA-JPL Deep Space Station (DSS 14) 64 m telescope. It is currently collecting data at the National Radio Astronomy Observatory 300 ft telescope.

A search for narrow band signals with SERENDIP II: a progress report.

PubMed

Werthimer, D; Brady, R; Berezin, A; Bowyer, S

1988-01-01

Commensal programs for the Search for Extraterrestrial Intelligence (SETI), carried out concurrently with conventional radio astronomical observing programs, can be an attractive and cost-effective means of exploring the large multidimensional search space intrinsic to this effort. Our automated commensal system, SERENDIP II, is a high resolution 131,072 channel spectrometer. It searches for 0.49 Hz signals in sequential 64,700 Hz bands of the IF signal from a radio telescope being used for an astronomical observation. Upon detection of a narrow band signal with power above a preset threshold, the frequency, power, time, and telescope direction are recorded for later study. The system has been tested at the Hat Creek Radio Astronomy Observatory 85 ft telescope and the NASA-JPL Deep Space Station (DSS 14) 64 m telescope. It is currently collecting data at the National Radio Astronomy Observatory 300 ft telescope.

The Early Development of Indian Radio Astronomy: A Personal Perspective

NASA Astrophysics Data System (ADS)

Swarup, Govind

In this chapter I recall my initiation into the field of radio astronomy during 1953-1955 at CSIRO, Australia; the transfer of thirty-two 6-feet (1.8-m) diameter parabolic dishes from Potts Hill, Sydney, to India in 1958; and their erection at Kalyan, near Bombay (Mumbai), in 1963-1965. The Kalyan Radio Telescope was the first modern radio telescope built in India. This led to the establishment of a very active radio astronomy group at the Tata Institute of Fundamental Research, which subsequently built two world-class radio telescopes during the last 50 years and also contributed to the development of an indigenous microwave antenna industry in India. The Ooty Radio Telescope, built during 1965-1970, has an ingenious design which takes advantage of India's location near the Earth's Equator. The long axis of this 530-m × 30-m parabolic cylinder was made parallel to the Equator, by placing it on a hill with the same slope as the geographic latitude ( 11°), thus allowing it to track celestial sources continuously for 9.5 h every day. By utilizing lunar occultations, the telescope was able to measure the angular sizes of a large number of faint radio galaxies and quasars with arc-second resolution for the first time. Subsequently, during the 1990s, the group set up the Giant Metrewave Radio Telescope (GMRT) near Pune in western India, in order to investigate certain astrophysical phenomena which are best studied at decimetre and metre wavelengths. The GMRT is an array of 30 fully steerable 45-m diameter parabolic dishes, which operates at several frequencies below 1.43 GHz. These efforts have also contributed to the international proposal to construct the Square Kilometre Array (SKA). This chapter is a revised version of Swarup (Journal of Astronomical History and Heritage, 9: 21-33, 2006).

A generalized measurement equation and van Cittert-Zernike theorem for wide-field radio astronomical interferometry

NASA Astrophysics Data System (ADS)

Carozzi, T. D.; Woan, G.

2009-05-01

We derive a generalized van Cittert-Zernike (vC-Z) theorem for radio astronomy that is valid for partially polarized sources over an arbitrarily wide field of view (FoV). The classical vC-Z theorem is the theoretical foundation of radio astronomical interferometry, and its application is the basis of interferometric imaging. Existing generalized vC-Z theorems in radio astronomy assume, however, either paraxiality (narrow FoV) or scalar (unpolarized) sources. Our theorem uses neither of these assumptions, which are seldom fulfiled in practice in radio astronomy, and treats the full electromagnetic field. To handle wide, partially polarized fields, we extend the two-dimensional (2D) electric field (Jones vector) formalism of the standard `Measurement Equation' (ME) of radio astronomical interferometry to the full three-dimensional (3D) formalism developed in optical coherence theory. The resulting vC-Z theorem enables full-sky imaging in a single telescope pointing, and imaging based not only on standard dual-polarized interferometers (that measure 2D electric fields) but also electric tripoles and electromagnetic vector-sensor interferometers. We show that the standard 2D ME is easily obtained from our formalism in the case of dual-polarized antenna element interferometers. We also exploit an extended 2D ME to determine that dual-polarized interferometers can have polarimetric aberrations at the edges of a wide FoV. Our vC-Z theorem is particularly relevant to proposed, and recently developed, wide FoV interferometers such as Low Frequency Array (LOFAR) and Square Kilometer Array (SKA), for which direction-dependent effects will be important.

Radio and Optical Telescopes for School Students and Professional Astronomers

NASA Astrophysics Data System (ADS)

Hosmer, Laura; Langston, G.; Heatherly, S.; Towner, A. P.; Ford, J.; Simon, R. S.; White, S.; O'Neil, K. L.; Haipslip, J.; Reichart, D.

2013-01-01

The NRAO 20m telescope is now on-line as a part of UNC's Skynet worldwide telescope network. The NRAO is completing integration of radio astronomy tools with the Skynet web interface. We present the web interface and astronomy projects that allow students and astronomers from all over the country to become Radio Astronomers. The 20 meter radio telescope at NRAO in Green Bank, WV is dedicated to public education and also is part of an experiment in public funding for astronomy. The telescope has a fantastic new web-based interface, with priority queuing, accommodating priority for paying customers and enabling free use of otherwise unused time. This revival included many software and hardware improvements including automatic calibration and improved time integration resulting in improved data processing, and a new ultra high resolution spectrometer. This new spectrometer is optimized for very narrow spectral lines, which will allow astronomers to study complex molecules and very cold regions of space in remarkable detail. In accordance with focusing on broader impacts, many public outreach and high school education activities have been completed with many confirmed future activities. The 20 meter is now a fully automated, powerful tool capable of professional grade results available to anyone in the world. Drop by our poster and try out real-time telescope control!

Reflections on works by I.S.Shklovsky regarding the nature of radio galaxies

NASA Astrophysics Data System (ADS)

Komberg, B. V.; Zhuravlev, V. I.

The paper is a brief overview of the works by Iosif S. Shklovsky (1916-1985), carried out over almost 30 years (1955-1985), on the nature of activity (primarily in the radio frequency range) in nuclei of some galaxies. Worthy of note is Shklovsky's pioneering work of 1962, in which he made an attempt to consider possible evolutionary tracks of extragalactic radio sources by constructing an analog of the Herzsprung-Russel diagram for stars (radio luminosity at 160 MHz was taken instead of optical luminosity; total radio size at the same frequency, as the other parameter). Later works by other authors are also discussed, where similar diagrams were plotted using a larger observational material. Special attention is paid to the evolution of Shklovsky's views regarding the possible ways of gas getting into radio galaxies' central regions, followed by high-velocity ejections of magnetized plasmons from their nuclei. Shklovsky's assumptions were mainly based on the observational data for the properties of the closest radio galaxy, NGC 4486 (Virgo A, M87), which he believed to be the same reference standard for extragalactic radio astronomy as the Crab Nebula for galactic radio astronomy. Shklovsky's approach to the recurrence of the activity phenomenon in galactic nuclei and the one-sided character of radio ejections from them is discussed. Modern views on these issues are also briefly considered.

Large Instrument Development for Radio Astronomy

NASA Astrophysics Data System (ADS)

Fisher, J. Richard; Warnick, Karl F.; Jeffs, Brian D.; Norrod, Roger D.; Lockman, Felix J.; Cordes, James M.; Giovanelli, Riccardo

2009-03-01

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 new technology provided by industry and the commercial market. Radio astronomy instrumentation has a very bright future, but a vigorous long-term R&D program not tied directly to specific projects needs to be restored, fostered, and preserved.

The Frontiers of the Astronomical Universe

ERIC Educational Resources Information Center

Pecker, Jean-Claude

1977-01-01

Reviews the current state of knowledge obtained by means of observations using the increasingly powerful or proficient instruments of astrophysics, radio astronomy, and space astronomy by satellite. In conclusion, he refers to certain mathematical entities introduced into the theory of the origins and evolution of the cosmos. (Author/MA)

Back to the future: SETI before the space age

NASA Astrophysics Data System (ADS)

Dick, Steven J.

1995-02-01

In the late 1890s and early 1900s, before the advent of formalized search for extraterrestrial intelligence (SETI) programs, scientists such as Nikola Tesla and Gulielmo Marconi reported evidence of extraterrestrial radio signals. This paper reviews the history of 'interstellar/interplanetary radio communication'. The investigations of David P. Todd and Donald Menzel are discussed, and the fields of radio communication and radio astronomy are mentioned briefly.

Plasma and radio waves from Neptune: Source mechamisms and propagation

NASA Technical Reports Server (NTRS)

Menietti, J. Douglas

1994-01-01

The purpose of this project was to conduct a comprehensive investigation of the radio wave emission observed by the planetary radio astronomy (PRA) instrument on board Voyager 2 as it flew by Neptune. The study has included data analysis, theoretical and numerical calculations, and ray tracing to determine the possible source mechanisms and locations of the radiation, including the narrowband bursty and smooth components of the Neptune radio emission.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1994-01-01

This quarterly publication provides archival reports on developments in programs in space communications, radio navigation, radio science, and ground-based radio and radar astronomy. It reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standardization activities at the Jet Propulsion Laboratory for space data and information systems.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1983-01-01

Archival reports on developments in programs managed by JPL's office of Telecommunications and Data Acquisition (TDA) are presented. In space communications, radio navigation, radio science, and ground-based radio astronomy, it reports on activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, in supporting research and technology, in implementation, and in operations.

CLOSE-UP LOOK AT A JET NEAR A BLACK HOLE

NASA Technical Reports Server (NTRS)

2002-01-01

[top left] - This radio image of the galaxy M87, taken with the Very Large Array (VLA) radio telescope in February 1989, shows giant bubble-like structures where radio emission is thought to be powered by the jets of subatomic particles coming from the the galaxy's central black hole. The false color corresponds to the intensity of the radio energy being emitted by the jet. M87 is located 50 million light-years away in the constellation Virgo. Credit: National Radio Astronomy Observatory/National Science Foundation [top right] - A visible light image of the giant elliptical galaxy M87, taken with NASA Hubble Space Telescope's Wide Field Planetary Camera 2 in February 1998, reveals a brilliant jet of high-speed electrons emitted from the nucleus (diagonal line across image). The jet is produced by a 3-billion-solar-mass black hole. Credit: NASA and John Biretta (STScI/JHU) [bottom] - A Very Long Baseline Array (VLBA) radio image of the region close to the black hole, where an extragalactic jet is formed into a narrow beam by magnetic fields. The false color corresponds to the intensity of the radio energy being emitted by the jet. The red region is about 1/10 light-year across. The image was taken in March 1999. Credit: National Radio Astronomy Observatory/Associated Universities, Inc.

The Astronomical Low Frequency Array: A Proposed Explorer Mission for Radio Astronomy

NASA Technical Reports Server (NTRS)

Jones, D.; Allen, R.; Basart, J.; Bastian, T.; Bougeret, J. L.; Dennison, B.; Desch, M.; Dwarakanath, K.; Erickson, W.; Finley, D.;

Developments of FPGA-based digital back-ends for low frequency antenna arrays at Medicina radio telescopes

NASA Astrophysics Data System (ADS)

Naldi, G.; Bartolini, M.; Mattana, A.; Pupillo, G.; Hickish, J.; Foster, G.; Bianchi, G.; Lingua, A.; Monari, J.; Montebugnoli, S.; Perini, F.; Rusticelli, S.; Schiaffino, M.; Virone, G.; Zarb Adami, K.

In radio astronomy Field Programmable Gate Array (FPGA) technology is largely used for the implementation of digital signal processing techniques applied to antenna arrays. This is mainly due to the good trade-off among computing resources, power consumption and cost offered by FPGA chip compared to other technologies like ASIC, GPU and CPU. In the last years several digital backend systems based on such devices have been developed at the Medicina radio astronomical station (INAF-IRA, Bologna, Italy). Instruments like FX correlator, direct imager, beamformer, multi-beam system have been successfully designed and realized on CASPER (Collaboration for Astronomy Signal Processing and Electronics Research, https://casper.berkeley.edu) processing boards. In this paper we present the gained experience in this kind of applications.

Introduction to the Special Issue on Digital Signal Processing in Radio Astronomy

NASA Astrophysics Data System (ADS)

Price, D. C.; Kocz, J.; Bailes, M.; Greenhill, L. J.

2016-03-01

Advances in astronomy are intimately linked to advances in digital signal processing (DSP). This special issue is focused upon advances in DSP within radio astronomy. The trend within that community is to use off-the-shelf digital hardware where possible and leverage advances in high performance computing. In particular, graphics processing units (GPUs) and field programmable gate arrays (FPGAs) are being used in place of application-specific circuits (ASICs); high-speed Ethernet and Infiniband are being used for interconnect in place of custom backplanes. Further, to lower hurdles in digital engineering, communities have designed and released general-purpose FPGA-based DSP systems, such as the CASPER ROACH board, ASTRON Uniboard, and CSIRO Redback board. In this introductory paper, we give a brief historical overview, a summary of recent trends, and provide an outlook on future directions.

Problem Solving in Homeland Security and Creating Policy Conditions for Enhanced Civic Engagement: An Examination of Crowdsourcing Models

DTIC Science & Technology

2017-06-01

crowdsourcing of resources.85 Observations take place at the National Astronomy and Ionospheric Center in Arecibo, Puerto Rico, using a 305-meter radio...crowdsourced contributions across a broad spectrum of disciplines, including the natural sciences, social sciences, technology, public health, astronomy

Stellar Ontogeny: From Dust...

ERIC Educational Resources Information Center

MOSAIC, 1978

1978-01-01

Discusses the process of star formation. Infrared and radio astronomy, particularly microwave astronomy is used to provide information on different stages of stellar formation. The role of dust and gas which swirl through the interstellar regions of a galaxy and the collapse of a cloud in star formation are also presented. (HM)

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1983-01-01

Developments in programs in telecommunication and data acquisition in space communications, radio navigation, radio science, and ground based radio astronomy are reported. Activities of the deep space network (DSN) and its associated ground communication facility (GCF) in planning, supporting research and technology, implementation, and in operations are outlined. The publication of reports on the application of radio interferometry at microwave frequencies for geodynamic measurements are presented. Implementation and operation for searching the microwave spectrum is reported.

The history of polarisation measurements: their role in studies of magnetic fields

NASA Astrophysics Data System (ADS)

Wielebinski, R.

2015-03-01

Radio astronomy gave us new methods to study magnetic fields. Synchrotron radiation, the main cause of comic radio waves, is highly linearly polarised with the `E' vector normal to the magnetic field. The Faraday Effect rotates the `E' vector in thermal regions by the magnetic field in the line of sight. Also the radio Zeeman Effect has been observed.

Time and Frequency Synchronization on the Virac Radio Telescope RT-32

NASA Astrophysics Data System (ADS)

Bezrukovs, V.

2016-04-01

One of the main research directions of Ventspils International Radio Astronomy Centre (VIRAC) is radio astronomy and astrophysics. The instrumental base for the centre comprised two fully steerable parabolic antennas, RT-16 and RT-32 (i.e. with the mirror diameter of 16 m and 32 m). After long reconstruction, radio telescope RT-32 is currently equipped with the receiving and data acquisition systems that allow observing in a wide frequency range from 327 MHz to 9 GHz. New Antenna Control Unit (ACU) allows stable, fast and precise pointing of antenna. Time and frequency distribution service provide 5, 10 and 100 MHz reference frequency, 1PPS signals and precise time stamps by NTP protocol and in the IRIG-B format by coaxial cable. For the radio astronomical observations, main requirement of spatially Very Long Base Line Interferometric (VLBI) observations for the observatory is precise synchronization of the received and sampled data and linking to the exact time stamps. During October 2015, radio telescope RT-32 performance was tested in several successful VLBI experiments. The obtained results confirm the efficiency of the chosen methods of synchronization and the ability to reproduce them on similar antennas.

Radio Astronomy on and Around the Moon

NASA Astrophysics Data System (ADS)

Falcke, Heino; Klein Wolt, Mark; Ping, Jinsong; Chen, Linjie

2018-06-01

The exploration of remote places on other planets has now become a major goal in current space flight scenarios. On the other hand, astronomers have always sought the most remote and isolated sites to place their observatories and to make their most precise and most breath taking discoveries. Especially for radio astronomy, lunar exploration offers a complete new window to the universe. The polar region and the far-side of the moon are acknowledged as unique locations for a low-frequency radio telescope providing scientific data at wavelengths that cannot be obtained from the Earth nor from single satellites. Scientific areas to be covered range from radio surveys, to solar-system studies, exo-planet detection, and astroparticle physics. The key science area, however, is the detection and measurement of cosmological 21 cm hydrogen emission from the still unexplored dark ages of the universe. Developing a lunar radio facility can happen in steps and may involve small satellites, rover-based radio antennas, of free- flying constellations around the moon. A first such step could be the Netherlands-Chinese Long Wavelength Explorer (NCLE), which is supposed to be launched in 2018 as part of the ChangE’4 mission to the moon-earth L2 point.

Dark Skies are a Universal Resource. So are Quiet Skies!

NASA Astrophysics Data System (ADS)

Maddalena, Ronald J.; Heatherly, S.

2008-05-01

You've just purchased your first telescope. But where to set it up? Certainly not a WalMart parking lot. Too much light pollution! In the same way that man-made light obscures our night sky and blinds ground-based optical telescopes, man-made radio signals blind radio telescopes as well. NRAO developed the Quiet Skies project to increase awareness of radio frequency interference (RFI) and radio astronomy in general by engaging students in local studies of RFI. To do that we created a sensitive detector which measures RFI. We produced 20 of these, and assembled kits containing detectors and supplementary materials for loan to schools. Students conduct experiments to measure the properties of RFI in their area, and input their measurements into a web-based data base. The Quiet Skies project is a perfect complement to the IYA Dark Skies Awareness initiative. We hope to place 500 Quiet Skies detectors into the field through outreach to museums and schools around the world. Should we be successful, we will sustain this global initiative via a continuing loan program. One day we hope to have a publicly generated image of the Earth which shows RFI much as the Earth at Night image illustrates light pollution. The poster will present the components of the project in detail, including our plans for IYA, and various low-cost alternative strategies for introducing RFI and radio astronomy to the public. We will share the results of some of the experiments already being performed by high school students. Development of the Quiet Skies project was funded by a NASA IDEAS grant. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Multi-messenger astronomy of gravitational-wave sources with flexible wide-area radio transient surveys

NASA Astrophysics Data System (ADS)

Kavic, Michael; Cregg C. Yancey, Brandon E. Bear, Bernadine Akukwe, Kevin Chen, Jayce Dowell, Jonathan D. Gough, Jonah Kanner, Kenneth Obenberger, Peter Shawhan, John H. Simonetti , Gregory B. Taylor , Jr-Wei Tsai

2016-01-01

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(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.

Multi-messenger Astronomy of Gravitational-wave Sources with Flexible Wide-area Radio Transient Surveys

NASA Astrophysics Data System (ADS)

Yancey, Cregg C.; Bear, Brandon E.; Akukwe, Bernadine; Chen, Kevin; Dowell, Jayce; Gough, Jonathan D.; Kanner, Jonah; Kavic, Michael; Obenberger, Kenneth; Shawhan, Peter; Simonetti, John H.; -Wei Tsai, Gregory B. Taylor, Jr.

2015-10-01

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 deg2 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.

Planetary radio astronomy: Earth, giant planets, and beyond

NASA Astrophysics Data System (ADS)

Rucker, H. O.; Panchenko, M.; Weber, C.

2014-11-01

The magnetospheric phenomenon of non-thermal radio emission is known since the serendipitous discovery of Jupiter as radio planet in 1955, opening the new field of "Planetary Radio Astronomy". Continuous ground-based observations and, in particular, space-borne measurements have meanwhile produced a comprehensive picture of a fascinating research area. Space missions as the Voyagers to the Giant Planets, specifically Voyager 2 further to Uranus and Neptune, Galileo orbiting Jupiter, and now Cassini in orbit around Saturn since July 2004, provide a huge amount of radio data, well embedded in other experiments monitoring space plasmas and magnetic fields. The present paper as a condensation of a presentation at the Kleinheubacher Tagung 2013 in honour of the 100th anniversary of Prof. Karl Rawer, provides an introduction into the generation mechanism of non-thermal planetary radio waves and highlights some new features of planetary radio emission detected in the recent past. As one of the most sophisticated spacecraft, Cassini, now in space for more than 16 years and still in excellent health, enabled for the first time a seasonal overview of the magnetospheric variations and their implications for the generation of radio emission. Presently most puzzling is the seasonally variable rotational modulation of Saturn kilometric radio emission (SKR) as seen by Cassini, compared with early Voyager observations. The cyclotron maser instability is the fundamental mechanism under which generation and sufficient amplification of non-thermal radio emission is most likely. Considering these physical processes, further theoretical investigations have been started to investigate the conditions and possibilities of non-thermal radio emission from exoplanets, from potential radio planets in extrasolar systems.

PARTNeR: A Tool for Outreach and Teaching Astronomy

NASA Astrophysics Data System (ADS)

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.

To See the Unseen: A History of Planetary Radar Astronomy

NASA Technical Reports Server (NTRS)

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-based facilities by this transformed planetary radar astronomy, as well as the upgrading of the Arecibo and Goldstone radars. A technical essay appended to this book provides an overview of planetary radar techniques, especially range-Doppler mapping.

Interagency telemetry arraying for Voyager-Neptune encounter

NASA Technical Reports Server (NTRS)

Brown, D. W.; Brundage, W. D.; Ulvestad, J. S.; Kent, S. S.; Bartos, K. P.

1990-01-01

The reception capability of the Deep Space Network (DSN) has been improved over the years by increasing both the size and number of antennas at each complex to meet spacecraft-support requirements. However, even more aperture was required for the final planetary encounters of the Voyager 2 spacecraft. This need was met by arraying one radio astronomy observatory with the DSN complex in the United States and another with the complex in Australia. Following a review of augmentation for the Uranus encounter, both the preparation at the National Radio Astronomy (NRAO) Very Large Array (VLA) and the Neptune encounter results for the Parkes-Canberra and VLA-Goldstone arrays are presented.

Tectonic motion site survey of the National Radio Astronomy Observatory, Green Bank, West Virginia

NASA Technical Reports Server (NTRS)

Webster, W. J., Jr.; Allenby, R. J.; Hutton, L. K.; Lowman, P. D., Jr.; Tiedemann, H. A.

1979-01-01

A geological and geophysical site survey was made of the area around the National Radio Astronomy Observatory (NRAO) to determine whether there are at present local tectonic movements that could introduce significant errors to Very Long Baseline Interferometry (VLBI) geodetic measurements. The site survey consisted of a literature search, photogeologic mapping with Landsat and Skylab photographs, a field reconnaissance, and installation of a seismometer at the NRAO. It is concluded that local tectonic movement will not contribute significantly to VLBI errors. It is recommended that similar site surveys be made of all locations used for VLBI or laser ranging.

On post-SKA radio astronomy

NASA Astrophysics Data System (ADS)

Parijskij, Yuri; Chernenkov, Vladimir

It is suggested that the development of the SKA will drastically change the face of radio astronomy in the 21st Century. A FAST-style SKA would admit observations of low contrast features, and would be the best design for studying the `dark ages' of the Universe (x>> 1) where sub-arcmin total power instruments can usefully be employed. To date there have been no proposals for post-SKA, billion square-metra instruments; we speculate that mobile communication systems can be used. In the very distant future, SKA multi-beam systems could be used to collect signals reflected by Solar system bodies such as the asteroid belt.

Radio astronomy Explorer-B in-flight mission control system development effort

NASA Technical Reports Server (NTRS)

Lutsky, D. A.; Bjorkman, W. S.; Uphoff, C.

1973-01-01

A description is given of the development for the Mission Analysis Evaluation and Space Trajectory Operations (MAESTRO) program to be used for the in-flight decision making process during the translunar and lunar orbit adjustment phases of the flight of the Radio Astronomy Explorer-B. THe program serves two functions: performance and evaluation of preflight mission analysis, and in-flight support for the midcourse and lunar insertion command decisions that must be made by the flight director. The topics discussed include: analysis of program and midcourse guidance capabilities; methods for on-line control; printed displays of the MAESTRO program; and in-flight operational logistics and testing.

Ronald N. Bracewell: An Appreciation

NASA Astrophysics Data System (ADS)

Thompson, A. Richard; Frater, Robert H.

2010-11-01

Ronald Newbold Bracewell (1921-2007) made fundamental contributions to the development of radio astronomy in the areas of interferometry, signal processing, and imaging, and also to tomography, various areas of data analysis, and the understanding of Fourier transforms. He was born in Sydney, Australia, and received a B.Sc. degree in mathematics and physics, and B.E. and M.E. degrees in electrical engineering from the University of Sydney, and his Ph.D. from the University of Cambridge, U.K., for research on the ionosphere. In 1949 he joined the Radiophysics Laboratory of CSIRO, where he became interested in radio astronomy. In 1955 he moved to Stanford University, California, where he became Lewis M. Terman Professor of Electrical Engineering. He retired from teaching in 1991, but continued to be active in radio astronomy and other applications of imaging techniques, etc. During his career he published ten books and more than 250 papers. Honors that he received include the Duddell Premium of the Institute of Electrical Engineers, London, the Hertz Medal of the IEEE, and the Order of Australia. For his work on imaging in tomography he was elected to Associate Membership of the Institute of Medicine of the U.S. National Academy of Sciences.

First Colombian Solar Radio Interferometer: current stage

NASA Astrophysics Data System (ADS)

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.

The Telecommunications and Data Acquisition Report. [Deep Space Network

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1988-01-01

In space communications, radio navigation, radio science, and ground based radio and radar astronomy, activities of the Deep Space Network and its associated Ground Communications Facility in planning, in supporting research and technology, in implementation, and in operations are reported. Also included is TDA funded activity at JPL on data and information systems and reimbursable DSN work performed for other space agencies through NASA.

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

NASA Astrophysics Data System (ADS)

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.

Warkworth 12-m VLBI Station: WARK12M

NASA Technical Reports Server (NTRS)

Weston, Stuart; Takiguchi, Hiroshi; Natusch, Tim; Woodburn, Lewis; Gulyaev, Sergei

2013-01-01

The Warkworth 12-m radio telescope is operated by the Institute for Radio Astronomy and Space Research (IRASR) at AUT University, Auckland, New Zealand. Here we review the characteristics of the 12-m VLBI station and report on a number of activities and technical developments in 2012.

The Quiet Skies Project

ERIC Educational Resources Information Center

Rapp, Steve

2008-01-01

To help promote student awareness of the connection between radio astronomy and radio frequency interference (RFI), an inquiry-based science curriculum was developed to allow high school students to determine RFI levels in their communities. The Quiet Skies Project--the result of a collaboration between the National Aeronautics and Space…

German Astronomer Karl Menten Is 2007 Jansky Awardee

NASA Astrophysics Data System (ADS)

2007-06-01

Associated Universities, Inc., (AUI) and the National Radio Astronomy Observatory (NRAO) have awarded the 2007 Karl G. Jansky Lectureship to Professor Karl M. Menten of the Max-Planck-Institute for Radioastronomy in Bonn, Germany. The Jansky Lectureship is an honor established by the trustees of AUI to recognize outstanding contributions to the advancement of astronomy. Karl M. Menten Professor Karl M. Menten CREDIT: NRAO/AUI Click on image for high-resolution file (433 KB) Professor Menten is an extraordinarily productive scientist whose research has improved our fundamental understanding in a number of areas of astronomy. He has studied the chemistry of molecular clouds from which new stars are formed, the process of star formation in our own Milky Way Galaxy and in the early Universe, and the outer atmospheres of stars nearing the end of their "normal" lives. In 1991, Menten used NRAO's 140-foot Telescope at Green Bank, West Virginia, to discover strong radio emission from methanol masers in star-forming regions. These masers amplify, or strengthen, radio emission the same way a laser amplifies visible-light emission. Menten developed the observation of these methanol masers into a powerful tool for studying the formation of stars much more massive than our Sun, because the strong maser emission points astronomers to the stellar birthplaces. In addition, Menten pioneered the use of ultra-high-resolution observations with NRAO's Very Long Baseline Array to observe masers to make precision determinations of the structure, size and dynamics of the Milky Way. Menten received his doctoral degree in 1987 from the University of Bonn, Germany. He then joined the Harvard-Smithsonian Center for Astrophysics, working there until 1996, when he became the Director for Millimeter and Submillimeter Astronomy at the Max-Planck-Institute for Radioastronomy. In addition to that position, he also has been a Professor for Experimental Astrophysics at the University of Bonn since 2001. He initiated the Atacama Pathfinder Experiment (APEX), a 12-meter diameter telescope high in Chile's Atacama Desert, where the Atacama Large Millimeter/submillimeter Array (ALMA) is being built. APEX pioneered submillimeter-wavelength observations at Atacama, proving the quality of the site for such research. As Jansky Lecturer, Menten will give a presentation entitled, "Tuning in to the Molecular Universe," at NRAO facilities in Charlottesville, Virginia, Green Bank, West Virginia, and Socorro, New Mexico. The dates of these lectures, which are free and open to the public, will be announced later this summer. This is the forty-second Jansky Lectureship. First awarded in 1966, it is named in honor of the man who, in 1932, first detected radio waves from a cosmic source. Karl Jansky's discovery of radio waves from the central region of the Milky Way started the science of radio astronomy. Other recipients of the Jansky award include five Nobel laureates (Drs. Subrahmanyan Chandrasekhar, Arno Penzias, Robert Wilson, William Fowler, and Joseph Taylor) as well as Jocelyn Bell-Burnell, discoverer of the first pulsar, and Vera Rubin, discoverer of dark matter in galaxies. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Radio Observations of the Type IIP Supernova 20017eaw

NASA Astrophysics Data System (ADS)

Stockdale, Christopher; Perez-Torres, Miguel; Argo, Megan; Ryder, Stuart D.; Panagia, Nino; Van Dyk, Schuyler; Bauer, Franz Erik; Roming, Peter; Marcaide, Jon; Pooley, Dave; Lien, Amy; Sramek, Richard A.

2018-01-01

We present the results of radio observations of the type IIP Supernova 2017eaw using the Very Large Array and the eMERLIN radio telescopes at centimeter wavelengths. SN 2017eaw is a rare type IIP that did not show prompt radio emission after initial explosion. We will present our analysis of the current data and discuss the implications for the pre-explosion evolution of the progenitor star of SN 20017eaw. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities.

tf_unet: Generic convolutional neural network U-Net implementation in Tensorflow

NASA Astrophysics Data System (ADS)

Akeret, Joel; Chang, Chihway; Lucchi, Aurelien; Refregier, Alexandre

2016-11-01

tf_unet mitigates radio frequency interference (RFI) signals in radio data using a special type of Convolutional Neural Network, the U-Net, that enables the classification of clean signal and RFI signatures in 2D time-ordered data acquired from a radio telescope. The code is not tied to a specific segmentation and can be used, for example, to detect radio frequency interference (RFI) in radio astronomy or galaxies and stars in widefield imaging data. This U-Net implementation can outperform classical RFI mitigation algorithms.

Multiverso: Rock'n'Astronomy

NASA Astrophysics Data System (ADS)

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.

NRAO Response to NSF Senior Review of Astronomy Facilities

NASA Astrophysics Data System (ADS)

2006-11-01

The National Science Foundation's (NSF) Astronomy Senior Review Committee report (pdf file), released today, made major recommendations for restructuring the NSF's ground-based astronomy efforts, including significant changes for the National Radio Astronomy Observatory (NRAO). The committee's report urged that leadership in radio astronomy, including millimeter- and submillimeter-wave observatories, "remain centered at NRAO as it is, by far, the largest radio astronomy organization in the world." The report praised the record of management of NRAO and the scientific capabilities of the Atacama Large Millimeter/submillimeter Array (ALMA), the Expanded Very Large Array (EVLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA). However, the report also recommended that some reductions and changes occur at the NRAO by 2011. Specifically, the report recommended that: (a) VLBA operations make a transition to a significant reliance on international funding or risk closure; (b) GBT operations costs be reduced; and (c) NRAO scientific staff costs be reduced. "The Senior Review Committee had the very difficult task of reconciling the needs of current facilities and funding new facilities for the future of astronomy. We appreciate their efforts and look forward to working with the NSF to ensure that the valuable and unique research capabilities of our NRAO telescopes continue to serve the astronomical community," said Dr. Fred K.Y. Lo, NRAO Director. The VLBA provides the greatest angular resolution, or ability to see fine detail, of any telescope in the world, greatly exceeding the capabilities of the Hubble Space Telescope and the future Square Kilometre Array. The committee recognized that, "if the VLBA is closed, a unique capability would likely be lost for decades." "The VLBA is used by scientists from around the world because of its unique capabilities. It has produced landmark research milestones and the committee recognized in its report that the VLBA now is poised to become even more scientifically productive. We will aggressively pursue international assistance in keeping this world-class research tool operational, and are optimistic that we will succeed," Lo said. The Robert C. Byrd Green Bank Telescope, termed by the committee a "new and highly promising telescope," already has taken the lead in some important research fields. While the committee recommended reductions in the operational costs of the GBT, the NRAO already has been taking steps to make the operations as efficient as possible, commensurate with adequate support for productive science operations. "We look forward to an independent cost analysis by specialists in telescope operations and business administration," Lo said, adding that, "In the meantime, we will redouble efforts to explore alternative modes of operation while continuing to enhance scientific capabilities." The scientific staff of NRAO, composed of Ph.D astronomers, provides scientific guidance for the development and operations of the telescopes, assistance and mentoring to scientists using the telescopes and to students, and serves in key management and operational roles. The expertise embodied in NRAO's staff is a unique resource for planning the next generation of radio astronomy facilities. "As astronomy becomes more reliant on multi-wavelength investigations and NRAO telescopes are used more by researchers unfamiliar with radio observational techniques, the support provided by an excellent scientific staff will become even more important," Lo said. "Throughout this whole process, the NRAO will continue to carry out its mission of enabling cutting-edge research, attracting and training future scientists and engineers, and stimulating public interest in science," Lo said. The NRAO will work closely with the NSF in the coming months as the NSF considers the Senior Review recommendations. "The future of the NRAO is extremely bright," Lo said. "Our scientific focus is on some of the most important and challenging questions of 21st-Century astronomy. With the GBT and VLBA, EVLA and ALMA coming on line, we will remain a flagship observatory for the astronomical research community of the U.S. and the world," he said. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1983-01-01

This publication reports on developments in programs managed by JPL's office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground based radio astronomy, it reports on activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, in supporting research and technology, in implementation and in operations. In geodynamics, the publication reports on the application of radio interferometry at microwave frequencies for geodynamic measurements. This publication also reports on implementation and operations for searching the microwave spectrum.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1993-01-01

Reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other agencies through NASA.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1994-01-01

Reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other agencies through NASA.

Meteor astronomy using a forward scatter set-up

NASA Astrophysics Data System (ADS)

Wislez, Jean-Marc

2006-08-01

An overview of the classical theory of the reflection of radio waves off meteor trails is given: the reflection conditions and mechanisms are discussed, and typical (t,A)-profiles of radio meteors are derived. Various configurations of the receive station(s) are proposed. The goal is to give the radio observer more insight in the possibilities, limitations and relevant parameters of forward scattering, and on how to obtain these through observations.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yancey, Cregg C.; Shawhan, Peter; Bear, Brandon E.

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 bemore » 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.« less

Education and public astronomy programs at the Carter Observatory: an overview

NASA Astrophysics Data System (ADS)

Orchiston, W.; Dodd, R. J.

1996-05-01

This paper outlines the extensive range of public programs offered by the Carter Observatory, including 'public nights', new planetarium and audio-visual shows, displays, the Carter Memorial Lectures, the annual 'Astronomical Handbook' and other publications, and a monthtly newspaper column and three monthly radio programs. It also deals with the Observatory's involvement in undergraduate and postgraduate astronomy at Victoria University of Wellington, various adult education training programs, holiday programs, and the recent development of the Education Service in response to the introduction of an Astronomy curriculum into schools throughout New Zealand. Some possible future developments in the public astronomy and education areas are also discussed.

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

NASA Astrophysics Data System (ADS)

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.

The Development of Astronomy and Emergence of Astrophysics in New Zealand

NASA Astrophysics Data System (ADS)

Hearnshaw, John; Orchiston, Wayne

The development of astronomy and astrophysics in New Zealand from the earliest European exploration and settlement to the present day is discussed. The major contributions to astronomy by amateur astronomers are covered, as is the later development of astronomy and astrophysics in New Zealand's universities. The account includes the founding of professional observatories for optical astronomy at Mt. John (belonging to the University of Canterbury) and for radio astronomy at Warkworth (belonging to the Auckland University of Technology). Several major international collaborations in which New Zealand is participating (or has participated) are described, including SALT, MOA, IceCube and SKA. The founding and history of the Carter Observatory in Wellington, of the Stardome Observatory in Auckland (both engaged in astronomical education and outreach) and of the Royal Astronomical Society of New Zealand are briefly covered.

Broadband Upgrade for the 1.668-GHz (L-Band) Radio Astronomy Feed System on the DSN 70-m Antennas

NASA Astrophysics Data System (ADS)

Hoppe, D.; Khayatian, B.; Lopez, B.; Torrez, T.; Long, E.; Sosnowski, J.; Franco, M.; Teitelbaum, L.

2015-08-01

Currently, each of the three Deep Space Network (DSN) 70-m antennas provides a narrowband, 1.668-GHz (L-band) receive capability for radio astronomy observations. This capability is delivered by a large feedhorn mounted on the exterior of one of the feedcones. It provides a single polarization into a pair of redundant low-noise amplifiers. Recently, funding was obtained to upgrade this system to wideband (1.4-1.9 GHz) dual-polarization operation. This required development of a new feedhorn, polarizer, orthomode transducer (OMT), and waveguide transitions. In this article, we describe the design and laboratory testing of these components.

Orbital assembly and maintenance study. Executive summary. [space erectable structures/structural design criteria

NASA Technical Reports Server (NTRS)

Gorman, D.; Grant, C.; Kyrias, G.; Lord, C.; Rombach, J. P.; Salis, M.; Skidmore, R.; Thomas, R.

1975-01-01

A sound, practical approach for the assembly and maintenance of very large structures in space is presented. The methods and approaches for assembling two large structures are examined. The maintenance objectives include the investigation of methods to maintain five geosynchronous satellites. The two assembly examples are a 200-meter-diameter radio astronomy telescope and a 1,000-meter-diameter microwave power transmission system. The radio astronomy telescope operates at an 8,000-mile altitude and receives RF signals from space. The microwave power transmission system is part of a solar power satellite that will be used to transmit converted solar energy to microwave ground receivers. Illustrations are included.

RF optics study for DSS-43 ultracone implementation

NASA Technical Reports Server (NTRS)

Lee, P.; Veruttipong, W.

1994-01-01

The Ultracone feed system will be implemented on DSS 43 to support the S-band (2.3 GHz) Galileo contingency mission. The feed system will be installed in the host country's cone, which is normally used for radio astronomy, VLBI, and holography. The design must retain existing radio-astronomy capabilities, which could be impaired by shadowing from the large S-band feed horn. Computer calculations were completed to estimate system performance and shadowing effects for various configurations of the host country's cone feed systems. Also, the DSS-43 system performance using higher gain S-band horns was analyzed. A new S-band horn design with improved return loss and cross-polarization characteristics is presented.

Satellite antenna dish acquired for use by the BAA

NASA Astrophysics Data System (ADS)

Ashton, T.

2007-10-01

The Radio Astronomy Group (RAG) of the BAA is pleased to announce it has obtained the use of the 2.4m diameter, fully-steerable satellite antenna dish residing on the roof of the National Space Centre (NSC) in Leicester (see Figure). The RAG is fortunate in having its assistant coordinator, Jeff Lashley, employed by the NSC as a technical support engineer and Jeff has worked tirelessly with coordinator Dr Laurence Newell in seeking permission for the Group to use the dish for radio astronomy purposes. Support has also been forthcoming via Terry Ashton, our university liaison officer, who works at the University of Leicester's Space Research Centre (SRC) which owns the dish.

Skynet Junior Scholars: Bringing Astronomy to Deaf and Hard of Hearing Youth

NASA Astrophysics Data System (ADS)

Meredith, Kate; Williamson, Kathryn; Gartner, Constance; Hoette, Vivian L.; Heatherly, Sue Ann

2016-01-01

Skynet Junior Scholars (SJS), funded by the National Science Foundation, aims to engage middle school youth from diverse audiences in investigating the universe with research quality robotic telescopes. SJS project development goals include: 1) Online access to optical and radio telescopes, data analysis tools, and professional astronomers, 2) An age-appropriate web-based interface for controlling remote telescopes, 3) Inquiry-based standards-aligned instructional modules. From an accessibility perspective, the goal of the Skynet Junior Scholars project is to facilitate independent access to the project by all youth including those with blindness or low vision and those who are Deaf or Hard of Hearing.Deaf and Hard of Hearing (DHH) students have long been an underserved population within STEM fields, including astronomy. Two main barriers include: (1) insufficient corpus of American Sign Language (ASL) for astronomy terminology, and (2) DHH education professionals who lack astronomy background. A suite of vocabulary, accessible hands-on activities, and interaction with trained professionals, are critical for enhancing the background experiences of DHH youth, as they may come to an astronomy lesson lacking the basic "incidental learning" that is often taken for granted with hearing peers (for example, from astronomy in the media).A collaboration between the Skynet Junior Scholars (SJS) project and the Wisconsin School for the Deaf is bringing astronomy to the DHH community in an accessible way for the first time. We follow a group of seven DHH youth over one semester as they interact with the SJS tools and curriculum to understand how they assimilate astronomy experiences and benefit from access to telescopes both directly (on school campus and at Yerkes Observatory) and through Skynet's robotic telescope network (optical and radio telescopes, inquiry-based modules, data analysis tools, and professional astronomers). We report on our first findings of resources and best practices for engaging DHH youth in astronomy in the future.

The Very Large Array: Pioneering New Directions in Radio Astronomy

NASA Astrophysics Data System (ADS)

McKinnon, Mark

2018-01-01

The Very Large Array (VLA) started science operations in 1980 and was rechristened the Jansky VLA after a major upgrade to its electronics system was completed in 2012. The VLA plays a prominent role in scientific discovery through studies of the Solar System, star and planet formation, galaxy formation, and time domain astronomy. It has attained iconic status as one of the most scientifically productive telescopes on EarthIn 2017, three major initiatives were launched at the VLA with the goal of maintaining its leadership role and impact in radio astronomy in the near and long term future:1. In September, the VLA embarked upon the VLA Sky Survey (VLASS), the highest resolution survey ever undertaken at radio wavelengths. The survey was planned in consultation with the astronomy community and will be used to search for transients, study the polarization properties of extragalactic radio sources, and study highly obscured sources in our Galaxy.2. Detailed planning for a next generation VLA (ngVLA) began in earnest in 2017. The ngVLA will open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milliarcsecond resolution, as well as unprecedented broad-band continuum polarimetric imaging of non-thermal processes. A proposal for the instrument will be submitted to the 2020 Decadal Survey.3. A multi-year program to replace the 40+ year old infrastructure at the VLA site was initiated in 2017. The program includes the replacement of the VLA’s electrical infrastructure in 2018, improvements to the VLA rail system, and the replacement of heavy maintenance equipment.The VLA continued to play a major role in discovering and explaining the physics of transient phenomena in 2017, to include fast transients, such as fast radio bursts, and long time scale transients, such as novae, tidal disruption events, and gamma-ray bursts.More thorough descriptions of the VLASS and ngVLA, along with the science that can be done with them, and of VLA observations of transient phenomena are given in the presentations in this session.

JPL Big Data Technologies for Radio Astronomy

NASA Astrophysics Data System (ADS)

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 (<< 1 second) transient events, require that data be analyzed rapidly and with robust RFI rejection. JPL, in collaboration with the International Center for Radio Astronomy Research in Australia, has developed a fast transient search 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.

The double quasar 0957+561: a radio study at 6-centimeters wavelength.

PubMed

Roberts, D H; Greenfield, P E; Burke, B F

1979-08-31

The optical double quasar 0957+561 has been interpreted as the gravitational double image of a single object. A radio map made with the Very Large Array of the National Radio Astronomy Observatory shows unresolved sources coincident With the optical images as well as a complex of related extended emission. Although the results cannot rule out the gravitational lens hypothesis, the complex radio structure is more easily interpreted as two separate quasars. The optical and radio properties of the two quasars are so similar that the two must have been formed at the same time with similar initial conditions.

The Deep Space Network

NASA Technical Reports Server (NTRS)

1988-01-01

The Deep Space Network (DSN) is the largest and most sensitive scientific telecommunications and radio navigation network in the world. Its principal responsibilities are to support unmanned interplanetary spacecraft missions and to support radio and radar astronomy observations in the exploration of the solar system and the universe. The DSN facilities and capabilities as of January 1988 are described.

Interplanetary Radio Transmission Through Serial Ionospheric and Material Barriers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, David; Kennedy, Robert G; Roy, Kenneth I

2013-01-01

A usual first principle in planning radio astronomy observations from the earth is that monitoring must be carried out well above the ionospheric plasma cutoff frequency (~5 MHz). Before space probes existed, radio astronomy was almost entirely done above 6 MHz, and this value is considered a practical lower limit by most radio astronomers. Furthermore, daytime ionization (especially D-layer formation) places additional constraints on wave propagation, and waves of frequency below 10-20 MHz suffer significant attenuation. More careful calculations of wave propagation through the earth s ionosphere suggest that for certain conditions (primarily the presence of a magnetic field) theremore » may be a transmission window well below this assumed limit. Indeed, for receiving extraterrestrial radiation below the ionospheric plasma cutoff frequency, a choice of VLF frequency appears optimal to minimize loss. The calculation, experimental validation, and conclusions are presented here. This work demonstrates the possibility of VLF transmission through the ionosphere and various subsequent material barriers. Implications include development of a new robust communications channel, communications with submerged or subterranean receivers / instruments on or offworld, and a new approach to SETI.« less

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1993-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA.

Big Data Challenges for Large Radio Arrays

NASA Technical Reports Server (NTRS)

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.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1991-01-01

This quarterly reports on space communications, radio navigation, radio science, and ground based radio and radar astronomy in connection with the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and in operations. Also included is standards activity at JPL for space data and information systems and DSN work. Specific areas of research are: Tracking and ground based navigation; Spacecraft and ground communications; Station control and system technology; DSN Systems Implementation; and DSN Operations.

FPGA applications for single dish activity at Medicina radio telescopes

NASA Astrophysics Data System (ADS)

Bartolini, M.; Naldi, G.; Mattana, A.; Maccaferri, A.; De Biaggi, M.

FPGA technologies are gaining major attention in the recent years in the field of radio astronomy. At Medicina radio telescopes, FPGAs have been used in the last ten years for a number of purposes and in this article we will take into exam the applications developed and installed for the Medicina Single Dish 32m Antenna: these range from high performance digital signal processing to instrument control developed on top of smaller FPGAs.

NRAO Salutes Past, Looks to Future In 50th-Anniversary Science Meeting

NASA Astrophysics Data System (ADS)

2007-06-01

Radio telescopes now in operation or under construction will be indispensible to scientists wrestling with the big, unanswered questions of 21st-Century astrophysics. That was the conclusion of a wide-ranging scientific meeting held in Charlottesville, Virginia, June 18-21, to mark the 50th anniversary of the National Radio Astronomy Observatory (NRAO). 1957 Dedication Dedication of NRAO, 17 October 1957. Left to right: R.M. Emberson, L.V. Berkner, G.A. Nay, J.W. Findlay (seated in front of 140ft telescope model), N.L. Ashton, D.S. Heeschen, H. Hockenberry. CREDIT: NRAO/AUI/NSF Click on Image for Larger File ALMA Artist's conception of completed ALMA. CREDIT: NRAO/AUI/ESO Click on Image for Larger File (2.4 MB) Nearly 200 scientists from around the world heard presentations about the frontiers of astrophysics and how the challenges at those frontiers will be met. In specialties as disparate as seeking the nature of the mysterious Dark Energy that is speeding the Universe's expansion to unraveling the details of how stars and planets are formed, more than 70 presenters looked toward future research breakthroughs. "NRAO's telescopes have made landmark contributions to the vast explosion of astronomical knowledge of the past half- century, and we look eagerly to making even more important contributions in the coming decades," said Fred K.Y. Lo, NRAO's director. Over the four days of the meeting, discussions ranged from recollections of radio astronomy's pioneering days of vacuum-tube equipment and paper chart recorders to the design of telescopes that will produce amounts of data that will strain today's computers. Presenters pointed out that, in the coming decades, radio telescope observations will advance not only astronomy but also fields of basic physics such as gravitational radiation, particle physics, and the fundamental physical constants. "This meeting provided a great overview of where astrophysics stands today and where the challenges and opportunities of the future lie. We had a good mix of veterans from the early days of radio astronomy and the young researchers who will carry the science well into the observatory's next half-century," said NRAO astronomer Jim Condon, who organized the scientific program. In addition to the presentations, meeting participants got an in-depth tour of the NRAO Technology Center, where the observatory is developing and building state-of-the-art electronics for radio astronomy. A half-century ago, NRAO staffers were preparing to break ground for the observatory's first telescope at Green Bank, West Virginia. That telescope was dedicated the next year. It was followed by ever more capable telescopes, culminating in the Robert C. Byrd Green Bank Telescope, the largest fully-steerable dish antenna in the world. Work at Green Bank laid the technical foundation for the Very Large Array, near Socorro, New Mexico, which was dedicated in 1980. The continent-wide Very Long Baseline Array was dedicated in 1993. NRAO, along with partners in Europe and Japan, is constructing the Atacama Large Millimeter Array (ALMA) in northern Chile, a facility that will bring entirely new observing capabilities to the world's astronomers. ALMA is expected to provide the opportunity for major advances in the understanding of how stars and planets are formed, and to reveal some of the first stars and galaxies that formed in the early Universe, among other achievements. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

A New Method to Cancel RFI---The Adaptive Filter

NASA Astrophysics Data System (ADS)

Bradley, R.; Barnbaum, C.

1996-12-01

An increasing amount of precious radio frequency spectrum in the VHF, UHF, and microwave bands is being utilized each year to support new commercial and military ventures, and all have the potential to interfere with radio astronomy observations. Some radio spectral lines of astronomical interest occur outside the protected radio astronomy bands and are unobservable due to heavy interference. Conventional approaches to deal with RFI include legislation, notch filters, RF shielding, and post-processing techniques. Although these techniques are somewhat successful, each suffers from insufficient interference cancellation. One concept of interference excision that has not been used before in radio astronomy is adaptive interference cancellation. The concept of adaptive interference canceling was first introduced in the mid-1970s 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 compartment of automobiles. Only recently have high-speed digital filter chips made adaptive filtering possible in a bandwidth as large a few megahertz, finally opening the door to astronomical uses. The system consists of two receivers: the main beam of the radio telescope receives the desired signal corrupted by RFI coming in the sidelobes, and the reference antenna receives only the RFI. The reference antenna is processed using a digital adaptive filter and then subtracted from the signal in the main beam, thus producing the system output. The weights of the digital filter are adjusted by way of an algorithm that minimizes, in a least-squares sense, the power output of the system. Through an adaptive-iterative process, the interference canceler will lock onto the RFI and the filter will adjust itself to minimize the effect of the RFI at the system output. We are building a prototype 100 MHz receiver and will measure the cancellation effectiveness of the system on the 140 ft telescope at Green Bank Observatory.

A Wide Spectrum of Solar Science for After School Astronomy Club

NASA Technical Reports Server (NTRS)

Mayo, Lou; Thieman, James R.

2008-01-01

After School Astronomy clubs are an important method of exposing students to astronomy at the critical middle school age when sparking an interest can inspire a lifelong career or hobby. We know that teachers complain that they can spend little time on astronomy in the classroom since they must teach to the test and the curriculum requirements do not have very extensive astronomy coverage. We also know that space is a very popular subject with students that can motivate them to join an after school club. One of the problems with after school astronomy clubs is that they don't often have a chance to observe the night sky. We propose to train club mentors on how to do daytime solar observing so students fulfill the IYA goal of looking through a telescope. We propose to provide a half day workshop for elementary and middle school teachers on starting and maintaining After School Astronomy clubs with special emphasis on observing the Sun not only in the visible spectrum but with radio waves and other parts of the spectrum as well. We will use NASA-oriented or NASA-funded educational materials and websites to bring a variety of ideas to the mentors and a broad knowledge of astronomy to the students. Attendees will be given an overview of the science of the Sun and how it can affect us on the Earth. They will be shown the dynamic nature of the Sun and what to look for to track the events happening there. The educators will be shown simple approaches to directly observing the Sun such as pinhole cameras, use of projection techniques with telescopes or binoculars, etc. They will be acquainted with sunspotter scopes and the advantages and disadvantages (such as expense) they pose for getting students involved. We will also point out the possibilities of using regular telescopes with solar filters and the specialized solar viewing telescopes such as the Coronado. Once the educators are comfortable with the simple approaches to viewing the Sun we will expose them to advanced topics such as remotely viewing the Sun using telescopes available on the web. Resources such as the Sun-Earth Viewer will allow them to study near real-time images of the Sun in multiple wavelengths. They will also be shown how they can monitor the Sun at radio wavelengths via remote telescopes or even how to purchase and build their own radio telescopes for hands-on monitoring of the Sun and other radio sources. We will conduct a brief evaluation of the participants knowledge of the Sun as they come into the workshop. We will also ask them to complete a brief knowledge survey at the end to determine if their knowledge and comfort level with solar science has improved significantly.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1987-01-01

Archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA) are provided. Activities of the Deep Space Network (DSN) in space communications, radio navigation, radio science, and ground-based radio astronomy are reported. Also included are the plans, supporting research and technology, implementation and operations for the Ground Communications Facility (GCF). In geodynamics, the publication reports on the application of radio interferometry at microwave frequencies for geodynamic measurements. In the search for extraterrestrial intelligence (SETI), it reports on implementation and operations for searching the microwave spectrum.

Socorro Students Translate NRAO Web Pages Into Spanish

NASA Astrophysics Data System (ADS)

2002-07-01

Six Socorro High School students are spending their summer working at the National Radio Astronomy Observatory (NRAO) on a unique project that gives them experience in language translation, World Wide Web design, and technical communication. Under the project, called "Un puente a los cielos," the students are translating many of NRAO's Web pages on astronomy into Spanish. "These students are using their bilingual skills to help us make basic information about astronomy and radio telescopes available to the Spanish-speaking community," said Kristy Dyer, who works at NRAO as a National Science Foundation postdoctoral fellow and who developed the project and obtained funding for it from the National Aeronautics and Space Administration. The students are: Daniel Acosta, 16; Rossellys Amarante, 15; Sandra Cano, 16; Joel Gonzalez, 16; Angelica Hernandez, 16; and Cecilia Lopez, 16. The translation project, a joint effort of NRAO and the NM Tech physics department, also includes Zammaya Moreno, a teacher from Ecuador, Robyn Harrison, NRAO's education officer, and NRAO computer specialist Allan Poindexter. The students are translating NRAO Web pages aimed at the general public. These pages cover the basics of radio astronomy and frequently-asked questions about NRAO and the scientific research done with NRAO's telescopes. "Writing about science for non-technical audiences has to be done carefully. Scientific concepts must be presented in terms that are understandable to non-scientists but also that remain scientifically accurate," Dyer said. "When translating this type of writing from one language to another, we need to preserve both the understandability and the accuracy," she added. For that reason, Dyer recruited 14 Spanish-speaking astronomers from Argentina, Mexico and the U.S. to help verify the scientific accuracy of the Spanish translations. The astronomers will review the translations. The project is giving the students a broad range of experience. "They are getting hands-on experience in language translation, in Web design and computer science, and learning some astronomy as well," said Dyer. "This is a challenging project, but these students are meeting the challenge well," she added. The students are enthusiastic. "I've always been interested in stars and space, and I love working with computers," said Amarante. "We are pleased that these local students are using their skills to enhance our public-education efforts," said NRAO's director of New Mexico operations James Ulvestad. "Our Web site is one of our best tools for informing the public about astronomy and the work done at our observatory. This translation project now allows us to reach an important new audience," Ulvestad added. The students began the project in June and will complete the effort on July 26. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Report of the Science Working Group: Science with a lunar optical interferometer

NASA Technical Reports Server (NTRS)

1992-01-01

Resolution is the greatest constraint in observational astronomy. The Earth's atmosphere causes on optical image to blur to about 1 arcsec or greater. Interferometric techniques have been developed to overcome atmospheric limitations for both filled aperture conventional telescopes and for partially filled aperture telescopes, such as the Michelson or the radio interferometer. The Hubble Space Telescope (HST) represents the first step toward space based optical astronomy. The HST represents an immediate short term evolution of observational optical astronomy. A longer time scale of evolution is focused on and the benefits are considered to astronomy of placing an array of telescopes on the Moon at a time when a permanent base may exist there.

Astronomy and astrophysics for the 1980's. Volume 1 - Report of the Astronomy Survey Committee. Volume 2 - Reports of the Panels

NASA Astrophysics Data System (ADS)

Recommended priorities for astronomy and astrophysics in the 1980s are considered along with the frontiers of astrophysics, taking into account large-scale structure in the universe, the evolution of galaxies, violent events, the formation of stars and planets, solar and stellar activity, astronomy and the forces of nature, and planets, life, and intelligence. Approved, continuing, and previously recommended programs are related to the Space Telescope and the associated Space Telescope Science Institute, second-generation instrumentation for the Space Telescope, and Gamma Ray Observatory, facilities for the detection of solar neutrinos, and the Shuttle Infrared Telescope Facility. Attention is given to the prerequisites for new research initiatives, new programs, programs for study and development, high-energy astrophysics, radio astronomy, theoretical and laboratory astrophysics, data processing and computational facilities, organization and education, and ultraviolet, optical, and infrared astronomy.

A Bibliography of Aerospace Books and Teaching Aids for Secondary School Students and Teachers

DTIC Science & Technology

1961-11-13

p., llus.. HEim-E5. KENNETH. A.N ADVENTURE IN ASTRO.NOMY. 19539. $2.50. An introduction to radio astrono )my Viking. 127 1P.. illus.. 1958. $3.30...8217. ASTRONO )MY. Watts. 2:A; l., illus.. 1960. outer Si1-Pe. 14.5. The history of astronomy, the development Mt-rz,. lai.tyl. Tilns IS OUTER SPACE

Astrometry VLBI in Space (AVS)

NASA Technical Reports Server (NTRS)

Cheng, Li-Jen; Reyes, George

1995-01-01

This paper describes a proposal for a new space radio astronomy mission for astrometry using Very Long Baseline Interferometry (VLBI) called Astrometry VLBI in Space (AVS). The ultimate goals of AVS are improving the accuracy of radio astrometry measurements to the microarcsecond level in one epoch of measurements and improving the accuracy of the transformation between the inertial radio and optical coordinate reference frames. This study will also assess the impact of this mission on astrophysics astrometry and geophysics.

Research at the Stanford Center for Radar Astronomy

NASA Technical Reports Server (NTRS)

1973-01-01

Theoretical and experimental radio and radar studies are presented concerning lunar and planetary atmospheres and surfaces; the sun and interplanetary medium; and software and hardware conceived while doing research. Emphasis is given to probe and radio accumulation measurements of planetary atmospheres. A list is included of recent publications, technical and scientific reports, and symposia with papers.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1984-01-01

Activities in space communication, radio navigation, radio science, and ground-based astronomy are reported. Advanced systems for the Deep Space Network and its Ground-Communications Facility are discussed including station control and system technology. Network sustaining as well as data and information systems are covered. Studies of geodynamics, investigations of the microwave spectrum, and the search for extraterrestrial intelligence are reported.

Ultra-Low-Noise W-Band MMIC Detector Modules

NASA Technical Reports Server (NTRS)

Gaier, Todd C.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Van Vinkle, Dan; Tantawi, Sami; Fox, John; Church, Sarah E.; Lau, Jusy M.; Sieth, Matthew M.; Voll, Patricia E.;

Collaboration and Development of Radio Astronomy in Australasia and South-Pacific Region: New Zealand Perspectives

NASA Astrophysics Data System (ADS)

Gulyaev, S.; Natusch, T.

2006-08-01

Radio telescopes in the Asia-Pacific region form a natural network for VLBI observations, similar to the very successful networks in North America (Network Users Group) and Europe (European VLBI Network). New Zealand's VLBI facility, which we are developing since 2005, has the potential to strengthen the Asian-Pacific VLBI network and its role in astronomy, geodesy and geoscience. It will positively influence regional and international activities in geoscience and geodesy that advance New Zealand's national interests. A self-contained radio astronomy system for VLBI, including a 1.658 GHz (centre frequency), 16 MHz bandwidth RF system (feed and downconversion system locked to a Rubidium maser and GPS clock), an 8-bit sampler/digitisation system, and a disk-based recording system built around a commodity PC was developed in New Zealand Centre for Radiophysics and Space Research. This was designed as a portable system for use on various radio telescopes. A number of Trans-Tasman tests has been conducted in 2005-2006 between the CRSR system installed on a 6 metre dish located in Auckland and the Australia Telescope Compact Array in Narrabri, Australia. This work has been successful, with fringes located from the recorded data and high resolution image of the quasar PKS1921-231 obtained. Experiments were recently conducted with Japan; new tests are planned with Korea and Fiji. Plans have been made to build a new 16.5 m antenna in New Zealand's North Island and to upgrade an 11 m dish in the South Island. A possible future of New Zealand's participation in the SKA is being discussed.

Type 2 solar radio events observed in the interplanetary medium. Part 1: General characteristics

NASA Technical Reports Server (NTRS)

Cane, H. V.; Stone, R. G.; Fainberg, J.; Steinberg, J. L.; Hoang, S.

1980-01-01

Twelve type 2 solar radio events were observed in the 2 MHz to 30 kHz frequency range by the radio astronomy experiment on the ISEE-3 satellite over the period from September 1978 to December 1979. These data provide the most comprehensive sample of type 2 radio bursts observed at kilometer wavelengths. Dynamic spectra of a number of events are presented. Where possible, the 12 events were associated with an initiating flare, ground based radio data, the passage of a shock at the spacecraft, and the sudden commencement of a geomagnetic storm. The general characteristics of kilometric type 2 bursts are discussed.

Interferometry meets the third and fourth dimensions in galaxies

NASA Astrophysics Data System (ADS)

Trimble, Virginia

2015-02-01

Radio astronomy began with one array (Jansky's) and one paraboloid of revolution (Reber's) as collecting areas and has now reached the point where a large number of facilities are arrays of paraboloids, each of which would have looked enormous to Reber in 1932. In the process, interferometry has contributed to the counting of radio sources, establishing superluminal velocities in AGN jets, mapping of sources from the bipolar cow shape on up to full grey-scale and colored images, determining spectral energy distributions requiring non-thermal emission processes, and much else. The process has not been free of competition and controversy, at least partly because it is just a little difficult to understand how earth-rotation, aperture-synthesis interferometry works. Some very important results, for instance the mapping of HI in the Milky Way to reveal spiral arms, warping, and flaring, actually came from single moderate-sized paraboloids. The entry of China into the radio astronomy community has given large (40-110 meter) paraboloids a new lease on life.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1991-01-01

This quarterly publication provides archival reports on developments in programs managed by the Jet Propulsion Laboratory's (JPL's) Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on the activities of the Deep Space Network (DSN) in planning, in supporting research and technology, in implementation, and in operations. Also included is standards activity at JPL for space data, information systems, and reimbursable DSN work performed for other space agencies through NASA.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1990-01-01

Archival reports on developments in programs managed by the Jet Propulsion Laboratory's (JPL) Office of Telecommunications and Data Acquisition (TDA) are given. Space communications, radio navigation, radio science, and ground-based radio and radar astronomy, activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, supporting research and technology, implementation, and operations are reported. Also included is TDA-funded activity at JPL on data and information systems and reimbursable Deep Space Network (DSN) work performed for other space agencies through NASA.

The Telecommunications and Data Acquisition

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1992-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

Highlighting the history of Japanese radio astronomy. 5: The 1950 Osaka solar grating array proposal

NASA Astrophysics Data System (ADS)

Wendt, Harry; Orchiston, Wayne; Ishiguro, Masato; Nakamura, Tsuko

2017-04-01

In November 1950, a paper was presented at the 5th Annual Assembly of the Physical Society of Japan that outlined the plan for a radio frequency grating array, designed to provide high-resolution observations of solar radio emission at 3.3 GHz. This short paper provides details of the invention of this array, which occurred independently of W.N. Christiansen's invention of the solar grating array in Australia at almost the same time.

International Lunar Observatory Association Advancing 21st Century Astronomy from the Moon

NASA Astrophysics Data System (ADS)

Durst, Steve

2015-08-01

Long considered a prime location to conduct astronomical observations, the Moon is beginning to prove its value in 21st Century astronomy through the Lunar Ultraviolet Telescope aboard China’s Chang’e-3 Moon lander and through the developing missions of the International Lunar Observatory Association (ILOA). With 24 hours / Earth day of potential operability facilitating long-duration observations, the stable platform of the lunar surface and extremely thin exosphere guaranteeing superior observation conditions, zones of radio-quiet for radio astronomy, and the resources and thermal stability at the lunar South Pole, the Moon provides several pioneering advantages for astronomy. ILOA, through MOUs with NAOC and CNSA, has been collaborating with China to make historic Galaxy observations with the Chang’e-3 LUT, including imaging Galaxy M101 in December 2014. LUT has an aperture of 150mm, covers a wavelength range of 245 to 340 nanometers and is capable of detecting objects at a brightness down to 14 mag. The success of China’s mission has provided support and momentum for ILOA’s mission to place a 2-meter dish, multifunctional observatory at the South Pole of the Moon NET 2017. ILOA also has plans to send a precursor observatory instrument (ILO-X) on the inaugural mission of GLXP contestant Moon Express. Advancing astronomy and astrophysics from the Moon through public-private and International partnerships will provide many valuable research opportunities while also helping to secure humanity’s position as multi world species.

Shoestring Budget Radio Astronomy

NASA Astrophysics Data System (ADS)

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.

Shoestring Budget Radio Astronomy (Abstract)

NASA Astrophysics Data System (ADS)

Hoot, J. E.

2017-12-01

(Abstract only) 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.

The ISPM unified radio and plasma wave experiment

NASA Technical Reports Server (NTRS)

Stone, R. G.; Caldwell, J.; Deconchy, Y.; Deschanciaux, C.; Ebbett, R.; Epstein, G.; Groetz, K.; Harvey, C. C.; Hoang, S.; Howard, R.

1983-01-01

Hardware for the International Solar Polar Mission (ISPM) Unified Radio and Plasma (URAP) wave experiment is presented. The URAP determines direction and polarization of distant radio sources for remote sensing of the heliosphere, and studies local wave phenomena which determine the transport coefficients of the ambient plasma. Electric and magnetic field antennas and preamplifiers; the electromagnetic compatibility plan and grounding; radio astronomy and plasma frequency receivers; a fast Fourier transformation data processing unit waveform analyzer; dc voltage measurements; a fast envelope sampler for the solar wind, and plasmas near Jupiter; a sounder; and a power converter are described.

Revealing the Hidden Wave: Using the Very Small Radio Telescope to Teach High School Physics

ERIC Educational Resources Information Center

Doherty, Michael; Fish, Vincent L.; Needles, Madeleine

2011-01-01

Scientists and teachers have worked together to produce teaching materials for the Very Small Radio Telescope (VSRT), an easy-to-use, low-cost apparatus that can be used in multiple laboratory experiments in high school and university physics and astronomy classes. In this article, we describe the motivation for the VSRT and several of the…

Using Group Research Projects to Stimulate Undergraduate Astronomy Major Learning

NASA Astrophysics Data System (ADS)

McGraw, Allison M.; Hardegree-Ullman, K. K.; Turner, J. D.; Shirley, Y. L.; Walker-LaFollette, A. M.; Robertson, A. N.; Carleton, T. M.; Smart, B. M.; Towner, A. P. M.; Wallace, S. C.; Smith, C. W.; Small, L. C.; Daugherty, M. J.; Guvenen, B. C.; Crawford, B. E.; Austin, C. L.; Schlingman, W. M.

2012-05-01

The University of Arizona Astronomy Club has been working on two large group research projects since 2009. One research project is a transiting extrasolar planet project that is fully student led and run. We observed the transiting exoplanets, TrES-3b and TrES-4b, with the 1.55 meter Kupier Telescope in near-UV and optical filters in order to detect any asymmetries between filters. The second project is a radio astronomy survey utilizing the Arizona Radio Observatory 12m telescope on Kitt Peak to study molecular gas in cold cores identified by the Planck all sky survey. This project provides a unique opportunity for a large group of students to get hands-on experience observing with a world-class radio observatory. These projects involve students in every single step of the process including: proposal writing to obtain telescope time on various Southern Arizona telescopes, observing at these telescopes, data reduction and analysis, managing large data sets, and presenting results at scientific meetings and in journal publications. The primary goal of these projects is to involve students in cutting-edge research early on in their undergraduate studies. The projects are designed to be continuous long term projects so that new students can easily join. As of January 2012 the extrasolar planet project became an official independent study class. New students learn from the more experienced students on the projects creating a learner-centered environment.

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

NASA Astrophysics Data System (ADS)

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 size. The book reprints internal memos, reports, and recollections of astronomers who were there, as the initial elation turned to frustration when the 140 Foot Telescope project became mired in technical difficulties, plans for larger dishes were put on hold, and the scientific staff of the fledgling Observatory struggled to create a National Observatory with inadequate equipment in a very remote location. Articles by David Heeschen and John Findlay tell the story of the creation of the 300 Foot Telescope, at that time the largest in the world, which went from initial concept to full operation in only 23 months, and began a rich life of research that put the NRAO on the world scientific map. The 300 Foot Telescope was originally intended to be an interim instrument, but as documented in the book, demand for its use was so high that it was kept in operation long after its initial planned retirement, with regular upgrades and new generations of electronics. The sudden collapse of the 300 Foot Telescope on a calm evening after 26 years of operation shocked the astronomical community. But it was Fun... features dramatic first-hand accounts by the people who were there that night: the telescope operator who found himself under a falling structure; the Observatory staff who at first could not believe what happened, and those who worked during the night and into the next day to secure the area, preserve information on what happened, and deal with the rush of publicity. The book includes extensive photographs and the Executive Summary Report of the panel which was commissioned to investigate the collapse and its implication for the design of other large radio telescopes. But it was Fun... will appeal to a variety of audiences. Historians of science will be interested in the articles by David Heeschen, Gerald Tape, and Hugh van Horn, on the evolution of the concept of a National Observatory, and the difficulties of putting the concepts into practice in Green Bank. Those interested in astronomical discovery will find fascinating and highly personal accounts by Peter Mezger on observations of radio recombination lines, by Lewis Snyder and Barry Turner on the early days of astrochemistry, by Don Backer and David Nice on observations of pulsars, and by David Shaffer, James Moran, Ken Kellermann and Barry Clark on aspects of the development of long baseline interferometric techniques. Today's generation of scientists will find interesting reminiscences by Patrick Palmer, Thomas Wilson, and Nobel Laureate Joseph Taylor on their experiences as graduate students doing thesis research at Green Bank, and from Sebastian von Hoerner and Jaap Baars on their work in telescope development. The volume also relates the entry of computers into radio astronomy, and reprints the one-page memo from 1960 which laid out the protocol for use of the new "single roll of magnetic tape" just acquired by the Observatory. A major portion of the book describes some singular events associated with this singular place: the first search for radio signals from extraterrestrial civilizations -- Project Ozma -- conducted by Dr. Frank Drake in 1960. But it was Fun... documents how this routine project thrust the NRAO into the national spotlight to the discomfort of its director, a distinguished astronomer of the old school. The book also recounts a few episodes in the amazing life of Grote Reber, the engineer who built the first-ever radio dish in his backyard and was a regular visitor to Green Bank. The NRAO Green Bank Observatory is an international center for research, and in two unique and frequently hilarious articles, Ken Kellermann and Barry Clark tell their stories of the first cooperative radio astronomical projects between the Soviet Union and the U.S., which involved transporting an atomic clock from Green Bank to a Soviet Observatory on the Black Sea at a time when international tensions were high, and it was impossible to make a phone call from the USSR to Green Bank. But it was Fun... includes a historical introduction which summarizes the early development of radio astronomy and events at the NRAO in Green Bank, a list of science highlights from the 300 Foot and 140 Foot Telescope research programs, chronologies of technical developments and lists of the early users. But it was Fun: the first 40 years of radio astronomy at Green Bank is a unique book which offers insight on the workings of a major scientific institution and the "overabundance of interesting people" who have populated it. The book is available from the NRAO. For information on ordering, see: http://www.gb.nrao.edu/epo/itwasfun.html The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Record-Breaking Radio Astronomy Project to Measure Sky with Extreme Precision

NASA Astrophysics Data System (ADS)

2009-11-01

Astronomers will tie together the largest collection of the world's radio telescopes ever assembled to work as a single observing tool in a project aimed at improving the precision of the reference frame scientists use to measure positions in the sky. The National Science Foundation's Very Long Baseline Array (VLBA) will be a key part of the project, which is coordinated by the International VLBI Service for Geodesy and Astrometry. For 24 hours, starting Wednesday, November 18, and ending Thursday, November 19, 35 radio telescopes located on seven continents will observe 243 distant quasars. The quasars, galaxies with supermassive black holes at their cores, are profuse emitters of radio waves, and also are so distant that, despite their actual motions in space, they appear stationary as seen from Earth. This lack of apparent motion makes them ideal celestial landmarks for anchoring a grid system, similar to earthly latitude and longitude, used to mark the positions of celestial objects. Data from all the radio telescopes will be combined to make them work together as a system capable of measuring celestial positions with extremely high precision. The technique used, called very long baseline interferometry (VLBI), has been used for decades for both astronomical and geodetic research. However, no previous position-measuring observation has used as many radio telescopes or observed as many objects in a single session. The previous record was a 23-telescope observation. At a meeting in Brazil last August, the International Astronomical Union adopted a new reference frame for celestial positions that will be used starting on January 1. This new reference frame uses a set of 295 quasars to define positions, much like surveyor's benchmarks in a surburban subdivision. Because even with 35 radio telescopes around the world, there are some gaps in sky coverage, the upcoming observation will observe 243 of the 295. By observing so many quasars in a single observing session, problems of linking positions from one observing session to another can be avoided, the astronomers say. The result will be a much stronger, more precise, reference grid. Telescopes in Asia, Australia, Europe, North America, South America, Antarctica, and in the Pacific will participate. Improving the celestial positional grid will allow astronomers better to pinpoint the locations and measure the motions of objects in the sky. As astronomers increasingly study objects using multiple telescopes observing at different wavelengths, such as visible light, radio, infrared, etc., the improved positional grid will allow more accurate overlaying of the different images. The improved celestial reference frame also strengthens a terrestrial reference frame used for radio-telescope measurements that contribute to geophysical research. The precise geodetic measurements help geophysicists understand phenomena such as plate tectonics, earth tides, and processes that affect our planet's orientation in space. The VLBA is a continent-wide radio telescope system with 10, 240-ton dish antennas ranging from Hawaii to the Virgin Islands. Operated from the National Radio Astronomy Observatory's Pete V. Domenici Science Operations Center in Socorro, New Mexico, the VLBA offers the greatest resolving power, or ability to see fine detail, of any telescope in astronomy. The multi-telescope observation will be accompanied by public-outreach activities in celebration of the International Year of Astronomy. A public web page devoted to the observation will be hosted at Bordeaux Observatory, and some of the participating telescopes will have webcams available.

Public Outreach and Educational Experiences in Mexico and Latin American communities in California

NASA Astrophysics Data System (ADS)

Andres De Leo-Winkler, Mario; Canalizo, Gabriela; Pichardo, Barbara; Arias, Brenda

2015-08-01

I have created and applied diverse methods in public outreach at National Autonomous Univerisity of Mexico (UNAM) since 2001.A student-led volunteer astronomical club has been created, the biggest in Mexico. We serve over 10,000 people per year. We have created public outreach activities for the general audience: archeo-astronomical outings, scientific movie debates, conferences, courses, public telescope viewings. We have also worked with juvenile delinquents to offer them scientific opportunities when released from jail.I've also created and worked the social media for the Institute of Astronomy UNAM, which is currently the biggest social media site on astronomy in Spanish in the world. I've created and organized a mass photo exhibition (over 1 million people served) for the Institute of Astronomy, UNAM which was citizen-funded through an online platform, the first of its kind in the country. Together with my colleages, we created workshops on astronomy for children with the Mexican's government funding.I've participated in several radio and television programs/capsules designed to bring astronomy to the general audience, one in particular ("Astrophysics for Dummies") was very successful in nation-wide Mexican radio.I am currently applying all experiences to develop a new public outreach project on astronomy for the University of California - Riverside and its on-campus and surrounding Latin American communities. We are offering new workshops for blind and deaf children. We want to integrate the Latino community to our outreach activities and offer science in their language in a simple and entertaining fashion. We have also successfully applied astrophotography as a course which brings social-science and arts undergraduate students into natural sciences.Sharing experiences, success and failure stories will help new and experienced educators and public outreach professionals learn and better from past experiences.

Matched wideband low-noise amplifiers for radio astronomy.

PubMed

Weinreb, S; Bardin, J; Mani, H; Jones, G

2009-04-01

Two packaged low noise amplifiers for the 0.3-4 GHz frequency range are described. The amplifiers can be operated at temperatures of 300-4 K and achieve noise temperatures in the 5 K range (<0.1 dB noise figure) at 15 K physical temperature. One amplifier utilizes commercially available, plastic-packaged SiGe transistors for first and second stages; the second amplifier is identical except it utilizes an experimental chip transistor as the first stage. Both amplifiers use resistive feedback to provide input reflection coefficient S11<-10 dB over a decade bandwidth with gain over 30 dB. The amplifiers can be used as rf amplifiers in very low noise radio astronomy systems or as i.f. amplifiers following superconducting mixers operating in the millimeter and submillimeter frequency range.

Voyager 1 Planetary Radio Astronomy Observations Near Jupiter

NASA Technical Reports Server (NTRS)

Warwick, J. W.; Pearce, J. B.; Riddle, A. C.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Thieman, J. R.; Carr, T. B.; Gulkis, S.; Boischot, A.

1979-01-01

Results are reported from the first low frequency radio receiver to be transported into the Jupiter magnetosphere. Dramatic new information was obtained both because Voyager was near or in Jupiter's radio emission sources and also because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio arcs, from above 30 MHz to about 1 MHz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Studies in progress are outlined briefly.

The Network for Astronomy in Education in Southwest New Mexico

NASA Astrophysics Data System (ADS)

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.

Astronomy Week in Madeira, Portugal

NASA Astrophysics Data System (ADS)

Augusto, P.; Sobrinho, J. L.

2012-05-01

The outreach programme Semanas da Astronomia (Astronomy Weeks) is held in late spring or summer on the island of Madeira, Portugal. This programme has been attracting enough interest to be mentioned in the regional press/TV/radio every year and is now, without doubt, the astronomical highlight of the year on Madeira. We believe that this programme is a good case study for showing how to attract the general public to astronomy in a small (population 250 000, area 900 km2) and fairly isolated place such as Madeira. Our Astronomy Weeks have been different each year and have so far included exhibitions, courses, talks, a forum, documentaries, observing sessions (some with blackouts), music and an astro party. These efforts may contribute towards putting Madeira on the map with respect to observational astronomy, and have also contributed to the planned installation of two observatories in the island.

Large-N correlator systems for low frequency radio astronomy

NASA Astrophysics Data System (ADS)

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 development of larger correlator systems, which in turn allows for improvements in sensitivity and resolution. This requires new calibration techniques which account for a broad range of systematic effects.

47 CFR 74.12 - Notification of filing of applications.

Code of Federal Regulations, 2010 CFR

2010-10-01

....1030 “Notification concerning interference to Radio Astronomy, Research, and Receiving Installations... remote pickup stations (subpart D). (b) TV pickup stations (subpart F). (c) Low power auxiliary stations...

Astrometry VLBI in Space (AVS

NASA Technical Reports Server (NTRS)

Altunin, V.; Alekseev, V.; Akim, E.; Eubanks, M.; Kingham, K.; Treuhaft, R.; Sukhanov, K.

1995-01-01

A proposed new space radio astronomy mission for astrometry is described. The Astrometry VLBI (very long baseline) in Space (AVS) nominal mission includes two identical spacecraft, each with a 4-m antenna sending data to a 70-m ground station. The goals of AVS are improving astrometry accuracy to the microarcsecond level and improving the accuracy of the transformation between the inertial radio and optical coordinate reference frames.

The Serendip piggyback SETI project

NASA Technical Reports Server (NTRS)

Lampton, Michael; Bowyer, Stuart; Werthimer, Dan; Donnelly, Charles; Herrick, Walter

1988-01-01

The Serendip project, an ongoing SETI program of monitoring and processing broadband radio signals acquired by existing radio astronomy observatories, are summarized. Serendip operates in a piggyback mode, making use of whatever observing plan is under way at its host observatory. The Serendip system at NRAO and the signature detection and identification techniques used by the project are described. The method used to reject terrestrial interference is discussed.

PRIFIRA: General regularization using prior-conditioning for fast radio interferometric imaging†

NASA Astrophysics Data System (ADS)

Naghibzadeh, Shahrzad; van der Veen, Alle-Jan

2018-06-01

Image formation in radio astronomy is a large-scale inverse problem that is inherently ill-posed. We present a general algorithmic framework based on a Bayesian-inspired regularized maximum likelihood formulation of the radio astronomical imaging problem with a focus on diffuse emission recovery from limited noisy correlation data. The algorithm is dubbed PRIor-conditioned Fast Iterative Radio Astronomy (PRIFIRA) and is based on a direct embodiment of the regularization operator into the system by right preconditioning. The resulting system is then solved using an iterative method based on projections onto Krylov subspaces. We motivate the use of a beamformed image (which includes the classical "dirty image") as an efficient prior-conditioner. Iterative reweighting schemes generalize the algorithmic framework and can account for different regularization operators that encourage sparsity of the solution. The performance of the proposed method is evaluated based on simulated one- and two-dimensional array arrangements as well as actual data from the core stations of the Low Frequency Array radio telescope antenna configuration, and compared to state-of-the-art imaging techniques. We show the generality of the proposed method in terms of regularization schemes while maintaining a competitive reconstruction quality with the current reconstruction techniques. Furthermore, we show that exploiting Krylov subspace methods together with the proper noise-based stopping criteria results in a great improvement in imaging efficiency.

Edward Mills Purcell, August 30, 1912-March 7, 1997

NASA Astrophysics Data System (ADS)

Rigden, John S.

2011-03-01

I discuss the life, education, personality, and contributions of Edward Mills Purcell (1912-1997) to physics, radio astronomy, astrophysics, biological physics, physics teaching and education, and to the nation.

Models of Uranium continuum radio emission

NASA Technical Reports Server (NTRS)

Romig, Joseph H.; Evans, David R.; Sawyer, Constance B.; Schweitzer, Andrea E.; Warwick, James W.

1987-01-01

Uranium continuum radio emission detected by the Voyager 2 Planetary Radio Astronomy experiment during the January 1986 encounter is considered. The continuum emissions comprised four components (equatorial emissions, anomaly emissions, strong nightside emissions, and weak nightside emissions) associated with different sources. The equatorial emissions appeared most prominently during the days before closest approach and extended from 40 kHz or below to about 120 kHz. The anomaly emissions were seen about 12 hours before closest approach and extended to about 250 kHz. The agreement found between Miranda's phase and strong radio emission at 20.4 kHz, just after closest approach, suggests intense dynamic activity on the Miranda L shell.

Concept and Analysis of a Satellite for Space-Based Radio Detection of Ultra-High Energy Cosmic Rays

NASA Astrophysics Data System (ADS)

Romero-Wolf, Andrew; Gorham, P.; Booth, J.; Chen, P.; Duren, R. M.; Liewer, K.; Nam, J.; Saltzberg, D.; Schoorlemmer, H.; Wissel, S.; Zairfian, P.

2014-01-01

We present a concept for on-orbit radio detection of ultra-high energy cosmic rays (UHECRs) that has the potential to provide collection rates of ~100 events per year for energies above 10^20 eV. The synoptic wideband orbiting radio detector (SWORD) mission's high event statistics at these energies combined with the pointing capabilities of a space-borne antenna array could enable charged particle astronomy. The detector concept is based on ANITA's successful detection UHECRs where the geosynchrotron radio signal produced by the extended air shower is reflected off the Earth's surface and detected in flight.

Centaurus A galaxy, type EO peculiar elliptical, also radio source

NASA Technical Reports Server (NTRS)

2002-01-01

Centaurus A galaxy, type EO peculiar elliptical, also radio source. CTIO 4-meter telescope, 1975. NGC 5128, a Type EO peculiar elliptical galaxy in the constellation Centaurus. This galaxy is one of the most luminous and massive galaxies known and is a strong source of both radio and X-ray radiation. Current theories suggest that the nucleus is experiencing giant explosions involving millions of stars and that the dark band across the galactic disk is material being ejected outward. Cerro Toloto 4-meter telescope photo. Photo credit: National Optical Astronomy Observatories

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, Edward C. (Editor)

1991-01-01

A compilation is presented of articles on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition. In space communications, radio navigation, radio science, and ground based radio and radar astronomy, activities of the Deep Space Network are reported in planning, in supporting research and technology, in implementation, and in operations. Also included is standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. In the search for extraterrestrial intelligence (SETI), implementation and operations are reported for searching the microwave spectrum.

Sensivity studies for the Cherenkov Telescope Array

NASA Astrophysics Data System (ADS)

Collado, Tarek Hassan

2015-06-01

Since the creation of the first telescope in the 17th century, every major discovery in astrophysics has been the direct consequence of the development of novel observation techniques, opening new windows in the electromagnetic spectrum. After Karl Jansky discovered serendipitously the first radio source in 1933, Grote Reber built the first parabolic radio telescope in his backyard, planting the seed of a whole new field in astronomy. Similarly, new technologies in the 1950s allowed the establishment of other fields, such as the infrared, ultraviolet or the X-rays. The highest energy end of the electromagnetic spectrum, the γ-ray range, represents the last unexplored window for astronomers and should reveal the most extreme phenomena that take place in the Universe. Given the technical complexity of γ-ray detection and the extremely relative low fluxes, γ-ray astronomy has undergone a slower development compared to other wavelengths. Nowadays, the great success of consecutive space missions together with the development and refinement of new detection techniques from the ground, has allowed outstanding scientific results and has brought gamma-ray astronomy to a worthy level in par with other astronomy fields. This work is devoted to the study and improvement of the future Cherenkov Telescope Array (CTA), the next generation of ground based γ-ray detectors, designed to observe photons with the highest energies ever observed from cosmic sources.

Recent Progress in Active Antenna Designs for the Long Wavelength Array (LWA)

NASA Astrophysics Data System (ADS)

Hicks, B. C.; Stewart, K. P.; Paravastu, N.; Bradley, R. F.; Parashare, C. R.; Erickson, W. C.; Gross, C.; Polisensky, E.; Crane, P. C.; Ray, P. S.; Kassim, N. E.; Weiler, K. W.

2005-12-01

We present new designs for active antenna systems optimized for HF/VHF radio astronomy, ionospheric science, space weather, and other radio science applications. Active antenna designs have been developed and tested which satisfy the need for high linearity and stability while achieving Galactic background dominated noise levels. The presence of very strong terrestrial radio-frequency interference (RFI), and world-wide propagation at these frequencies require that the preamplifiers have very high dynamic range. Distortion products must be below the Galactic background level for RFI mitigation techniques to be successful. Individual antennas should have broad response patterns to cover most of the sky without pointing mechanisms, but with decreased sensitivity at low elevations. Ideal designs would also be immune to environmental effects such as temperature variations and precipitation. For projects such as the LWA, where thousands of receptors will be needed, they must also be robust, inexpensive, and easy to manufacture and install. We discuss high-performance designs that are optimized for cost-sensitive applications such as the LWA. Basic research in astronomy is supported by the Office of Naval Research.

3He Abundances in Planetary Nebulae

NASA Astrophysics Data System (ADS)

Guzman-Ramirez, Lizette

2017-10-01

Determination of the 3He isotope is important to many fields of astrophysics, including stellar evolution, chemical evolution, and cosmology. The isotope is produced in stars which evolve through the planetary nebula phase. Planetary nebulae are the final evolutionary phase of low- and intermediate-mass stars, where the extensive mass lost by the star on the asymptotic giant branch is ionised by the emerging white dwarf. This ejecta quickly disperses and merges with the surrounding ISM. 3He abundances in planetary nebulae have been derived from the hyperfine transition of the ionised 3He, 3He+, at the radio rest frequency 8.665 GHz. 3He abundances in PNe can help test models of the chemical evolution of the Galaxy. Many hours have been put into trying to detect this line, using telescopes like the Effelsberg 100m dish of the Max Planck Institute for Radio Astronomy, the National Radio Astronomy Observatory (NRAO) 140-foot telescope, the NRAO Very Large Array, the Arecibo antenna, the Green Bank Telescope, and only just recently, the Deep Space Station 63 antenna from the Madrid Deep Space Communications Complex.

PWV, Temperature and Wind Statistics at Sites Suitable For mm and Sub-mm Wavelengths Astronomy

NASA Astrophysics Data System (ADS)

Otarola, Angel; Travouillon, Tony; De Breuck, Carlos; Radford, Simon; Matsushita, Satoki; Pérez-Beaupuits, Juan P.

2018-01-01

Atmospheric water vapor is the main limiting factor of atmospheric transparency in the mm and sub-mm wavelength spectral windows. Thus, dry sites are needed for the installation and successful operation of radio astronomy observatories exploiting those spectral windows. Other parameters that play an important role in the mechanical response of radio telescopes exposed to the environmental conditions are: temperature, and in particular temperature gradients that induce thermal deformation of mechanical structures, as well as wind magnitude that induce pointing jitter affecting this way the required accuracy in the ability to point to a cosmic source during the observations. Temperature and wind are variables of special consideration when planning the installation and operations of large aperture radio telescopes. This work summarizes the statistics of precipitable water vapor (PWV), temperature and wind monitored at sites by the costal mountain range, as well as on t he west slope of the Andes mountain range in the region of Antofagasta, Chile. This information could prove useful for the planning of the Atacama Large-Aperture Submm/mm Telescope (AtLast).

Thunderstorms observed by radio astronomy Explorer 1 over regions of low man made noise

NASA Technical Reports Server (NTRS)

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

1974-01-01

Radio Astronomy Explorer (RAE) I observations of thunderstorms over regions of low man-made noise levels are analyzed to assess the satellite's capability for noise source differentiation. The investigation of storms over Australia indicates that RAE can resolve noise generation due to thunderstorms from the general noise background over areas of low man-made noise activity. Noise temperatures observed by RAE over stormy regions are on the average 10DB higher than noise temperatures over the same regions in the absence of thunderstorms. In order to determine the extent of noise contamination due to distant transmitters comprehensive three dimensional computer ray tracings were generated. The results indicate that generally, distant transmitters contribute negligibly to the total noise power, being 30DB or more below contributions arriving from an area immediately below the satellite.

Maxwell's Enduring Legacy

NASA Astrophysics Data System (ADS)

Longair, Malcolm

2016-07-01

Preface; Acknowledgements; Figure credits; Part I. To 1874: 1. Physics in the nineteenth century; 2. Mathematics and physics in Cambridge in the nineteenth century; Part II. 1874 to 1879: 3. The Maxwell era; Part III. 1879 to 1884: 4. Rayleigh's Quinquennium; Part IV. 1884 to 1919: 5. The challenges facing J. J. Thomson; 6. The J. J. Thomson era, 1884-1900 - the electron; 7. The Thomson era, 1900-19 - atomic structure; Part V. 1919 to 1937: 8. Rutherford at McGill and Manchester Universities - new challenges in Cambridge; 9. The Rutherford era - the radioactivists; 10. Rutherford era - the seeds of the new physics; Part VI. 1938 to 1953: 11. Bragg and the war years; 12. Bragg and the post-war years; Part VII. 1953 to 1971: 13. The Mott era - an epoch of expansion; 14. The Mott era - radio astronomy and high energy physics; 15. The Mott era - the growth of condensed matter physics; Part VIII. 1971 to 1982: 16. The Pippard era - a new laboratory and a new vision; 17. The Pippard era - radio astronomy, high energy physics and laboratory astrophysics; 18. The Pippard era - condensed matter physics; Part IX. 1984 to 1995: 19. The Edwards era - a new epoch of expansion; 20. The Edwards era - new directions in condensed matter physics; 21. The Edwards era - high energy physics and radio astronomy; Part X. 1995 to present: 22. Towards the new millennium and beyond; 23. The evolution of the New Museums site; Notes; Bibliography; Author index; Index.

UniBoard: generic hardware for radio astronomy signal processing

NASA Astrophysics Data System (ADS)

Hargreaves, J. E.

2012-09-01

UniBoard is a generic high-performance computing platform for radio astronomy, developed as a Joint Research Activity in the RadioNet FP7 Programme. The hardware comprises eight Altera Stratix IV Field Programmable Gate Arrays (FPGAs) interconnected by a high speed transceiver mesh. Each FPGA is connected to two DDR3 memory modules and three external 10Gbps ports. In addition, a total of 128 low voltage differential input lines permit connection to external ADC cards. The DSP capability of the board exceeds 644E9 complex multiply-accumulate operations per second. The first production run of eight boards was distributed to partners in The Netherlands, France, Italy, UK, China and Korea in May 2011, with a further production runs completed in December 2011 and early 2012. The function of the board is determined by the firmware loaded into its FPGAs. Current applications include beamformers, correlators, digital receivers, RFI mitigation for pulsar astronomy, and pulsar gating and search machines The new UniBoard based correlator for the European VLBI network (EVN) uses an FX architecture with half the resources of the board devoted to station based processing: delay and phase correction and channelization, and half to the correlation function. A single UniBoard can process a 64MHz band from 32 stations, 2 polarizations, sampled at 8 bit. Adding more UniBoards can expand the total bandwidth of the correlator. The design is able to process both prerecorded and real time (eVLBI) data.

Voyager 1 planetary radio astronomy observations near jupiter.

PubMed

Warwick, J W; Pearce, J B; Riddle, A C; Alexander, J K; Desch, M D; Kaiser, M L; Thieman, J R; Carr, T D; Gulkis, S; Boischot, A; Harvey, C C; Pedersen, B M

1979-06-01

We report results from the first low-frequency radio receiver to be transported into the Jupiter magnetosphere. We obtained dramatic new information, both because Voyager was near or in Jupiter's radio emission sources and also because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio spectral arcs, from above 30 to about 1 megahertz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Detailed studies are in progress and are out-lined briefly.

Radio evidence for shock acceleration of electrons in the solar corona

NASA Technical Reports Server (NTRS)

Cane, H. V.; Stone, R. G.; Fainberg, J.; Steinberg, J. L.; Hoang, S.; Stewart, R. T.

1981-01-01

It is pointed out that the new class of kilometer-wavelength solar radio bursts observed with the ISEE-3 Radio Astronomy Experiment occurs at the reported times of type II events, which are indicative of a shock wave. An examination of records from the Culgoora Radio Observatory reveals that the associated type II bursts have fast drift elements emanating from them; that is, a herringbone structure is formed. It is proposed that this new class of bursts is a long-wavelength continuation of the herringbone structure, and it is thought probable that the electrons producing the radio emission are accelerated by shocks. These new events are referred to as shock-accelerated events, and their characteristics are discussed.

The Gum nebula and related problems

NASA Technical Reports Server (NTRS)

Maran, S. P.; Brandt, J. C.; Stecher, T. P.

1971-01-01

Papers were presented in conference sessions on the Gum nebula, the Vela X remnant, the hot stars gamma Velorum and zeta Puppis, the B associations in the Vela-Puppis complex, and pulsars. Ground-based optical and radio astronomy; rocket and satellite observations in the radio, visible, ultraviolet, and X-ray regions; and theoretical problems in the physical state of the interstellar medium, stellar evolution, and runaway star dynamics were considered.

Geophysicists: Jules Aarons (1921-2008)

NASA Astrophysics Data System (ADS)

Mendillo, Michael

2009-03-01

Jules Aarons, a pioneer in satellite radio beacon studies of the ionosphere, died peacefully at his home in Newton, Mass., on 21 November 2008 at age 87. When considering his college career, Jules was drawn toward the humanities, an interest subsequently redirected by his parents toward science as a more suitable way to earn a living, and then by the U.S. Army Air Corps toward radio technology as a more suitable way to win World War II. Both goals were readily accomplished, perhaps instilling in Jules the value of proper mentorship, that central aspect of his life that so dominates our recollections of him. After the war, and with a variety of options before him, Jules decided upon civilian government service at the U.S. Air Force's then new field station in Cambridge, Mass. This was the founding entity of the Air Force Cambridge Research Laboratory (AFCRL), and those five famous letters became identified with his professional career (1946-1981). With Russia's launch of Sputnik in 1957, the era of space-based radio communications began, and with it the need to understand the sporadic crackling and fading (``scintillations'') of radio transmissions from satellites to ground receiving stations. Wartime efforts also gave birth to radio astronomy. Jules fostered ways to fund the synergies he saw between the radio technologies of space science and those of ground-based radio astronomy in ways almost unimaginable today (and certainly not by former U.S. senator Mike Mansfield, whose 1973 amendment to the U.S. Congress's defense appropriations bill limited the financing of basic research by military agencies only to projects that have direct military consequences; the amendment resulted in a permanent restructuring of how U.S. Department of Defense (DOD) agencies fund university-based research).

Radio Telescopes "Save the Day," Produce Data on Titan's Winds

NASA Astrophysics Data System (ADS)

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 measurements were carried out and processed jointly by scientists from the NASA Jet Propulsion Laboratory (JPL, USA), and the Joint Institute for VLBI in Europe (JIVE, The Netherlands) working within an international Doppler Wind Experiment team. The GBT made the first detection of Huygens' radio signal during the descent, and gave flight controllers and scientists the first indication that the spacecraft's parachute had deployed and that it was "alive" after entering Titan's atmosphere. The radio-telescope measurements also indicated changes in Huygens' speed when it exchanged parachutes and when it landed on Titan's surface. The original plan for gauging Titan's winds called for measuring the Doppler shift in the probe's signal frequency both by Cassini and by ground-based radio telescopes in the U.S., Australia, Japan and China. Cassini was best positioned to gain information on the east-west component of the winds, and the ground-based telescopes were positioned to help learn about the north-south wind component. Unfortunately, the communications error lost all the wind data from Cassini. The VLBA The VLBA CREDIT: NRAO/AUI/NSF (Click on image for VLBA gallery) "I've never felt such exhilarating highs and dispiriting lows than those experienced when we first detected the signal from the GBT, indicating 'all's well,' and then discovering that we had no signal at the operations center, indicating 'all's lost.' The truth, as we have now determined, lies somewhat closer to the former than the latter." said Michael Bird of the University of Bonn. In addition to measuring the motion-generated frequency shift of Huygens' radio signal, radio telescopes also were used to make extremely precise measurements of the probe's position (to within three-quarters of a mile, or one kilometer) during its descent. This experiment used the VLBA antennas, along with others employing the technique of Very Long Baseline Interferometry (VLBI). Combination of the Doppler and VLBI data will eventually provide a three-dimensional record of motion for the Huygens Probe during its mission at Titan. Huygens was built by the European Space Agency. The radio astronomy support of the Huygens mission is coordinated by JIVE and JPL and involves the National Radio Astronomy Observatory (Green Bank, WV and Socorro, NM), the Netherlands Foundation for Research in Astronomy (ASTRON, The Netherlands), the University of Bonn (Germany), Helsinki University of Technology (Espoo, Finland), the MERLIN National Facility (Jodrell Bank, UK), the Onsala Space Observatory (Sweden), the NASA Jet Propulsion Laboratory (Pasadena, CA), the CSIRO Australia Telescope National Facility (ATNF, Sydney, Australia), the University of Tasmania (Hobart, Australia), the National Astronomical Observatories of China, the Shanghai Astronomical Observatory (Shanghai and Urumqi, China) and the National Institute of Information and Communications Technologies (Kashima Space Research Center, Japan). The Joint Institute for VLBI in Europe is hosted by ASTRON and funded by the national research councils, national facilities and institutes of The Netherlands (NOW), the United Kingdom (PPARC), Italy (CNR), Sweden (Onsala Space Observatory, National Facility), Spain (IGN) and Germany (MPIfR). The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. The Cassini-Huygens mission is a cooperation between NASA, ESA and ASI, the Italian space agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA's Office of Space Science, Washington DC. JPL designed, developed and assembled the Cassini orbiter while ESA operated the Huygens atmospheric probe. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Voyager planetary radio astronomy studies

NASA Technical Reports Server (NTRS)

Staelin, David H.; Eikenberry, Stephen S.

1993-01-01

Analysis of nonthermal radio emission data obtained by the Planetary Radio Astronomy (PRA) spectrometers on the Voyager 1 and 2 spacecraft was performed. This PRA data provided unique insights into the radio emission characteristics of the outer planets because of PRA's unique spectral response below the terrestrial ionospheric plasma frequency and its unprecedented proximity to the source. Of those results which were documented or published, this final report surveys only the highlights and cites references for more complete discussions. Unpublished results for Uranus, Neptune, and theoretical Ionian current distributions are presented at greater length. The most important conclusion to be drawn from these observations is that banded spectral emission is common to the radio emission below 1-2 MHz observed from all four Jovian planets. In every case multiple spectral features evolve on time scales of seconds to minutes. To the extent these features drift in frequency, they appear never to cross one another. The Neptunian spectral features appear to drift little or not at all, their evolution consisting principally of waxing and waning. Since other evidence strongly suggests that most or all of this radio emission is occurring near the local magnetospheric electron cyclotron frequency, this implies that this emission preferentially occurs at certain continually changing planetary radii. It remains unknown why certain radii might be favored, unless radial electric field components or other means serve to differentiate radially the magnetospheric plasma density, particle energy vectors, or particle coherence. Calculation of the spatial distribution and intensity of the Io-generated magnetospheric currents are also presented; these currents may be limited principally by wave impedance and local field strengths.

Astronomers' Do-It-Yourself Project Opening A New Window on the Universe

NASA Astrophysics Data System (ADS)

1999-05-01

Rolling up their sleeves to build and install new equipment for the National Science Foundation's (NSF) Very Large Array (VLA) radio telescope, a team of astronomers has opened a new window on the universe, revealing tantalizing new information about the explosions of massive stars, the workings of galaxies with supermassive black holes at their centers, and clusters of galaxies. "We're going back to the region of wavelengths where Karl Jansky started radio astronomy in 1932," said Namir Kassim, of the Naval Research Laboratory (NRL), in Washington, D.C. "This is one of the most poorly explored regions of the electromagnetic spectrum, yet it offers tremendous potential to learn exciting new information about everything from the Sun and planets to galaxy clusters and the universe itself," Kassim said. Kassim, along with Rick Perley of the National Radio Astronomy Observatory (NRAO) in Socorro, NM; William Erickson, a professor emeritus at the University of Maryland; and Joseph Lazio, also of NRL, presented results of their observations with the new VLA system at the American Astronomical Society's meeting in Chicago. The new system uses the 27 dish antennas of the VLA, each 25 meters (82 feet) in diameter, to receive cosmic radio emissions at a frequency of 74 MHz, or a wavelength of about four meters. This frequency, lower than that of the FM broadcast band, is far below the usual frequencies, 1- 50 GHz, used for radio astronomy. "Though the region of 15-150 MHz is where Jansky and Grote Reber did the first radio-astronomy work in the 1930s and 1940s, it has long been neglected because of technical difficulties of working in that region," said Perley. Still, the astronomers said, there is much to be learned by studying the universe at these wavelengths. "There are phenomena associated with the Sun and planets, with other objects in our own Milky Way Galaxy, and with other galaxies and clusters of galaxies, and potentially ancient emission from the Universe itself that we can see only by observing at these longer wavelengths," Kassim said. The results of their first observations with the new VLA system have proven their point. Aiming the VLA at the supernova remnant Cassiopeia A, the shell of debris from a giant stellar explosion, they found evidence for cool gas inside the shell that has not yet been shocked by the "reverse shock" that propagates backwards through the "ejecta" towards the explosion's center "We know how old this supernova remnant is -- about 300 years -- and whether or not the reverse shock would have passed through all the ejecta yet depends on the nature of the star that exploded and the characteristics of its winds and surroundings before its death," Kassim said. "Finding unshocked gas inside this remnant, the first direct case for such material detected in the radio part of the spectrum, confirms the predictions of supernova evolution theory and thereby advances them." Other observations showed giant, radio-emitting "bubbles" in the galaxy M87 in the constellation Virgo. These objects, also seen with the VLA at the somewhat higher frequency of 330 MHz, raised questions about how old they were and how they were powered, as well as how they are linked to the even larger halo of X-ray emission generated around this galaxy. "The shape and extent of these huge, radio-emitting regions suggests that they are relatively young, expanding, and are being powered by particles shot out of the galaxy's nucleus by the gravitational energy of a supermassive black hole," said Kassim. "Comparison of the higher frequency images with our new one made at 74 MHz show exactly the correspondence we would expect if the black hole is powering these regions," he added. The researchers, together with astronomer Phillip Kronberg and his collaborators from the University of Toronto, also looked at the Coma Cluster of galaxies, some 450 million light-years distant. "There is a radio-emitting halo around this cluster, and our image made at 74 MHz greatly improves our knowledge of its extent and properties. This is crucial to figuring out how the halo got there in the first place," Kassim said. In the region of the Coma Cluster, the scientists made a "super" wide-field image. This image, showing an area some 15 degrees on a side, shows hundreds of radio-emitting objects, including extremely distant galaxies. Dubbed the "VLA Coma Deep Field," the image is "one of the most spectacular made recently at the VLA," Kassim said. "The amount of information obtained from only a single pointing of the VLA is awesome. Images like this will be extremely valuable in learning about the early universe," he said. All of these results came about because of the astronomers' persistence in pursuing a long-sought goal of equipping the VLA to observe at the new frequency. Erickson has been a long-time proponent of low-frequency radio astronomy. Both Perley and Kassim were Ph.D students of Erickson at the University of Maryland. The 330-MHz capability, also supported by NRL, was added to the VLA in the 1980s, and the group managed to install equipment for 74 MHz on eight of the VLA's 27 antennas a few years ago. They still wanted all the antennas equipped, however. "We knew we could use off-the-shelf components and equip antennas for about a thousand dollars each," said Perley, "but we just couldn't seem to squeeze the loose change out of anyone." Then Kassim pursuaded the Naval Research Laboratory to provide funding for the project. The astronomers then went to work to get the most performance for the money. Erickson, aided by NRL engineer Brian Hicks and Kassim, did the actual construction of 74-MHz receivers at NRL. The astronomers also worked alongside engineers and technicians, climbing on the VLA's giant dish antennas to install the new equipment. Hicks is presently constructing additional 74 MHz receivers at NRL for eventual tests on Very Long Baseline Array antennas The result, Perley said, "is not bad for a do-it-yourself project." In the first observing session using the new equipment, astronomers from four continents studied a wide range of celestial objects, and the results "were a spectacular success. We proved that you can make good images with the VLA at this frequency. The problem always was the difficulty in processing data to correct for ionospheric effects on the incoming radio waves. New computing techniques now have solved that problem." "We have shattered the ionospheric barrier and solved the wide- field imaging problem," Kassim said. The research results presented at the AAS meeting "show the great value of this new capability," Kassim said. "In addition to our work on supernova remnants, active galaxies and galaxy clusters, other papers presented at this meeting show that this frequency range is extremely valuable for solar research," Kassim added. "In fact, the success of the VLA at this frequency shows that we could learn even more from this new window on the universe by building a much larger and more sensitive instrument dedicated to long-wavelength radio astronomy -- the Low Frequency Array (LOFAR). An international consortium, initially involving NRL, NRAO, and the Netherlands Foundation for Radio Astronomy, currently is forming to develop LOFAR, an instrument which would see more detail and fainter objects than we can today," Kassim said. The VLA is an instrument of the National Radio Astronomy Observatory, a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Basic research in radio astronomy at the Naval Research Laboratory is supported by the Office of Naval Research.

New Images Show Unprecedented Detail of Neighbor Galaxy's Gas

NASA Astrophysics Data System (ADS)

2001-01-01

Using radio telescopes in the United States and Europe, astronomers have made the most detailed images ever of Hydrogen gas in a spiral galaxy other than the Milky Way. The scientists used the National Science Foundation's Very Large Array (VLA) radio telescope in New Mexico and the Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands to produce an image of the galaxy M33, known to amateur astronomers as the Pinwheel Galaxy. Doppler-Shift Image of M33's Gas "An image with the level of detail we have achieved opens the door to learning fundamental new facts about the relationship between massive stars and the galaxy's complicated gaseous environment. This, in turn, will help us better understand how galaxies age," said David Thilker, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Thilker worked with Robert Braun of the Netherlands Foundation for Research in Astronomy and Rene Walterbos of New Mexico State University in Las Cruces. The scientists reported their findings today at the American Astronomical Society's meeting in San Diego, CA. The VLA and WSRT received radio waves at a wavelength of 21 centimeters that are naturally emitted by Hydrogen atoms. Using this data, the astronomers produced images showing the distribution of neutral atomic Hydrogen in M33. In addition, because the atoms emit at a very specific wavelength, the scientists could detect the galaxy's rotation by tuning the telescopes' radio receivers to receive radio waves whose length has been changed by Doppler shifting. The new images show details of the galaxy smaller than 130 light-years. "With more computer processing, we will be able to see features as small as 65 light-years," Thilker said. "This, we believe, will allow us to see 'bubbles' in the galaxy's gas that have been inflated as the result of one or more supernova explosions," Thilker added. At a distance from Earth of about 2.7 million light-years, M33 is a member of the Local Group of galaxies, which also includes our own Milky Way and the Andromeda Galaxy. With a diameter of about 60,000 light-years, it is roughly half the size of the Milky Way. Under vary dark skies, people with excellent vision can see M33 with the unaided eye. With common amateur telescopes, its spiral arms can be seen. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The National Astronomy Consortium (NAC)

NASA Astrophysics Data System (ADS)

Von Schill, Lyndele; Ivory, Joyce

2017-01-01

The National Astronomy Consortium (NAC) program is designed to increase the number of underrepresented minority students into STEM and STEM careers by providing unique summer research experiences followed by long-term mentoring and cohort support. Hallmarks of the NAC program include: research or internship opportunities at one of the NAC partner sites, a framework to continue research over the academic year, peer and faculty mentoring, monthly virtual hangouts, and much more. NAC students also participate in two professional travel opportunities each year: the annual NAC conference at Howard University and poster presentation at the annual AAS winter meeting following their summer internship.The National Astronomy Consortium (NAC) is a program led by the National Radio Astronomy Consortium (NRAO) and Associated Universities, Inc. (AUI), in partnership with the National Society of Black Physicist (NSBP), along with a number of minority and majority universities.

47 CFR 5.85 - Frequencies and policy governing frequency assignment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (including the radio astronomy service). Stations authorized under subparts E and F are subject to additional... flux density assuming a free space characteristic impedance of 120π ohms) at the reference coordinates...

47 CFR 5.85 - Frequencies and policy governing frequency assignment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (including the radio astronomy service). Stations authorized under subparts E and F are subject to additional... flux density assuming a free space characteristic impedance of 120π ohms) at the reference coordinates...

Gravitational Waves and Time Domain Astronomy

NASA Technical Reports Server (NTRS)

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.

Advanced Technologies and Instrumentation at the National Science Foundation

NASA Astrophysics Data System (ADS)

Kurczynski, Peter; Neff, James E.

2018-01-01

Over its more than thirty-year history, the Advanced Technologies and Instrumentation (ATI) program within the Division of Astronomical Sciences has provided grants to support the development and deployment of detectors and instrumentation for ground-based astronomy. This program has enabled scientific advances in diverse fields from solar physics to exoplanets to cosmology. ATI has provided instrumentation for both small and large observatories from radio through visible wavebands. It has played a role in the early development of major initiatives such as the Large Synoptic Survey Telescope. Technology development for astronomy unfolds over a longer period than the lifetime of a single grant. This review will consider ATI from an historical perspective to assess its impact on astronomy.

Some innovative programmes in Astronomy education

NASA Astrophysics Data System (ADS)

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 includes the visiting Scientists and Professors from various Research Organizations located in and around Bangalore as well as the in-house Scientific staff. It is gratifying to note that several students, after going through one or more of these courses, have indeed made commitments to pursue Astronomy as their career, some of them even obtaining admissions in to the institutes and universities in India and abroad for further studies in this field.

Protection of SAAO observing site against light and dust pollution

NASA Astrophysics Data System (ADS)

Sefako, Ramotholo; Väisänen, Petri

2016-10-01

The South African Astronomical Observatory (SAAO) observing station near Sutherland, Northern Cape in South Africa, is one of the darkest sites in the world for optical and IR astronomy. The SAAO hosts and operates several facilities, including the Southern African Large Telescope (SALT) and a number of international robotic telescopes. To ensure that the conditions remain optimal for astronomy, legislation called the Astronomy Geographic Advantage (AGA) Act, of 2007, was enacted. The Act empowers the Department of Science and Technology (DST) to regulate issues that pose a threat to optical and/or radio astronomy in areas declared Astronomy Advantage Areas in South Africa. For optical astronomy, the main challenges are those posed by light and dust pollution as result of wind energy developments, and petroleum gas and oil exploration/exploitation in the area. We give an update of possible threats to the quality of the night skies at SAAO, and the challenges relating to the AGA Act implementation and enforcement. We discuss measures that are put in place to protect the Observatory, including a study to quantify the threat by a planned wind energy facility.

Launching GUPPI: the Green Bank Ultimate Pulsar Processing Instrument

NASA Astrophysics Data System (ADS)

DuPlain, Ron; Ransom, Scott; Demorest, Paul; Brandt, Patrick; Ford, John; Shelton, Amy L.

2008-08-01

The National Radio Astronomy Observatory (NRAO) is launching the Green Bank Ultimate Pulsar Processing Instrument (GUPPI), a prototype flexible digital signal processor designed for pulsar observations with the Robert C. Byrd Green Bank Telescope (GBT). GUPPI uses field programmable gate array (FPGA) hardware and design tools developed by the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California, Berkeley. The NRAO has been concurrently developing GUPPI software and hardware using minimal software resources. The software handles instrument monitor and control, data acquisition, and hardware interfacing. GUPPI is currently an expert-only spectrometer, but supports future integration with the full GBT production system. The NRAO was able to take advantage of the unique flexibility of the CASPER FPGA hardware platform, develop hardware and software in parallel, and build a suite of software tools for monitoring, controlling, and acquiring data with a new instrument over a short timeline of just a few months. The NRAO interacts regularly with CASPER and its users, and GUPPI stands as an example of what reconfigurable computing and open-source development can do for radio astronomy. GUPPI is modular for portability, and the NRAO provides the results of development as an open-source resource.

[An encounter with extraterrestrial intelligence].

PubMed

Hisabayashi, Hisashi

2003-12-01

It is much easier to find extraterrestrial intelligence than to detect simple organisms living on other planets. However, it is hard to communicate with such intelligence without the mutual understanding of inter-stellar communication protocol. The radio SETI (The Search for Extra-Terrestrial Intelligence) was initiated with the pioneering work of F. Drake in 1960, one year after the historical SETI paper by Cocconi and Morrison. This talk explains that SETI evolves with two bases of science; the understanding of our universe and the development of technology. Since SETI has had strong connection with radio astronomy from its early beginning, the impacts of radio astronomical findings and technological breakthrough can be seen in many aspects of the SETI history. Topics of this talk include the detection of microwave 3 K background radiation in the universe. Interstellar atomic and molecular lines found in radio-wave spectra provide the evidence of pre-biotic chemical evolution in such region. Radio telescope imaging and spectral technique are closely associated with methodology of SETI. Topics of the talk extend to new Allen Telescope Array and projected Square Kilometer Array. Recent optical SETI and the discoveries of extra solar planets are also explained. In the end, the recent understanding of our universe is briefly introduced in terms of matter, dark matter and dark energy. Even our understanding of the universe has been evolutionarily revolved and accumulated after 1960, we must recognize that our universe is still poorly understood and that astronomy and SETI are required to proceed hand in hand.

Astronomy Education Challenges in Egypt

NASA Astrophysics Data System (ADS)

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.

Revealing the Hidden Wave: Using the Very Small Radio Telescope to Teach High School Physics

NASA Astrophysics Data System (ADS)

Doherty, Michael; Fish, Vincent L.; Needles, Madeleine

2011-12-01

Scientists and teachers have worked together to produce teaching materials for the Very Small Radio Telescope (VSRT), an easy-to-use, low-cost apparatus that can be used in multiple laboratory experiments in high school and university physics and astronomy classes. In this article, we describe the motivation for the VSRT and several of the laboratory investigations that are being used in local high schools.

The Pulsar Search Collaboratory: A Comprehensive Project for Students and Teachers

NASA Astrophysics Data System (ADS)

Rosen, Rachel; Heatherly, S.; McLauglin, M.; Lorimer, D.

2009-01-01

The National Radio Astronomy Observatory (NRAO) and West Virginia University (WVU) have partnered to improve the quality of science education in West Virginia high schools through the Pulsar Search Collaboratory (PSC). One of the primary goals of the PSC is to engage students in STEM (science, technology, engineering, and mathematics) and related fields by using information technology to conduct current scientific research, specifically searching for new pulsars. To this end, we also are improving rural teachers' knowledge of the nature of science, the importance of information technology to scientific discovery, and methodologies for incorporating inquiry-based education into the classroom. The PSC hopes to make school science more like the practice of science and to make science fun and interesting for high school students. In 2007, an international team of astronomers received 900 hours of time on the Green Bank Telescope (GBT) during the summer shutdown to search for new pulsars. In conjunction with this group, we applied for and received 300 hours of observing time on the GBT for the PSC students. Around the same time, we were awarded an NSF iTEST grant to fund the Pulsar Search Collaboratory (PSC) project. Over the past year, we have been working with colleagues in the WVU Department of Computer Science to develop a graphical interface through which the students will analyze pulsar search plots (see psrsearch.wvu.edu). We also initiated a robust processing pipeline on a cluster in the WVU Computer Science Department. The PSC started in earnest this summer with a three week workshop in Green Bank where the teachers attended an intensive astronomy mini-course and techniques on introducing astronomy into the classroom. The students joined their teachers for the third week and participated in various activities to teach them about radio astronomy, radio frequency interference, and pulsars.

Application of new radio tracking data types to critical spacecraft navigation problems

NASA Technical Reports Server (NTRS)

Ondrasik, V. J.; Rourke, K. H.

1972-01-01

Earth-based radio tracking data types are considered, which involve simultaneous or nearly simultaneous spacecraft tracking from widely separated tracking stations. These data types are conventional tracking instrumentation analogs of the very long baseline interferometry (VLBI) of radio astronomy-hence the name quasi-VLBI. A preliminary analysis of quasi-VLBI is presented using simplified tracking data models. The results of accuracy analyses are presented for a representative mission, Viking 1975. The results indicate that, contingent on projected tracking system accuracy, quasi-VLBI can be expected to significantly improve navigation performance over that expected from conventional tracking data types.

Analysis of the Capability and Limitations of Relativistic Gravity Measurements Using Radio Astronomy Methods

NASA Technical Reports Server (NTRS)

Shapiro, I. I.; Counselman, C. C., III

1975-01-01

The uses of radar observations of planets and very-long-baseline radio interferometric observations of extragalactic objects to test theories of gravitation are described in detail with special emphasis on sources of error. The accuracy achievable in these tests with data already obtained, can be summarized in terms of: retardation of signal propagation (radar), deflection of radio waves (interferometry), advance of planetary perihelia (radar), gravitational quadrupole moment of sun (radar), and time variation of gravitational constant (radar). The analyses completed to date have yielded no significant disagreement with the predictions of general relativity.

Semi-Supervised Novelty Detection with Adaptive Eigenbases, and Application to Radio Transients

NASA Technical Reports Server (NTRS)

Thompson, David R.; Majid, Walid A.; Reed, Colorado J.; Wagstaff, Kiri L.

2011-01-01

We present a semi-supervised online method for novelty detection and evaluate its performance for radio astronomy time series data. Our approach uses adaptive eigenbases to combine 1) prior knowledge about uninteresting signals with 2) online estimation of the current data properties to enable highly sensitive and precise detection of novel signals. We apply the method to the problem of detecting fast transient radio anomalies and compare it to current alternative algorithms. Tests based on observations from the Parkes Multibeam Survey show both effective detection of interesting rare events and robustness to known false alarm anomalies.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1994-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DS) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1993-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The papers included in this document cover satellite tracking and ground-based navigation, spacecraft-ground communications, and optical communication systems for the Deep Space Network.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Yuen, Joseph H. (Editor)

1995-01-01

This quarterly publication provides archival reports on developments in programs managed by JPL's Telecommunications and Mission Operations Directorate (TMOD), which now includes the former Telecommunications and Data Acquisition (TDA) Office. In space communications, radio navigation, radio science, and ground-based radio and radar astronomy, it reports on activities of the Deep Space Network (DSN) in planning, supporting research and technology, implementation, and operations. Also included are standards activity at JPL for space data and information systems and reimbursable DSN work performed for other space agencies through NASA. The preceding work is all performed for NASA's Office of Space Communications (OSC).

Space science public outreach at Louisiana State University

NASA Astrophysics Data System (ADS)

Guzik, T.; Babin, E.; Cooney, W.; Giammanco, J.; Hartman, D.; McNeil, R.; Slovak, M.; Stacy, J.

Over the last seven years the Astronomy / Astrophysics group in the Department of Physics and Astronomy of Louisiana State University has developed an exten- sive Space Science education and public outreach program. This program includes the local park district (the Recreation and Park Commission for the Parish of East Baton Rouge, BREC), the local amateur astronomer group (the Baton Rouge As- tronomical Society, BRAS), the Louisiana Arts and Science Museum (LASM), and Southern University (SU, part of the largest HBCU system in the nation). Our effort has directly led to the development of the Highland Road Park Observatory (HRPO, http://www.bro.lsu.edu/hrpo) that supports student astronomy training at LSU and SU, amateur observations and a public program for adults and children, establishment of a series of teacher professional development workshops in astronomy and physics, and the "Robots for Internet Experiences (ROBIE)" project (http://www.bro.lsu.edu/) where we have several instruments (e.g. HAM radio, radio telescope, optical tele- scopes) that can be controlled over the internet by students and teachers in the class- room along with associated lessons developed by a teacher group. In addition, this year the LASM, will be opening a new planetarium / space theater in downtown Baton Rouge, Louisiana. We are currently working to bring live views of the heavens from the HRPO telescope to audiences attending planetarium shows and will be working closely with planetarium staff to develop shows that highlight LSU astronomy / space science research. During the presentation we will provide some details about our in- dividual projects, the overall structure of our program, establishing community links and some of the lessons we learned along the way. Finally, we would like to acknowl- edge NASA, Louisiana State University, the Louisiana Systemic Initiatives Program and the Louisiana Technology Innovation Fund for their support.

Radio Astronomy Tools in Python: Spectral-cube, pvextractor, and more

NASA Astrophysics Data System (ADS)

Ginsburg, A.; Robitaille, T.; Beaumont, C.; Rosolowsky, E.; Leroy, A.; Brogan, C.; Hunter, T.; Teuben, P.; Brisbin, D.

2015-12-01

The radio-astro-tools organization has been established to facilitate development of radio and millimeter analysis tools by the scientific community. The first packages developed under its umbrella are: • The spectral-cube package, for reading, writing, and analyzing spectral data cubes • The pvextractor package for extracting position-velocity slices from position-position-velocity cubes along aribitrary paths • The radio-beam package to handle gaussian beams in the context of the astropy quantity and unit framework • casa-python to enable installation of these packages - and any other - into users' CASA environments without conflicting with the underlying CASA package. Community input in the form of code contributions, suggestions, questions and commments is welcome on all of these tools. They can all be found at http://radio-astro-tools.github.io.

Power monitoring and control for large scale projects: SKA, a case study

NASA Astrophysics Data System (ADS)

Barbosa, Domingos; Barraca, João. Paulo; Maia, Dalmiro; Carvalho, Bruno; Vieira, Jorge; Swart, Paul; Le Roux, Gerhard; Natarajan, Swaminathan; van Ardenne, Arnold; Seca, Luis

2016-07-01

Large sensor-based science infrastructures for radio astronomy like the SKA will be among the most intensive datadriven projects in the world, facing very high demanding computation, storage, management, and above all power demands. The geographically wide distribution of the SKA and its associated processing requirements in the form of tailored High Performance Computing (HPC) facilities, require a Greener approach towards the Information and Communications Technologies (ICT) adopted for the data processing to enable operational compliance to potentially strict power budgets. Addressing the reduction of electricity costs, improve system power monitoring and the generation and management of electricity at system level is paramount to avoid future inefficiencies and higher costs and enable fulfillments of Key Science Cases. Here we outline major characteristics and innovation approaches to address power efficiency and long-term power sustainability for radio astronomy projects, focusing on Green ICT for science and Smart power monitoring and control.

Is HDF5 a Good Format to Replace UVFITS?

NASA Astrophysics Data System (ADS)

Price, D. C.; Barsdell, B. R.; Greenhill, L. J.

2015-09-01

The FITS (Flexible Image Transport System) data format was developed in the late 1970s for storage and exchange of astronomy-related image data. Since then, it has become a standard file format not only for images, but also for radio interferometer data (e.g. UVFITS, FITS-IDI). But is FITS the right format for next-generation telescopes to adopt? The newer Hierarchical Data Format (HDF5) file format offers considerable advantages over FITS, but has yet to gain widespread adoption within the radio astronomy. One of the major holdbacks is that HDF5 is not well supported by data reduction software packages. Here, we present a comparison of FITS, HDF5, and the MeasurementSet (MS) format for storage of interferometric data. In addition, we present a tool for converting between formats. We show that the underlying data model of FITS can be ported to HDF5, a first step toward achieving wider HDF5 support.

Q-band 4-state phase shifter in planar technology: Circuit design and performance analysis.

PubMed

Villa, E; Cagigas, J; Aja, B; de la Fuente, L; Artal, E

2016-09-01

A 30% bandwidth phase shifter with four phase states is designed to be integrated in a radio astronomy receiver. The circuit has two 90° out-of-phase microwave phase-shifting branches which are combined by Wilkinson power dividers. Each branch is composed of a 180° phase shifter and a band-pass filter. The 180° phase shifter is made of cascaded hybrid rings with microwave PIN diodes as switching devices. The 90° phase shift is achieved with the two band-pass filters. Experimental characterization has shown significant results, with average phase shift values of -90.7°, -181.7°, and 88.5° within the operation band, 35-47 GHz, and mean insertion loss of 7.4 dB. The performance of its integration in a polarimetric receiver for radio astronomy is analyzed, which validates the use of the presented phase shifter in such type of receiver.

On the existence of planets around the pulsar PSR B0329+54

NASA Astrophysics Data System (ADS)

Starovoit, E. D.; Rodin, A. E.

2017-11-01

Results of timing measurements of the pulsar PSR B0329+54 obtained in 1968-2012 using the Big Scanning Antenna of the Pushchino Radio Astronomy Observatory (at 102 and 111 MHz), the DSS 13 and DSS 14 telescopes of the Jet Propulsion Laboratory (2388 MHz), and the 64 m telescope of the Kalyazin Radio Astronomy Observatory (610 MHz) are presented. The astrometric and rotational parameters of the pulsar are derived at a new epoch. Periodic variations in the barycentric timing residuals have been found, which can be explained by the presence of a planet orbiting the pulsar, with an orbital period P 1 = 27.8 yr, mass m c sin i = 2 M ⨁, and orbital semi-major axis a = 10.26 AU. The results of this study do not confirm existence of a proposed second planet with orbital period P 2 = 3 yr.

Evolving Cosmos

NASA Astrophysics Data System (ADS)

Schilling, Govert

2005-02-01

Science journalist Govert Schilling takes the reader on a whirlwind journey through time by describing the evolution of the cosmos, from the beginning of space and time fourteen billion years ago, to the creation of the Earth and humankind. Ending with a glance into the distant future of the universe, the book's combination of compelling text and breathtaking photographs provides an impressive vision of the place of man in the cosmos. Govert Schilling is a Dutch science writer and astronomy publicist. He is a contributing editor of Sky and Telescope magazine, and regularly writes for the news sections of Science and New Scientist. Schilling is the astronomy writer for de Volkskrant, one of the largest national daily newspapers in The Netherlands, and frequently talks about the Universe on Dutch radio broadcasts. He is the author of more than twenty popular astronomy books, including Flash! (Cambridge, 2002), and hundreds of newspaper and magazine articles on astronomy.

Astronomers Make First Images With Space Radio Telescope

NASA Astrophysics Data System (ADS)

1997-07-01

Marking an important new milestone in radio astronomy history, scientists at the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, have made the first images using a radio telescope antenna in space. The images, more than a million times more detailed than those produced by the human eye, used the new Japanese HALCA satellite, working in conjunction with the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) and Very Large Array (VLA) ground-based radio telescopes. The landmark images are the result of a long-term NRAO effort supported by the National Aeronautics and Space Administration (NASA). "This success means that our ability to make detailed radio images of objects in the universe is no longer limited by the size of the Earth," said NRAO Director Paul Vanden Bout. "Astronomy's vision has just become much sharper." HALCA, launched on Feb. 11 by Japan's Institute of Space and Astronautical Science (ISAS), is the first satellite designed for radio astronomy imaging. It is part of an international collaboration led by ISAS and backed by NRAO; Japan's National Astronomical Observatory; NASA's Jet Propulsion Laboratory (JPL); the Canadian Space Agency; the Australia Telescope National Facility; the European VLBI Network and the Joint Institute for Very Long Baseline Interferometry in Europe. On May 22, HALCA observed a distant active galaxy called PKS 1519-273, while the VLBA and VLA also observed it. Data from the satellite was received by a tracking station at the NRAO facility in Green Bank, West Virginia. Tape-recorded data from the satellite and from the radio telescopes on the ground were sent to NRAO's Array Operations Center (AOC) in Socorro, NM. In Socorro, astronomers and computer scientists used a special-purpose computer to digitally combine the signals from the satellite and the ground telescopes to make them all work together as a single, giant radio telescope. This dedicated machine, the VLBA Correlator, built as part of the VLBA instrument, was modified over the past four years to allow it to incorporate data from the satellite. Correlation of the observational data was completed successfully on June 12, after the exact timing of the satellite recording was established. Further computer processing produced an image of PKS 1519-273 -- the first image ever produced using a radio telescope in space. For Jim Ulvestad, the NRAO astronomer who made the first image, the success ended a long quest for this new capability. Ulvestad was involved in an experiment more than a decade ago in which a NASA communications satellite, TDRSS, was used to test the idea of doing radio astronomical imaging by combining data from space and ground radio telescopes. That experiment showed that an orbiting antenna could, in fact, work in conjunction with ground-based radio observatories, and paved the way for HALCA and a planned Russian radio astronomy satellite called RadioAstron. "This first image is an important technical milestone, and demonstrates the feasibility of a much more advanced mission, ARISE, currently being considered by NASA," Ulvestad said. The first image showed no structure in the object, even at the extremely fine level of detail achievable with HALCA; it is what astronomers call a "point source." This object also appears as a point source in all-ground-based observations. In addition, the 1986 TDRSS experiment observed the object, and, while this experiment did not produce an image, it indicated that PKS 1519-273 should be a point source. "This simple point image may not appear very impressive, but its beauty to us is that it shows our entire, complex system is functioning correctly. The system includes not only the orbiting and ground-based antennas, but also the orbit determination, tracking stations, the correlator, and the image-processing software," said Jonathan Romney, the NRAO astronomer who led the development of the VLBA correlator, and its enhancement to process data from orbiting radio telescopes. "We would be skeptical of a complex image if we had not been able to obtain a good point image first," Romney added. A second observing target, the quasar 1156+295, observed on June 5, made a more interesting picture. Seen by ground-based radio observatories, this object, at a distance of 6.5 billion light years, has been known to show an elongation in its structure to the northeast of the core. However, seen with the space-ground system, it is clearly shown to have both a core and a complex "jet" emerging from the core. Such jets, consisting of subatomic particles moving near the speed of light, are seen in many quasars and active galaxies throughout the universe. In fact, 1156+295 is one of a class of objects recently found by NASA's Compton Gamma-Ray Observatory to exhibit powerful gamma-ray emission; such objects are among the most compact and energetic known in the universe. "By showing that this object actually is a core-jet system, HALCA has produced its first new scientific information, and demonstrates its imaging capabilities for a variety of astrophysical investigations," Romney said. "This image shows that the jet extends much closer to the core, or 'central engine' of the quasar than is shown by ground-only imaging," Romney added. "This is an exciting and historical achievement for radio astronomy," said Miller Goss, NRAO's VLA/VLBA Director. "At NRAO, we have seen our colleagues -- scientists, electrical engineers, computer programmers and technicians in Socorro and Green Bank -- work for years on this project. Now, they can take pride in their success." Radio astronomers, like astronomers using visible light, usually seek to make images of the objects at which they aim their telescopes. Because radio waves are much longer than light waves, a radio telescope must be much larger than an optical instrument in order to see the same amount of detail. Greater ability to see detail, called resolving power, has been a quest of radio astronomers for more than half a century. To see a level of detail equal to that revealed by optical telescopes would require a radio-telescope dish miles across. In the 1950s, British and Australian scientists developed a technique that used smaller, widely-separated antennas, and combined their signals to produce resolving power equal to that of a single dish as large as the distance between the smaller dishes. This technique, called interferometry, is used by the VLA, with 27 antennas and a maximum separation of 20 miles, and the VLBA, with 10 antennas and a maximum separation of 5,000 miles. Systems such as the VLBA, in which the antennas are so widely separated that data must be individually tape-recorded at each site and combined after the observation, are called Very Long Baseline Interferometry (VLBI) systems. VLBI was developed by American and Canadian astronomers and was first successfully demonstrated in 1967. The VLBA, working with radio telescopes in Europe, represents the largest radio telescope that can be accommodated on the surface of the Earth. With an orbit that carries it more than 13,000 miles above the Earth, HALCA, working with the ground-based telescopes, extends the "sharp vision" of radio astronomy farther than ever before. Using HALCA, radio astronomers expect to routinely produce images with more than 100 times the detail seen by the Hubble Space Telescope. Astronomers around the world are waiting to use the satellite to seek answers to questions about some of the most distant and intriging objects in the universe. As much as one-third of the VLBA's observing time will be devoted to observations in conjunction with HALCA. Over the expected five-year lifetime of HALCA, scientists hope to observe hundreds of quasars, pulsars, galaxies, and other objects. Launched from Japan's Kagoshima Space Center, HALCA orbits the Earth every six hours, ranging from 350 to 13,200 miles high. The 1,830-pound satellite has a dish antenna 26 feet in diameter. The antenna, folded like an umbrella for the launch, was unfolded under radio control from the ground on Feb. 26. The antenna was pointed toward PKS 1519-273 after a three-month checkout of the spacecraft's electronics, computers and guidance systems. HALCA observations represent a true international scientific collaboration. In addition to the HALCA spacecraft, built, launched, and operated by Japan's ISAS, the participation of a large number of ground-based radio telescopes is also essential. NRAO's VLBA and VLA instruments, including the VLBA correlator, will be a vital component of this collaboration. Other radio telescopes in the U.S., Japan, Europe, and Australia, also will participate. NRAO's facility at Green Bank, WV, is one of five tracking stations where the data collected on the spacecraft are received and recorded. Another is at an ISAS facility in Japan, and JPL operates three additional tracking stations, in California, Australia, and Spain. JPL also collects information from all tracking stations to determine the very accurate spacecraft orbit necessary to reduce these observations. The NRAO Space VLBI efforts in Socorro and Green Bank were supported by funding from the National Aeronautics and Space Administration. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The Shklovsky phenomenon

NASA Astrophysics Data System (ADS)

Kardashev, N. S.; Marochnik, L. S.

Joseph Samuelovich Shklovsky was born in the town of Glukhov in Ukraine. In 1933 he entered the physicsmath department of Vladivostok University and two years later transferred to the physics department of Moscow University (MGU). In 1938 this young physicist-optician was accepted as a graduate student by the astrophysics department of the P.K. Shternberg State Astronomical Institute (GAISh) at MGU, an institute with which he was to be associated his entire life.Then there followed the start of the war, evacuation to Ashkhabad (because of his poor eyesight he was not sent to the front), then his return to Moscow and GAISh, where he worked for many years at the leading edge of the post-war revolution in astronomy. The last forty years have been characterized by unprecedented development of observational methods and technology such as radio telescopes and interferometers and infrared, ultraviolet, X-ray, and gamma-ray astronomy. New classes of objects have been discovered: radio stars, radio galaxies, quasars, infrared sources, pulsars, cosmic ray bursters, sources of gamma bursts, background radiation at all wave- lengths, and, in particular, background radio radiation. "The question `What is this?' must be central." This is the main testament that Shklovsky left to younger researchers. He was one of the first astronomers to recognize the necessity of studying any astronomical object at all wavelengths in the electromagnetic spectrum. Only under such conditions can one hope to construct a proper model and understand the object's nature. His study of galactic radio emissions appeared in 1947. In that same year he participated in an expedition to observe the total star eclipse in Brazil, the first such expedition to be equipped with a radio telescope. Beginning in 1950 Shklovsky took part in the first infrared observations using an image convertor. His pioneering work: Galactic Infrared Radiation, was published in 1953.

Radio Synthesis Imaging - A High Performance Computing and Communications Project

NASA Astrophysics Data System (ADS)

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-distance distributed computing. Finally, the project is developing 2D and 3D visualization software as part of the international AIPS++ project. This research and development project is being carried out by a team of experts in radio astronomy, algorithm development for massively parallel architectures, high-speed networking, database management, and Thinking Machines Corporation personnel. The development of this complete software, distributed computing, and data archive and library solution to the radio astronomy computing problem will advance our expertise in high performance computing and communications technology and the application of these techniques to astronomical data processing.

Electromagnetic Compatibility (EMC) Requirements for Military and Commercial Equipment

DTIC Science & Technology

2009-09-01

Commercial off-the shelf (COTS) use also provides access to what has become a much larger industrial base. With these goals in mind, the Secretary of...Band (110 – 300 GHz) 10–1 mm Microwave data links, radio astronomy , amateur radio, remote sensing, advanced weapons systems 12 Radiated EMI...to what has become a much larger industrial base. With these goals in mind, the Secretary of Defense issued a directive in June 1994 requiring the

The emergence of x-ray astronomy, neutron stars and black holes

NASA Astrophysics Data System (ADS)

Gursky, H.

2003-10-01

Remo Ruffini's professional career began just as X-ray astronomy began its second decade. His paper on the maximum mass of cold stars was instrumental in establishing Cygnus X-1 as a black hole. The idea of black holes and neutron stars had originated more than 40 years earlier based on considerations of white dwarfs. It was not until the explosion of technology that emerged after World War II that the observational evidence developed which enabled establishing the existence of these objects. The discovery of X-ray sources in 1962 and the subsequent maturing of that discipline and of radio astronomy were the key elements. By now a large number of stellar objects are found to be neutron stars and black holes.

The Nature of Optical Features in the Inner Region of the 3C 48 Host Galaxy

NASA Astrophysics Data System (ADS)

Stockton, Alan; Canalizo, Gabriela; Fu, Hai; Keel, William

2007-04-01

The well-known quasar 3C 48 is the most powerful compact steep-spectrum radio-loud QSO at low redshifts. It also has two unusual optical features within the radius of the radio jet (~1"): (1) an anomalous, high-velocity narrow-line component, and (2) a bright continuum peak (3C 48A) ~1" northeast of the quasar. Both of these optical features have been conjectured to be related to the radio jet. We have obtained Gemini North GMOS integral field unit (IFU) spectroscopy of the central region around 3C 48. We use the unique features of the IFU data to remove unresolved emission at the position of the quasar. The resolved emission at the wavelength of the high-velocity component is peaked <~0.25" north of the quasar, at the same position angle as the base of the radio jet. These observations appear to confirm that this high-velocity gas is connected with the radio jet. However, most of the emission comes from a region where the jet is still well collimated, rather than from the regions where the radio maps indicate strong disruption. We also present the results of HST STIS spectroscopy of 3C 48A. We show that 3C 48A is dominated by stars with a luminosity-weighted age of ~1.4×108 yr, substantially older than any reasonable estimate for the age of the radio source. Thus, 3C 48A almost certainly cannot be attributed to jet-induced star formation. The host galaxy of 3C 48 is clearly the result of a merger, and 3C 48A seems much more likely to be the distorted nucleus of the merging partner in which star formation was induced during the previous close passage. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-09365. Also based in part on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

Radio Wavelength Studies of the Galactic Center Source N3, Spectroscopic Instrumentation For Robotic Telescope Systems, and Developing Active Learning Activities for Astronomy Laboratory Courses

NASA Astrophysics Data System (ADS)

Ludovici, Dominic Alesio

2017-08-01

The mysterious radio source N3 appears to be located within the vicinity of the Radio Arc region of the Galactic Center. To investigate the nature of this source, we have conducted radio observations with the VLA and the VLBA. Continuum observations between 2 and 50 GHz reveal that N3 is an extremely compact and bright source with a non-thermal spectrum. Molecular line observations with the VLA reveal a compact molecular cloud adjacent to N3 in projection. The properties of this cloud are consistent with other galactic center clouds. We are able to rule out several hypotheses for the nature of N3, though a micro-blazar origin cannot be ruled out. Robotic Telescope systems are now seeing widespread deployment as both teaching and research instruments. While these systems have traditionally been able to produce high quality images, these systems have lacked the capability to conduct spectroscopic observations. To enable spectroscopic observations on the Iowa Robotic Observatory, we have developed a low cost (˜ 500), low resolution (R ˜ 300) spectrometer which mounts inside a modified filter wheel and a moderate cost (˜ 5000), medium resolution (R ˜ 8000) fiber-fed spectrometer. Software has been developed to operate both instruments robotically and calibration pipelines are being developed to automate calibration of the data. The University of Iowa offers several introductory astronomy laboratory courses taken by many hundreds of students each semester. To improve student learning in these laboratory courses, we have worked to integrate active learning into laboratory activities. We present the pedagogical approaches used to develop and update the laboratory activities and present an inventory of the current laboratory exercises. Using the inventory, we make observations of the strengths and weaknesses of the current exercises and provide suggestions for future refinement of the astronomy laboratory curriculum.

Harold F. Weaver: California Astronomer

NASA Astrophysics Data System (ADS)

Shields, J. C.

1993-05-01

This talk will give an overview of an oral history recently completed with Harold F. Weaver, Professor Emeritus of Astronomy at the University of California at Berkeley. Weaver grew up in California and studied as an undergraduate at Berkeley, where he also pursued graduate work incorporating research at Lick and Mount Wilson Observatories. After pursuing postdoctoral research at Yerkes Observatory and war work in Cambridge (Massachusetts) and Berkeley, Weaver was appointed to the staff of Lick Observatory. In 1951 he joined the faculty at Berkeley, where he later played a major role in founding Hat Creek Radio Observatory. As Director of the Berkeley Radio Astronomy Laboratory, Weaver oversaw construction of the 85-foot telescope at Hat Creek, which is the subject of a special session at this meeting. Two aspects of Weaver's career will be highlighted. The first is the somewhat unusual and very successful transition in Weaver's observational research from emphasis on classical photographic techniques at optical wavelengths to use of emerging radio technology for the study of Galactic structure. The second is service provided by Weaver to the American Astronomical Society and Astronomical Society of the Pacific at several key junctures in the development of both organizations.

The SERENDIP piggyback SETI project

NASA Technical Reports Server (NTRS)

Lampton, M.; Bowyer, S.; Werthimer, D.; Donnelly, C.; Herrick, W.

1992-01-01

The SERENDIP project is an ongoing program of monitoring and processing broadband radio signals acquired by existing radio astronomy observatories. SERENDIP operates in a piggyback mode: it makes use of whatever observing plan (sequence of frequencies, sky coordinates, and polarizations) is under way at its host observatory. Moreover, the SERENDIP data acquisition system, once installed, operates autonomously. This approach makes it possible to obtain large amounts of high quality observing time in a manner that is economical and that does not adversely affect ongoing radio astronomy survey work. The SERENDIP II system has been installed at the NRAO 300-foot telescope at Green Bank, West Virginia, and has operated there for several thousand hours. In this report, we summarize our findings from these observations and describe the present status of the project. Two key elements of SERENDIP are the automated data acquisition system that uses adaptive thresholds and logs only statistically significant peaks in the real-time power spectra, and the subsequent off-line analysis programs that identify and reject a variety of interference signals. Several specific correlations have been identified that offer promise. At present, the development and testing of these interference rejection algorithms is the main thrust of our work.

The SERENDIP piggyback SETI project.

PubMed

Lampton, M; Bowyer, S; Werthimer, D; Donnelly, C; Herrick, W

1992-01-01

The SERENDIP project is an ongoing program of monitoring and processing broadband radio signals acquired by existing radio astronomy observatories. SERENDIP operates in a piggyback mode: it makes use of whatever observing plan (sequence of frequencies, sky coordinates, and polarizations) is under way at its host observatory. Moreover, the SERENDIP data acquisition system, once installed, operates autonomously. This approach makes it possible to obtain large amounts of high quality observing time in a manner that is economical and that does not adversely affect ongoing radio astronomy survey work. The SERENDIP II system has been installed at the NRAO 300-foot telescope at Green Bank, West Virginia, and has operated there for several thousand hours. In this report, we summarize our findings from these observations and describe the present status of the project. Two key elements of SERENDIP are the automated data acquisition system that uses adaptive thresholds and logs only statistically significant peaks in the real-time power spectra, and the subsequent off-line analysis programs that identify and reject a variety of interference signals. Several specific correlations have been identified that offer promise. At present, the development and testing of these interference rejection algorithms is the main thrust of our work.

Radio observations of the Milky Way from the classroom

NASA Astrophysics Data System (ADS)

Chyży, Krzysztof T.

2014-12-01

We present the project to introduce the first European network of radio telescopes for education. It enables pupils to detect spectral line emission of neutral hydrogen in the Milky Way at a wavelength of 21 cm. Any classroom connected to Internet via any web-browser can remotely control one of the radio-telescopes, observe and analyse obtained spectra: derive the Milky-Way rotation curve and recognise spiral arms in hydrogen distribution. Doing exercises pupils, guided by their teachers, learn the basics of radio astronomy research, use scientific method to explore and interpret the attained spectral data. A range of attractive educational materials are prepared to help in disseminating the scientific knowledge in the classroom and demonstrate the modern information technology.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1987-01-01

This quarterly publication (July-September 1987) provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio astronomy, it reports on activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, in supporting research and technology, in implementation, and in operations. This work is performed for NASA's Office of Space Tracking and Data Systems (OSTDS). In geodynamics, the publication reports on the application of radio interferometry at microwave frequencies for geodynamic measurements. In the Search for Extraterrestrial Intelligence (SETI), it reports on implementation and operations for searching the microwave spectrum. The latter two programs are performed for NASA's Office of Space Science and Applications (OSSA).

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1986-01-01

This quarterly publication (July-Sept. 1986) provides archival reports on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA). In space communications, radio navigation, radio science, and ground-based radio astronomy, it reports on activities of the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, in supporting research and technology, in implementation, and in operations. This work is performed for NASA's Office of Space Tracking and Data Systems (OSTDS). In geodynamics, the publication reports on the application of radio interferometry at microwave frequencies for geodynamic measurements. In the search for extraterrestrial intelligence (SETI), it reports on implementation and operations for searching the microwave spectrum. The latter two programs are performed for NASA's Office of Space Science and Applications (OSSA).

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

NASA Technical Reports Server (NTRS)

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.

Taking the Radio Blinders Off of M83: A Wide Spectrum Analysis of the Historical Point Source Population

NASA Astrophysics Data System (ADS)

Stockdale, Christopher; Keefe, Clayton; Nichols, Michael; Rujevcan, Colton; Blair, William P.; Cowan, John J.; Godfrey, Leith; Miller-Jones, James; Kuntz, K. D.; Long, Knox S.; Maddox, Larry A.; Plucinsky, Paul P.; Pritchard, Tyler A.; Soria, Roberto; Whitmore, Bradley C.; Winkler, P. Frank

2015-01-01

We present low frequency observations of the grand design spiral galaxy, M83, using the C and L bands of the Karl G. Jansky Very Large Array (VLA). With recent optical (HST) and X-ray (Chandra) observations and utilizing the newly expanded bandwidth of the VLA, we are exploring the radio spectral properties of the historical radio point sources in M83. These observations allow us to probe the evolution of supernova remnants (SNRs) and to find previously undiscovered SNRs. These observations represent the fourth epoch of deep VLA observations of M83. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities.

DSPSR: Digital Signal Processing Software for Pulsar Astronomy

NASA Astrophysics Data System (ADS)

van Straten, W.; Bailes, M.

2010-10-01

DSPSR, written primarily in C++, is an open-source, object-oriented, digital signal processing software library and application suite for use in radio pulsar astronomy. The library implements an extensive range of modular algorithms for use in coherent dedispersion, filterbank formation, pulse folding, and other tasks. The software is installed and compiled using the standard GNU configure and make system, and is able to read astronomical data in 18 different file formats, including FITS, S2, CPSR, CPSR2, PuMa, PuMa2, WAPP, ASP, and Mark5.

Open Astronomy Catalogs API

NASA Astrophysics Data System (ADS)

Guillochon, James; Cowperthwaite, Philip S.

2018-05-01

We announce the public release of the application program interface (API) for the Open Astronomy Catalogs (OACs), the OACAPI. The OACs serve near-complete collections of supernova, tidal disruption, kilonova, and fast stars data (including photometry, spectra, radio, and X-ray observations) via a user-friendly web interface that displays the data interactively and offers full data downloads. The OACAPI, by contrast, enables users to specifically download particular pieces of the OAC dataset via a flexible programmatic syntax, either via URL GET requests, or via a module within the astroquery Python package.

Radio Frequency Interference Detection using Machine Learning.

NASA Astrophysics Data System (ADS)

Mosiane, Olorato; Oozeer, Nadeem; Aniyan, Arun; Bassett, Bruce A.

2017-05-01

Radio frequency interference (RFI) has plagued radio astronomy which potentially might be as bad or worse by the time the Square Kilometre Array (SKA) comes up. RFI can be either internal (generated by instruments) or external that originates from intentional or unintentional radio emission generated by man. With the huge amount of data that will be available with up coming radio telescopes, an automated aproach will be required to detect RFI. In this paper to try automate this process we present the result of applying machine learning techniques to cross match RFI from the Karoo Array Telescope (KAT-7) data. We found that not all the features selected to characterise RFI are always important. We further investigated 3 machine learning techniques and conclude that the Random forest classifier performs with a 98% Area Under Curve and 91% recall in detecting RFI.

Radio Frequency Interference Mitigation

NASA Astrophysics Data System (ADS)

An, T.; Chen, X.; Mohan, P.; Lao, B. Q.

2017-09-01

The observational facilities of radio astronomy keep constant upgrades and developments to achieve better capabilities including increasing the time of the data recording and frequency resolutions, and increasing the receiving and recording bandwidth. However in contrast, only a limited spectrum resource has been allocated to radio astronomy by the International Telecommunication Union, resulting in that the radio observational instrumentations are inevitably exposed to undesirable radio frequency interference (RFI) signals which originate mainly from the terrestrial human activity and are becoming stronger with time. RFIs degrade the quality of data and even lead to invalid data. The impact of RFIs on scientific outcome becomes more and more serious. In this article, the requirement for RFI mitigation is motivated, and the RFI characteristics, mitigation techniques, and strategies are reviewed. The mitigation strategies adopted at some representative observatories, telescopes, and arrays are also introduced. The advantages and shortcomings of the four classes of RFI mitigation strategies are discussed and presented, applicable at the connected causal stages: preventive, pre-detection, pre-correlation, and post-correlation. The proper identification and flagging of RFI is the key to the reduction of data loss and improvement in data quality, and is also the ultimate goal of developing RFI mitigation technique. This can be achieved through a strategy involving a combination of the discussed techniques in stages. The recent advances in the high speed digital signal processing and high performance computing allow for performing RFI excision of the large data volumes generated from large telescopes or arrays in both real time and offline modes, aiding the proposed strategy.

Scientists Detect Radio Emission from Rapidly Rotating Cosmic Dust Grains

NASA Astrophysics Data System (ADS)

2001-11-01

Astronomers have made the first tentative observations of a long-speculated, but never before detected, source of natural radio waves in interstellar space. Data from the National Science Foundation's 140 Foot Radio Telescope at the National Radio Astronomy Observatory in Green Bank, W.Va., show the faint, tell-tale signals of what appear to be dust grains spinning billions of times each second. This discovery eventually could yield a powerful new tool for understanding the interstellar medium - the immense clouds of gas and dust that populate interstellar space. The NRAO 140 Foot Radio Telescope The NRAO 140-Foot Radio Telescope "What we believe we have found," said Douglas P. Finkbeiner of Princeton University's Department of Astrophysics, "is the first hard evidence for electric dipole emission from rapidly rotating dust grains. If our studies are confirmed, it will be the first new source of continuum emission to be conclusively identified in the interstellar medium in nearly the past 20 years." Finkbeiner believes that these emissions have the potential in the future of revealing new and exciting information about the interstellar medium; they also may help to refine future studies of the Cosmic Microwave Background Radiation. The results from this study, which took place in spring 1999, were accepted for publication in Astrophysical Journal. Other contributors to this paper include David J. Schlegel, department of astrophysics, Princeton University; Curtis Frank, department of astronomy, University of Maryland; and Carl Heiles, department of astronomy, University of California at Berkeley. "The idea of dust grains emitting radiation by rotating is not new," comments Finkbeiner, "but to date it has been somewhat speculative." Scientists first proposed in 1957 that dust grains could emit radio signals, if they were caused to rotate rapidly enough. It was believed, however, that these radio emissions would be negligibly small - too weak to be of any impact to current radio astronomy research, and the idea was largely forgotten. In the 1990s this perception began to change when scientists and engineers designed sensitive instruments to detect the faint afterglow of the Big Bang, which is seen in the Universe as the Cosmic Microwave Background Radiation. While making detailed maps of this faint and cold radiation, scientists also detected signals at approximately the same wavelength and intensity as the background radiation, but clearly emanating from within the Milky Way's galactic plane. The researchers expected to detect some emission from the Milky Way, but what they encountered was much brighter than anticipated. This discovery caused some concern among researchers because of the need to have a very clear "window" on the Universe to study the background radiation in great detail. If there were a source of radio emission in our own galactic "back yard," then studies of the microwave background radiation would need to recognize these emissions and correct for them. "We want to be clear, however, that nothing we have found invalidates the current interpretation of the Cosmic Microwave Background Radiation," assured Finkbeiner. "Nobody has done anything wrong in neglecting these signals - so far." Scientists considered several plausible mechanisms for this anomalous emission, but these theories failed to explain the observed spatial distribution of this emission across the sky. This predicament prompted theorists to rethink the spinning dust idea, leading to a 1998 model by Bruce Draine (Princeton University) and Alex Lazarian (University of Wisconsin), which proposed rotational dust-grain emission as an important mechanism. Draine and Lazarian assumed that small dust grains, perhaps having no more than 100 atoms each, would populate many interstellar dust clouds in the Galaxy. Each grain would have a small electric dipole and would therefore react to the charged ions that race through the clouds at tremendous speeds. As an ion either strikes or passes near a dust grains, the grain would "spin up," reaching speeds of up to one trillion revolutions per minute, causing it to radiate. The rate of rotation of these dust grains directly correlates to the frequencies at which they radiate. For example, a dust grain rotating 10 billion times each second would emit radio waves at 10 gigahertz (GHz). In looking for this elusive signal, the researchers narrowed their search to 10 dust clouds within the Milky Way Galaxy. These specific clouds were selected because their location and properties would help to eliminate other possibilities for these emissions. "Our goal was to find those areas within the Milky Way Galaxy that would help us rule out other sources of emission," said Finkbeiner. "By selected these specific targets, we believe that the signals we received are very indicative of rapidly rotating dust grains." The researchers emphasize, however, that additional observations will be required to confirm their results, and other potential emission mechanisms have not been ruled out. Particularly, it is possible that a portion of this radiation is due to the presence of ferro-magnetic minerals within the dust grains. Additional studies with more sensitive equipment will be necessary to confirm these results conclusively. "What we think is the most intriguing, however," said Finkbeiner, "is that with further advances in radio astronomy, the faint emissions from rotating dust grains may reveal previously unknown details about the dynamics of the interstellar medium. By detecting and understanding this emission we also hope to give astronomers a tool to greatly refine future studies of the Cosmic Microwave Background Radiation." The NSF's 140 Foot Radio Telescope now is decommissioned after a long and highly productive career. Research will continue on the newly commissioned Robert C. Byrd Green Bank Telescope, which is the world's largest fully steerable radio telescope. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Brown Dwarfs: A New Class of Stellar Lighthouse

NASA Astrophysics Data System (ADS)

2007-04-01

Brown dwarfs, thought just a few years ago to be incapable of emitting any significant amounts of radio waves, have been discovered putting out extremely bright "lighthouse beams" of radio waves, much like pulsars. A team of astronomers made the discovery using the National Science Foundation's Very Large Array (VLA) radio telescope. Artist's Conception of Brown Dwarf Artist's conception of "mini-aurorae" at poles of brown dwarf, producing beams of strong radio emission. CREDIT: Hallinan et al., NRAO/AUI/NSF Click on image for page of graphics and full information "These beams rotate with the brown dwarf, and we see them when the beam passes over the Earth. This is the same way we see pulses from pulsars," said Gregg Hallinan of the National University of Ireland Galway. "We now think brown dwarfs may be a missing link between pulsars and planets in our own Solar System, which also emit, but more weakly," he added. Brown dwarfs are enigmatic objects that are too small to be stars but too large to be planets. They are sometimes called "failed stars" because they have too little mass to trigger hydrogen fusion reactions at their cores, the source of the energy output in larger stars. With roughly 15 to 80 times the mass of Jupiter, the largest planet in our Solar System, brown dwarfs were long thought to exist. However, it was not until 1995 that astronomers were able to actually find one. A few dozen now are known. In 2001, a group of summer students at the National Radio Astronomy Observatory used the VLA to observe a brown dwarf, even though they had been told by seasoned astronomers that brown dwarfs are not observable at radio wavelengths. Their discovery of a strong flare of radio emission from the object surprised astronomers and the students' scientific paper on the discovery was published in the prestigous scientific journal Nature. Hallinan and his team observed a set of brown dwarfs with the VLA last year, and found that three of the objects emit extremely strong, repeating pulses of radio waves. They concluded that the pulses come from beams emitted from the magnetic poles of the brown dwarfs. This is similar to the beamed emission from pulsars, which are superdense neutron stars, and much more massive than brown dwarfs. The characteristics of the beamed radio emission from the brown dwarfs suggest to the scientists that it is produced by a mechanism also seen at work in planets, including Jupiter and Earth. This process involves electrons interacting with the planet's magnetic field to produce radio waves that then are amplified, or strengthened, by natural masers that amplify radio waves the same way a laser amplifies light waves. "The brown dwarfs we observed are between planets and pulsars in the strength of their radio emissions," said Aaron Golden, also of the National University of Ireland Galway. "While we don't think the mechanism that's producing the radio waves in brown dwarfs is exactly the same as that producing pulsar radio emissions, we think there may be enough similarities that further study of brown dwarfs may help unlock some of the mysteries about how pulsars work," he said. While pulsars were discovered 40 years ago, scientists still do not understand the details of how their strong radio emissions are produced. The brown dwarfs rotate at a much more leisurely pace than pulsars. While pulsars rotate -- and produce observed pulses -- typically several times a second to hundreds of times a second, the brown dwarfs observed with the VLA are showing pulses roughly once every two to three hours. Hallinan and Golden worked with Stephen Bourke and Caoilfhionn Lane, also of the National University of Ireland Galway; Tony Antonova and Gerry Doyle of Armagh Observatory in Northern Ireland; Robert Zavala and Fred Vrba of the U.S.Naval Observatory in Flagstaff, Arizona; Walter Brisken of the National Radio Astronomy Observatory in Socorro, New Mexico; and Richard Boyle of the Vatican Observatory Research Group at Steward Observatory in Arizona. The scientists presented their results to the Royal Astronomical Society's National Astronomy Meeting at the University of Central Lancashire in the United Kingdom. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. This work was supported by Science Foundation Ireland under its Research Frontiers Programme, the Higher Education Authority's Programme for Research in Third Level Institutions, and the Irish Research Council for Science, Engineering and Technology.

Archiving of interferometric radio and mm/submm data at the National Radio Astronomy Observatory

NASA Astrophysics Data System (ADS)

Lacy, Mark

2018-06-01

Modern radio interferometers such as ALMA and the VLA are capable of producing ~1TB/day of data for processing into image products of comparable size. Besides the shear volume of data, the products themselves can be complicated and are sometimes hard to map into standard astronomical archive metadata. We also face similar issues to those faced by archives at other wavelengths, namely the role of archives as the basis of reprocessing platforms and facilities, and the validation and ingestion of user-derived products. In this talk I shall discuss the plans of NRAO in these areas over the next decade.

News and Views: Research council resource allocations: managing demand; e-MERLIN radio telescope network is up and running

NASA Astrophysics Data System (ADS)

2011-02-01

The research councils discovered in December the allocation of money from the UK government's Comprehensive Spending Review, and have set out their delivery plans outlining how they will spend it. Details and decisions will follow consultation in the coming months. The first image from eMerlin, the UK's national radio astronomy facility, shows the power of the enhanced network of radio telescopes spread over 220 km and now linked by fibre optics. These links and advanced receivers will allow astronomers to see in a single day what would have previously taken them more than a year of observations.

The radio astronomy explorer satellite, a low-frequency observatory.

NASA Technical Reports Server (NTRS)

Weber, R. R.; Alexander, J. K.; Stone, R. G.

1971-01-01

The RAE-1 is the first spacecraft designed exclusively for radio astronomical studies. It is a small, but relatively complex, observatory including two 229-meter antennas, several radiometer systems covering a frequency range of 0.2 to 9.2 MHz, and a variety of supporting experiments such as antenna impedance probes and TV cameras to monitor antenna shape. Since its launch in July, 1968, RAE-1 has sent back some 10 billion data bits per year on measurements of long-wavelength radio phenomena in the magnetosphere, the solar corona, and the Galaxy. In this paper we describe the design, calibration, and performance of the RAE-1 experiments in detail.

Radio Astronomers Get Their First Glimpse of Powerful Solar Storm

NASA Astrophysics Data System (ADS)

2001-08-01

Astronomers have made the first radio-telescope images of a powerful coronal mass ejection on the Sun, giving them a long-sought glimpse of hitherto unseen aspects of these potentially dangerous events. "These observations are going to provide us with a new and unique tool for deciphering the mechanisms of coronal mass ejections and how they are related to other solar events," said Tim Bastian, an astronomer at the National Science Foundation's National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia. Radio image of coronal mass ejection; circle indicates the size and location of the Sun. White dots are where radio spectral measurements were made. Bastian, along with Monique Pick, Alain Kerdraon and Dalmiro Maia of the Paris Observatory, and Angelos Vourlidas of the Naval Research Laboratory in Washington, D.C., used a solar radio telescope in Nancay, France, to study a coronal mass ejection that occurred on April 20, 1998. Their results will be published in the September 1 edition of the Astrophysical Journal Letters. Coronal mass ejections are powerful magnetic explosions in the Sun's corona, or outer atmosphere, that can blast billions of tons of charged particles into interplanetary space at tremendous speeds. If the ejection is aimed in the direction of Earth, the speeding particles interact with our planet's magnetic field to cause auroral displays, radio-communication blackouts, and potentially damage satellites and electric-power systems. "Coronal mass ejections have been observed for many years, but only with visible-light telescopes, usually in space. While previous radio observations have provided us with powerful diagnostics of mass ejections and associated phenomena in the corona, this is the first time that one has been directly imaged in wavelengths other than visible light," Bastian said. "These new data from the radio observations give us important clues about how these very energetic events work," he added. The radio images show an expanding set of loops similar to the loops seen at visible wavelengths. The radio loops, astronomers believe, indicate regions where electrons are being accelerated to nearly the speed of light at about the time the ejection process is getting started. The same ejection observed by the radio telescope also was observed by orbiting solar telescopes. Depending on what later radio observations show, the solar studies may reveal new insights into the physics of other astronomical phenomena. For example, shocks in the corona and the interplanetary medium accelerate electrons and ions, a process believed to occur in supernova remnants - the expanding debris from stellar explosions. The electrons also may be accelerated by processes associated with magnetic reconnection, a process that occurs in the Earth's magnetosphere. "The Sun is an excellent physics laboratory, and what it teaches us can then help us understand other astrophysical phenomena in the universe," Bastian said. The radio detection of a coronal mass ejection also means that warning of the potentially dangerous effects of these events could come from ground-based radio telescopes, rather than more-expensive orbiting observatories. "With solar radio telescopes strategically placed at three or four locations around the world, coronal mass ejections could be detected 24 hours a day to provide advance warning," Bastian said. The Nancay station for radio astronomy is a facility of the Paris Observatory. The Nancay Radioheliograph is funded by the French Ministry of Education, the Centre National de la Recherche Scientifique, and by the Region Centre. This research has also been supported by the Centre National d'Etudes Spatiales. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Radio Searches for Signatures of Advanced Extraterrestrial Life

NASA Astrophysics Data System (ADS)

Siemion, Andrew

Over the last several decades, observational astronomy has produced a flood of discoveries that suggest that the building blocks and circumstances that gave rise to life on Earth may be the rule rather than the exception. It has now been conclusively shown that planets are common and that some 5-15% of FGKM stars host planets existing in their host star's habitable zone. Further, terrestrial biology has demonstrated that life on our own planet can thrive in extraordinarily extreme environments, dramatically extending our notion of what constitutes habitability. The deeper question, yet unanswered, is whether or not life in any form has ever existed in an environment outside of the Earth. As humans, we are drawn to an even more profound question, that of whether or not extraterrestrial life may have evolved a curiosity about the universe similar to our own and the technology with which to explore it. Radio astronomy has long played a prominent role in searches for extraterrestrial intelligence (SETI), beginning with the first suggestions by Cocconi and Morrison (1959) that narrow-band radio signals near 1420 MHz might be effective tracers of advanced technology and early experiments along these lines by Frank Drake in 1961, continuing through to more recent investigations searching for several types of coherent radio signals indicative of technology at a wider range of frequencies. The motivations for radio searches for extraterrestrial intelligence have been throughly discussed in the literature, but the salient arguments are the following: 1. coherent radio emission is commonly produced by advanced technology (judging by Earth’s technological development), 2. electromagnetic radiation can convey information at the maximum velocity currently known to be possible, 3. radio photons are energetically cheap to produce, 4. certain types of coherent radio emissions are easily distinguished from astrophysical background sources, especially within the so-called ``terrestrial microwave window'' and 5. these emissions can transit vast regions of interstellar space relatively unaffected by gas, plasma and dust. Our group is conducting a variety of radio SETI at a wide range of frequencies, from 50 MHz to 230 GHz, using several facilities: the Dutch/European Low-Frequency Array (LOFAR), Arecibo Observatory, the Green Bank Telescope and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Our experiments employ a variety of strategies, including searches of nearby stars, stars with known exoplanets and the galactic center. We have also developed an observing pipeline that targets systems of multiple exoplanets at epochs in which two or more planets are aligned relative to Earth, which we have dubbed exoplanetary interplanetary communication (EPIC) SETI. Our detection algorithms are sensitive to a wide range of signal types, and we have developed numerous radio interference rejection techniques. Many of our experiments operate ``commensally'' with other science projects, providing thousands of hours of observations with the largest telescopes in the world. Here we present the status of our radio SETI efforts, discuss observations conducted to-date and review the various regions of parameter space probed by each experiment.

Obituary: Grote Reber, 1911-2002

NASA Astrophysics Data System (ADS)

Kellermann, Kenneth I.

2003-12-01

Grote Reber, a pioneer of radio astronomy died in Tasmania, Australia on 20 December 2002, two days before his 91st birthday. Reber was born in Chicago on 22 December 1911 and grew up in the Chicago suburb of Wheaton, IL. His father, Schuyler Colefax Reber, who was a lawyer and part owner of a canning factory, died when Grote was only 21; his mother, Harriet Grote was an elementary school teacher in Wheaton. Among her 7th and 8th grade students at Longfellow School in Wheaton was young Edwin Hubble with whom Grote later exchanged views on cosmology. Grote graduated from the Armour Institute of Technology (now the Illinois Institute of Technology) with a degree in Electrical Engineering. He excelled in electronics courses but did less well in mathematics. After receiving his degree in 1933, Grote held a series of jobs with various Chicago companies including the Stewart-Warner and Belmont Radio Corporations. Grote had a lifelong interest in electronics. At the age of 16, he received his amateur radio license, W9GFZ, signed by then Secretary of the Interior, Herbert Hoover. After contacting over 50 countries, he was looking for new challenges. He had read about Karl Jansky's discovery of cosmic radio emission and tried to interest astronomers at Yerkes Observatory, but except for Jesse Greenstein, they showed little interest. ``So," as he later related, ``I consulted with myself and decided to build a dish." He took astronomy courses from Philip Keenan and others at the University of Chicago. Using $2,000 of his own funds (about his annual salary), he took the summer of 1937 off from his engineering job at the Stewart-Warner Corporation to erect a 32-ft parabolic transit dish in a vacant lot next to his mother's house. Using his experience and skills as an electrical engineer and radio amateur he designed, built and tested a series of sensitive radio receivers, which he placed at the focal point of his parabolic dish. Following a succession of failures, in the spring of 1939, he finally succeeded in detecting the galactic radio noise and went on to make the first maps of radio emission from the galaxy and, in 1943, to detect radio emission from the sun. Automobile ignition noise interfered with Reber's observations, so he observed only at night, laboriously writing down every minute the readings from his detector output. In the daytime, he returned to his job in Chicago, catching a few hours sleep each evening before returning to his observations; on weekends he analyzed his data. At first, Grote's discoveries were received with skepticism by the astronomical community and he had great difficulty in getting his papers accepted for publication in the astronomical literature. As he later claimed, ``The astronomers of the time didn't know anything about radio or electronics, and the radio engineers didn't know anything about astronomy. They thought the whole affair was at best a mistake, and at worst a hoax." But, following visits of Kennan and others to his Wheaton facility, he finally convinced "Astrophysical Journal" editor, Otto Struve, and others of the importance of his work. In addition to his classic publications in the "Astrophysical Journal", "Nature", and the "Proceedings of the Institute of Radio Engineers" (now the Institute of Electronic and Electrical Engineering), he also wrote influential reports in "Popular Science", "Scientific American" and "Sky and Telescope". In 1947, together with Jesse Greenstein, he wrote the first review of radio astronomy which was published in the journal, "Observatory". Plagued by local interference, he discussed with Otto Struve moving his antenna to a better site in Texas and also the possibility of building a much larger 200-ft dish. Reber recognized that an equatorial mount would be very expensive and proposed to use an alt-az mount together with an analogue coordinate converter of the type later implemented in Dwingeloo and Jodrell Bank. Through his younger brother Schuyler, then a business student at Harvard, he gained the interest of Harlow Shapley and Fred Whipple but he was unable to obtain any financial support from Harvard or any other university. Following his mother's death in 1945, Grote reluctantly accepted a position with the National Bureau of Standards in Washington and arranged to have his antenna re-erected in Washington where it was put on an alt-azimuth mount. But he was frustrated with government bureaucracy and disillusioned by the growing atmosphere of McCarthyism in Washington. In 1951, he moved to Hawaii where he pursued a variety of research programs in radio astronomy as well as atmospheric and ionospheric physics from the top of Haleakula on the island of Maui. From Hawaii, he moved on to Tasmania in 1954, in order to exploit the ionospheric transparency associated with the south magnetic pole. While radio astronomers in the rest of the world were exploiting the newly emerging microwave technology to move to shorter and shorter wavelengths, Grote, characteristically departing from conventional ``wisdom," concentrated on the extremely long wavelengths. Working with Bill Ellis at the University of Tasmania, Reber designed and built a series of arrays to study Galactic radio emission and absorption at wavelengths of a few hundred meters. Following several years spent at the CSIRO Ionospheric Prediction Service, Grote moved from Hobart to Bothwell, in central Tasmania, where he designed and built an energy efficient home and where he lived for many years and made good friends. With the growing importance after WWII of the contributions being made throughout the world by radio astronomy, Reber's pioneering studies ultimately became widely recognized. In 1961 he received the Cresson Prize from the Franklin Institute and in 1962, an honorary Doctor of Science degree from Ohio State University. He also received the AAS Russell Lecture Prize and the Bruce Medal of the Astronomical Society of the Pacific. Throughout his life, he had a strong interest in political and social issues. Writing to the Director of the NSF and the President of the NAS, he argued against big science and to reduce funding for large radio telescopes such as the VLA. Throughout his career, he questioned the ``big-bang" universe and authored a widely distributed paper on ``The Endless Boundless Universe." He was greatly concerned about the consequences of world population growth and preserving our natural resources, particularly the overuse of fossil fuels, which motivated his research on electric cars and consideration of increased use of sailing ships. He had no tolerance for scientific or other activities that did not meet his high standards but he was generous in giving recognition and praise to those whose work he admired. A college era friend recently described Grote as ``nervously energetic, enthusiastic, with a keen mind that went everywhere, an ever present, lively, sardonic, iconoclastic sense of humor, and strong opinions." In addition to his pioneering work in radio astronomy, Reber also pursued and published research in a variety of fields ranging from radio circuitry and ionospheric physics to studies of cosmic rays, the atmosphere, archaeology and the growth of beans. He held a number of patents, including one for a radio sextant to ``shoot the sun" on cloudy days. Throughout most of his career, he worked as an amateur relying on his deep curiosity along with his imagination and skills as an electronics engineer combined with his persistent, forceful personality, and stubborn disregard for conventional opinion. At various times, he held guest appointments at the National Radio Astronomy Observatory, Ohio State University, the Australian Commonwealth Scientific and Industrial Research Organization and, starting in 1951, he also received generous support from the Research Corporation in New York. However, he valued his independence and was skeptical of the strings that would be attached to any institutional support. He was scornful of establishment science, with its ``self appointed pontiffs," but his achievements were ultimately widely recognized by professional astronomers. Reber's extraordinary achievements as an amateur were probably unique in 20th century science.

The Mobile Laboratory for Radio-Frequency Interference Monitoring at the Sardinia Radio Telescope

NASA Astrophysics Data System (ADS)

Bolli, Pietro; Gaudiomonte, Francesco; Ambrosini, Roberto; Bortolotti, Claudio; Roma, Mauro; Barberi, Carlo; Piccoli, Fabrizio

2013-10-01

In this paper, a quite unique mobile laboratory for monitoring radio-frequency interference with a radio-astronomical observatory is described. The unit is fully operational at the new Sardinia Radio Telescope, a 64-m antenna now in the commissioning phase in Italy. The mobile laboratory is mainly used to identify the source of interference with the radio astronomy service using iterative triangulations in the azimuth directions. Both the design and realization of this prototype were handled with outstanding care to limit the emission of self-interference as much as possible. The laboratory was equipped with excellent microwave instruments in terms of sensitivity, frequency coverage, dynamic range, and various demodulation and signal-analysis facilities. The unit can be quickly switched to different RF and power-supply configurations, while offering operators a safe and efficient workplace, even in adverse meteorological and driving conditions. In the past months, the mobile laboratory has proven to be successful in detecting and identifying many radio interferers. Two examples of measurement campaigns are described.

Observatories and Telescopes of Modern Times

NASA Astrophysics Data System (ADS)

Leverington, David

2016-11-01

Preface; Part I. Optical Observatories: 1. Palomar Mountain Observatory; 2. The United States Optical Observatory; 3. From the Next Generation Telescope to Gemini and SOAR; 4. Competing primary mirror designs; 5. Active optics, adaptive optics and other technical innovations; 6. European Northern Observatory and Calar Alto; 7. European Southern Observatory; 8. Mauna Kea Observatory; 9. Australian optical observatories; 10. Mount Hopkins' Whipple Observatory and the MMT; 11. Apache Point Observatory; 12. Carnegie Southern Observatory (Las Campanas); 13. Mount Graham International Optical Observatory; 14. Modern optical interferometers; 15. Solar observatories; Part II. Radio Observatories: 16. Australian radio observatories; 17. Cambridge Mullard Radio Observatory; 18. Jodrell Bank; 19. Early radio observatories away from the Australian-British axis; 20. The American National Radio Astronomy Observatory; 21. Owens Valley and Mauna Kea; 22. Further North and Central American observatories; 23. Further European and Asian radio observatories; 24. ALMA and the South Pole; Name index; Optical observatory and telescope index; Radio observatory and telescope index; General index.

Matching radio catalogues with realistic geometry: application to SWIRE and ATLAS

NASA Astrophysics Data System (ADS)

Fan, Dongwei; Budavári, Tamás; Norris, Ray P.; Hopkins, Andrew M.

2015-08-01

Cross-matching catalogues 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 catalogues 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 Spitzer Wide-Area Infrared Extragalactic and Australia Telescope Large Area Survey CDF-S catalogues shows that this method performs well without human intervention.

VizieR Online Data Catalog: Parallaxes of high mass star forming regions (Reid+, 2014)

NASA Astrophysics Data System (ADS)

Reid, M. J.; Menten, K. M.; Brunthaler, A.; Zheng, X. W.; Dame, T. M.; Xu, Y.; Wu, Y.; Zhang, B.; Sanna, A.; Sato, M.; Hachisuka, K.; Choi, Y. K.; Immer, K.; Moscadelli, L.; Rygl, K. L. J.; Bartkiewicz, A.

2016-04-01

Table1 lists the parallaxes and proper motions of 103 regions of high-mass star formation measured with Very Long Baseline Interferometry (VLBI) techniques, using the National Radio Astronomy Observatory's Very Long Baseline Array (VLBA), the Japanese VLBI Exploration of Radio Astrometry (VERA; http://veraserver.mtk.nao.ac.jp) project, and the European VLBI Network (EVN). We have include three red supergiants (NML Cyg, S Per, VY CMa) as indicative of high-mass star forming regions. (2 data files).

Voyager 1 examines Jupiter

NASA Technical Reports Server (NTRS)

1979-01-01

An overview of the Voyager mission to Jupiter, Saturn, and possibly Uranus is presented. Scientific instruments onboard the spacecraft are described as well as methods used for their calibration and evaluation during the cruise phase of the mission. Experiments to be performed cover the following areas: imaging science, radio science, cosmic rays, ultraviolet spectroscopy, photopolarimetry, planetary radio astronomy, magnetic fields, low-energy charged particles, plasma science, and infrared radiometry and spectroscopy. A list of the satellites of Jupiter and their diameters, distances, and periods is included.

Astronomical observations with the University College London balloon borne telescope

NASA Technical Reports Server (NTRS)

Jennings, R. E.

1974-01-01

The characteristics of a telescope system which was developed for high altitude balloon astronomy are discussed. A drawing of the optical system of the telescope is provided. A sample of the signals recorded during one of the flights is included. The correlation between the infrared flux and the radio continuum flux is analyzed. A far infrared map of the radio and infrared peaks of selected stars is developed. The spectrum of the planet Saturn is plotted to show intensity as compared with wavenumber.

New Technologies Promise Dramatic Increase In Capabilities of the Very Large Array

NASA Astrophysics Data System (ADS)

1996-06-01

The National Science Foundation's Very Large Array (VLA) radio telescope in New Mexico is an exceedingly powerful scientific instrument, and has transformed many areas of astronomy in its more than 15 years of operation. It has been used by more astronomers and has produced more scientific papers than any other radio telescope. Though its position as one of the world's premier radio telescopes will remain unchallenged for a long time, new technologies could increase its scientific capabilities greater than tenfold. Details were presented today to the American Astronomical Society's meeting in Madison, Wisconsin. An enhanced VLA, incorporating state-of-the-art technologies, would provide scientists with a number of important, new capabilities, including detailed investigations of the physics of solar radio bursts; improved radar probes of planets, asteroids and comets; the ability to image protoplanetary disks around young stars; more rapid response and effective observations of transient events such as supernovae; new types of information about gas both within our own Galaxy and in other galaxies; and greatly improved ability to study clusters of galaxies and extremely distant objects in the Universe. In addition, the enhanced VLA will serve as an improved partner with the Very Long Baseline Array (VLBA), a continent-wide radio telescope, also part of the National Radio Astronomy Observatory (NRAO). "The VLA upgrade proposes an essentially new instrument, created from two existing instruments, with power and capability far exceeding that of either one alone," said Rick Perley, NRAO Project Scientist for the VLA Upgrade Project. "It builds on the existing staff and infrastructure and would hardly affect operations costs. In today's fiscal climate, this provides the benefit of a `new' instrument with outstanding scientific capability at the least cost," Perley added. The VLA was built in the 1970s and dedicated in 1980. At the time of its completion, it was a state-of-the-art instrument. Even today, "it exceeds all other radio astronomy facilities with its combination of sensitivity, flexibility, speed, and overall imaging quality," Perley said. However, many of the technologies used by the VLA, such as computing, high-speed data transfer, and radio receivers, have greatly advanced over the past 15 years. "The VLA has in place all the needed infrastructure to take maximum advantage of these technological advances at minimum cost," Perley said. The VLA of the future, Perley said, could have: * Sensitivity improved by a factor of 2 to 15, depending on frequency; * A capacity for gathering information on spectral lines increased by a factor of 16; * Complete frequency coverage, versus very spotty current coverage; * Resolution increased by a factor of about 8; and * Complete integration with the VLBA (a long-term project). This would produce an instrument with "an outstanding, unique capability: continuous frequency coverage over a factor of 500 and continuous resolution coverage over a factor of a million, with the best sensitivity of any current instrument," Perley said. The scientific capability of the VLA now is limited in many areas by the aging technology currently employed. These limitations can be solved inexpensively by replacing the older equipment with new, state-of-the-art technology. The National Radio Astronomy Observatory began the VLA Upgrade Project with a scientific workshop held in Socorro, NM, in January of 1995. Scientists from many specialties within astronomy and planetary science were invited to this workshop to present their needs for future observations. The participants of this workshop produced a book outlining the goals of the VLA Upgrade Project. Another scientific workshop is planned for 1997. NRAO scientists and engineers now are working in groups to focus on specific aspects of the upgrade project. "We continue to solicit feedback from all interested members of the scientific community on how we can best serve their needs with an improved VLA for the next century," Perley said. For more information about the VLA Upgrade Project, and other NRAO instruments, visit the NRAO World Wide Web Home Page.

Simulating 3D Spacecraft Constellations for Low Frequency Radio Imaging

NASA Astrophysics Data System (ADS)

Hegedus, A. M.; Amiri, N.; Lazio, J.; Belov, K.; Kasper, J. C.

2016-12-01

Constellations of small spacecraft could be used to realize a low-frequency phased array for either heliophysics or astrophysics observations. However, there are issues that arise with an orbiting array that do not occur on the ground, thus rendering much of the existing radio astronomy software inadequate for data analysis and simulation. In this work we address these issues and consider the performance of two constellation concepts. The first is a 32-spacecraft constellation for astrophysical observations, and the second is a 5-element concept for pointing to the location of radio emission from coronal mass ejections (CMEs). For the first, we fill the software gap by extending the APSYNSIM software to simulate the aperture synthesis for a radio interferometer in orbit. This involves using the dynamic baselines from the relative motion of the individual spacecraft as well as the capability to add galactic noise. The ability to simulate phase errors corresponding to positional uncertainty of the antennas was also added. The upgraded software was then used to model the imaging of a 32 spacecraft constellation that would orbit the moon to image radio galaxies like Cygnus A at .3-30 MHz. Animated images showing the improvement of the dirty image as the orbits progressed were made. RMSE plots that show how well the dirty image matches the input image as a function of integration time were made. For the second concept we performed radio interferometric simulations of the Sun Radio Interferometer Space Experiment (SunRISE) using the Common Astronomy Software Applications (CASA) package. SunRISE is a five spacecraft phased array that would orbit Earth to localize the low frequency radio emission from CMEs. This involved simulating the array in CASA, creating truth images for the CMEs over the entire frequency band of SunRISE, and observing them with the simulated array to see how well it could localize the true position of the CME. The results of our analysis show that we can localize the radio emission originating from the head or flanks of the CMEs in spite of the phase errors introduced by uncertainties in orbit and clock estimation.

The General History of Astronomy

NASA Astrophysics Data System (ADS)

Gingerich, Owen

2010-04-01

Foreword; Preface; Acknowledgements; Part I. The Birth of Astrophysics and Other Late Nineteenth-Century Trends (c.1850-c.1920); 1. The origins of astrophysics A. J. Meadows; 2. The impact of photography on astronomy John Lankford; 3. Telescope building, 1850-1900 Albert Van Helden; 4. The new astronomy A. J. Meadows; 5. Variable stars Helen Sawyer Hogg; 6. Stellar evolution and the origin of the Hertzsprung-Russell diagram David DeVorkin; Part II. Observatories and Instrumentation: 7. Astronomical institutions. Introduction Owen Gingerich, Greenwich Observatory Philip S. Laurie, Paris Observatory Jacques Lévy, Pulkovo Observatory Aleksandr A. Mikhailov, Harvard College Observatory Howard Plotkin, United States Naval Observatory Deborah Warner, Lick Observatory Trudy E. Bell, Potsdam Astrophysical Observatory Dieter B. Herrmann; 8. Building large telescopes, 1900-1950 Albert Van Helden; 9. Astronomical institutions in the southern hemisphere, 1850-1950 David S. Evans; 10. Twentieth-century instrumentation Charles Fehrenbach, with a section on 'Early rockets in astronomy' Herbert Friedman; 11. Early radio astronomy Woodruff T. Sullivan III; Appendix: The world's largest telescopes, 1850-1950 Barbara L. Welther; Illustrations: acknowledgements and sources; Index.

The National Astronomy Consortium: Lessons learned from a program to support underrepresented students in pursuing STEM careers

NASA Astrophysics Data System (ADS)

Mills, Elisabeth A.; Sheth, Kartik; Giles, Faye; Strolger, Louis-Gregory; Brisbin, Drew; Boyd, Patricia T.; Benjamin, Robert A.; NAC Consortium

2016-01-01

The National Astronomy Consortium (NAC) is a program partnering physics and astronomy departments in majority and minority-serving institutions across the country. The primary aim of this program is to support traditionally underrepresented students interested in pursuing a career in STEM through a 9-10 week summer astronomy research project and a year of additional mentoring after they return to their home institution. Students are also given an opportunity to apply for a second year in this program, often at a different site. In addition to providing research and professional experience, the NAC also seeks to strengthen ties between the majority and minority-serving institutions in order to better serve these students throughout their careers. I will report on lessons learned from the second year of hosting a cohort at the National Radio Astronomy Observatory in Socorro, NM. I will discuss the program structure during and after the summer, mentoring challenges, and ways that these challenges were addressed, including organizing a series of guest speakers and connecting students with a broader community of remote mentors.

Astronomy in Cuba: practice and trends. An effort to develop a non-formal education programme

NASA Astrophysics Data System (ADS)

Pomares, Oscar A.

In the recent past years, a daily stronger movement of non-professional astronomers has become the center of development for astronomy, a subject of study practically absent now from the national education system in Cuba. A key roll in this movement has been played by the professional staff of the Department of Astronomy of the Institute of Geophysics and Astronomy. As direct outcome of this joint effort between astronomers and amateurs is the research on meteors and comets, presented in two national and one international scientific meeetings. The opening last year of the "Palacio de las Ciencias" in the main building of the country, "El Capitolio Nacional", the participation in conferences and workshops of professional astronomers facing the general public, and their participation in prime-time TV and radio programs open a way for the growth of astronomical knowledge among the Cuban people. Two national meeetings gathering together professional and non- professional astronomers have been held already. Future works in the NEOs international campaign are foreseen. Practice and trends of astronomy in Cuba clarify views of our future in the oldest natural science.

High-Tech 'Heart' of New-Generation Radio Telescope Passes First Test

NASA Astrophysics Data System (ADS)

2008-08-01

The Expanded Very Large Array (EVLA), part of the National Radio Astronomy Observatory (NRAO), took a giant step toward completion on August 7 with successful testing of advanced digital hardware designed to combine signals from its upgraded radio-telescope antennas to produce high resolution images of celestial objects. Successful Moment NRAO Crew Views Successful Computer Display Of WIDAR "First Fringes" Seated, front to back: Barry Clark, Ken Sowinski, Michael Rupen, Kevin Ryan. Standing, front to rear: Mark McKinnon, Rick Perley, Hichem Ben Frej. CREDIT: Dave Finley, NRAO/AUI/NSF Click on image for larger file. By upgrading the 1970s-era electronics of its original Very Large Array (VLA), NRAO is creating a major new radio telescope that is ten times more sensitive than before. Using the EVLA, astronomers will observe fainter and more-distant objects than previously possible and use vastly improved analysis tools to decipher their physics. The heart of the new electronics that makes this transformation possible is a high-performance, special-purpose supercomputer, called the WIDAR Correlator. It has been designed and is being built by the National Research Council of Canada at the Dominion Radio Astrophysical Observatory (DRAO) of the Herzberg Institute for Astrophysics, and serves as Canada's contribution to the EVLA project. The design of the correlator incorporates an NRC-patented new digital electronic architecture. The successful test, at the VLA site 50 miles west of Socorro, New Mexico, used prototype correlator electronics to combine the signals from two upgraded VLA antennas to turn them into a single, high-resolution telescope system, called an interferometer. The technical term for this achievement is called "first fringes." Each upgraded EVLA antenna produces 100 times more data than an original VLA antenna. When all 27 antennas are upgraded, they will pump data into the WIDAR correlator at a rate equal to 48 million digital telephone calls. To process this torrent of data, the correlator will make 10 million billion calculations per second. Powerful, multi-antenna imaging radio-telescope systems use pairs of antennas as their basic building blocks. Each of the VLA's 27 giant dish antennas is combined electronically with every other antenna to form a multitude of pairs. Each pair contributes unique information that is used to build a highly-detailed image of some astronomical object. The successful two-antenna test thus verifies the design of the new correlator. "This achievement marks the first time that the complete chain of electronics for the EVLA has worked together, and represents a huge milestone in the project. Our congratulations go to our Canadian colleagues and to the NRAO staff members participating in this project. This is a job well done," said Fred Lo, Director of the National Radio Astronomy Observatory. The VLA Expansion, a ten-year project approved in 2001, is funded by 55 million from the United States National Science Foundation (NSF) and 1.75 million from the Mexican government. The Canadian correlator represents a contribution of about $17 million to the project. Throughout the project, the VLA has continued to operate, using a mix of the old and new-style antennas to provide an ongoing research tool. Over its lifetime, the VLA has been the most scientifically-productive ground-based telescope in the history of astronomy. When completed in 2012, the EVLA will be the most powerful centimeter-wavelength radio telescope in the world. The technology developed for the EVLA will enable progress on the next generation radio telescope called the Square Kilometer Array (SKA). The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. Plots of amplitude (top) and phase (bottom) from WIDAR correlator "first fringes" on August 7, 2008.

Obituary: John Daniel Kraus, 1910-2004

NASA Astrophysics Data System (ADS)

Kraus, John D., Jr.; Marhefka, Ronald J.

2005-12-01

John Daniel Kraus, 94, of Delaware, Ohio, director of the Ohio State University "Big Ear" Radio Observatory, physicist, inventor, and environmentalist died 18 July 2004 at his home in Delaware, Ohio. He was born on 28 June 1910 in Ann Arbor, Michigan. He received a Bachelor of Science in 1930, a Master of Science in 1931, and a PhD in physics in 1933 (at 23 years of age), all from the University of Michigan, Ann Arbor. During the 1930s at Michigan, he was involved in physics projects, antenna consulting, and in atomic-particle-accelerator research using the University of Michigan's premier cyclotron. Throughout the late 1920s and the 1930s, John was an avid radio amateur with call sign W8JK. He was back on the air in the 1970s. In 2001 the amateur radio magazine CQ named him to the inaugural class of its Amateur Radio Hall of Fame. He developed many widely used innovative antennas. The "8JK closely spaced array" and the "corner reflector" were among his early designs. Edwin H. Armstrong wrote John in July 1941 indicating in part, "I have read with interest your article in the Proceedings of the Institute on the corner reflector...Please let me congratulate you on a very fine piece of work." Perhaps John's most famous invention, and a product of his intuitive reasoning process, is the helical antenna, widely used in space communications, on global positioning satellites, and for other applications. During World War II, John was in Washington, DC as a civilian scientist with the U.S. Navy responsible for "degaussing" the electromagnetic fields of steel ships to make them safe from magnetic mines. He also worked on radar countermeasures at Harvard University's Radio Research Laboratory. He received the U.S. Navy Meritorious Civilian Service Award for his war work. In 1946 he took a faculty position at Ohio State University, becoming professor in 1949, and retiring in 1980 as McDougal Professor Emeritus of Electrical Engineering and Astronomy. Even so, he never retired. He was always working, researching, writing, and seeking new knowledge. He was active and vital to the end. Early on, John became fascinated by Karl Jansky's discoveries of radio noise from space and the potential to use radio waves rather than visible light to "see" the universe. He maintained contact with radio astronomy pioneer, Grote Reber. John pursued radio-astronomy research in parallel with textbook writing and his OSU teaching responsibilities. By 1953 he was observing with a 96 helix antenna and had produced one of the first maps of the radio sky. This was followed by his design and construction of the innovative, 110-meter, "Big Ear" Radio Telescope - a tiltable, flat reflector joined to a fixed, standing, paraboloidal reflector. Observations began in the mid-1960s. Interspersed with this work were radio observations of Jupiter, Mars, and Venus as well as of the ionized trails of the Sputniks and U.S. satellites. John and his radio astronomy team discovered some of the most distant known objects at the edge of the universe and produced one of the most complete surveys of the radio sky. As he stated, "The radio sky is no carbon copy of the visible; it is a new and different firmament." He was closely identified with efforts and activities related to the Search for Extraterrestrial Intelligence or SETI. He edited and published the first magazine on the subject called Cosmic Search. The now famous "WOW!" signal, of possible extraterrestrial origin, was detected by "Big Ear" in 1977. He was the author of hundreds of technical articles and the holder of many patents. John was a dedicated educator and inspiring teacher, renown for providing plain English solutions to complicated problems. He was thesis advisor to 58 PhD and Master's candidates. His textbooks made complex subjects accessible to many readers. They have been widely used throughout the world and include "Antennas" (McGraw-Hill: 1950, 1988, 2002) and "Electromagnetics" (McGraw-Hill: 1953, 1973, 1984, 1992, 1999) and "Radio Astronomy" (McGraw-Hill: 1966; Cygnus-Quasar: 1986). They have appeared in Chinese, Japanese, Korean, Spanish, Russian, and Portuguese. He also wrote popular books, including the autobiographical "Big Ear" and "Big Ear Two" (Cygnus-Quasar: 1976, 1995), and the instructional "Our Cosmic Universe" (Cygnus-Quasar: 1980). His professional memberships included the American Astronomical Society, election to the National Academy of Engineering (1972), and Fellow of the Institute of Electrical and Electronic Engineers. He received the Centennial Medal (1984), the Edison Medal (1985), and the Heinrich Hertz Medal (1990) from the IEEE. The Antenna and Propagation Society of IEEE twice awarded him its Distinguished Achievement Award, the last in 2003. He was awarded the Sullivant Medal (1970) from the Ohio State University and the Outstanding Achievement Award (1981) from the University of Michigan. John and his wife, Alice Nelson Kraus, whom he married in 1941, were committed environmentalists. Alice and he donated the 80-acre Kraus Wilderness Preserve to the Ohio Wesleyan University in 1976. They also endowed scholarships to enhance environmental learning for students at Ohio Wesleyan and OSU. In addition, John was a passionate advocate of metrification in the USA. Predeceased in 2002 by his beloved wife, he is survived by two sons, John D. Kraus, Jr., and Nelson H. Kraus, and five grandchildren. His professional and personal papers are housed at the National Radio Astronomy Observatory archives in Charlottesville, Virginia. John was viewed by many as a last living link to many of the astonishing scientific discoveries of the 20th century. He valued an open mind and direct physical insights and was of a by-gone era of hands-on invention, empirical testing, and observational research. Yet, he commanded an insightful grasp of the theory, which he could translate into thought provoking learning experiences for students and working engineers alike. In his epilogue to "Big Ear", John said, "I haven't discovered the ultimate truths of the universe but I have experienced the thrill and excitement of playing a small part in the adventure of exploring the astounding, baffling, stranger-than-fiction cosmos in which we dwell."

Pulkovo Observatory: An essay on its history and scientific activity

NASA Technical Reports Server (NTRS)

Dadaev, A. N.

1978-01-01

A history of the observatory and of the development of astronomy in Russia during the past 150 years is presented. Scientific activity was traced from the earliest objectives of precise stellar coordinates to the problems of radio variabilities of quasars.

Trapped strontium ion optical clock

NASA Astrophysics Data System (ADS)

Barwood, G. P.; Gill, P.; Klein, H. A.; Hosaka, K.; Huang, G.; Lea, S. N.; Margolis, H. S.; Szymaniec, K.; Walton, B. R.

2017-11-01

Increasingly stringent demands on atomic timekeeping, driven by applications such as global navigation satellite systems (GNSS), communications, and very-long baseline interferometry (VBLI) radio astronomy, have motivated the development of improved time and frequency standards. There are many scientific applications of such devices in space.

47 CFR 73.801 - Broadcast regulations applicable to LPFM stations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... engineering practice. Section 73.593Subsidiary communications services. Section 73.1015Truthful written... interference to radio astronomy, research and receiving installations. Section 73.1201Station identification.... Section 73.1250Broadcasting emergency information. Section 73.1300Unattended station operation. Section 73...

47 CFR 73.801 - Broadcast regulations applicable to LPFM stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... engineering practice. Section 73.593Subsidiary communications services. Section 73.1015Truthful written... interference to radio astronomy, research and receiving installations. Section 73.1201Station identification.... Section 73.1250Broadcasting emergency information. Section 73.1300Unattended station operation. Section 73...

The New Cosmos

ERIC Educational Resources Information Center

McCray, Richard A.

1970-01-01

Discusses areas of modern astronomy that owe their development largely to nonoptical radiation: radio, infrared, ultraviolet, and x-ray radiation. Indicates new observations favor the big-bang" model of the universe, for it is now established that the earth is expanding at a measurable rate. Annotated bibliography. (LS)

Astronomy and its importance for everyday life

NASA Astrophysics Data System (ADS)

Tiron, Stefan

2010-12-01

The author is dialogging with a journalist from the Moldavian National radio about the following topics: 1) The winter solstice 2) The astronomical phenomena for 2011 in Moldova (Sun's and Moon's eclipses) 3) The solar activity, its increasing during next year and its maximum

QUARTERLY PROGRESS REPORT NO. 83,

DTIC Science & Technology

Topics included are: microwave spectroscopy; radio astronomy; solid-state microwave electronics; optical and infrared spectroscopy; physical electronics and surface physics; physical acoustics; plasma physics; gaseous electronics; plasmas and controlled nuclear fusion ; energy conversion research; statistical communication theory; linguistics; cognitive information processing; communications biophysics; neurophysiology; computation research.

Obituary: Daniel E. Harris (1934 - 2015)

NASA Astrophysics Data System (ADS)

Madrid, Juan P.; Massaro, Francesco; Cheung, Teddy

Our friend and colleague, Daniel E. Harris, died on December 6th 2015. Dan was a passionate astronomer and world traveller. He led a rich and scientifically productive life until the end. Dan was the first person to receive a PhD in radio astronomy at Caltech where he was a student of John Bolton, one of the fathers of Radio Astronomy and the founder of the Owens Valley Radio Observatory that Dan used for his thesis and first publications. One of Dan's first projects was with Jim Roberts to measure improved positions and flux densities for radio sources in the newly released 3C catalog. During this study, Dan discovered the first flat spectrum radio sources, which he named CTA 21, CTA 26, and CTA 102 and which were later identified as quasars. His PhD thesis resulted in the then definitive study of the evolution of supernova remnants. Later Dan worked on radio galaxies and active galactic nuclei (AGN) first at radio and then at X-ray wavelengths with the Einstein, ROSAT, and Chandra Observatories where he pioneered the new field of relativistic X-ray jets and how they relate to radio galaxies and AGN. After graduating from Caltech in 1961, Dan wanted to see the world. Beginning in 1962, Dan lived in Bologna, Italy, where he worked with Professor Marcello Ceccarelli and the radio astronomy group and was active in the construction of the Northern Cross Radio Observatory ("la Croce"), the first Italian radio telescope. He left Bologna in the Spring of 1964 as his friends remember him to "divenir del mondo esperto e de li vizi umani e del valore"1, as he joined V. Radhakrishnan (Rad) and Dave Morris to sail in a 36-ft trimaran from England to Puerto Rico where he took a position at the Arecibo Observatory working with Marshall Cohen on interplanetary scintillations. After five years at the Arecibo Observatory, Dan went on to work at the Argentinian Institute of Radio Astronomy, Harvard University, the Dwingeloo Radio Observatory in the Netherlands, and at the Dominion Radio Observatory in Penticton, Canada. He finally returned to the U.S. in 1980 and spent the next 35 years at the Smithsonian Astrophysical Observatory (SAO) in Cambridge, Massachusetts. One of Dan's most memorable attributes was his cheerful enjoyment of life. Dan was the life of the party; he was joyful, open and friendly. Dan enjoyed good food, drinks, and conversations with friends and strangers alike. Dan belonged to a time prior to big egos when scientific discoveries seemed to be made by the curious, adventurous, and non-conformists. Dan's free spirit manifested itself in his publications. Dan was a rigorous scientist who was not afraid of writing his papers with a hint of good humour. When presenting new radio measurements Dan went for "descriptive names" to describe radio maps2 such as the "original," the "goldfish," the "double," the "beaver," the "bean." At a recent IAU symposium held in the Galápagos Islands, where many of his colleagues and friends gathered to celebrate his 80th birthday, Dan's talk was entitled: "Slugs and Snails and Puppy Dog Tails: jets from an unconventional angle." As Dan worked with observatories outside the university system he was not officially a faculty member, but he mentored and collaborated with many younger researchers. This younger crowd that with sadness write these lines, always looked up to Dan as a role model in life as well as science, and will most of all miss his steadfast support. He was always ready to share his experience, expertise, and data. Even after leaving his full-time position with Chandra, Dan never retired. He kept working part-time at the SAO where he continued his research and was awarded competitive grants, telescope time, published, and led collaborations. Dan also worked for peace causes throughout his life. Dan joined the tax resistance movement during the Vietnam war, a movement of hundreds of thousands of Americans who refused to pay a portion of their income tax to the government in order to defund the war. He was also an active member of the organization that published the Astronomers and the Arms Race Newsletter. As a concerned scientist, Dan advocated against the star wars agenda and the militarization of space during the eighties. Dan was an active member of the AAS and frequent participant at meetings. The last meeting he attended was the 2015 Seattle one where he presented a talk and chaired a session. His presence at the 2015 meeting is a testament of his unwavering energy. Dan is survived by his wife Barbara, three children: Justine, Seth, and Leila, and four grandchildren.

Riccardo Giacconi to Receive National Medal of Science

NASA Astrophysics Data System (ADS)

2005-02-01

Riccardo Giacconi, very recently retired President of Associated Universities, Inc. (AUI), will be awarded the National Medal of Science by President George W. Bush on March 14, according to the White House. Giacconi, who received the Nobel Prize in Physics in 2002, will be honored for his pioneering research in X-ray astronomy and for his visionary leadership of major astronomy facilities. Established by Congress in 1959, the National Medal of Science is the Nation's highest honor for American scientists and is awarded annually by the President of the United States to individuals "deserving of special recognition for their outstanding contributions to knowledge." "We are extremely proud that Riccardo Giacconi has been selected to receive the nation's highest award for scientific achievement," said current AUI President Ethan J. Schreier, a long-term colleague of Dr. Giacconi. "It is another fitting recognition for an outstanding scientific career that has enhanced our basic understanding of the universe," Schreier added. Giacconi, known as the father of X-ray astronomy, used X-ray detectors launched on rockets to discover the first cosmic X-ray source in 1962. Because X-ray radiation is absorbed in Earth's atmosphere, space-based instruments are necessary to study it. Giacconi outlined a methodical program to investigate this new X-ray universe and, working with his research group at American Science and Engineering, Inc. in Cambridge, Massachusetts, developed the first space satellite dedicated to the new field of X-ray astronomy. Named Uhuru, this X-ray satellite observatory was launched in 1970 and subsequently discovered hundreds of X-ray sources. The ground-breaking work of Giacconi and his group led to the discovery of black holes, which to that point had been hypothesized but never seen. Giacconi was also the first to prove that the universe contains background radiation of X-ray light. Riccardo Giacconi has played a key role in many other landmark astronomy programs. He was the Principal Investigator for the Einstein Observatory, the first imaging X-ray observatory, and led the team that proposed the current Chandra X-ray Observatory. He became the first director of the Space Telescope Science Institute, responsible for conducting the science program of the Hubble Space Telescope. He later moved to Germany to become Director-General of the European Southern Observatory (ESO), building the Very Large Telescope, an array of four 8-meter telescopes in Chile. While Director-General of ESO, Giacconi initiated a new cooperative program between the United States, ESO, and Canada to develop and build a large array of antennas for radio astronomy, the Atacama Large Millimeter Array (ALMA), in northern Chile. Giacconi was President of AUI from 1999 to 2004, managing the world-class National Radio Astronomy Observatory (NRAO), an astronomical research facility of the National Science Foundation. During his tenure, Giacconi's scientific vision dramatically advanced the observatory's capabilities. NRAO began the construction of ALMA in Chile and also the Expansion of the Very Large Array (EVLA) in New Mexico, opening new scientific frontiers across the entire radio spectrum. "I am delighted that Riccardo Giacconi has received this recognition," said NRAO Director Fred K.Y. Lo. "The value and impact of the multi-wavelength astronomy which he enabled has been nothing short of revolutionary. This honor recognizes Giacconi's contributions to astronomy and the broader scientific community." Dr. Giacconi is currently a University Professor at Johns Hopkins University in Baltimore, and remains a Distinguished Advisor to the Trustees of Associated Universities, Inc.

National Academy of Sciences Recommends Continued Support of ALMA Project

NASA Astrophysics Data System (ADS)

2000-05-01

A distinguished panel of scientists today announced their support for the continued funding of the Atacama Large Millimeter Array (ALMA) Project at a press conference given by the National Academy of Sciences. The ALMA Project is an international partnership between U.S. and European astronomy organizations to build a complete imaging telescope that will produce astronomical images at millimeter and submillimeter wavelengths. The U.S. partner is the National Science Foundation, through Associated Universities, Inc., (AUI), led by Dr. Riccardo Giacconi, and the National Radio Astronomy Observatory (NRAO). "We are delighted at this show of continued support from our peers in the scientific community," said Dr. Robert Brown, ALMA U.S. Project Director and Deputy Director of NRAO. "The endorsement adds momentum to the recent strides we've made toward the building of this important telescope." In 1998, the National Research Council, the working arm of the National Academy of Sciences, charged the Astronomy and Astrophysics Survey Committee to "survey the field of space- and ground-based astronomy and astrophysics" and to "recommend priorities for the most important new initiatives of the decade 2000-2010." In a report released today, the committee wrote that it "re-affirms the recommendations of the 1991 Astronomy and Astrophysics Survey Committee by endorsing the completion of . . . the Millimeter Array (MMA, now part of the Atacama Large Millimeter Array)." In the 1991 report "The Decade of Discovery," a previous committee chose the Millimeter Array as one of the most important projects of the decade 1990-2000. Early last year, the National Science Foundation signed a Memorandum of Understanding with a consortium of European organizations that effectively merged the MMA Project with the European Large Southern Array project. The combined project was christened the Atacama Large Millimeter Array. ALMA, expected to consist of 64 antennas with 12-meter diameter dishes, will be built at a high-altitude, extremely dry mountain site in Chile's Atacama desert. The array is scheduled to be completed sometime in this decade. Millimeter-wave astronomy studies the universe in the spectral region where most of its energy lies, between the long-wavelength radio waves and the shorter-wavelength infrared waves. In this realm, ALMA will study the structure of the early universe and the evolution of galaxies; gather crucial data on the formation of stars, protoplanetary disks, and planets; and provide new insights on the familiar objects of our own solar system. "Most of the photons in the Universe lie in the millimeter wavelength regime; among existing or planned instruments only ALMA can image the sources of these photons with the crispness required to understand the events of galaxy, star and planet formation which launched them into space," said NRAO's Dr. Alwyn Wootten, U.S. ALMA Project Scientist. ALMA is an international partnership between the United States (National Science Foundation) and Europe. European participants include the European Southern Observatory, the Centre National de la Recherche Scientifique (France), the Max-Planck Gesellschaft (Germany), the Netherlands Foundation for Research in Astronomy, the United Kingdom Particle Physics and Astronomy Research Council, the Oficina de Ciencia Y Tecnologia/Instituto Geografico Nacional (Spain), and the Swedish Natural Science Research Council. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

A Cluster Of Activities On Coma From The Hubble Space Telescope, StarDate, And McDonald Observatory

NASA Astrophysics Data System (ADS)

Hemenway, Mary Kay; Jogee, S.; Fricke, K.; Preston, S.

2011-01-01

With a goal of providing a vast audience of students, teachers, the general public, and Spanish-speakers with activities to learn about research on the Coma cluster of galaxies based on the HST ACS Treasury survey of Coma, McDonald Observatory used a many-faceted approach. Since this research offered an unprecedented legacy dataset, part of the challenge was to convey the importance of this project to a diverse audience. The methodology was to create different products for different (overlapping) audiences. Five radio programs were produced in English and Spanish for distribution on over 500 radio stations in the US and Mexico with a listening audience of over 2 million; in addition to the radio listeners, there were over 13,000 downloads of the English scripts and almost 6000 of the Spanish. Images were prepared for use in the StarDate Online Astronomy Picture of the Week, for ViewSpace (used in museums), and for the StarDate/Universo Teacher Guide. A high-school level activity on the Coma Cluster was prepared and distributed both on-line and in an upgraded printed version of the StarDate/Universo Teacher Guide. This guide has been distributed to over 1700 teachers nationally. A YouTube video about careers and research in astronomy using the Coma cluster as an example was produced. Just as the activities were varied, so were the evaluation methods. This material is based upon work supported by the National Aeronautics and Space Administration under Grant/Contract/Agreement No. HST-EO-10861.35-A issued through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Analysis of satellite measurements of terrestrial radio noise

NASA Technical Reports Server (NTRS)

Bakalyar, G.; Caruso, J. A.; Vargas-Vila, R.; Ziemba, E.

1974-01-01

Worldwide distributions of terrestrial radio noise as monitored by Radio Astronomy Explorer 1 (RAE 1) generated and compared with CCIR predictions. These contour maps show the global morphology of radio noise at 6.55 and 9.18 MHz for fall, winter, spring and summer during the local time blocks of 00-08 LT and 16-24 LT. These computer produced maps show general agreement with CCIR predictions over large land masses. The RAE and CCIR maps diverge at high latitudes over Asia and frequently over ocean regions. Higher noise levels observed by RAE at high latitudes are attributed to magnetospheric emission while higher noise levels observed by RAE over Asia are attributable to high power transmitters. Analysis of RAE noise observations in conjunction with various geophysical phenomena showed no obvious correlation.

Research in space physics at the University of Iowa. [energetic particles and electric, magnetic, and electromagnetic fields

NASA Technical Reports Server (NTRS)

Vanallen, J. A.

1978-01-01

Specific fields of current investigation by satellite observation and ground-based radio-astronomical and optical techniques are discussed. Topics include: aspects of energetic particles trapped in the earth's magnetic field and transiently present in the outer magnetosphere and the solar, interplanetary, and terrestrial phenomena associated with them; plasma flows in the magnetosphere and the ionospheric effects of particle precipitation, with corresponding studies of the magnetosphere of Jupiter, Saturn, and possibly Uranus; the origin and propagation of very low frequency radio waves in the earth's magnetosphere and ionosphere; solar particle emissions and their interplanetary propagation and acceleration; solar modulation and the heliocentric radial dependence of the intensity of galactic cosmic rays; radio frequency emissions from the quintescent and flaring sun; shock waves in the interplanetary medium; radio emissions from Jupiter; and radio astronomy of pulsars, flare stars, and other stellar sources.

The Gum nebula

NASA Technical Reports Server (NTRS)

Brandt, J. C.

1972-01-01

The distance from the sun to the center of the star, Gamma Velorium, is determined in an effort to draw a physical model and identify the ionized energy source of the Gum nebula. The distance is calculated from the local hydrogen density of radio astronomy studies and the hydrogen measure.

Free radical OH, a molecule of astrophysical and aeronomic interest. [radio sources (astronomy) - spectroscopic analysis

NASA Technical Reports Server (NTRS)

Mohan, H.; SHARDANAND

1975-01-01

The chemistry and physics of the gaseous OH free radical as it applies to interstellar space, planetary atmospheres, and the sun is presented. Topics considered are: (1) rotational-vibrational transitions; (2) dissociation and ionization processes; (3) spectral characteristics.

The science case for simultaneous mm-wavelength receivers in radio astronomy

NASA Astrophysics Data System (ADS)

Dodson, Richard; Rioja, María J.; Jung, Taehyun; Goméz, José L.; Bujarrabal, Valentin; Moscadelli, Luca; Miller-Jones, James C. A.; Tetarenko, Alexandra J.; Sivakoff, Gregory R.

2017-11-01

This review arose from the European Radio Astronomy Technical Forum (ERATec) meeting held in Firenze, October 2015, and aims to highlight the breadth and depth of the high-impact science that will be aided and assisted by the use of simultaneous mm-wavelength receivers. Recent results and opportunities are presented and discussed from the fields of: continuum VLBI (observations of weak sources, astrometry, observations of AGN cores in spectral index and Faraday rotation), spectral line VLBI (observations of evolved stars and massive star-forming regions) and time domain observations of the flux variations arising in the compact jets of X-ray binaries. Our survey brings together a large range of important science applications, which will greatly benefit from simultaneous observing at mm-wavelengths. Such facilities are essential to allow these applications to become more efficient, more sensitive and more scientifically robust. In some cases without simultaneous receivers the science goals are simply unachievable. Similar benefits would exist in many other high frequency astronomical fields of research.

The Search for Extraterrestrial Intelligence in the 1960s: Science in Popular Culture

NASA Astrophysics Data System (ADS)

Smith, Sierra

2012-01-01

Building upon the advancement of technology during the Second World War and the important scientific discoveries which have been made about the structure and components of the universe, scientists, especially in radio astronomy and physics, began seriously addressing the possibility of extraterrestrial intelligence in the 1960s. The Search for Extraterrestrial Intelligence (SETI) quickly became one of the most controversial scientific issues in the post Second World War period. The controversy played out, not only in scientific and technical journals, but in newspapers and in popular literature. Proponents for SETI, including Frank Drake, Carl Sagan, and Philip Morrison, actively used a strategy of engagement with the public by using popular media to lobby for exposure and funding. This paper will examine the use of popular media by scientists interested in SETI to popularize and heighten public awareness and also to examine the effects of popularization on SETI's early development. My research has been generously supported by the National Radio Astronomy Observatory.

Internet Resources for Radio Astronomy

NASA Astrophysics Data System (ADS)

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.

GPU-Based High-performance Imaging for Mingantu Spectral RadioHeliograph

NASA Astrophysics Data System (ADS)

Mei, Ying; Wang, Feng; Wang, Wei; Chen, Linjie; Liu, Yingbo; Deng, Hui; Dai, Wei; Liu, Cuiyin; Yan, Yihua

2018-01-01

As a dedicated solar radio interferometer, the MingantU SpEctral RadioHeliograph (MUSER) generates massive observational data in the frequency range of 400 MHz-15 GHz. High-performance imaging forms a significantly important aspect of MUSER’s massive data processing requirements. In this study, we implement a practical high-performance imaging pipeline for MUSER data processing. At first, the specifications of the MUSER are introduced and its imaging requirements are analyzed. Referring to the most commonly used radio astronomy software such as CASA and MIRIAD, we then implement a high-performance imaging pipeline based on the Graphics Processing Unit technology with respect to the current operational status of the MUSER. A series of critical algorithms and their pseudo codes, i.e., detection of the solar disk and sky brightness, automatic centering of the solar disk and estimation of the number of iterations for clean algorithms, are proposed in detail. The preliminary experimental results indicate that the proposed imaging approach significantly increases the processing performance of MUSER and generates images with high-quality, which can meet the requirements of the MUSER data processing. Supported by the National Key Research and Development Program of China (2016YFE0100300), the Joint Research Fund in Astronomy (No. U1531132, U1631129, U1231205) under cooperative agreement between the National Natural Science Foundation of China (NSFC) and the Chinese Academy of Sciences (CAS), the National Natural Science Foundation of China (Nos. 11403009 and 11463003).

The beginnings of radio astronomy in the Netherlands

NASA Astrophysics Data System (ADS)

van Woerden, Hugo; Strom, Richard G.

2006-06-01

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 cm ought to be detectable. Both published material and letters from the Oort Archive have been consulted. Not having direct access to either radar technology or trained engineers, as was the case in countries like England and Australia, Jan Oort had to turn to a diversity of organizations: Philips Electronics Company, the Post Office, and academic colleagues in other disciplines. It was the Post Office's head of radio, A.H. de Voogt, who provided a 7.5 m Würzburg radar reflector and technical support at the Kootwijk station, starting in 1948. We trace the events leading up to the 21 cm line's detection in 1951, and discuss the early results. After a year spent rebuilding and thereby improving the receiver, C.A. Muller, together with Oort, Van de Hulst and others, was able to initiate an extensive HI survey of the Galaxy. The results fully justified the year's wait: a map of the Galaxy, spiral arms, the first rotation curve, and a much improved system of Galactic coordinates. We also present a discussion of Würzburg antennas used for research in the Netherlands, and a brief biography of A.H. de Voogt.

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

NASA Astrophysics Data System (ADS)

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 development is teaching materials and a package for students at this level. The program has also been used to inform the development of educational programs for new telescopes such as the Australian SKA Pathfinder (ASKAP) and the SKA.http://pulseatparkes.atnf.csiro.au/

Young Astronomers and Astronomy teaching in Moldavia

NASA Astrophysics Data System (ADS)

Gaina, Alex

1998-09-01

Curricular Astronomy is taught in Moldavia , except Transnistria and Gagauzia, in the final (11th class) of the secondary schools and gymnasiums, and in the 12th class of the lyceums. The program takes 35 academic hours. The basic book is by Vorontsov-Veliaminov, used in the former USSR, but the Romanian one is also used, in spite of many criticisms addressed to both by our astronomy teachers. In Transinstria (on the left of the Dniester river)astronomy is taught 17 hours. Extracurricular activities develop at the Real Lyceum, where students and amateur astronomers carry out regular observations. Particularly, photographs of the comet Hale-Bopp have been realized using a Cassegrain 450 mm telescope by young astronomers under supervision of S. Luca and D. Gorodetzky (Gorodetchi). Except the telescope from the Real Lyceum other few telescopes are in construction. Unfortunately, no planetarium exists now in Chisinau, since the old one was returned to church. Astronomy courses are taught at the physical and mathematical departments of the Pedagogical University, Transnistrian Moldavian University in Tiraspol and the State University of |Moldavia. Many efforts were made by the State University lecturers and scientists to popularize Astronomy and Astrophysics in the books and in the press, at the radio and TV. No astronomy is taught at the Gagauzian National University in Comrat. No astronomiucal departments exist in Universities of |Moldavia.

High energy particles and quanta in astrophysics

NASA Technical Reports Server (NTRS)

Mcdonald, F. B. (Editor); Fichtel, C. E.

1974-01-01

The various subdisciplines of high-energy astrophysics are surveyed in a series of articles which attempt to give an overall view of the subject as a whole by emphasizing the basic physics common to all fields in which high-energy particles and quanta play a role. Successive chapters cover cosmic ray experimental observations, the abundances of nuclei in the cosmic radiation, cosmic electrons, solar modulation, solar particles (observation, relationship to the sun acceleration, interplanetary medium), radio astronomy, galactic X-ray sources, the cosmic X-ray background, and gamma ray astronomy. Individual items are announced in this issue.

Determining Thunderstorm Electric Fields using Radio Emission from Cosmic-Ray Air Showers

NASA Astrophysics Data System (ADS)

Hare, B.; Scholten, O.; Trinh, G. T. N.; Ebert, U.; Rutjes, C.

2017-12-01

We report on a novel non-intrusive way to investigate electric fields in thunderclouds.Energetic cosmic rays penetrating the atmosphere create a particle avalanche called an extensive air shower. The front of the shower is a plasma cloud that contains 10^6 or more free electrons and positrons moving towards the Earth's surface at the speed of light. The electric fields that exists in thunderclouds induces electric currents in the plasma cloud that emit radio waves. The radio footprint for intensity, linear and circular polarization thus contains the finger print of the atmospheric electric fields along the path of the air shower.Here we report on the analysis of many cosmic-ray radio footprints as have been measured at LOFAR, a dense array of simple radio antennas (several thousands of dual-polarized antennas) primarily developed for radio-astronomy observations. We show that this method can be used to determine the charge structure in thunderclouds and discuss the accuracy of the method. We have observed seasonal dependencies.

Detection of fundamental and harmonic type III radio emission and the associated Langmuir waves at the source region

NASA Technical Reports Server (NTRS)

Reiner, M. J.; Stone, R. G.; Fainberg, J.

1992-01-01

Type III radio emission generated in the vicinity of the Ulysses spacecraft has been detected at both the fundamental and harmonic of the local plasma frequency. The observations represent the first clear evidence of locally generated type III radio emission. This local emission shows no evidence of frequency drift, exhibits a relatively short rise time, is less intense than the observed remotely generated radio emission, and is temporally correlated with observed in situ Langmuir waves. The observations were made with the unified radio astronomy and wave (URAP) experiment on the Ulysses spacecraft between 1990 November 4 and 1991 April 30, as it traveled from 1 to 3 AU from the sun. During this time period many thousands of bursts were observed. However, only three examples of local emission and associated Langmuir waves were identified. This supports previous suggestions that type III radio emission is generated in localized regions of the interplanetary medium, rather than uniformly along the extent of the electron exciter beam.

The Telecommunications and Data Acquisition Report

NASA Technical Reports Server (NTRS)

Posner, E. C. (Editor)

1990-01-01

Archival reports are given on developments in programs managed by JPL's Office of Telecommunications and Data Acquisition (TDA), including space communications, radio navigation, radio science, ground-based radio and radar astronomy, and the Deep Space Network (DSN) and its associated Ground Communications Facility (GCF) in planning, supporting research and technology, implementation, and operations. Also included is TDA-funded activity at JPL on data and information systems and reimbursable DSN work performed for other space agencies through NASA. In the search for extraterrestrial intelligence (SETI), implementation and operations for searching the microwave spectrum are reported. Use of the Goldstone Solar System Radar for scientific exploration of the planets, their rings and satellites, asteroids, and comets are discussed.

A Cryogenic SiGe Low-noise Amplifier Optimized for Phased-array Feeds

NASA Astrophysics Data System (ADS)

Groves, Wavley M., III; Morgan, Matthew A.

2017-08-01

The growing number of phased-array feeds (PAF) being built for radio astronomy demonstrates an increasing need for low-noise amplifiers (LNA), which are designed for repeatability, low noise, and ease of manufacture. Specific design features that help to achieve these goals include the use of unpackaged transistors (for cryogenic operation); single-polarity biasing; straight plug-in radio frequency (RF) interfaces to facilitate installation and re-work; and the use of off-the-shelf components. The focal L-band array for the Green Bank Telescope (FLAG) is a cooperative effort by Brigham Young University and the National Radio Astronomy Observatory using warm dipole antennae and cryogenic Silicon Germanium Heterojunction Bipolar Transistor (SiGe HBT) LNAs. These LNAs have an in band gain average of 38 dB and 4.85 Kelvin average noise temperature. Although the FLAG instrument was the driving instrument behind this development, most of the key features of the design and the advantages they offer apply broadly to other array feeds, including independent-beam and phased, and for many antenna types such as horn, dipole, Vivaldi, connected-bowtie, etc. This paper focuses on the unique requirements array feeds have for low-noise amplifiers and how amplifier manufacturing can accommodate these needs.

SwaMURAy - Swapping Memory Unit for Radio Astronomy

NASA Astrophysics Data System (ADS)

Winberg, Simon

2016-03-01

This paper concerns design and performance testing of an HDL module called SwaMURAy that is a configurable, high-speed data sequencing and flow control module serving as an intermediary between data acquisition and subsequent processing stages. While a FIFO suffices for many applications, our case needed a more elaborate solution to overcome legacy design limitations. The SwaMURAy is designed around a system where a block of sampled data is acquired at a fast rate and is then distributed among multiple processing paths to achieve a desired overall processing rate. This architecture provides an effective design pattern around which various software defined radio (SDR) and radio astronomy applications can be built. This solution was partly in response to legacy design restrictions of the SDR platform we used, a difficulty likely experienced by many developers whereby new sampling peripherals are inhibited by legacy characteristics of an underlying reconfigurable platform. Our SDR platform had a planned lifetime of at least five years as a complete redesign and refabrication would be too costly. While the SwaMURAy overcame some performance problems, other problems arose. This paper overviews the SwaMURAy design, performance improvements achieved in an SDR case study, and discusses remaining limitations and workarounds we expect will achieve further improvements.

Chimenea and other tools: Automated imaging of multi-epoch radio-synthesis data with CASA

NASA Astrophysics Data System (ADS)

Staley, T. D.; Anderson, G. E.

2015-11-01

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, of the sort typically acquired for transient surveys or follow-up. The algorithm aims to improve upon standard imaging pipelines by utilizing iterative RMS-estimation and automated source-detection to avoid so called 'Clean-bias', and makes 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. While targeted at automated imaging, the drive-casa interface can also be used to automate interaction with any of the CASA subroutines from a generic Python process. Additionally, these packages may be of wider technical interest beyond radio-astronomy, since they demonstrate use of the Python library pexpect to emulate terminal interaction with an external process. This approach allows for rapid development of a Python interface to any legacy or externally-maintained pipeline which accepts command-line input, without requiring alterations to the original code.

Found: The Original 1945 Records of Australian Radio Astronomy

NASA Astrophysics Data System (ADS)

Goss, Miller; Ekers, Ron; Sim, Helen

2015-08-01

In July 2014, we found the original records of the first published Australian radio astronomy observations. These were obtained by Joseph L. Pawsey and Ruby Payne-Scott in early October 1945. The observations gave strong evidence of a million degree corona as well as frequent radio bursts.These observations followed earlier detections of the radio sun by Stanley Hey, George Southworth, Grote Reber and Elizabeth Alexander. The latter observations (the "Norfolk Island Effect" of March 1945) were the immediate motivation for the campaign carried out by Pawsey and Payne-Scott.These observations formed the basis for a number of pioneering publications: the 9 February 1946 Nature paper of Pawsey, Payne-Scott and McCready which was submitted on the last date on which data was obtained on 23 October 1945, the major publication of the initial Australian radio solar publication in the Proceedings of the Royal Society of London in August 1947 and Pawsey's presentation of the radio properties of the million degree corona in the Nature of 2 November 1946. Contemporaneously with these publications, D. F.Martyn was involved in an independent theoretical study of the properties of the solar corona.(Ginzburg and Shklovsky were also involved in this era in a study of the properties of the corona.) The back-to-back Martyn and Pawsey Nature papers were the first that described the radio properties of the hot corona, due to free-free emission. The division of the observed emission into "bursting" and "quiet" modes was challenging for the novice radio astronomers.These historical records had been recognized by Paul Wild in 1968, who instructed the CSIRO Division of Radiophysics secretary to E.("Taffy") G. Bowen, Ms. Sally Atkinson, to submit these to the Australian Academy of Science. Wild characterized these documents as "of considerable historical interest". Apparently the transmission of the documents was not done; a thorough search of the Australian Academy Library in August 2014 failed to locate them. The original papers were only found in Ms. Atkinson's files after her death on 13 November 2012 in Sydney.

Big Computing in Astronomy: Perspectives and Challenges

NASA Astrophysics Data System (ADS)

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 a distinguished doctorate and a Habilitation degree in Computer Science from the University of Karlsruhe. Contact him at pankrat@mit.edu, victorpankratius.com, or Twitter @vpankratius.

Astronomy Camp = IYA x 22: 22 Years of International Astronomy Education

NASA Astrophysics Data System (ADS)

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.

LEAP: Looking beyond pixels with continuous-space EstimAtion of Point sources

NASA Astrophysics Data System (ADS)

Pan, Hanjie; Simeoni, Matthieu; Hurley, Paul; Blu, Thierry; Vetterli, Martin

2017-12-01

Context. Two main classes of imaging algorithms have emerged in radio interferometry: the CLEAN algorithm and its multiple variants, and compressed-sensing inspired methods. They are both discrete in nature, and estimate source locations and intensities on a regular grid. For the traditional CLEAN-based imaging pipeline, the resolution power of the tool is limited by the width of the synthesized beam, which is inversely proportional to the largest baseline. The finite rate of innovation (FRI) framework is a robust method to find the locations of point-sources in a continuum without grid imposition. The continuous formulation makes the FRI recovery performance only dependent on the number of measurements and the number of sources in the sky. FRI can theoretically find sources below the perceived tool resolution. To date, FRI had never been tested in the extreme conditions inherent to radio astronomy: weak signal / high noise, huge data sets, large numbers of sources. Aims: The aims were (i) to adapt FRI to radio astronomy, (ii) verify it can recover sources in radio astronomy conditions with more accurate positioning than CLEAN, and possibly resolve some sources that would otherwise be missed, (iii) show that sources can be found using less data than would otherwise be required to find them, and (iv) show that FRI does not lead to an augmented rate of false positives. Methods: We implemented a continuous domain sparse reconstruction algorithm in Python. The angular resolution performance of the new algorithm was assessed under simulation, and with visibility measurements from the LOFAR telescope. Existing catalogs were used to confirm the existence of sources. Results: We adapted the FRI framework to radio interferometry, and showed that it is possible to determine accurate off-grid point-source locations and their corresponding intensities. In addition, FRI-based sparse reconstruction required less integration time and smaller baselines to reach a comparable reconstruction quality compared to a conventional method. The achieved angular resolution is higher than the perceived instrument resolution, and very close sources can be reliably distinguished. The proposed approach has cubic complexity in the total number (typically around a few thousand) of uniform Fourier data of the sky image estimated from the reconstruction. It is also demonstrated that the method is robust to the presence of extended-sources, and that false-positives can be addressed by choosing an adequate model order to match the noise level.

Automated radio astronomy operations

NASA Technical Reports Server (NTRS)

Livermore, R. W.

1978-01-01

The improvements in using a computer to drive a DSN 64-meter antenna are described. The development is used to simplify operation, improve antenna safety, reduce antenna wear, present the abuse of antenna by misoperation, increase quantity and quality of data gathered, and give users a greater choice of automatic operations.

The Pulsar Search Collaboratory

ERIC Educational Resources Information Center

Rosen, R.; Heatherly, S.; McLaughlin, M. A.; Kondratiev, V. I.; Boyles, J. R.; Wilson, M.; Lorimer, D. R.; Lynch, R.; Ransom, S.

2010-01-01

The Pulsar Search Collaboratory (PSC) (NSF #0737641) is a joint project between the National Radio Astronomy Observatory and West Virginia University designed to interest high school students in science, technology, engineering, and mathematics related career paths by helping them to conduct authentic scientific research. The 3 year PSC program,…

Asteroids, Comets, Meteors 1991

NASA Technical Reports Server (NTRS)

Harris, Alan W. (Editor); Bowell, Edward (Editor)

1992-01-01

Papers from the conference are presented and cover the following topics with respect to asteroids, comets, and/or meteors: interplanetary dust, cometary atmospheres, atmospheric composition, comet tails, astronomical photometry, chemical composition, meteoroid showers, cometary nuclei, orbital resonance, orbital mechanics, emission spectra, radio astronomy, astronomical spectroscopy, photodissociation, micrometeoroids, cosmochemistry, and interstellar chemistry.

Minicourses in Astrophysics, Modular Approach, Vol. I.

ERIC Educational Resources Information Center

Illinois Univ., Chicago.

This is the first volume of a two-volume minicourse in astrophysics. It contains chapters on the following topics: planetary atmospheres; X-ray astronomy; radio astrophysics; molecular astrophysics; and gamma-ray astrophysics. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are included with…

Continent-Spanning Radio Telescope Blazes Trails At the Frontiers of Astrophysics

NASA Astrophysics Data System (ADS)

1999-06-01

The supersharp radio "vision" of the National Science Foundation's (NSF) Very Long Baseline Array (VLBA) is revealing unprecedented details of astronomical objects from stars in our own cosmic neighborhood to galaxies billions of light-years away. Astronomers from across North America and beyond are presenting the results of VLBA research at the American Astronomical Society's (AAS) meeting in Chicago. "The VLBA is one of the most powerful tools in the world for astronomy," said Paul Vanden Bout, Director of the National Radio Astronomy Observatory (NRAO), which operates the VLBA. "It can produce images hundreds of times more detailed than those produced by the Hubble Space Telescope, and that capability has yielded some spectacular scientific results." Examples of VLBA research presented at the AAS meeting include the most accurate measurement ever made of the distance to another galaxy; the detection of our Solar System's orbital motion around the center of our own Galaxy; a "movie" showing the expansion of debris from a star's explosion in a galaxy 11 million light-years away; and a "movie" of gas motions in the atmosphere of a star more than 1,000 light-years away -- the first time gas motions have ever been tracked in a star other than the Sun. With ten giant dish antennas spread from Hawaii in the Pacific to St. Croix in the Caribbean, all working together as a single telescope, the VLBA is "the world's biggest astronomical instrument," Vanden Bout said. The VLBA has been in full operation for more than five years. A pair of sessions at the AAS meeting is devoted to reports of research using the VLBA. In more than 40 scientific presentations, astronomers tell how they used the VLBA to gain valuable new information about nearly every area from the frontiers of astrophysics. Some of those reporting on their VLBA research are graduate students working on their Ph.D degrees. "We are particularly proud that this instrument, one of the world's premier facilities for astronomy, is being used by the next generation of astronomers," said Miller Goss, NRAO's Director for VLA/VLBA Operations. "In addition, we are telling astronomers who have not yet used the VLBA how we can help them use it for their own research." As a national facility provided by the NSF, the VLBA is available free of charge to scientists, based on peer review of their proposed observing projects. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Sky Survey Provides New Radio View of Universe

NASA Astrophysics Data System (ADS)

2004-10-01

Astronomers using the National Science Foundation's Very Large Array (VLA) have overcome longstanding technical hurdles to map the sky at little-explored radio frequencies that may provide a tantalizing look deep into the early Universe. The scientists have released images and data covering half of the sky visible from the VLA, and hope to complete their survey within a year. Radio Galaxies A "rogues' gallery" of radio galaxy types seen in the VLSS. CREDIT: NRAO/AUI/NSF (Click on Image for Graphics Page) The VLA Low-frequency Sky Survey (VLSS) is producing sky images made at an observing frequency of 74 MHz, a far lower frequency than used for most current radio-astronomy research. "Because of the Earth's ionosphere, such a low frequency has proven very difficult for high-quality imaging, and it is only in the past few years that we have developed the techniques that make a project like the VLSS possible," said Rick Perley, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Because the high-quality VLSS images will give astronomers a look at the Universe through what essentially is a new "window," they expect the images to reveal some rare and important objects. "We expect to find very distant radio galaxies -- galaxies spewing jets of material at nearly light speed and powered by supermassive black holes," said Joseph Lazio of the Naval Research Laboratory in Washington, DC. "By determining just how distant these radio galaxies are, we will learn how early the black holes formed in the history of the Universe," he added. Another tantalizing possibility is that the low-frequency images may reveal "halos" and "relics" produced by collisions of galaxies in clusters. If the halos and relics are found in the distant, and thus early, Universe, it will give scientists important clues about the timetable for formation of large-scale structure. In addition, the astronomers hope that the VLSS images may show previously-undiscovered pulsars -- superdense, spinning neutron stars. Massive planets -- "super Jupiters" circling stars beyond the Sun -- also might reveal themselves through bursts of radio emission at the frequency of this survey, the astronomers speculated. Images from the survey are being made available to other scientists as soon as they are completed. The survey will use some 800 hours of VLA observing time. The newly-released images and data are available via the NRAO Web site. "By doing this survey and making the results available, we are bringing low-frequency radio data, previously quite difficult to produce, to all astronomers in a simple and easy manner," Perley said. "We also expect that this survey will spur additional research into objects that scientists find puzzling or interesting," Perley saidd. "We really will have to wait for years to know the full scientific benefit of this survey," he said. In addition to Perley and Lazio, the VLSS team includes James Condon and William Cotton of NRAO; Aaron Cohen and Wendy Lane of the National Research Council and the Naval Research Laboratory; Namir Kassim of the Naval Research Laboratory; and William Erickson of the University of Maryland and University of Tasmania. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Overview of lunar-based astronomy

NASA Technical Reports Server (NTRS)

Smith, Harlan J.

1988-01-01

The opportunities along with the advantages and disadvantages of the Moon for astronomical observatories are carefully and methodically considered. Taking a relatively unbiased approach, it was concluded that lunar observatories will clearly be a major factor in the future of astronomy in the next century. He concludes that ground based work will continue because of its accessibility and that Earth orbital work will remain useful, primarily for convenience of access in constructing and operating very large space systems. Deep space studies will feature not only probes but extensive systems for extremely long baseline studies at wavelengths from gamma rays through visible and IR out to radio is also a conclusion drawn, along with the consideration that lunar astronomy will have found important permanent applications along lines such as are discussed at the present symposium and others quite unsuspected today.

Launching Light: Beyond the Bulb for the United Nations' International Year of Light 2015

NASA Astrophysics Data System (ADS)

Arcand, K. K.; Watzke, M.

2015-09-01

In astronomy, light is the language used to understand the Universe. From radio waves to gamma rays, light in all its forms delivers information that helps astronomers learn about the Universe. When the United Nations declared 2015 to be the International Year of Light and Light-based Technologies (IYL2015), it presented an opportunity to share the role that light plays in astronomy and beyond. The IYL2015 also offered a chance to build on experiences and sustain networks from the International Year of Astronomy in 2009. Light: Beyond the Bulb is an IYL2015 project that melds both of these goals. The project takes the form of an exhibit that showcases what light can do, from here on Earth and across the vastness of space, hosted by volunteer networks in public spaces for informal science learning.

Studying AGN Jets At Extreme Angular Resolution

NASA Astrophysics Data System (ADS)

Bruni, Gabriele

2016-10-01

RadioAstron is a 10m antenna orbiting on the Russian Speckt-R spacecraft, launched in 2011. Performing radio interferometry with a global array of ground telescopes, it is providing record angular resolution. The Key Science Project on AGN polarization is exploiting it to study in great detail the configuration of magnetic fields in AGN jets, and understand their formation and collimation. To date, the project has already achieved the highest angular resolution image ever obtained in Astronomy, and detected brightness temperatures exceeding the ones predicted by theory of AGN.

Enormous Disc of Cool Gas Surrounding the Nearby Powerful Radio Galaxy NGC 612 (PKS 0131-36)

DTIC Science & Technology

2008-05-22

galaxies in clus- ters appear to be much more devoid of H I gas, as sug- gested by a recent H I survey of the VIRGO cluster by di Serego Alighieri et...120th Street, New York, N.Y. 10027, USA 2Netherlands Foundation for Research in Astronomy, Postbus 2, 7990 AA Dwingeloo, the Netherlands 3Kapteyn...NGC 612. This paper is part of an ongoing study to map the large-scale neutral hydrogen properties of nearby radio galaxies and it presents the first

Indirect observation of unobservable interstellar molecules

NASA Technical Reports Server (NTRS)

Herbst, E.; Green, S.; Thaddeus, P.; Klemperer, W.

1977-01-01

It is suggested that the abundances of neutral non-polar interstellar molecules unobservable by radio astronomy can be systematically determined by radio observation of the protonated ions. As an example, observed N2H(+) column densities are analyzed to infer molecular nitrogen abundances in dense interstellar clouds. The chemistries and expected densities of the protonated ions of O2, C2, CO2, C2H2 and CH4 are then discussed. Microwave transition frequencies fo HCO2(+) and C2H3(+) are estimated, and a preliminary astronomical search for HCO2(+) is described.

Radio Spectrum Management in the Asia-Pacific Region

NASA Astrophysics Data System (ADS)

Tzioumis, T.

2004-06-01

The Asia-Pacific region comprises countries in ITU-R Region 3 from South and East Asia, Oceania and the Pacific islands, while excluding the Americas. Organizations in the Asia- Pacific region face special challenges in coping with the very diverse cultures and languages of the different nations. Telecommunications in each country are usually administered by a single National Communications Administration. These administrations participate in a number of regional umbrella organizations which promote cooperation in the development of communications in the Asia-Pacific. Those with relevance to radio astronomy are briefly oulined in this paper.

Radio Videos of Orion Protostars (with X-ray Colors!)

NASA Astrophysics Data System (ADS)

Forbrich, Jan; Wolk, Scott; Menten, Karl; Reid, Mark; Osten, Rachel

2013-07-01

High-energy processes in Young Stellar Objects (YSOs) can be observed both in X-rays and in the centimetric radio wavelength range. While the past decade has brought a lot of progress in the field of X-ray observations of YSOs, (proto)stellar centimetric radio astronomy has only recently begun to catch up with the advent of the newly expanded Karl G. Jansky Very Large Array (JVLA). The enhanced sensitivity is fundamentally improving our understanding of YSO radio properties by providing unprecedented sensitivity and thus spectral as well as temporal resolution. As a result, it is becoming easier to disentangle coronal-type nonthermal radio emission emanating from the immediate vicinity of YSOs from thermal emission on larger spatial scales, for example ionized material at the base of outflows. Of particular interest is the correlation of the by now relatively well-characterized X-ray flaring variability with the nonthermal radio variability. We present first results of multi-epoch simultaneous observations using Chandra and the JVLA, targeting the Orion Nebula Cluster and highlighting the capabilities of the JVLA for radio continuum observations of YSOs.

A theory for narrow-banded radio bursts at Uranus - MHD surface waves as an energy driver

NASA Technical Reports Server (NTRS)

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.

System of the optic-electronic sensors for control position of the radio telescope elements

NASA Astrophysics Data System (ADS)

Konyakhin, Igor; Stepashkin, Ivan; Petrochenko, Andrey

2016-04-01

A promising area of modern astronomy is the study of the field of millimeter waves. The use of this band is due to a large extent the spectrum characteristics of the propagation of waves in the atmosphere, short wavelength. Currently, Russia jointly with Uzbekistan is implementing a project to build a radio astronomy observatory on the Suffa plateau (Uzbekistan). The main instrument of the observatory is fully steerable radio telescope RT-70 type. Main mirror telescope is a fragment of an axisymmetric parabolic with a focal length of 21 m, consisting of 1200 reflecting panels; main mirror diameter - 70 m; diameter of counter reflector - 3 m. A feature of the radio telescope as a means of research in the millimeter wavelength range are high for the quality requirements parabolic surface of the primary mirror (standard deviation of points on the surface of the theoretical parabolic is not more than 0.05 mm), to the stability of the mutual arrangement of the primary mirror and the counter reflector (not more than 0, 07 mm) for precision guidance in the corners of the mirror system azimuth and elevation (margin of error 1.5-2"). Weight of structure, temperature changes and air shock result in significant deformation elements radio telescope construction (progressive linear displacements of points of the surface of the main mirror), reaching in the marginal zone of 30 mm; counter reflector shift of up to 60 mm; Unlike the angular position of the axis of the beam pattern of the radio telescope of the measured angle transducers can reach 10 ". Therefore, to ensure the required quality of the reflective elements RT-70 systems, as well as the implementation of precision-guided munitions needs complex measuring deformation elements telescope design. This article deals with the construction of opto-electronic system of remote optoelectronic displacement sensor control elements mirror telescope system.

The proposed NRAO millimeter array and its use for solar studies

NASA Technical Reports Server (NTRS)

Kundu, Mukul R.

1986-01-01

A brief summary is given of the proposed National Radio Astronomy Observatory (NRAO) Millimeter Array discussed at a workshop held in Green Bank, W. Va., September 30 to October 2, 1985. A brief description of the solar studies that can be made with such an array is provided.

Erratum: Retraction Note to: "The Second Version of the OCARS Catalog of Optical Characteristics of Astrometric Radio Sources" [Astronomy Reports 60, 996 (2016)

NASA Astrophysics Data System (ADS)

Malkin, Z. M.

2018-04-01

The Editor-in-Chief is retracting this article [1] because data from the RFC catalog, http://astrogeo.org/rfc, were used without permission from the copyright holder. The author admitted the decision to retract.

Author Correction: A massive core for a cluster of galaxies at a redshift of 4.3.

PubMed

Miller, T B; Chapman, S C; Aravena, M; Ashby, M L N; Hayward, C C; Vieira, J D; Weiß, A; Babul, A; Béthermin, M; Bradford, C M; Brodwin, M; Carlstrom, J E; Chen, Chian-Chou; Cunningham, D J M; De Breuck, C; Gonzalez, A H; Greve, T R; Harnett, J; Hezaveh, Y; Lacaille, K; Litke, K C; Ma, J; Malkan, M; Marrone, D P; Morningstar, W; Murphy, E J; Narayanan, D; Pass, E; Perry, R; Phadke, K A; Rennehan, D; Rotermund, K M; Simpson, J; Spilker, J S; Sreevani, J; Stark, A A; Strandet, M L; Strom, A L

2018-06-21

Change history: In this Letter, the Acknowledgements section should have included the following sentence: "The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.". This omission has been corrected online.

The Medicina Station Status Report

NASA Technical Reports Server (NTRS)

Orfei, Alessandro; Orlati, Andrea; Maccaferri, Giuseppe

2013-01-01

General information about the Medicina Radio Astronomy Station, the 32-m antenna status, and the staff in charge of the VLBI observations is provided. In 2012, the data from geodetic VLBI observations were acquired using the Mark 5A recording system with good results. Updates of the hardware were performed and are briefly described.

Summary of spacecraft technology, systems reliability, and tracking data acquisition

NASA Technical Reports Server (NTRS)

1973-01-01

Goddard activities are reported for 1973. An eight-year flight schedule for projected space missions is presented. Data acquired by spacecraft in the following disciplines are described: stellar ultraviolet, stellar X-rays, stellar gamma rays, solar radiation, radio astronomy, particles/fields, magnetosphere, aurora, and the upper atmosphere.

Potential Improvements to VLBA UV-Coverages by the Addition of a 32-m Peruvian Antenna

NASA Astrophysics Data System (ADS)

Horiuchi, S.; Murphy, D. W.; Ishitsuka, J. K.; Ishitsuka, M.

2005-12-01

A plan is being currently developed to convert a 32-m telecomunications antenna in the Peruvian Andes into a radio astronomy facility. Significant improvements to stand-alone VLBA UV-coverages can be obtained with the addition of this southern hemisphere telescope to VLBA observations.

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

NASA Astrophysics Data System (ADS)

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.

National Science Board Approves VLA Expansion

NASA Astrophysics Data System (ADS)

2001-11-01

The National Science Board, the governing body for the National Science Foundation (NSF), has approved an expansion project for the Very Large Array (VLA) radio telescope in New Mexico. The board recommended an NSF award of approximately 58.3 million for the project over the next decade. The action came at the Board's meeting in Washington on Nov. 15. The Very Large Array The Very Large Array "This approval means that the VLA, already the most scientifically productive ground-based telescope in all of astronomy, will remain at the cutting edge of astrophysical research through the coming decades," said Paul Vanden Bout, director of the National Radio Astronomy Observatory (NRAO). The expansion project will replace aging equipment left over from the VLA's construction during the 1970s with modern technology, improving the VLA's scientific capabilities more than tenfold. Using the existing 27 dish antennas, each weighing 230 tons, the Expanded VLA will have greatly improved ability to image distant celestial objects and to decipher the physical nature of those objects. In addition to the 58.3 million NSF allocation, the governments of Canada and Mexico plan to provide funding for the VLA expansion. The VLA Expansion Project was formally proposed to the NSF, which owns the VLA, last year. Also last year, the project received a strong endorsement from the Astronomy and Astrophysics Survey Committee of the National Research Council, the working arm of the National Academies of Sciences and Engineering. That committee had been given the task of setting nationwide priorities for astronomy spending over the next decade. The Survey Committee report listed the Expanded VLA as an important contributor to new understanding in three high-priority research areas for the next decade: studies of star and planet formation; research into black holes; and unraveling details about the "dawn of the modern universe." Dedicated in 1980, the VLA is the most powerful, flexible and widely- used radio telescope in the world. It brought dramatically-improved observational capabilities to the scientific community two decades ago, and has contributed significantly to nearly every branch of astronomy. More than 2,200 scientists have used the VLA for more than 10,000 separate observing projects. Astronomers seek more than twice as much VLA observing time than can be provided. Since the VLA's dedication, many technical improvements have made it much more capable than its original design contemplated. However, some of the technologies incorporated into the VLA during its construction, while highly advanced for their time, now limit its capabilities. The VLA Expansion Project will replace those older technologies with modern technology, allowing the VLA to realize its full potential as a tool for scientific research. "Keeping the VLA at the forefront of technology is an important priority, and we are fortunate that Sen. Pete Domenici (R-NM) has recognized this for many years. We appreciate his longtime support for this valuable scientific facility," Vanden Bout said. "Senator Domenici is one of the VLA's strongest advocates, and as a leader in the U.S. Senate, has continually supported the VLA and its expansion in Congress and the Federal Government," Vanden Bout added. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Astronomy Education and Popularization Facilities at Guanajuato University in Mexico

NASA Astrophysics Data System (ADS)

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.