Science.gov

Sample records for nuffield radio astronomy

  1. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Wolken, P. R.; Schaffer, R. D.; Gorenstein, M. V.

    1981-01-01

    The activities of the Deep Space Network in support of Radio Astronomy Operations during April and May 1981 are reported. Work in progres in support of an experiment selected for use of the DSN by the Radio Astronomy Experiment Selection Panel, Twin Quasi-Stellar Object VLBI, is reported.

  2. 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.

  3. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Shaffer, R. D.; Wolken, P. R.; Gulkis, S.

    1981-01-01

    The activities of the Deep Space Network in support of radio astronomy operations during the first quarter of 1981 are reported. Results of the use of a low noise maser are presented, as well as updates in DSN support of experiments sanctioned by the Radio Astronomy Experiment Selection Panel.

  4. Radio Astronomy

    NASA Technical Reports Server (NTRS)

    Shaffer, R. D.; Wolken, P. R.; Niell, A. E.

    1981-01-01

    The activities of the DSN in support of Radio and Radar Astronomy Operations during September through December 1980 are described. Emphasis is on a report of an experiment selected for use of the DSN by the radio Astronomy Experiment Selection Panel: that of VLBI observations of the energetic galactic object SS-433.

  5. 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.

  6. Radio Astronomy

    NASA Technical Reports Server (NTRS)

    Wolken, P. R.; Shaffer, R. D.

    1983-01-01

    Deep Space Network (DSN) 26- and 64-meter antenna stations were utilized in support of Radio Astronomy Experiment Selection Panel experiments. Within a time span of 10 days, in May 1983 (267.75 hours total), nine RAES experiments were supported. Most of these experiments involved multifacility interferometry using Mark 3 data recording terminals and as many as six non-DSN observatories. Investigations of black holes, quasars, galaxies, and radio sources are discussed.

  7. Torun Radio Astronomy Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Torun Center for Astronomy is located at Piwnice, 15 km north of Torun, Poland. A part of the Faculty of Physics and Astronomy of the Nicolaus Copernicus University, it was created by the union of Torun Radio Astronomy Observatory (TRAO) and the Institute of Astronomy on 1 January 1997....

  8. Radio astronomy with microspacecraft

    NASA Technical Reports Server (NTRS)

    Collins, D.

    2001-01-01

    A dynamic constellation of microspacecraft in lunar orbit can carry out valuable radio astronomy investigations in the frequency range of 30kHz--30MHz, a range that is difficult to explore from Earth. In contrast to the radio astronomy ivestigations that have flown on individual spacecraft, the four microspacecraft together with a carrier spacecraft, which transported them to lunar orbit, form an interferometer with far superior angular resolution. Use of microspacecraft allows the entire constellation to be launched with a Taurus-class vehicle. Also distinguishing this approach is that the Moon is used as needed to shield the constellation from RF interference from the Earth and Sun.

  9. 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.

  10. 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

  11. Soviet radio telescopes and solar radio astronomy

    NASA Astrophysics Data System (ADS)

    Alekseev, V. A.; Gel'Freikh, Georgii B.; Zaitsev, Valerii V.; Iliasov, Iurii P.; Kaidanovskii, N. L.

    Soviet radio telescopes of different type and purpose are described, with particular emphasis on very long baseline interferometry. Soviet radio-astronomy studies of solar radio emission and the interplanetary medium are also discussed, with particular attention given to the investigation of the sun's supercorona and the interplanetary plasma.

  12. Division X: Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Nan, Ren-Dong; Taylor, Russ; Rodriguez, Luis F.; Chapman, Jessica; Dubner, Gloria; Garrett, Michael; Goss, W. Miller; Torrelles, Jose M.; Hirabayashi, Hisashi; Carilli, Chris; Hills, Richard; Shastri, Prajval

    2010-05-01

    The business meeting of Division X in the IAU 2009GA took place in three sessions during the day of August 6, 2009. The meeting, being well attended, started with the approval for the meeting agenda. Then the triennium reports were made in the first session by the president of Division X, Ren-Dong Nan, and by the chairs of three working groups: “Historic Radio Astronomy WG” by Wayne Orchiston, “Astrophysically Important Lines WG” by Masatoshi Ohishi, and “Global VLBI WG” by Tasso Tzioumis (proxy chair appointed by Steven Tingay). Afterwards, a dozen reports from observatories and worldwide significant projects have been presented in the second session. Business meeting of “Interference Mitigation WG” was located in the third session.

  13. The future for radio astronomy

    NASA Astrophysics Data System (ADS)

    Breton, Rene P.; Hassall, Tom

    2013-12-01

    THE TRANSIENT UNIVERSE Rene P Breton and Tom Hassall argue that, while radio astronomy has always involved transient phenomena, exploration of this part of the electromagnetic spectrum has been falling behind because of the lack of data. But the advent of a new generation of radio telescopes such as LOFAR, could change that.

  14. Radio Frequency Interference and the National Radio Astronomy Observatory

    NASA Astrophysics Data System (ADS)

    Smith, Sierra

    2014-01-01

    Radio frequency interference (RFI) and radio astronomy have been closely linked since the emergence of radio astronomy as a scientific discipline in the 1930s. Even before the official establishment of the National Radio Astronomy Observatory, protection against contemporary and future radio noise levels was seen as crucial to ensure success of any new observatory. My talk will examine the various local, regional, national, and international efforts enacted to protect NRAO and other American radio astronomy sites from RFI.

  15. Planetary radio astronomy from Voyager

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.

    1983-01-01

    The technique of radio astronomy makes it possible for a remote observer to detect the presence of magnetic fields and plasmas in planetary environments. Prior to the flights of the Voyager spacecraft, radio astronomical studies of Jupiter from earth and from earth orbit had correctly predicted the strength and orientation of Jupiter's magnetic field and trapped radiation belts. The Voyager Planetary Radio Astronomy investigations have now provided measurements of the complete spectrum of low frequency radio emissions from both planets. Each Voyager instrument consists of a pair of orthogonal, 10-m, electric monopole antennas which are connected to a step-tuned, superheterodyne receiver operating over the frequency range from 1.2 kHz to 40.5 MHz. The Voyager trajectory provided observations from above both the sunlit and nightside hemispheres of Jupiter. Saturn's nonthermal radio emission has been observed at frequencies as low as 3 kHz and as high as 1.2 MHz.

  16. The Helios radio astronomy experiment

    NASA Technical Reports Server (NTRS)

    Kayser, S.; Stone, R.

    1984-01-01

    Radio bursts traveling between the Sun and the Earth were tracked by radio astronomy experiments on Helios 1 and 2. A relatively short dipole antenna with a well-defined toroidal reception pattern was flown. The antenna spins in the ecliptic at 60.3 rpm and 2 frequencies are measured in each revolution. The signal analysis determines the strength of the signal, the direction of the source in the ecliptic, and the degree of modulation, and estimates source size. The experiments provide three-dimensional direction finding in space. They extend the radio frequency window beyond what is observable on Earth, and offer a long triangulation baseline.

  17. Division B Commission 40: Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Chapman, Jessica M.; Giovaninni, Gabriele; Taylor, Russell; Carilli, Christopher; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin L.; Lazio, Joseph; Morganti, Rafaella; Nan, Rendong; Rubio, Monica; Shastri, Prjaval; Kellermann, Ken; Ekers, Ronald; Ohishi, Masatoshi

    2016-04-01

    IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the Commission had approximately 1,100 members from 49 countries, corresponding to nearly 10 per cent of the total IAU membership.

  18. Industrial interference and radio astronomy

    NASA Astrophysics Data System (ADS)

    Jessner, A.

    2013-07-01

    The interferer - victim scenario is described for the case of industrial interference affecting radio astronomical observatories. The sensitivity of radio astronomical receivers and their interference limits are outlined. EMC above 30 MHz is a serious problem for Radio Astronomy. Interferer (CISPR) and victim (ITU-R RA 769) standards are not harmonised. The emissions from the interferer and their spectral characteristics are not defined sufficiently well by CISPR standards. The required minimum coupling losses (MCL) between an industrial device and radio astronomical antenna depends on device properties but is shown to exceed 140 dB in most cases. Spatial separation of a few km is insufficient on its own, the terrain must shield > 30-40 dB, additional mitigations such as extra shielding or suppression of high frequency emissions may be necessary. A case by case compatibility analysis and tailored EMC measures are required for individual installations. Aggregation of many weak rfi emitters can become serious problem. If deployment densities are high enough, the emission constraints can even exceed those for a single interferer at a short distance from the radio observatory. Compatibility studies must account not only for the single interferer but also for many widely distributed interference sources.

  19. 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.

  20. Radio Astronomy in Serbia: A Short Review

    NASA Astrophysics Data System (ADS)

    Urosevic, D.

    In this lecture, I presented a short review of: 1. the brief history of development of radio astronomy in Serbia, and 2. the present state of research and university teaching in Serbia on this interesting and modern field of astronomy. Since 1970's, the continuum observations at the lowest radio frequencies (e.g. 38 MHz) and the Galactic radio loops have been represented the topics of main research interest for the first radio astronomer in Serbia, prof. dr Jelena Milogradov-Turin. In 1983, she introduced Radio astronomy as two semester course at 4th year of studies at Department of astronomy, Faculty of Mathematics, University of Belgrade. In this moment we have radio astronomy group with 5 (mainly younger) researchers from Department of Astronomy and Belgrade Astronomical Observatory. The main fields of research interest are, as a part of tradition, the Galactic radio loops and additionally, the hydrodynamic and radio evolution of supernova remnants. Our future projects will be connected with radio evolution of nova remnants and planetary nebulae.

  1. Python Ephemeris Module for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Kuiper, T. B.

    2013-05-01

    An extension of the Python pyephem module was developed for Deep Space Network (DSN) radio astronomy. The class DSS( ) provides the geodetic coordinates of the DSN stations as well as other properties such as antenna diameter. The class Quasar( ) provides positional data for the sources in the National Radio Astronomy Observatory Very Large Array (NRAO VLA) Calibrator Handbook and flux estimates based the University of Michigan Radio Astronomy Observatory (UMRAO) Database or the VLA Calibrator Handbook. Flux calibration data are also available for the bright planets. Class Pulsar( ) provides the data from the Australia Telescope National Facility (ATNF) Pulsar Catalogue in Python format.

  2. 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.

  3. The Golden Years of Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Kellermann, Kenneth I.

    2016-01-01

    The 1960s were the Golden Years of Radio Astronomy. During this decade a new generation of young scientists discovered quasars, pulsars, the cosmic microwave background, cosmic masers, giant molecular clouds, radio source variability, superluminal motion, radio recombination lines, the rotation of Mercury and Venus, the Venus Greenhouse effect, Jupiter's radiation belts, and opened up the high redshift Universe. On the technical side, the 1960s saw the completion of the NRAO 140-ft and 300-ft radio telescopes, the Haystack, Arecibo and Parkes antennas, the Owens Valley Interferometer, the first practical demonstrations of aperture synthesis, VLBI, and CLEAN, the Cambridge 1-mile radio telescope, the most precise tests of GR light bending, and the introduction of the 4th test of GR. Following sessions at the recent IAU 29th General Assembly on the "Golden Years of Radio Astronomy," we will discuss the circumstances surrounding these transformational discoveries which changed the course of modern astronomy.

  4. New vistas in planetary radio astronomy

    NASA Technical Reports Server (NTRS)

    Alexander, J. K., Jr.

    1976-01-01

    Recent progress in planetary radio astronomy is reviewed, where the most significant advances have come from spacecraft observations. The low-frequency radio spectra of the earth, Jupiter, and Saturn are compared, and the striking similarity in shapes is noted. New radio data are examined which provide a way to compare the magnetic field strengths of the planets. More detailed information on the radio structures of Jupiter and Saturn, and possibly on Uranus, is expected from the 1977 Mariner Jupiter-Saturn mission.

  5. A Teaching Lab in Radio Astronomy

    ERIC Educational Resources Information Center

    Smith, Kirk R.; Cudaback, David D.

    1976-01-01

    Describes a study in which participants in a summer institute for secondary science teachers performed a series of experiments with a radio telescope. Concludes that a radio astronomy teaching facility would encourage students to use their own initiative and strategy in working with the scientific concepts involved. (MLH)

  6. 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.

  7. 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

  8. Forty Years of Radio Astronomy at Hartebeesthoek

    NASA Astrophysics Data System (ADS)

    Gaylard, M. J.; Nicolson, G. D.

    2007-07-01

    In 1961 an 85-foot (26-metre) diameter radio antenna was erected at Hartebeesthoek near Johannesburg, as NASA's Deep Space Instrumentation Facility 51. A young South African engineer employed there soon initiated a radio astronomy research programme to use free time between tracking spacecraft. On the closure of the facility by NASA in 1974, it was re-constituted as a radio astronomy observatory operated by the CSIR. In this paper, we highlight various strands of the forty year history of radio astronomy at Hartebeesthoek. We also cover some of the perhaps surprising spinoffs that it has generated, both scientifically and practically. Some of these hark back to measurements taken by the Abbé de la Caille at the Cape in the 1750's, and to the reasons for establishing a Royal Observatory there in the 1820's.

  9. Radio Jove: Jupiter Radio Astronomy for Citizens

    NASA Astrophysics Data System (ADS)

    Higgins, Charles; Thieman, J. R.; Flagg, R.; Reyes, F. J.; Sky, J.; Greenman, W.; Brown, J.; Typinski, D.; Ashcraft, T.; Mount, A.

    2014-01-01

    Radio JOVE is a hands-on educational activity that brings the radio sounds of the Sun, Jupiter, the Milky Way Galaxy, and terrestrial radio noise to students, teachers, and the general public. Participants may build a simple radio telescope kit, make scientific observations, and interact with professional radio observatories in real-time over the Internet. Our website (http://radiojove.gsfc.nasa.gov) includes science information, construction manuals, observing guides, and education resources for teachers and students. Radio Jove is continually expanding its participants with over 1800 kits sold to more than 70 countries worldwide. Recently some of our most dedicated observers have upgraded their Radio Jove antennas to semi-professional observatories. We have spectrographs and wide band antennas, some with 8 MHz bandwidth and some with dual polarization capabilities. In an effort to add to the science literature, these observers are coordinating their efforts to pursue some basic questions about Jupiter’s radio emissions (radio source locations, spectral structure, long term changes, etc.). We can compare signal and ionosphere variations using the many Radio Jove observers at different locations. Observers are also working with members of the Long Wavelength Array Station 1 (LWA1) radio telescope to coordinate observations of Jupiter; Radio Jove is planning to make coordinated observations while the Juno Mission is active beginning in 2015. The Radio Jove program is overviewed, its hardware and software are highlighted, recent sample observations are shown, and we demonstrate that we are capable of real citizen science.

  10. 47 CFR 2.107 - Radio astronomy station notification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  11. 47 CFR 2.107 - Radio astronomy station notification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy...

  12. 47 CFR 2.107 - Radio astronomy station notification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy...

  13. 47 CFR 2.107 - Radio astronomy station notification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy...

  14. 47 CFR 2.107 - Radio astronomy station notification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Radio astronomy station notification. 2.107....107 Radio astronomy station notification. (a) Pursuant to No. 1492 of Article 13 and Section F of Appendix 3 to the international Radio Regulations (Geneva, 1982), operators of radio astronomy...

  15. Early Radio Astronomy in the USSR

    NASA Astrophysics Data System (ADS)

    Kellermann, Kenneth I.

    2007-12-01

    As in many other countries, radio astronomy in the Soviet Union began as an outgrowth of wartime radar research. The early leaders of Soviet radio astronomy, including Simon Braude, Vladimir Kotelnikov, Vladimir Troitskii, and Viktor Vitkevitch, all began their careers during WWII. Although the theoretical contributions of people like Iosef Shklovsky and Vitaly Ginzburg were well known in the West, the early experimental and observational programs received much less attention, partially the result of cold war military secrecy. When they were noticed, the Soviet observations were largely ignored or declared wrong. We will discuss the controversial Soviet contributions to the detection of polarized cosmic radio emission, the development of very long baseline interferometry, the prediction and verification of radio recombination lines, and the first detection of variability in an extragalactic radio source.

  16. National Radio Astronomy International Exchange Program (NINE)

    NASA Astrophysics Data System (ADS)

    Wingate, Lory Mitchell

    2016-01-01

    NINE aims to create synergistic partnerships between NRAO and its US-Based NINE partner institutions and universities, with astronomy-related institutions in other countries. We seek to create a vibrant exchange of students that are interested in learning about activities associated with the radio astronomy field, and to create enduring partnerships that will help train a global, collaborative Science, Technology, Engineering, and Mathematics (STEM) knowledgeable workforce.

  17. 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.

  18. The IAU Early French Radio Astronomy Project

    NASA Astrophysics Data System (ADS)

    Orchiston, Wayne; Boischot, A.; Delannoy, J.; Kundu, M.; Lequeux, J.; Pick, M.; Steinberg, J.

    2011-01-01

    In 2006 an ambitious project was launched under the auspices of the IAU Working Group on Historic Radio Astronomy to document important developments in French radio astronomy from 1901 through to the 1960s, in a series of papers published, in English, in the Journal of Astronomical History and Heritage. This successful project has now come to an end with the sixth and final paper in the series about to be published (and a new WG project, on the history of early Japanese radio astronomy, has just been launched). In this paper we discuss Nordmann's abortive attempt to detect solar radio emission in 1901, and the important roles played by staff from the École Normale Supérieure and the Institut d'Astrophysique in Paris during the 1940s through 60s in developing new radio astronomy instrumentation and pursuing a range of solar and non-solar research projects in Paris itself and at field stations established at Marcoussis, Nançay and the Haute Provence Observatory.

  19. Radio quiet, please! - protecting radio astronomy from interference

    NASA Astrophysics Data System (ADS)

    van Driel, W.

    2011-06-01

    The radio spectrum is a finite and increasingly precious resource for astronomical research, as well as for other spectrum users. Keeping the frequency bands used for radio astronomy as free as possible of unwanted Radio Frequency Interference (RFI) is crucial. The aim of spectrum management, one of the tools used towards achieving this goal, includes setting regulatory limits on RFI levels emitted by other spectrum users into the radio astronomy frequency bands. This involves discussions with regulatory bodies and other spectrum users at several levels - national, regional and worldwide. The global framework for spectrum management is set by the Radio Regulations of the International Telecommunication Union, which has defined that interference is detrimental to radio astronomy if it increases the uncertainty of a measurement by 10%. The Radio Regulations are revised every three to four years, a process in which four organisations representing the interests of the radio astronomical community in matters of spectrum management (IUCAF, CORF, CRAF and RAFCAP) participate actively. The current interests and activities of these four organisations range from preserving what has been achieved through regulatory measures, to looking far into the future of high frequency use and giant radio telescope use.

  20. 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.

  1. Solar system radio astronomy at low frequencies

    NASA Technical Reports Server (NTRS)

    Desch, M. D.

    1987-01-01

    The planetary radio-astronomy observations obtained with the two Voyager spacecraft since their launch in 1977 are briefly characterized and illustrated with graphs, diagrams, and sample spectra. Topics addressed include the spacecraft designs and trajectories, the wavelength coverage of the radio instruments, the Io-controlled LF emission of Jupiter, the solar-wind effect on the Saturn kilometric radiation, the Saturn electrostatic discharges, and the use of the clocklike feature of the Uranus emission to measure the planet's rotation period.

  2. Radio astronomy. [principles and observations

    NASA Technical Reports Server (NTRS)

    Alexander, J.; Clark, T.

    1974-01-01

    The origins, generation, detection, and interpretation of radio signals are discussed for signals with an assumed random polarization. After defining the basic parameters, the discussion moves to such topics as synchrotron radiation, plasma effects, changes in the electron energy spectrum in the radiating regions, energy loss to ionization, bremsstrahlung, radio astronomical observations of high-energy particles, emission by energetic particles, observation of supernova remnants and pulsars, galactic background continuum radiation, and others.

  3. Advances in solar radio astronomy

    NASA Technical Reports Server (NTRS)

    Kundu, M. R.

    1982-01-01

    The status of the observations and interpretations of the sun's radio emission covering the entire radio spectrum from millimeter wavelengths to hectometer and kilometer wavelengths is reviewed. Emphasis is given to the progress made in solar radio physics as a result of recent advances in plasma and radiation theory. It is noted that the capability now exists of observing the sun with a spatial resolution of approximately a second of arc and a temporal resolution of about a millisecond at centimeter wavelengths and of obtaining fast multifrequency two-dimensional pictures of the sun at meter and decameter wavelengths. A summary is given of the properties of nonflaring active regions at millimeter, centimeter, and meter-decameter wavelengths. The properties of centimeter wave bursts are discussed in connection with the high spatial resolution observations. The observations of the preflare build-up of an active region are reviewed. High spatial resolution observations (a few seconds of arc to approximately 1 arcsec) are discussed, with particular attention given to the one- and two-dimensional maps of centimeter-wavelength burst sources.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  5. GPU accelerated radio astronomy signal convolution

    NASA Astrophysics Data System (ADS)

    Harris, Chris; Haines, Karen; Staveley-Smith, Lister

    2008-10-01

    The increasing array size of radio astronomy interferometers is causing the associated computation to scale quadratically with the number of array signals. Consequently, efficient usage of alternate processing architectures should be explored in order to meet this computational challenge. Affordable parallel processors have been made available to the general scientific community in the form of the commodity graphics card. This work investigates the use of the Graphics Processing Unit in the parallelisation of the combined conjugate multiply and accumulation stage of a correlator for a radio astronomy array. Using NVIDIA’s Compute Unified Device Architecture, our testing shows processing speeds from one to two orders of magnitude faster than a Central Processing Unit approach.

  6. Need a Classroom Stimulus? Introduce Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Derman, Samuel

    2010-04-01

    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 radio astronomy is all about. This ever-present radiation provides astronomers with an alternate, non-optical window to the universe, revealing exotic and unfamiliar phenomena previously undetected by even the most powerful optical telescopes. For physics teachers, a classroom discussion of these radio discoveries, however brief, offers an opportunity for igniting interest (and possibly a career option) in even the most apathetic of students. This paper describes, first, the background of some of these events, and second (in the appendixes), a selection of numerical problems so that students can derive for themselves the truly mind-stretching features of these celestial objects.

  7. The beginnings of Australian radio astronomy

    NASA Astrophysics Data System (ADS)

    Sullivan, Woodruff T.

    2005-06-01

    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.

  8. Auto-Adaptive Radio Astronomy Instruments

    NASA Astrophysics Data System (ADS)

    Pankratius, Victor; Lonsdale, C. J.

    2014-04-01

    Progress in the field of radio astronomy depends heavily on advances in instrumental capabilities, characterized by properties such as collecting area, resolution in the angular, spectral and temporal domains, field of view, and spatial aperture sampling. Generally, such advances in capability represent increases in the formal quantity of astronomical information that is received and processed by the instrument. The current generation of radio astronomy arrays can generate antenna voltage data at rates of Tbits per second, and forthcoming instruments will quickly expand these rates by multiple orders of magnitude. Future Exascale systems will have to make many choices on how to process subsets of big data. As human capacity will be overwhelmed at this scale, part of the discovery process will have to be handled by algorithms and machines. A key challenge will be to identify patterns of scientific significance in massive data sets and adjust instruments to become more sensitive to such patterns. As a step towards realization, we will revisit the current data collection and analysis pipelines from a fresh perspective that treats them as one system. In this system, multicore parallelism reduces big data accumulation by moving fragments of analysis and filtering closer to the data acquisition. MIT Haystack is pursuing approaches that enable future scientists to shift their interaction with bare metal instruments to steering search algorithms. Our vision is to create auto-adaptive instruments that can automatically adjust to identify and characterize interesting data patterns and properties, to optimize signal to noise ratios, and balance the search process depending on environmental changes. Bios Victor Pankratius is a principal investigator and computer scientist at MIT Haystack Observatory, where he advances new directions of computing in astronomy. Contact him at [pankrat at mit dot edu], victorpankratius.com, or Twitter @vpankratius. Colin Lonsdale is Director of

  9. The first radio astronomy from space - RAE

    NASA Technical Reports Server (NTRS)

    Kaiser, M. L.

    1987-01-01

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

  10. 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.

  11. The Importance of Site Selection for Radio Astronomy

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  12. Radio Astronomy Software Defined Receiver Project

    SciTech Connect

    Vacaliuc, Bogdan; Leech, Marcus; Oxley, Paul; Flagg, Richard; Fields, David

    2011-01-01

    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 user 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.

  13. 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

    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.

  14. Radio Astronomy: A Strong Link between Undergraduate Education and Research.

    ERIC Educational Resources Information Center

    Pratap, Preethi; Salah, Joseph E.

    2001-01-01

    Describes a successful pilot program to develop and test a program that facilitates the linking of undergraduate research and education through radio astronomy. Based on the pilot experiences, students everywhere should be able to exploit the opportunity to strengthen their education through practical research using radio astronomy. (Author/SAH)

  15. 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

  16. A satellite swarm for radio astronomy

    NASA Astrophysics Data System (ADS)

    Dekens, E.; Engelen, S.; Noomen, R.

    2014-09-01

    At present the celestial sky has been mapped in considerable detail for every major wavelength band, except for the ultra-long radiowave band. A space-based interferometer consisting of a swarm of satellites would make it possible to map the celestial sources of 0.1-10 MHz radiation. Such a mission concept called the Orbiting Low Frequency Array (OLFAR) is currently undergoing a feasibility study. This paper presents an analysis of possible operational orbits for the OLFAR satellites. The strategy for OLFAR is to let the satellites drift freely after release into initial orbits. The design of the swarm's reference orbit is primarily motivated by the need for a low radio-noise environment. This results in lunar orbits being main candidates. The design of the initial swarm configuration is primarily motivated by the need for uvw-space coverage. This quantity expresses the variation of lengths and orientations of the satellite relative position vectors over time. Numerical simulations give strong indications that the required uvw-coverage can be met within 1 year of operations with a number of satellites ranging between 25 and 100. A key conclusion is that the orbital behavior of a swarm (characterized by the absence of continuous formation control) is well suited for ultra-long wavelength radio astronomy.

  17. 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.

  18. I.S. Shklovsky and modern radio astronomy

    NASA Astrophysics Data System (ADS)

    Rudnitskij, G. M.

    2006-10-01

    Iosif Samuilovich Shklovsky is one of the founders of radio astronomy as a leading branch in the modern science. Under his leadership in 1953 the Radio Astronomy Department was formed at the Sternberg Astronomical Institute of Moscow State University. Shklovsky's research covered a large variety of topics in radio astronomy, space research, solar physics, X-ray astronomy, etc. In this contribution, Shklovsky's life story is reviewed, including the famous expedition to Brazil for radio observations of the solar eclipse. His main works are presented, such as the prediction of the possibility of observing the 21 cm radio line of neutral hydrogen in the interstellar medium together with some molecular radio lines, the explanation of the spectrum of the Crab Nebula in the optical and radio ranges by a unified synchrotron mechanism, and his studies on the radio emission of the solar corona, including the explanation of drifting solar radio bursts by a plasma mechanism. Other research achievements are reviewed, among which are his idea on the artificial comet implemented during the first lunar launches, and his work on the problem of the search for extraterrestrial intelligence.

  19. International Agreement Will Advance Radio Astronomy

    NASA Astrophysics Data System (ADS)

    2007-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Varano, S.

    2008-06-01

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

  1. 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.

  2. 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.

  3. Planetary radio astronomy observations from Voyager 1 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Pearce, J. B.; Evans, D. R.; Carr, T. D.; Schauble, J. J.; Alexander, J. K.; Kaiser, M. L.; Desch, M. D.; Pedersen, M.; Lecacheux, A.

    1981-01-01

    The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings.

  4. Planetary radio astronomy observations from voyager 1 near saturn.

    PubMed

    Warwick, J W; Pearce, J B; Evans, D R; Carr, T D; Schauble, J J; Alexander, J K; Kaiser, M L; Desch, M D; Pedersen, M; Lecacheux, A; Daigne, G; Boischot, A; Barrow, C H

    1981-04-10

    The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings. PMID:17783837

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

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

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 47 CFR 73.1030 - Notifications concerning interference to radio astronomy, research and receiving installations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  17. 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…

  18. The World of Radio Astronomy, Part 3

    NASA Astrophysics Data System (ADS)

    Dahlem, Michael; Brinks, Elias

    1996-07-01

    Street lamps are like quasars. Lightning bolts are like the Orion nebula. In addition to showing how celestial phenomenon resemble everyday doodads, radio astronomers are answering an age-old question: Where are we in the universe?

  19. 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

  20. Planetary radio astronomy observations during the Voyager 1 Titan flyby

    NASA Technical Reports Server (NTRS)

    Daigne, G.; Pedersen, B. M.; Kaiser, M. L.; Desch, M. D.

    1982-01-01

    During the Voyager 1 Titan flyby, unusual radio emissions were observed by the planetary radio astronomy experiment in the 20- to 97-kHz frequency range. It is shown that Titan itself is not the source of the observed radio emission. The emission features are attributed to modification of the normal Saturn kilometric radiation by propagation effects in enhanced density structures within the Titan wake. Furthermore, spiky emissions observed in the magnetic wake of Titan are interpreted in terms of local electrostatic instabilities at the electron plasma frequency. From these measurements a range of electron densities in the wake region is derived, and the consistency of the results is discussed.

  1. Ionospheric wave and irregularity measurements using passive radio astronomy techniques

    NASA Technical Reports Server (NTRS)

    Erickson, W. C.; Mahoney, M. J.; Jacobson, A. R.; Knowles, S. H.

    1988-01-01

    The observation of midlatitude structures using passive radio astronomy techniques is discussed, with particular attention being given to the low-frequency radio telescope at the Clark Lake Radio Observatory. The present telescope operates in the 10-125-MHz frequency range. Observations of the ionosphere at separations of a few kilometers to a few hundreds of kilometers by the lines of sight to sources are possible, allowing the determination of the amplitude, wavelength, direction of propagation, and propagation speed of ionospheric waves. Data are considered on large-scale ionospheric gradients and the two-dimensional shapes and sizes of ionospheric irregularities.

  2. 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.

  3. Solar radio astronomy at low frequencies

    NASA Technical Reports Server (NTRS)

    Dulk, George A.

    1990-01-01

    The characteristics of solar radio emissions at decametric to kilometric wavelengths are reviewed. Special attention is given to the radiation of the quiet sun at several metric and decametric wavelengths and to nonthermal radiation from the active sun, including radio bursts of type III (electron beams), type-III bursts from behind the sun, storms of type III bursts, the flare-associated radio bursts, type II bursts (shock waves), and shock-associated bursts. It is pointed out that almost no observations have been made so far of solar radiation between about 20 MHz and about 2 MHz. Below about 2 MHz, dynamic spectra of flux densities of solar burst have been recorded in space and observations were made of the directions of centroids and characteristic sizes of the emitting sources.

  4. Hartebeesthoek Radio Astronomy Observatory (HartRAO)

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  5. Wide field imaging problems in radio astronomy

    NASA Astrophysics Data System (ADS)

    Cornwell, T. J.; Golap, K.; Bhatnagar, S.

    2005-03-01

    The new generation of synthesis radio telescopes now being proposed, designed, and constructed face substantial problems in making images over wide fields of view. Such observations are required either to achieve the full sensitivity limit in crowded fields or for surveys. The Square Kilometre Array (SKA Consortium, Tech. Rep., 2004), now being developed by an international consortium of 15 countries, will require advances well beyond the current state of the art. We review the theory of synthesis radio telescopes for large fields of view. We describe a new algorithm, W projection, for correcting the non-coplanar baselines aberration. This algorithm has improved performance over those previously used (typically an order of magnitude in speed). Despite the advent of W projection, the computing hardware required for SKA wide field imaging is estimated to cost up to $500M (2015 dollars). This is about half the target cost of the SKA. Reconfigurable computing is one way in which the costs can be decreased dramatically.

  6. Developments in Coherent Amplifiers and Miniaturized Receivers for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Cleary, Kieran; Readhead, A. C.; Reeves, R.; Gawande, R.; Kooi, J.; Gaier, T.; Lawrence, C. R.; Kangaslahti, P.; Samoska, L.; Varonen, M.; Lai, R.; Sarkozy, S.; Church, S. E.; Sieth, M.; Devaraj, K.; Voll, P.

    2013-01-01

    Recent advances in the development of InP HEMT amplifiers have produced a breakthrough in the cryogenic noise performance of these devices. Caltech's Cahill Radio Astronomy Lab (CRAL), JPL and Northrop Grumman (NGAS) are working to produce new amplifiers which can exploit this improved performance for radio astronomy. In parallel, these new amplifiers are being integrated into a family of miniaturized modular receivers which have wide application as focal plane arrays. Such arrays will have a major impact on a diverse range of scientific goals, such as measurement of integrated CO from the Epoch of Reionization, efficient spectroscopic and continuum mapping of Galactic emission and measurement of the B-mode polarization of the cosmic microwave background. We report on these developments and prospects for the future.

  7. Olof Rydbeck and Early Swedish Radio Astronomy: A Personal Perspective

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, V.

    2006-12-01

    The spectacular development of radio astronomy in Europe and Australia in the period soon after World War II was mostly propelled by ‘amateur’ scientists motivated by a spirit of adventure. Totally untrained in astronomy, these pioneers were necessarily courageous and highly individualistic. Each of the leaders was ‘a character’, and often larger than life. And among these personalities there was none bigger than Olof Rydbeck of Sweden. He was already well known for his studies of electromagnetic theory and the invention and fabrication of devices for ever higher frequencies. He was one of the pioneers in the study of the ionosphere, and had built powerful sounders and also detectors for meteor trails. The creation of the Onsala Radio Observatory was entirely due to his efforts.

  8. 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.

  9. 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.

  10. The Lunar Observer Radio Astronomy Experiment (LORAE)

    NASA Technical Reports Server (NTRS)

    Burns, Jack O.

    1990-01-01

    The paper proposes to place a simple low-frequency dipole antenna on board the Lunar Observer (LO) satellite. LO will orbit the moon in the mid-1990's, mapping the surface at high resolution and gathering new geophysical data. In its modest concept, LORAE will collect crucial data on the radio interference environment while on the near-side (to aid in planning future arrays) and will monitor bursts of emission from the sun and the Jovian planets. LORAE will also be capable of lunar occultation studies of greater than 100 of the brightest sources, gathering arcminute resolution data on sizes and measuring source fluxes. A low resolution all-sky map below 10 MHz, when combined with data from the Gamma-Ray Observatory, will uniquely determine the density of Galactic cosmic ray electrons and the strength of the Galaxy's magnetic field. LORAE also will be able to measure the density of the moon's ionosphere.

  11. Acousto-optic spectrometer for radio astronomy

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    Recent developments in acousto-optic techniques and in photodetector arrays have made feasible a new type of RF spectrometer, offering the advantages of wide bandwidth, high resolution, large number of channels in compact, lightweight, energy efficient, and relatively low cost systems. Such a system employs an acousto-optic diffraction cell which serves the key role of converting RF signals to ultrasonic traveling-waves modulating the optical index of the cell. The cell is illuminated across its aperture by a monochromatic laser beam. A fraction of the light is diffracted by the acoustic waves. A focusing lens follows the cell and essentially performs a Fourier transform of the RF signal into a far-field intensity pattern. CSIRO in Australia and the Tokyo Astronomical Observatory in Japan have taken the lead in using acousto-optic techniques in astronomical applications. The first practical device was successfully made at CSIRO for obtaining dynamical spectrographs of solar radio emission.

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  13. Accurate Weather Forecasting for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Maddalena, Ronald J.

    2010-01-01

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

  14. Radio Astronomy in Malaysia: Current Status and Outreach Activities

    NASA Astrophysics Data System (ADS)

    Hashim, N.; Abidin, Z. Z.; Ibrahim, U. F. S. U.; Umar, R.; Hassan, M. S. R.; Rosli, Z.; Hamidi, Z. S.; Ibrahim, Z. A.

    2011-12-01

    In this paper, we will present the current status of radio astronomical research and outreach in Malaysia. We will also present a short history of our research group, which is currently the only radio astronomical facility in Malaysia. Our group is called the Radio Cosmology Research Lab and was established in 2005 by Dr Zamri Zainal Abidin and Prof Dr Zainol Abidin Ibrahim. We will discuss the future plans for this group including our keen interest in being part of a more global network of radio astronomers. We are already an active member of the South-East Asia Astronomy Network (SEAAN) and aims to have a radio astronomical facility in order to join the Global Very Long Baseline Interferometer (VLBI) as well becoming a research hub for the future Square Kilometer Array (SKA) project. We will also present some of the scientific goals of our group including providing a platform for radio astronomers to be able to do observations of weak and high red-shifted radio objects such as galaxy clusters and supernovae.

  15. Space situational awareness applications for radio astronomy assets

    NASA Astrophysics Data System (ADS)

    Watts, Galen; Ford, John M.; Ford, H. Alyson

    2015-05-01

    The National Radio Astronomy Observatory (NRAO) builds, operates, and maintains a suite of premier radio antennas, including the 100m aperture Green Bank Telescope, the largest fully-steerable antenna in the world. For more than five decades the NRAO has focused on astrophysics, providing researchers with the most advanced instruments possible: large apertures, extremely low-noise receivers, and signal processors with high frequency and time resolution. These instruments are adaptable to Space Situational Awareness (SSA) tasks such as radar detection of objects in near-Earth and cis-Lunar space, high accuracy orbit determination, object surveillance with passive methods, and uplink and downlink communications. We present the capabilities of antennas and infrastructure at the NRAO Green Bank Observatory in the context of SSA tasks, and discuss what additions and modifications would be necessary to achieve SSA goals while preserving existing radio astronomy performance. We also discuss how the Green Bank Observatory's surrounding topography and location within the National Radio Quiet Zone will enhance SSA endeavors.

  16. Voyager planetary radio astronomy at neptune.

    PubMed

    Warwick, J W; Evans, D R; Peltzer, G R; Peltzer, R G; Romig, J H; Sawyer, C B; Riddle, A C; Schweitzer, A E; Desch, M D; Kaiser, M L; Farrell, W M; Carr, T D; de Pater, I; Staelin, D H; Gulkis, S; Poynter, R L; Boischot, A; Genova, F; Leblanc, Y; Lecacheux, A; Pedersen, B M; Zarka, P

    1989-12-15

    Detection of very intense short radio bursts from Neptune was possible as early as 30 days before closest approach and at least 22 days after closest approach. The bursts lay at frequencies in the range 100 to 1300 kilohertz, were narrowband and strongly polarized, and presumably originated in southern polar regions ofthe planet. Episodes of smooth emissions in the frequency range from 20 to 865 kilohertz were detected during an interval of at least 10 days around closest approach. The bursts and the smooth emissions can be described in terms of rotation in a period of 16.11 +/- 0.05 hours. The bursts came at regular intervals throughout the encounter, including episodes both before and after closest approach. The smooth emissions showed a half-cycle phase shift between the five episodes before and after closest approach. This experiment detected the foreshock of Neptune's magnetosphere and the impacts of dust at the times of ring-plane crossings and also near the time of closest approach. Finally, there is no evidence for Neptunian electrostatic discharges. PMID:17756007

  17. Voyager planetary radio astronomy at Neptune

    NASA Technical Reports Server (NTRS)

    Warwick, James W.; Evans, David R.; Peltzer, Gerard R.; Peltzer, Robert G.; Romig, Joseph H.; Sawyer, Constance B.; Riddle, Anthony C.; Schweitzer, Andrea E.; Desch, Michael D.; Kaiser, Michael L.

    1989-01-01

    Detection of very intense short radio bursts from Neptune was possible as early as 30 days before closest approach and at least 22 days after closest approach. The bursts lay at frequencies in the range 100 to 1300 kilohertz, were narrowband and strongly polarized, and presumably originated in southern polar regions of the planet. Episodes of smooth emissions in the frequency range from 20 to 865 kilohertz were detected during an interval of at least 10 days around closest approach. The bursts and the smooth emissions can be described in terms of rotation in a period of 16.11 + or - 0.05 hours. The bursts came at regular intervals throughout the encounter, including episodes both before and after closest approach. The smooth emissions showed a half-cycle phase shift between the five episodes before and after closest approach. This experiment detected the foreshock of Neptune's magnetosphere and the impacts of dust at the times of ring-plane crossings and also near the time of closest approach. Finally, there is no evidence for Neptunian electrostatic discharges.

  18. From radio-astronomy to medical imaging.

    PubMed

    Peters, T M

    1991-12-01

    A common thread in much of the medical imaging that has developed over the past 20 years has been the Fourier transform. It was Richard Bates' interest in radio-interferometry, as well as his fascination with problems of medical imaging that prompted an initial interest in applying Fourier techniques to medical imaging in general and to Computed Tomography in particular. This resulted 20 years ago in one of the earliest technical papers advocating Fourier techniques for reconstructing cross-sections from radiographic projections (Bates and Peters, NZ J Science 14:883-896, 1971). Since those early days, medical imaging has explored into a multi-billion dollar industry. The CT scanner has become the workhorse imaging modality in the radiology department, while its more recent relative, the MR scanner, is rapidly gaining ground as a technique of even greater importance. Richard Bates, with his team of "Medical Imagers" was a very significant force in the development of the field of Medical Imaging as we know it today. This paper attempts to chronicle the genesis of this process from the personal perspective of the author. PMID:1789769

  19. 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.

  20. Reflections on the Radio Astronomy Explorer program of the 1960s and 70s

    NASA Technical Reports Server (NTRS)

    Kaiser, M. L.

    1990-01-01

    The Radio Astronomy Explorer (RAE) program of the late 1960s and early 1970s is, to date, the only totally dedicated radio astronomy mission to have flown. However, only some of the prelaunch goals were achieved due to the unexpectedly high levels of interference from the earth in the form of both naturally occurring and man-made noise. Some important lessons in receiver design were learned which could and should be applied to any future radio astronomy missions.

  1. An evolutionary sequence of low frequency radio astronomy missions

    NASA Technical Reports Server (NTRS)

    Jones, Dayton L.

    1990-01-01

    Many concepts for space-based low frequency radio astronomy missions are being developed, ranging from simple single-satellite experiments to large arrays on the far side of the moon. Each concept involves a different tradeoff between the range of scientific questions it can answer and the technical complexity of the experiment. Since complexity largely determines the development time, risk, launch vehicle requirements, cost, and probability of approval, it is important to see where the ability to expand the scientific return justifies a major increase in complexity. An evolutionary series of increasingly capable missions, similar to the series of missions for infrared or X-ray astronomy, is advocated. These would range from inexpensive 'piggy-back' experiments on near-future missions to a dedicated low frequency array in earth orbit (or possibly on the lunar nearside) and eventually to an array on the lunar farside.

  2. Dirichlet Methods for Bayesian Source Detection in Radio Astronomy Images

    NASA Astrophysics Data System (ADS)

    Friedlander, A. M.

    2014-02-01

    The sheer volume of data to be produced by the next generation of radio telescopes - exabytes of data on hundreds of millions of objects - makes automated methods for the detection of astronomical objects ("sources") essential. Of particular importance are low surface brightness objects, which are not well found by current automated methods. This thesis explores Bayesian methods for source detection that use Dirichlet or multinomial models for pixel intensity distributions in discretised radio astronomy images. A novel image discretisation method that incorporates uncertainty about how the image should be discretised is developed. Latent Dirichlet allocation - a method originally developed for inferring latent topics in document collections - is used to estimate source and background distributions in radio astronomy images. A new Dirichlet-multinomial ratio, indicating how well a region conforms to a well-specified model of background versus a loosely-specified model of foreground, is derived. Finally, latent Dirichlet allocation and the Dirichlet-multinomial ratio are combined for source detection in astronomical images. The methods developed in this thesis perform source detection well in comparison to two widely-used source detection packages and, importantly, find dim sources not well found by other algorithms.

  3. Computing Algorithms for Nuffield Advanced Physics.

    ERIC Educational Resources Information Center

    Summers, M. K.

    1978-01-01

    Defines all recurrence relations used in the Nuffield course, to solve first- and second-order differential equations, and describes a typical algorithm for computer generation of solutions. (Author/GA)

  4. Revised Nuffield Chemistry: October 1979 School Survey.

    ERIC Educational Resources Information Center

    Dawson, B. E.

    1980-01-01

    Presents some of the preliminary results of a survey study about the use of both the revised publications and GCE O-Level examinations for Nuffield Chemistry in 495 British schools and colleges in 1979. (HM)

  5. RASDR: Benchtop Demonstration of SDR for Radio Astronomy

    SciTech Connect

    Vacaliuc, Bogdan; Oxley, Paul; Fields, David; Kurtz, Dr. Stan; Leech, Marcus

    2012-01-01

    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 Complex 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.

  6. A review of decametric radio astronomy - Instruments and science

    NASA Technical Reports Server (NTRS)

    Erickson, W. C.; Cane, H. V.

    1987-01-01

    The techniques and instruments used in Galactic and extragalactic radio astronomy at dkm wavelengths are surveyed, and typical results are summarized. Consideration is given to the large specialized phased arrays used for early surveys, the use of wideband elements to increase frequency agility, experimental VLBI observations, and limitations on ground-based observations below about 10 MHz (where the proposed LF Space Array, with resolution 0.5-5 arcmin, could make a major contribution). Observations discussed cover the Galactic center, the Galactic background radiation, SNRs, compact Galactic sources, the ISM, and large extragalactic sources.

  7. Planetary radio astronomy receiver. [experiment on Voyager spacecraft

    NASA Technical Reports Server (NTRS)

    Lang, G. J.; Peltzer, R. G.

    1977-01-01

    The planetary radio astronomy (PRA) experiment on the Voyager spacecraft will measure the amplitude, spectrum, time variations, and polarization of radio emissions over a frequency range of 1.2 kHz to 40.5 MHz with the aid of the PRA receiver (PRAR) and two 10-m orthogonal monopoles. Sensitivity and dynamic range will allow observation of a wide range of Jovian emissions from near earth to encounter. This paper describes the system elements, including the preamp/attenuator/calibrator, the LF polarization discriminator, the four LF-IF amplifier stages, the HF polarization discriminator, the translation LO, the log-IF and detector, the frequency synthesizer, the data processor, control system, power supply, and antennas.

  8. 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

  9. Site selection for a radio astronomy observatory in Turkey: atmospherical, meteorological, and radio frequency analyses

    NASA Astrophysics Data System (ADS)

    Küçük, Ibrahim; Üler, Ipek; Öz, Şükriye; Onay, Sedat; Özdemir, Ali Rıza; Gülşen, Mehmet; Sarıkaya, Mikail; Dag˜Tekin, Nazlı Derya; Özeren, Ferhat Fikri

    2012-03-01

    Selecting the future site for a large Turkish radio telescope is a key issue. The National Radio Astronomy Observatory is now in the stage of construction at a site near Karaman City, in Turkey. A single-dish parabolic radio antenna of 30-40 m will be installed near a building that will contain offices, laboratories, and living accommodations. After a systematic survey of atmospheric, meteorological, and radio frequency interference (RFI) analyses, site selection studies were performed in a predetermined location in Turkey during 2007 and 2008. In this paper, we described the experimental procedure and the RFI measurements on our potential candidate's sites in Turkey, covering the frequency band from 1 to 40 GHz.

  10. Embracing the Wave: Using the Very Small Radio Telescope to Teach Students about Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Fish, Vincent L.; Needles, M. M.; Rogers, A. E. E.; Doherty, M.; Minnigh, S.; Arndt, M. B.; Pratap, P.

    2010-01-01

    The Very Small Radio Telescope (VSRT) is a low-cost educational tool appropriate for laboratory demonstrations of the nature of radio waves and the principles of interferometry for use in both high school and undergraduate physics/astronomy classes. The system consists of small direct broadcast antenna dishes and other commercially available parts and can be assembled for under $500. Complete teaching units have been developed and tested by high school physics teachers to demonstrate radio wave transmission and exponential absorption though materials (Beer's law), the polarization of electromagnetic waves (Malus' law), the inverse square law, and interferometry. These units can be used to explore the properties of electromagnetic waves, including similarities and differences between radio and visible light, while challenging students' misconceptions about a wavelength regime that is important to both astronomy and everyday life. In addition, the VSRT can be used as a radio astronomical interferometer to measure the diameter of the Sun at 12 GHz. Full details, including a parts list, comprehensive assembly instructions, informational memos, teaching units, software, and conformance to national and Massachusetts educational standards, are available on the web at http://www.haystack.mit.edu/edu/undergrad/VSRT/index.html . Development of the VSRT at MIT Haystack Observatory is made possible through funding provided by the National Science Foundation.

  11. 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

  12. User friendly database for Neptune planetary radio astronomy observations

    NASA Technical Reports Server (NTRS)

    Evans, David R.

    1993-01-01

    Planetary Radio Astronomy (PRA) data from the Voyager Neptune encounter were cleaned and reformatted in a variety of formats. Most of these formats are new and have been specifically designed to provide easy access and use of the data without the need to understand esoteric characteristics of the PRA instrument or the Voyager spacecraft. Several data sets were submitted to the Planetary Data System (PDS) and have either appeared already on peer reviewed CDROM's or are in the process of being reviewed for inclusion in forthcoming CD-ROM's. Many of the data sets are also available online electronically through computer networks; it is anticipated that as time permits, the PDS will make all the data sets that were a part of this contract available both online and on CD-ROM's.

  13. Planetary radio astronomy observations from Voyager 2 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. D.; Gulkis, S.; Boischot, A.

    1979-01-01

    The Voyager 2 Planetary Radio Astronomy experiment to Jupiter has confirmed and extended to higher zenomagnetic latitudes results from the identical experiment carried by Voyager 1. The kilometric emissions discovered by Voyager 1 often extended to 1 megahertz or higher on Voyager 2 and often consisted of negatively, or less frequently, positively drifting narrowband bursts. On the basis of tentative identification of plasma wave emissions similar to those detected by Voyager 1, the plasma torus associated with Io appeared somewhat denser to Voyager 2 than it did to Voyager 1. The paper reports on quasi-periodic sinusoidal or impulsive bursts in the broadcast band range of wavelengths (800 to 1800 kHz). A Faraday effect appears at decametric frequencies, which probably results from propagation of the radiation near its sources on Jupiter. Finally, the occurrence of decametric emission in homologous arc families is discussed.

  14. 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. PMID:19405681

  15. Analysis of the Radio Astronomy Explorer lunar orbit mission.

    NASA Technical Reports Server (NTRS)

    Groves, R. T.

    1972-01-01

    The second Radio Astronomy Explorer spacecraft (RAE-B) is planned to be inserted into lunar orbit in 1973. The transfer trajectory design, lunar orbit selection and launch opportunities are developed in relation to the spacecraft mass properties, propulsion capability and the scientific, environmental and engineering constraints. Alternative midcourse guidance and lunar orbit trim strategies are analyzed and compared. A means of achieving a launch window without varying launch azimuth and park orbit coast time is described. The resulting mission design is characterized by near-minimum energy lunar transfer trajectories and low eccentricity, retrograde critical inclination lunar orbits. Acceptable launch periods are shown to exist for six consecutive months and for two to four consecutive days per month.

  16. Molecules in Space: A Chemistry lab using Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Lekberg, M. J.; Pratap, P.

    2000-12-01

    We present the results of a laboratory exercise developed with the support of the NSF Research Experiences for Teachers program at MIT Haystack Observatory. The exercise takes the students beyond the traditional test tubes of a chemistry laboratory into the interstellar medium, where the same principles that they study about in the classroom are found to hold. It also utilizes the true multi-disciplinary nature of radio astronomy and allows the students to realize how much can be learnt by studying the universe at various wavelengths. The astronomical chemistry laboratory is presented wherein students from Chelmsford High School in Massachusetts operate the 37-m telescope at Haystack Observatory via the internet to observe radio signals from galactic chemicals. The laboratory is designed to be the means by which students witness physical evidence for molecular and orbital shapes by observing the radio emission from rotating dipoles. The laboratory described is a lynch pin activity for an integrated unit that moves from the valance shell electron configurations through molecular and orbital geometry to an understanding that many physical and chemical properties of chemicals are ultimately dependent upon the shape/geometry and consequently, dipole of the molecule. Students are expected to interpret and evaluate the nature of molecular dipoles and account for the diversity of rotational spectra using their conceptual knowledge of bonding orbital theory and their knowledge of the electronic atom. Flexibility in the lab allows students to identify individual chemicals by cross referencing radio emission from the galactic sources they have chosen against a prepared catalogue listing or by choosing to "listen" for specific chemicals at exact frequencies. A teacher resource manual containing information and data on a variety of daytime galactic source and individual chemical flux densities of molecular candidates has been prepared. Collaborative exercises and activities

  17. 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.

  18. An Overview of W.N. Christiansen's Contribution to Australian Radio Astronomy, 1948-1960

    NASA Astrophysics Data System (ADS)

    Wendt, Harry; Orchiston, Wayne; Slee, Bruce

    In 1948, an accomplished industrial physicist who had harboured a long-term ambition to become an astronomer joined the newly-formed Radio Astronomy Group in the CSIR's Division of Radiophysics in Sydney, Australia. Thus, W.N. (`Chris') Christiansen (1913-2007) began a new career in the fledgling field of radio astronomy. This paper reviews Christiansen's contribution to both instrumentation development and scientific research during the first phase of his career in radio astronomy, covering his work at the Potts Hill and Fleurs field stations prior to his resignation from the Division of Radiophysics in 1960.

  19. Nuffield Secondary Science, Theme 4, Harnessing Energy.

    ERIC Educational Resources Information Center

    Howard, Edgar

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable to other countries. The Teachers' Guide to the entire set of Themes is described in SE 015 440…

  20. Nuffield Secondary Science, Theme 7, Using Materials.

    ERIC Educational Resources Information Center

    Blackledge, J.; And Others

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable for other countries. The Teachers' Guide to the entire set of materials is described in SE 015…

  1. Nuffield A-level Biological Science Project

    ERIC Educational Resources Information Center

    Kelly, P. J.; Dowdeswell, W. H.

    1970-01-01

    Describes the objectives, intended outcomes, subject matter content, and methods of examining practical and theoretical work in Nuffield A-level biology. Outlines rationale for the organization of the materials produced, justifies using compulsory investigative student projects, suggests procedures for introducing the course and lists relevant…

  2. Nuffield Secondary Science, Theme 6, Movement.

    ERIC Educational Resources Information Center

    Richardson, W.; Tollyfield, J. K.

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable for other countries. The Teachers' Guide to the entire set of materials is described in SE 015…

  3. Radio frequency interference measurements in Indonesia. A survey to establish a radio astronomy observatory

    NASA Astrophysics Data System (ADS)

    Hidayat, Taufiq; Munir, Achmad; Dermawan, Budi; Jaelani, Anton Timur; Léon, Stéphane; Nugroho, Dading Hadi; Suksmono, Andriyan Bayu; Mahasena, Putra; Premadi, Premana Wardayanti; Herdiwijaya, Dhani; Kunjaya, Chatief; Dupe, Zadrach Ledoufij; Brahmantyo, Budi; Mandey, Denny; Yusuf, Muhammad; Tri Wulandari, Hesti Retno; Arief, Falahuddin; Irfan, Muhammad; Puri Jatmiko, Agus Triono; Akbar, Evan Irawan; Sianturi, Hery Leo; Tanesib, Jehunias Leonidas; Warsito, Ali; Utama, Judhistira Aria

    2014-02-01

    We report the first measurements of radio frequency spectrum occupancy performed at sites aimed to host the future radio astronomy observatory in Indonesia. The survey is intended to obtain the radio frequency interference (RFI) environment in a spectral range from low frequency 10 MHz up to 8 GHz. The measurements permit the identification of the spectral occupancy over those selected sites in reference to the allocated radio spectrum in Indonesia. The sites are in close proximity to Australia, the future host of Square Kilometre Array (SKA) at low frequency. Therefore, the survey was deliberately made to approximately adhere the SKA protocol for RFI measurements, but with lower sensitivity. The RFI environment at Bosscha Observatory in Lembang was also measured for comparison. Within the sensitivity limit of the measurement equipment, it is found that a location called Fatumonas in the surrounding of Mount Timau in West Timor has very low level of RFI, with a total spectrum occupancy in this measured frequency range being about 1 %, mostly found at low frequency below 20 MHz. More detailed measurements as well as a strategy for a radio quiet zone must be implemented in the near future.

  4. Network Development of the Pushchino Radio Astronomy Observatory of ASC LPI

    NASA Astrophysics Data System (ADS)

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

    All main changes in the network of the Pushchino Radio Astronomy Observatory has been related to introduction of the buffer data center in the recent years, upgrading internal and external communication channels and the exploitation of ip-telephony.

  5. Radio Jupiter after Voyager: An overview of the Planetary Radio Astronomy observations

    NASA Technical Reports Server (NTRS)

    Boischot, A.; Lecacheux, A.; Kaiser, M. L.; Desch, M. D.; Alexander, J. K.; Warwick, J. W.

    1980-01-01

    Jupiter's low frequency radio emission morphology as observed by the Planetary Radio Astronomy (PRA) instrument onboard the Voyager spacecraft is reviewed. The PRA measurement capabilities and limitations are summarized following over two years of experience with the instrument. As a direct consequence of the PRA spacecraft observations, unprecedented in terms of their sensitivity and frequency coverage, at least three previous unrecognized emission components were discovered: broadband and narrow band kilometric emission and the lesser arc decametric emission. Their properties are reviewed. In addition, the fundamental structure of the decameter and hectometer wavelength emission, which is believed to be almost exclusively in the form of complex but repeating arc structures in the frequency time domain, is described. Dramatic changes in the emission morphology of some components as a function of Sun-Jupiter-spacecraft angle (local time) are described. Finally, the PRA in suit measurements of the Io plasma torus hot to cold electron density and temperature ratios are summarized.

  6. 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.

  7. Planetary radio astronomy observations from Voyager-2 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Evans, D. R.; Romig, J. H.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Aubier, M.; Leblanc, Y.; Lecacheux, A.; Pedersen, B. M.

    1981-01-01

    Voyager-2 planetry radio astronomy measurements obtained near Saturn are discussed. They indicate that Saturnian kilometric radiation is emitted by a strong, dayside source at auroral latitudes in the northern hemisphere and by a weaker (by more than an order of magnitude) source at complementary latitudes in the southern hemisphere. These emissions are variable both due to Saturn's rotation and, on longer time scales, probably due to influences of the solar wind and the satellite Dione. The Saturn electrostatic discharge bursts first discovered by Voyager-1 and attributed to emissions from the B-ring were again observed with the same broadband spectral properties and a 10(h)11(m) + or - 5(m) episodic recurrence period but with an occurrence frequency of only of about 30 percent of that detected with Voyager-1. During the crossing of the ring plane at a distance of 2.88 R sub S, an intense noise event is interpreted to be consequence of the impact/vaporization/ionization of charged micron-size G-ring particles distributed over a total vertical thickness of about 1500 km.

  8. Planetary radio astronomy observations from Voyager 2 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Evans, D. R.; Romig, J. H.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Aubier, M.; Leblanc, Y.; Lecacheux, A.; Pedersen, B. M.

    1982-01-01

    Planetary radio astronomy measurements obtained by Voyager 2 near Saturn have added further evidence that Saturnian kilometric radiation is emitted by a strong dayside source at auroral latitudes in the northern hemisphere and by a weaker source at complementary latitudes in the southern hemisphere. These emissions are variable because of Saturn's rotation and, on longer time scales, probably because of influences of the solar wind and Dione. The electrostatic discharge bursts first discovered by Voyager 1 and attributed to emissions from the B ring were again observed with the same broadband spectral properties and an episodic recurrence period of about 10 hours, but their occurrence frequency was only about 30 percent of that detected by Voyager 1. While crossing the ring plane at a distance of 2.88 Saturn radii, the spacecraft detected an intense noise event extending to above 1 megahertz and lasting about 150 seconds. The event is interpreted to be a consequence of the impact, vaporization, and ionization of charged, micrometer-size G ring particles distributed over a vertical thickness of about 1500 kilometers.

  9. Radio Astronomy in Holland Before 1960: Just a Bit More than HI

    NASA Astrophysics Data System (ADS)

    Strom, Richard

    2005-01-01

    The history of early radio astronomy in the Netherlands is explored, especially that which did not involve neutral hydrogen studies. Although little of this early—mainly solar—work was published in professional journals, there is some information in a popular Dutch astronomy magazine. From this it is clear that the early radio observations of the Sun were driven as much by the needs of radio communication as by solar physics. The important role which A.H. de Voogt, Head of the PTT's radio service, played in both Dutch and international radio astronomy is described. A brief sketch is given of the history of the two PTT stations where the early observations were made.

  10. Infrared Submillimeter and Radio Astronomy Research and Analysis Program

    NASA Technical Reports Server (NTRS)

    Traub, Wesley A.

    2000-01-01

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

  11. Radio astronomy from space; Proceedings of the Workshop, Green Bank, WV, Sept. 30-Oct. 2, 1986

    SciTech Connect

    Weiler, K.W.

    1987-01-01

    The scientific aims and technological implementation of planned and proposed space radio observatories are examined in reviews and reports. Observations at mm and submm, cm, dkm, and hm wavelengths are considered, and particular attention is given to astrophysical problems requiring space-based observations; radio astronomy from the moon; coordination of ground, airborne, balloon-borne, and space-based mm and submm astronomy; microwave-background observations at 15-90 GHz, the Large Deployable Reflector, the Space Station mm-wave facility, the use of TDRSS as an orbiting VLBI observatory, and interstellar scattering and resolution limitations. Also discussed are Quasat, Astro-Array, VLBA, solar-system radio astronomy at low frequencies, radio emission from coronal and interplanetary shocks, and Tasmanian LF Galactic background surveys.

  12. 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.).

  13. Radio Jupiter after Voyager - An overview of the planetary radio astronomy observations

    NASA Technical Reports Server (NTRS)

    Boischot, A.; Lecacheux, A.; Kaiser, M. L.; Desch, M. D.; Alexander, J. K.; Warwick, J. W.

    1981-01-01

    An overview of Jupiter's low-frequency radio emission morphology as observed by the planetary radio astronomy (PRA) instrument onboard the Voyager spacecraft is presented. The PRA measurement capabilities and limitations are summarized, based on over two years of experience with the instrument. As a direct consequence of the PRA spacecraft observations, unprecedented in terms of their sensitivity and frequency coverage, at least three previously-unrecognized emission components have been discovered: broadband and narrow-band kilometric emission, and the lesser-arc decametric emission. Their properties are reviewed. In addition, the fundamental structure of the decameter wavelength and hectometer wavelength emission, now believed to be almost exclusively in the form of complex but repeating arc structures in the frequencytime domain, is described. Dramatic changes in the emission morphology of some components as a function of the sun-Jupiter-spacecraft angle (local time) are described. Finally, the PRA in situ measurements of the Io plasma torus hot-to-cold electron density and temperature ratios are summarized.

  14. 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.

  15. 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.

  16. Nuffield A-Level Chemistry: A Personal View

    ERIC Educational Resources Information Center

    Bailey, Roy

    1972-01-01

    Maintains that there are topics of thermodynamics and organic chemistry in Nuffield A-level chemistry program which should be reviewed critically for their content organization. The Nuffield course is considered better than the traditional courses in its educational value, yet highly biased for preparing students for college chemistry courses. (PS)

  17. Analysis of radio astronomy bands using CALLISTO spectrometer at Malaysia-UKM station

    NASA Astrophysics Data System (ADS)

    Zavvari, Azam; Islam, Mohammad Tariqul; Anwar, Radial; Abidin, Zamri Zainal; Asillam, Mhd Fairos; Monstein, Christian

    2016-02-01

    The e-CALLISTO system is a worldwide network that aims to observe solar radio emission for astronomical science. CALLISTO instruments have been deployed worldwide in various locations that together can provide continuous observation of the solar radio spectrum for 24 h per day year-round. Malaysia-UKM is a strategic equatorial location and can observe the Sun 12 h per day. This paper gives an overview of the spectrum allocation for radio astronomy, which falls in the specified operating frequency band of the CALLISTO spectrometer. The radio astronomy bands are analyzed at the Malaysia-UKM station according to the International Telecommunication Union recommendations. Some observational results are also presented in this paper.

  18. European Frequency Management and the Role of CRAF for Radio Astronomy

    NASA Astrophysics Data System (ADS)

    van Driel, W.; Spoelstra, T. A. Th.

    2004-06-01

    In Europe, radio frequency regulation is managed by the CEPT, the Conference of European Posts and Telecommunications Administrations (under an MoU with the European Commission). The CEPT develops guidelines and provides national Administrations with tools for harmonised European frequency management. In frequency management matters, the European radio astronomy community is represented by CRAF, the Committee on Radio Astronomy Frequencies of the ESF, the European Science Foundation. CRAF at present has members from 17 CEPT countries and a number of international organisations and it employs a full-time pan-European spectrum manager. Like several other non-government organis-ations, CRAF participates actively in this process through collaboration and communication with national Administrations and at CEPT level. CRAF has an observer status within the CEPT and is a Sector Member of the ITU-R, allowing it to participate in its own right in European and global fora dealing with radio frequency management.

  19. Outer planets grand tours: Planetary radio astronomy team report

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.

    1972-01-01

    Requirements related to scientific observations of planetary radio emissions during outer planets grand tours are discussed. Observations at low frequencies where non-thermal cooperative plasma phenomena play a major role are considered for determining dynamical processes and magnetic fields near a planet. Magnetic field measurements by spacecraft magnetometers, and by radio receivers in their harmonic modes are proposed for interpretation of planetary radio emission.

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

    NASA Astrophysics Data System (ADS)

    Ramesh, R.

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

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  2. The First Steps of Radio Astronomy in Czestochowa

    NASA Astrophysics Data System (ADS)

    Jarosik, M.; Starzyński, S.; Szcześniak, M.; Szcześniak, R.; Ceglarek, A.

    2007-12-01

    In the paper, technical documentation and the principle of operation is presented. "KLAUDIA" radio telescope was built in Rabka in 2007 and it is used to receive secondary radio waves, emitted by the Earth's ionosphere at frequency of 40 kHz.

  3. Cyclostationary approaches for spatial RFI mitigation in radio astronomy

    NASA Astrophysics Data System (ADS)

    Hellbourg, Grégory; Weber, Rodolphe; Capdessus, Cécile; Boonstra, Albert-Jan

    2012-01-01

    Radio astronomical observations are increasingly corrupted by radio frequency interferences (RFIs), and real time filtering algorithms are becoming essential. In this article, it is shown how spatial processing techniques can limit the impact of the incoming RFIs for phased array radio telescopes. The proposed approaches are based on estimation of the RFI spatial signature. It requires the diagonalization of either the classic correlation matrix or the cyclic correlation matrix of the array. Different diagonalization techniques are compared. Then, RFI detection and RFI filtering techniques are illustrated through simulations on data acquired with the Low Frequency Array Radio telescope, LOFAR. The originality of the study is the use of the cyclostationarity property, in order to improve the spatial separation between cosmic sources and RFIs.

  4. 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.

  5. 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. D.; Gulkis, S.; Boischot, A.

    1979-01-01

    Results from the first low-frequency radio receiver to be transported into the Jupiter magnetosphere are reported. Dramatic new information was obtained, both because Voyager was near or in Jupiter's radio emission sources and 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 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. Detailed studies are in progress and are outlined briefly.

  6. 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).

  7. Scientific instrumentation of the Radio-Astronomy-Explorer-2 satellite

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.; Kaiser, M. L.; Novaco, J. C.; Grena, F. R.; Weber, R. R.

    1975-01-01

    The instrumentation of the RAE-2 spacecraft is described. The instruments include a pair of long travelling-wave antennas, a 37-m dipole, two radiometers making one frequency scan every 144 sec, and two rapid-sampling total-power burst receivers which cover the range from 0.025 to 13.1 MHz in 32 discrete steps. Effects of terrestrial noise on RAE-1 and RAE-2 observations are discussed, and it is noted that RAE-2 is uniquely capable of observing repeated lunar occultations of strong radio sources at very low frequencies. Some observational programs are briefly noted, including observations of the galactic background distribution, measurements of lunar occultations of solar radio bursts, and searches for more radio sources among the planets, galactic objects, and extragalactic sources.

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

    NASA Astrophysics Data System (ADS)

    Ferrari, C.

    2016-09-01

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

  9. 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.

  10. Scientific instrumentation of the Radio-Astronomy-Explorer-2 satellite

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.; Kaiser, M. L.; Novaco, J. C.; Grena, F. R.; Weber, R. R.

    1974-01-01

    The RAE-2 spacecraft has been collecting radio astronomical measurements in the 25 kHz to 13 MHz frequency range from lunar orbit since June, 1973. A summary is given of the technical aspects of the program including the calibration, instrumentation and operation of the RAE-2 experiments. Performance of the experiments over the first 18 months of the flight is summarized and illustrated. Among the unique features of the RAE-2 is the capability to observe repeated lunar occultations of strong radio sources at very low frequencies.

  11. Problems and Rewards in Teaching Nuffield A-Level

    ERIC Educational Resources Information Center

    Lumb, Nora

    1972-01-01

    Discusses several problems in the teaching of Nuffield A-level chemistry: content organization, shortage of time, finances and treatment of selected topics. Believes the rewards of the overall approach are very worthwhile. (PS)

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

  13. Probing the field of radio astronomy with the SKA and the Hartebeesthoek Radio observatory: an engineer's perspective

    NASA Astrophysics Data System (ADS)

    Otto, Sunelle

    2011-07-01

    The Square Kilometre Array (SKA) is an international project to build the world's largest and most sensitive radio telescope interferometer. It will consist of thousands of antennas distributed over many kilometers, with the hosting country being either South Africa or Australia. This talk will give some background on the SKA technologies, pathfinders and Key Science Projects and also consider the system design options for the SKA Pulsar science case. The Hartebeesthoek Radio Astronomy Observatory (HartRAO) is the only major radio astronomy observatory in Africa; with KAT-7 in testing and the MeerKAT still in it's design phase. Some of my research work at HartRAO is presented, which includes data analysis of the pointing model for the 26m radio telescope and evaluating the performance of the GPS-disciplined Rubidium and Hydrogen Maser frequency standards. I will also talk about our project to build a 1.4GHz receiver for a commercial satellite TV antenna as well as calibrating data at 22GHz for observing water masers in Orion.

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

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  16. A very low frequency radio astronomy observatory on the Moon

    NASA Technical Reports Server (NTRS)

    Douglas, James N.; Smith, Harlan J.

    1988-01-01

    Because of terrestrial ionospheric absorption, very little is known of the radio sky beyond 10 m wavelength. An extremely simple, low cost very low frequency radio telescope is proposed, consisting of a large array of short wires laid on the lunar surface, each wire equipped with an amplifier and a digitizer, and connected to a common computer. The telescope could do simultaneous multifrequency observations of much of the visible sky with high resolution in the 10 to 100 m wavelength range, and with lower resolution in the 100 to 1000 m range. It would explore structure and spectra of galactic and extragalactic point sources, objects, and clouds, and would produce detailed quasi-three-dimensional mapping of interstellar matter within several thousand parsecs of the Sun.

  17. The time resolution domain of stellar radio astronomy

    NASA Technical Reports Server (NTRS)

    Bookbinder, J.

    1985-01-01

    The high time resolution (HTR) radio observation of late-type stars and RS CVn systems is discussed. Some examples of these sources are addressed, identifying what information HTR observations can provide. HTR can provide important information on flares in late-type stars, and can be used to study coronal structure and the particle acceleration mechanism in these stars. The possible use of HTR to establish the nature of quiescent emission form RS CVn systems is discussed.

  18. The birthplace of planetary radio astronomy: The Seneca, Maryland observatory 50 years after Burke and Franklin's Jupiter radio emission discovery.

    NASA Astrophysics Data System (ADS)

    Garcia, L. N.; Thieman, J. R.; Higgins, C. A.

    2004-12-01

    Burke and Franklin's discovery of radio emissions from Jupiter in 1955 effectively marked the birth of the field of planetary radio astronomy. The discovery was made near Seneca, Maryland using the Department of Terrestrial Magnetism/Carnegie Institution of Washington's Mills Cross Array. Fifty years later there is very little evidence of this 96-acre X-shaped array of dipoles still in existence, nor evidence of any of the other antennas used at this site. The site, now known as the McKee Besher Wildlife Management Area, is owned by the State of Maryland Department of Natural Resources. Radio Jove, a NASA/GSFC education and public outreach project, will recognize the 50th anniversary of this discovery through an historic reenactment using their receiver and dual-dipole array system. Our search through the DTM/CIW archives, our visit to the site to look for evidence of this array, and other efforts at commemorating this anniversary will be described.

  19. 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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  1. New Skills of Radio Astronomy Data Center (RADC) at PRAO ASC LPI

    NASA Astrophysics Data System (ADS)

    Samodurov, V. A.; Kitaeva, M. A.; Isaev, E. A.; Dumsky, D. V.; Pugachev, V. D.; Logvinenko, S. V.; Zaitsev, A. U.

    Now a day the task of comparative analysis of sample sources from different astronomical catalogs is becoming very topical for astronomers. It is useful both for the same spectral range data and for their cross-analysis for different spectral ranges. It is also important, that the real data from astronomical instruments is placed on-line. For the above purposes we are developing a website for the PRAO ASC LPI (www.prao.ru) and, based upon it, the Radio Astronomy Data Center (RADC). The RADC is a system for storage and processing of radio astronomical data. Here you can find a collection of tools for preparing radio astronomical observations, which includes a base set of main astronomical catalogues useful to radio astronomers, as well as a database of observation results from the Observatory.

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

    SciTech Connect

    Stokes, G.M.; Ekstrom, P.A.

    1980-04-01

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

  3. The history of early low frequency radio astronomy in Australia. 1: The CSIRO Division of Radiophysics

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    During the 1950s and 1960s Australia was a world leader in the specialised field of low frequency radio astronomy, with two geographically-distinct areas of activity. One was in the Sydney region and the other in the island of Tasmania to the south of the Australian mainland. Research in the Sydney region began in 1949 through the CSIRO's Division of Radiophysics, and initially was carried out at the Hornsby Valley field station before later transferring to the Fleurs field station. In this paper we summarise the low frequency radio telescopes and research programs associated with the historic Hornsby Valley and Fleurs sites.

  4. Reference antenna-based subspace tracking for RFI mitigation in radio astronomy

    NASA Astrophysics Data System (ADS)

    Hellbourg, G.; Chippendale, A. P.; Kesteven, M. J.; Jeffs, B. D.

    2014-12-01

    Interference mitigation is becoming necessary to make radio astronomy work in bands that are heavily used to support our modern lives. It is becoming particularly difficult to work at frequencies between 1100 MHz and 1300 MHz that are rapidly filling up with satellite navigation signals. Antenna array radio telescopes present the possibility of applying spatial Radio Frequency Interference (RFI) mitigation. Spatial filtering techniques for RFI mitigation have been introduced to radio astronomy in the last decades. The success of these techniques relies on accurately estimating the RFI spatial signature (or RFI subspace). The use of a reference antenna steering at the RFI sources provides a good estimation of the RFI subspace when correlated with an array radio telescope. However, predicting the evolution of this subspace with time is necessary in a multiple RFI scenario, when only a single RFI source can be monitored at a time with the reference antenna. This paper introduces a subspace tracking approach, based on the power method applied to covariance data. The RFI spatial signature estimates provided by the reference antenna are used to initialize the power method to support a faster convergence. Practical examples are shown, applying the method to real data from a single 188 element phased array feed designed for the Australian Square Kilometre Array Pathfinder (ASKAP) telescope.

  5. Planetary Radio Astronomy: The 60 Years from Burke and Franklin to ALMA

    NASA Astrophysics Data System (ADS)

    Steffes, Paul G.

    2014-11-01

    For nearly 60 years, radio astronomy has played a major role in the characterization and monitoring of thermal structure, composition, and temporal changes of the planets and small bodies in our solar system. At this, the 60th anniversary of the initial detection of radio emission by a planet, the role radio astronomy has played in the early characterization of solar system objects, in raising basic scientific questions and motivating planetary exploration missions, and in providing insight into the structure and temporal variations of planets is explored. The evolution of the instrumentation capabilities from crude total-power, or bolometric measurements averaged over an entire planetary disk to today's instrumentation providing radio images of planets and comets with high spectral resolution is also discussed. Major developments such as precise total-power calibration, ultra-large apertures, microwave and millimeter-wave array technology, and supporting laboratory spectroscopy have played major roles in enhancing the effectiveness of radio astronomical observations. The newest generation instruments such as the upgraded Jansky Very Large Array (VLA) and the Altacama Large Millimeter Array (ALMA) now usher in a whole new level of capability in observation of solar system objects.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  7. Low-Power Architectures for Large Radio Astronomy Correlators

    NASA Technical Reports Server (NTRS)

    D'Addario, Larry R.

    2011-01-01

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

  8. Instrumentation for Kinetic-Inductance-Detector-Based Submillimeter Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Duan, Ran

    A substantial amount of important scientific information is contained within astronomical data at the submillimeter and far-infrared (FIR) wavelengths, including information regarding dusty galaxies, galaxy clusters, and star-forming regions; however, these wavelengths are among the least-explored fields in astronomy because of the technological difficulties involved in such research. Over the past 20 years, considerable efforts have been devoted to developing submillimeter- and millimeter-wavelength astronomical instruments and telescopes. The number of detectors is an important property of such instruments and is the subject of the current study. Future telescopes will require as many as hundreds of thousands of detectors to meet the necessary requirements in terms of the field of view, scan speed, and resolution. A large pixel count is one benefit of the development of multiplexable detectors that use kinetic inductance detector (KID) technology. This dissertation presents the development of a KID-based instrument including a portion of the millimeter-wave bandpass filters and all aspects of the readout electronics, which together enabled one of the largest detector counts achieved to date in submillimeter-/millimeter-wavelength imaging arrays: a total of 2304 detectors. The work presented in this dissertation has been implemented in the MUltiwavelength Submillimeter Inductance Camera (MUSIC), a new instrument for the Caltech Submillimeter Observatory (CSO).

  9. Electronic Multi-beam Radio Astronomy Concept: Embrace a Demonstrator for the European SKA Program

    NASA Astrophysics Data System (ADS)

    Ardenne, A.; Wilkinson, P. N.; Patel, P. D.; Vaate, J. G. Bij

    2004-06-01

    ASTRON has demonstrated the capabilities of a 4 m2, dense phased array antenna (Bij de Vaate et al., 2002) for radio astronomy, as part of the Thousand Element Array project (ThEA). Although it proved the principle, a definitive answer related to the viability of the dense phased array approach for the SKA could not be given, due to the limited collecting area of the array considered. A larger demonstrator has therefore been defined, known as “Electronic Multi-Beam Radio Astronomy Concept”, EMBRACE, which will have an area of 625 m2, operate in the band 0.4 1.550 GHz and have at least two independent and steerable beams. With this collecting area EMBRACE can function as a radio astronomy instrument whose sensitivity is comparable to that of a 25-m diameter dish. The collecting area also represents a significant percentage area (˜10%) of an individual SKA “station.” This paper presents the plans for the realisation of the EMBRACE demonstrator.

  10. Characterising the Venezuelan Troposphere for Radio-Astronomy Studies

    NASA Astrophysics Data System (ADS)

    Pacheco, R.; Muñoz, A. G.; Brito, A.; Cubillán, N.

    2009-05-01

    Venezuela possesses a very useful geographical location for doing Radioastronomy. Recently, the Venezuelan Government (via FIDETEL-Ministerio de Ciencia y Tecnología) has aproved to the Laboratorio de Astronomía y Física Teórica (LAFT) of La Universidad del Zulia (Venezuela) the adquisition of four 3 meter diameter parabolic dishes that will be set as a radio-interferometer receiver and that can be used for certain Radioastronomy purposes. The specifications of the instrument will be treated elsewhere (Muñoz and Hernández 2007). To this aim, as ussually, the first step is to characterize the losses due to the atmosphere, and their evolution over time. In previous works (Muñoz et al. 2004, Memoires of V RIAO/VIII OPTILAS, M10-5 Modelling Tropospheric Radio-Attenuation Parameters for Venezuela, 359; Muñoz et al. 2006, CIENCIA, Vol. 14, 4, 428) we have studied some relevant electromagnetic (e-m) attenuation parameters dueto hydrometeors and absortion gases in the lower atmosphere, focused in local telecommunication applications (surface e-m trajectories). In this work we extend our results to include the cenital and quasi-cenital e-m trajectories, characterizing thus the medium losses in the 0.4-4.0 GHz spectral window for several Venezuelan locations. We report refractivity values and their gradients, tropospheric indexes, extinction coefficients and the total rain attenuation for the whole territory under study.

  11. Solar Astronomy at DSES: Plasma Motion Detection at Radio Frequencies

    NASA Astrophysics Data System (ADS)

    Howe, Rodney

    2008-05-01

    This article discusses a proposed study of solar plasma motion, a radio receiving system designed to detect plasma motion-driven microwaves, and the initial radio analysis to understand the receiving system characteristics. A phenomenon of interest is the increasing temperature from the solar photosphere to the solar corona. I've been thinking about testable hypothesis[es] for how to measure the different altitudes (via a temperature scale) of the transition zone (between photosphere and corona) of the sun. I think if we choose the appropriate frequencies, one close to the surface, say 11.7 GHz and one above the 2km breakpoint, say 12.7 GHz we might test for a couple of possible phenomena: (1) At Extremely Low Frequencies (ELF), are we seeing a Doppler shifting in the phase of plasma motions, and (2) in a polarized recording of data, can we measure electro- magnetic waves in both electric and magnetic components. The temperatures that are being measured at 11.7 GHz are approximately 15,000 Kelvin and the temperature at 12.7 GHz is approximately 17,000 Kelvin.

  12. Scientific Visualization of Radio Astronomy Data using Gesture Interaction

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  13. Fast pulsars, strange stars: An opportunity in radio astronomy

    SciTech Connect

    Glendenning, N.K.

    1990-07-15

    The world's data on radio pulsars is not expected to represent the underlying pulsar population because of a search bias against detection of short periods, especially below 1 ms. Yet pulsars in increasing numbers with periods right down to this limit have been discovered suggesting that there may be even shorter ones. If pulsars with periods below 1/2 ms were found, the conclusion that the confined hadronic phase of nucleons and nuclei is only metastable would be almost inescapable. The plausible ground state in that event is the deconfined phase of (3-flavor) strange-quark-matter. From the QCD energy scale this is as likely a ground state as the confined phase. We show that strange matter as the ground state is not ruled out by any known fact, and most especially not by the fact that the universe is in the confined phase. 136 refs.

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  15. Astronomy.

    ERIC Educational Resources Information Center

    Greenstone, Sid; Smith, Murray

    Selected materials needed to teach an astronomy unit as well as suggested procedures, activities, ideas, and astronomy fact sheets published by the Manitoba Planetarium are provided. Subjects of the fact sheets include: publications and classroom picture sets available from the National Aeronautics and Space Administration and facts and statistics…

  16. PARAS program: Phased array radio astronomy from space

    NASA Technical Reports Server (NTRS)

    Jakubowski, Antoni K.; Haynes, David A.; Nuss, Ken; Hoffmann, Chris; Madden, Michael; Dungan, Michael

    1992-01-01

    An orbiting radio telescope is proposed which, when operated in a Very Long Baseline Interferometry (VLBLI) scheme, would allow higher (than currently available) angular resolution and dynamic range in the maps, and the ability of observing rapidly changing astronomical sources. Using a passive phases array technology, the proposed design consists of 656 hexagonal modules forming a 150 meter diameter dish. Each observatory module is largely autonomous, having its own photovoltaic power supply and low-noise receiver and processor for phase shifting. The signals received by the modules are channeled via fiber optics to the central control computer in the central bus module. After processing and multiplexing, the data is transmitted to telemetry stations on the ground. The truss frame supporting each observatory pane is a hybrid structure consisting of a bottom graphite/epoxy tubular triangle and rigidized inflatable Kevlar tubes connecting the top observatory panel and bottom triangle. Attitude control and stationkeeping functions are performed by a system of momentum wheels in the bus and four propulsion modules located at the compass points on the periphery of the observatory dish. Each propulsion module has four monopropellant thrusters and six hydrazine arcjets, the latter supported by a nuclear reactor. The total mass of the spacecraft is 22,060 kg.

  17. Project PARAS: Phased array radio astronomy from space

    NASA Technical Reports Server (NTRS)

    Nuss, Kenneth; Hoffmann, Christopher; Dungan, Michael; Madden, Michael; Bendakhlia, Monia

    1992-01-01

    An orbiting radio telescope is proposed which, when operated in a very long baseline interferometry (VLBI) scheme, would allow higher than currently available angular resolution and dynamic range in the maps and the ability to observe rapidly changing astronomical sources. Using passive phased array technology, the proposed design consists of 656 hexagonal modules forming a 150-m diameter antenna dish. Each observatory module is largely autonomous, having its own photovoltaic power supply and low-noise receiver and processor for phase shifting. The signals received by the modules are channeled via fiber optics to the central control computer in the central bus module. After processing and multiplexing, the data are transmitted to telemetry stations on the ground. The truss frame supporting each observatory panel is a novel hybrid structure consisting of a bottom graphite/epoxy tubular triangle and rigidized inflatable Kevlar tubes connecting the top observatory panel and the bottom triangle. Attitude control and station keeping functions will be performed by a system of momentum wheels in the bus and four propulsion modules located at the compass points on the periphery of the observatory dish. Each propulsion module has four monopropellant thrusters and four hydrazine arcjets, the latter supported by either a photovoltaic array or a radioisotope thermoelectric generator. The total mass of the spacecraft is about 20,500 kg.

  18. Bayesian detection of radar interference in radio astronomy

    NASA Astrophysics Data System (ADS)

    Jeffs, Brian D.; Lazarte, Weizhen; Fisher, J. Richard

    2006-06-01

    L-Band observations at the Green Bank Telescope (GBT) and other radio observatories are often made in frequency bands allocated to aviation pulsed radar transmissions. It is possible to mitigate radar contamination of the astronomical signal by time blanking data containing these pulses. However, even when strong direct path pulses and nearby fixed clutter echoes are removed there are still undetected weaker aircraft echoes present which can corrupt the data. In a previous paper we presented an algorithm to improve real-time echo blanking by forming a Kalman filter tracker to follow the path of a sequence of echoes observed on successive radar antenna sweeps. The tracker builds a history which can be used to predict the location of upcoming echoes. We now present details of a new Bayesian detection algorithm which uses this prediction information to enable more sensitive weak pulse acquisition. The developed track information is used to form a spatial prior probability distribution for the presence of the next echoes. Regions with higher probability are processed with a lower detection threshold to pull out low level pulses without increasing the overall probability of false alarm detection. The ultimate result is more complete removal, by blanking the detected pulse, of radar corruption in astronomical observations.

  19. Radar interference blanking in radio astronomy using a Kalman tracker

    NASA Astrophysics Data System (ADS)

    Dong, W.; Jeffs, B. D.; Fisher, J. R.

    2005-06-01

    Radio astronomical observations of highly Doppler shifted spectral lines of neutral hydrogen and the hydroxyl molecule must often be made at frequencies allocated to pulsed air surveillance radar in the 1215-1350 MHz frequency range. The Green Bank telescope (GBT) and many other observatories must deal with these terrestrial signals. Even when strong radar fixed clutter echoes are removed, there are still weaker aircraft echoes present which can corrupt the data. We present an algorithm which improves aircraft echo blanking using a Kalman filter tracker to follow the path of a sequence of echoes observed on successive radar antenna sweeps. Aircraft tracks can be used to predict regions (in bearing and range) for the next expected echoes, even before they are detected. These data can then be blanked in real time without waiting for the pulse peak to arrive. Additionally, we briefly suggest an approach for a new Bayesian algorithm which combines tracker and pulse detector operations to enable more sensitive weak pulse detection. Examples are presented for Kalman tracking and radar transmission blanking using real observations at the GBT.

  20. Accelerating radio astronomy cross-correlation with graphics processing units

    NASA Astrophysics Data System (ADS)

    Clark, M. A.; LaPlante, P. C.; Greenhill, L. J.

    2013-05-01

    We present a highly parallel implementation of the cross-correlation of time-series data using graphics processing units (GPUs), which is scalable to hundreds of independent inputs and suitable for the processing of signals from 'large-Formula' arrays of many radio antennas. The computational part of the algorithm, the X-engine, is implemented efficiently on NVIDIA's Fermi architecture, sustaining up to 79% of the peak single-precision floating-point throughput. We compare performance obtained for hardware- and software-managed caches, observing significantly better performance for the latter. The high performance reported involves use of a multi-level data tiling strategy in memory and use of a pipelined algorithm with simultaneous computation and transfer of data from host to device memory. The speed of code development, flexibility, and low cost of the GPU implementations compared with application-specific integrated circuit (ASIC) and field programmable gate array (FPGA) implementations have the potential to greatly shorten the cycle of correlator development and deployment, for cases where some power-consumption penalty can be tolerated.

  1. Radio Frequency Interference: Projects and Activities Developed for the High School Earth Science, Astronomy, and Physics Classroom

    NASA Astrophysics Data System (ADS)

    Dunn, S. K.; Brown, J.

    2003-12-01

    Radio Frequency Interference: Projects and Activities Developed for the High School Earth Science, Astronomy, and Physics Classroom Susan Dunn Tewksbury Memorial High School Jason Brown Tyngsboro High School Preethi Pratap MIT Haystack Observatory The Research Experiences for Teachers (RET) program, funded by the NSF, brings teachers into research environments to interact with scientists and translate the experience into the classroom. We will describe a RET experience at the MIT Haystack Observatory which involved using an AR3000A communications receiver and a discone antenna as the basis for an Earth Science, Astronomy, and Physics classroom unit. The projects and activities in this unit were developed to help foster student learning and understanding of radio astronomy, the electromagnetic spectrum, wave dynamics, signal propagation, meteor detection, and radio frequency interference. Additionally, this RET project utilizes the SEARFE (Students Examining Australia???s Radio Frequency Environment) software developed for use with the AR3000A communications receiver to scan and monitor frequencies across the radio bandwidth to determine areas of low and high usage in the radio spectrum. Classroom activities include Scanning Protected Radio Astronomy Bandwidths, Investigating the Radio Environment, Time Variation of Signal Strength, Signal Strength vs. Location Studies, Detecting Meteors using the AR300A Receiver, Mapping the RFI Environment of Your School, AM Radio Interference, and Signal Propagation Effects. The primary focus of the unit???s activities is to address the Massachusetts State Science Frameworks for electromagnetic radiation, waves, cosmology, and matter and energy in the Earth system and foster an understanding of how everyday communications devices may cause radio frequency interference with sensitive radio astronomy equipment. The projects and activities in the unit will be used in the classroom, amended, and the results of the classroom

  2. 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

  3. Radio astronomy with the European Lunar Lander: Opening up the last unexplored frequency regime

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    The Moon is a unique location in our solar system and provides important information regarding the exposure to free space that is essential for future human space exploration to mars and beyond. The active broadband (100 kHz-100 MHz) tripole antenna now envisaged to be placed on the European Lunar Lander located at the Lunar South Pole allows for sensitive measurements of the exosphere and ionosphere, and their interaction with the Earths magnetosphere, solar particles, wind and CMEs and studies of radio communication on the Moon, that are essential for future lunar human and science exploration. In addition, the Lunar South Pole provides an excellent opportunity for radio astronomy. Placing a single radio antenna in an eternally dark crater or behind a mountain at the South (or North) pole would potentially provide perfect shielding from man-made radio interference (RFI), absence of ionospheric distortions, and high temperature and antenna gain stability that allows detection of the 21 cm wave emission from pristine hydrogen formed after the Big Bang and into the period where the first stars formed. A detection of the 21 cm line from the Moon at these frequencies would allow for the first time a clue on the distribution and evolution on mass in the early universe between the Epoch of Recombination and Epoch of Reionization (EoR). Next to providing a cosmological breakthrough, a single lunar radio antenna would allow for studies of the effect of solar flares and coronal mass ejections (CMEs) on the solar wind at distances close to Earth (space weather) and would open up the study of low frequency radio events (flares and pulses) from planets such as Jupiter and Saturn, which are known to emit bright (kJy-MJy) radio emission below 30 MHz (Jester and Falcke, 2009). Finally, a single radio antenna on the lunar lander would pave the way for a future large lunar radio interferometer; not only will it demonstrate the possibilities for lunar radio science and open up the

  4. Image Analysis, Modeling, Enhancement, Restoration, Feature Extraction and Their Applications in Nondestructive Evaluation and Radio Astronomy.

    NASA Astrophysics Data System (ADS)

    Zheng, Yi.

    The principal topic of this dissertation is the development and application of signal and image processing to Nondestructive Evaluation (NDE) and radio astronomy. The dissertation consists of nine papers published or submitted for publication. Each of them has a specific and unique topic related to signal processing or image processing in NDE or radio astronomy. Those topics are listed in the following. (1) Time series analysis and modeling of Very Large Array (VLA) phase data. (2) Image analysis, feature extraction and various applied enhancement methods for industrial NDE X-ray radiographic images. (3) Enhancing NDE radiographic X-ray images by adaptive regional Kalman filtering. (4) Robotic image segmentation, modeling, and restoration with a rule based expert system. (5) Industrial NDE radiographic X-ray image modeling and Kalman filtering considering signal-dependent colored noise. (6) Computational study of Kalman filtering VLA phase data and its computational performance on a supercomputer. (7) A practical and fast maximum entropy deconvolution method for de-blurring industrial NDE X-ray and infrared images. (8) Local feature enhancement of synthetic radio images by adaptive Kalman filtering. (9) A new technique for correcting phase data of a synthetic -aperture antenna array.

  5. Pulsars in a Box: A Radio Astronomy Exercise for Windows from PROJECT CLEA

    NASA Astrophysics Data System (ADS)

    Marschall, L. A.; Snyder, G. A.; Good, R. F.; Hayden, M. B.; Cooper, P. R.

    1996-12-01

    The latest astronomy laboratory exercise from PROJECT CLEA, "Radio Astronomy of Pulsars", is designed for use in introductory astronomy classes, but contains options and features that make it usable by upperclass astronomy students as well. The heart of the exercise is a simulated radio telescope, whose aperture, location, and beamwidth can be set by the instructor. It is steered by pushing buttons, but instead of seeing a star field on the field monitor,students see a projection of the sky showing, with a colored dot,where the beam is pointing. Large LED-like readouts display time and telescope coordinates. The telescope can be operated in either a tracking or transit mode. Using the telescope, students point to several pulsars suggested by the write-up (from an on-line catalog of over 500). Students can then use a multi-channel tunable receiver, with multiple oscilloscope displays, to view the incoming signal vs. time. The signal received is a combination of random receiver and background noise plus the pulsar signal (if it is in the beam) Receivers are tunable from 400 to 1400 MHz, and both the time and frequency behavior of signals can be studied. By measuring the dispersion delay at a number of different frequencies, students can determine the pulsar's distance. Data can be stored, displayed, and printed using a versatile measuring window. Though we provide a manual for a 2-3 hour lab exercise involving dispersion measures, the database and receivers can be used for a wide variety of other exercises, for instance the measurement of pulsar spin-down rates. We welcome suggestions for improvements and applications.

  6. NASA IDEAS EPO Support of the School of Galactic Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Castelaz, M.; Daugherty, J.; Moffett, D.; Case, J.

    2005-05-01

    The Pisgah Astronomical Research Institute (PARI) was awarded a STScI IDEAS Program grant to develop the School of Galactic Radio Astronomy (SGRA). SGRA enhances education of science, mathematics, and technology of students in grades 8-12. The purpose of SGRA is to teach the basics of scientific inquiry, which includes methodology, critical thinking, and communication of the results. To facilitate the excitement of science and discovery, teachers and students use the PARI 4.6m ``Smiley" radio telescope via the Internet. The IDEAS grant supported the development of the science curriculum and labs that use the 4.6m radio telescope, teacher workshops, and high speed internet service necessary for remote access to the radio telescope. Partnerships with Brevard High School , Furman University, and the University of North Carolina-Asheville have proven important to the success of the program. In addition, the IDEAS grant was important in our success in acquiring grants from the foundations at Z. Smith Reynolds and Progress Energy, a AAS Small Grant, and a STScI HST/EPO award to further enhance and continue the SGRA Program. More than 100 teachers are now involved in SGRA. To increase awareness of SGRA, we have presented the program at meetings of the AAS, North Carolina Science Teachers Association, the North Carolina Science Museum, and Pisgah Forest Institute summer workshops. Our experience in writing and carrying out the program, along with the NASA components in the program, teachers' comments, and lessons learned, will be presented. We are extremely grateful to the IDEAS Grant Program for helping PARI initiate and develop an exciting program of hands-on Internet radio astronomy from high school classrooms.

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

    NASA Technical Reports Server (NTRS)

    Mulhall, B. D. L.

    1977-01-01

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

  8. 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.

  9. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

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

    NASA Astrophysics Data System (ADS)

    Welch, J.; Backer, D.; Blitz, L.; Bock, D. C.-J.; Bower, G. C.; Cheng, C.; Croft, S.; Dexter, M.; Engargiola, G.; Fields, E.; Forster, J.; Gutierrez-Kraybill, C.; Heiles, C.; Helfer, T.; Jorgensen, S.; Keating, G.; Lugten, J.; MacMahon, D.; Milgrome, O.; Thornton, D.; Urry, L.; van Leeuwen, J.; Werthimer, D.; Williams, P. H.; Wright, M.; Tarter, J.; Ackermann, R.; Atkinson, S.; Backus, P.; Barott, W.; Bradford, T.; Davis, M.; Deboer, D.; Dreher, J.; Harp, G.; Jordan, J.; Kilsdonk, T.; Pierson, T.; Randall, K.; Ross, J.; Shostak, S.; Fleming, M.; Cork, C.; Vitouchkine, A.; Wadefalk, N.; Weinreb, S.

    2009-08-01

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

  12. Nuffield Secondary Science, Theme 5, Extension of Sense Perception.

    ERIC Educational Resources Information Center

    Howard, Edgar

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable for other countries. The Teachers' Guide to the entire set of Themes is described in SE 015 440…

  13. Nuffield Secondary Science, Theme 3, Biology of Man.

    ERIC Educational Resources Information Center

    Fox, Dennis

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable to other countries. The Teachers' Guide to the entire set of Themes is described in SE 015 440…

  14. Nuffield Secondary Science, Theme 1, Interdependence of Living Things.

    ERIC Educational Resources Information Center

    Marson, J. Eric

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools. The Teachers' Guide to the entire set of Themes is described in SE 015 440. Each Theme is a teachers' guide to a…

  15. The New Nuffield Combined Science Themes for the Middle Years

    ERIC Educational Resources Information Center

    Bingham, C. D.

    1976-01-01

    Described are the development, materials, and use of English developed science activities for junior high schools, the Nuffield Combined Science Themes for the Middle Years. The program, when completed will present 24 themes including: color, water, air, plastics, metals, insects, food, light, and electricity. (SL)

  16. Nuffield Secondary Science, Theme 2, Continuity of Life.

    ERIC Educational Resources Information Center

    Wigglesworth, George

    Nuffield Secondary Science is a set of tested materials from which teachers can prepare courses for students in grades 9-11 (approximately) who do not intend to major in science. The materials are designed for British secondary schools but are adaptable to other countries. The Teachers' Guide to the entire set of Themes is described in SE 015 440…

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

    NASA Astrophysics Data System (ADS)

    2009-11-01

    , 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.

  18. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Shaffer, R. D.; Gulkis, S.

    1982-01-01

    Use of the Tidbinbilla Interferometer to refine the source positions in the Parkes 2.7 GHz survey of the southern sky is described. A result of the first phase of this work was the identification of a quasi-stellar object which appears to be the most remote object yet observed. This object has a red shift of 3.78 (PKS 2000-330, and a velocity of recession equal to 91% of that light. Based on Hubble's law, PKS 2000-330 appears to be 12 billion light years away.

  19. Radio astronomy

    NASA Technical Reports Server (NTRS)

    Shaffer, R. D.; Mccluskey, J. T.; Gulkis, S.; Klein, M.; Kuiper, T.

    1981-01-01

    A K-band reflected-wave ruby maser was used on the 64-meter (DSS-43) antenna at the Tidbinbilla Tracking Station, near Canberra, Australia. Spectral line observations were carried out near 22 GHz for water vapor sources and near 24 GHz for ammonia sources. The water vapor observations were made in the direction of known southern OH and H2O maser sources. All of the previously detected water line sources examined were detected. In addition, two new water vapor maser sources were discovered, G301.1+1.1and G308.9+0.1. The spectrum of G301.0+1.1 is presented six ammonia sources were found: G291.3-0.7, G305.4+0.2, G322.2+0.6, G327.3-0.5, G333.6-0.2, and G268.4-0.8. Spectra of two of these sources, G291.3-0.7 (RCW 57) and G305.4+0.2, are presented. Both show clearly the presence of the quadrupole splitting satellite lines that will allow the determination of NH3 optical depths in these clouds.

  20. Radio astronomy

    NASA Astrophysics Data System (ADS)

    Shaffer, R. D.; McCluskey, J. T.; Gulkis, S.; Klein, M.; Kuiper, T.

    1981-10-01

    A K-band reflected-wave ruby maser was used on the 64-meter (DSS-43) antenna at the Tidbinbilla Tracking Station, near Canberra, Australia. Spectral line observations were carried out near 22 GHz for water vapor sources and near 24 GHz for ammonia sources. The water vapor observations were made in the direction of known southern OH and H2O maser sources. All of the previously detected water line sources examined were detected. In addition, two new water vapor maser sources were discovered, G301.1+1.1and G308.9+0.1. The spectrum of G301.0+1.1 is presented six ammonia sources were found: G291.3-0.7, G305.4+0.2, G322.2+0.6, G327.3-0.5, G333.6-0.2, and G268.4-0.8. Spectra of two of these sources, G291.3-0.7 (RCW 57) and G305.4+0.2, are presented. Both show clearly the presence of the quadrupole splitting satellite lines that will allow the determination of NH3 optical depths in these clouds.

  1. ASTRONOMY.

    ERIC Educational Resources Information Center

    Louisiana Arts and Science Center, Baton Rouge.

    THIS TEACHER'S GUIDE FOR A UNIT ON ASTRONOMY ESTABLISHES (1) UNDERSTANDINGS AND ATTITUDES, (2) SKILLS, AND (3) CONCEPTS TO BE GAINED IN THE STUDY. THE OVERVIEW EXPLAINS THE ORGANIZATION AND OBJECTIVES OF THE UNIT. TOPICAL DIVISIONS ARE (1) THE EARTH, (2) THE MOON, (3) THE SUN, (4) THE SOLAR SYSTEM, (5) THE STARS, (6) THE UNIVERSE, AND (7) SPACE…

  2. 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

  3. Research on Haystack radiometer, 20-24 GHz maser, and radio astronomy programs

    NASA Technical Reports Server (NTRS)

    1973-01-01

    During the first half of 1973, the Haystack antenna was utilized 76% of the time. Of this useful time, 72% was devoted to radio astronomy observing, 5% was spent on radar-related research and 23% went into maintenance and system improvements. Twenty-eight new radio astronomy programs were accepted, eight of which were completed during the period. One new radar program, topographic observations of Mars, was started in June and will be completed early in 1974. Fourteen programs continued from the previous period were also defined as complete. As of 1 July, 28 ratio observing programs were in a continuing status on the Haystack books. Four radar projects were also continuing. The 20-24 GHz maser development described in the preceding report progressed very well during an on-antenna test phase which began early in the year, but which terminated unfortunately in June with the complete loss of gain in the maser. Investigation of this problem is in progress. During this on-antenna test phase, the most sensitive water vapor observing capability which has yet become available was demonstrated.

  4. A New Geodetic Research Data Management System at the Hartebeesthoek Radio Astronomy Observatory

    NASA Astrophysics Data System (ADS)

    Coetzer, G. L.; Botha, R. C.; Combrinck, L.; Fourie, S. C.

    2015-04-01

    The Hartebeesthoek Radio Astronomy Observatory (HartRAO) hosts two research programmes: radio astronomy and space geodesy. The Space Geodesy programme has four main co-located space geodetic techniques, making HartRAO a true fiducial site. The HartRAO Space Geodesy Programme is expanding its geodetic techniques to include Lunar Laser Ranging (LLR) as well as a network of seismometers, accelerometers, tide gauges, and gravimeters. These instruments will be installed across the southern African region and will generate large volumes of data that will be streamed to and stored at HartRAO. Our objective is to implement a complete Geodetic Research Data Management System (GRDMS) to handle all HartRAO's geodetic data on-site in terms of archiving, indexing, processing, and extraction. These datasets and subsequent data products will be accessible to both the scientific community and general public through an intuitive and easy to use web-based front-end. As the first step in this process, we are currently working on establishing a new data centre. This opens up the possibility for the librarian to provide data services and support by working together with researchers and information technology staff. We discuss the rationale, role players and top-level system design of this GRDMS, as well as the current status and planned products thereof.

  5. The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey

    NASA Astrophysics Data System (ADS)

    Jackson, J. M.; Rathborne, J. M.; Shah, R. Y.; Simon, R.; Bania, T. M.; Clemens, D. P.; Chambers, E. T.; Johnson, A. M.; Dormody, M.; Lavoie, R.; Heyer, M. H.

    2006-03-01

    The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey is a new survey of Galactic 13CO J=1-->0 emission. The survey used the SEQUOIA multipixel array on the Five College Radio Astronomy Observatory 14 m telescope to cover a longitude range of l=18deg-55.7d and a latitude range of |b|<1deg, a total of 75.4 deg2. Using both position-switching and On-The-Fly mapping modes, we achieved an angular sampling of 22", better than half of the telescope's 46" angular resolution. The survey's velocity coverage is -5 to 135 km s-1 for Galactic longitudes l<=40deg and -5 to 85 km s-1 for Galactic longitudes l>40deg. At the velocity resolution of 0.21 km s-1, the typical rms sensitivity is σ(T*A)~0.13 K. The survey comprises a total of 1,993,522 spectra. We show integrated intensity images (zeroth moment maps), channel maps, position-velocity diagrams, and an average spectrum of the completed survey data set. We also discuss the telescope and instrumental parameters, the observing modes, the data reduction processes, and the emission and noise characteristics of the data set. The Galactic Ring Survey data are available to the community online or in DVD form by request.

  6. 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.

  7. 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.

  8. Estimating the size of a radio quiet zone for the radio astronomy service

    NASA Astrophysics Data System (ADS)

    Peng, Bo; Han, Wenjun

    2009-12-01

    The size of a radio quiet zone (RQZ) is largely determined by transmission losses of interfering signals, which can be divided into free space loss and diffraction loss. The free space loss is dominant. The diffraction loss presented in this paper is described as unified smooth spherical and knife edge diffractions, which is a function of minimum path clearance. We present a complete method to calculate the minimum path clearance. The cumulative distribution of the lapse rate of refractivity ( g n ), between the earth surface and 1 km above, is studied by using Chinese radio climate data. Because the size of an RQZ is proportional to g n , the cumulative distribution of g n can be used as an approximation for the size of the RQZ. When interference originates from mobile communication or television transmissions at a frequency of 408 MHz, and overline {g_n } is 40 N/km, where the refractivity N=left( {n-1} right) × 10^6, the size of the RQZ would be 180 km for a mobile source or 210 km for a television source, with a probability in the range of 15-100% in different months and for different stations. When speaking of the size of an RQZ, the radius in the case of a circular zone is implied. It results that a size of an RQZ is mainly influenced by transmission loss rather than effective radiated power. In the case where the distance between an interfering source and a radio astronomical observatory is about 100 km, at a frequency of 408 MHz, the allowable effective radiated power of the interfering source should be less than -30 dBW with a probability of about 85% for overline {g_n } equals 40 N/km, or -42 dBW with a probability less than 1 % for overline {g_n } equals 80 N/km.

  9. Coherence theory applied to space radio astronomy: Cassini/RPWS, a practical implementation.

    NASA Astrophysics Data System (ADS)

    Lecacheux, A.

    2009-04-01

    Solar and planetary, space radio astronomy has taken advantage of several technical and methodological improvements, from the first age - when simple wire antennas and analogue filters were used (RAE, IMP, Voyager) -, later - when spacecraft spin (ISEE, Ulysses) could be exploited for source direction retrieval, and up to now - with the current use of on board digital correlators analyzing multiple wire antennas (Cassini, Stereo). Indeed, correlation analysis from multiple sensors allows, in principle, the full second order statistics of the analyzed signal to be retrieved, thus providing, with respect to simple antenna system, some extra information on the received radio waves (mainly the spatial brightness distribution and intrinsic polarisation of the observed radio source). In the real case of experiments aboard interplanetary spacecraft, one has to take into account a number of undesirable instrumental effects, for instance the perturbation of the antenna response by the spacecraft conductive body or the limitation of the signal to noise ratio by the available telemetry rate. In this talk, taking as a working example the Cassini/RPWS data, we develop a consistent statistical model of such a correlator, which allows actual measurements to be easily characterized and reliably inverted. Some results from observations of Jovian and Saturnian radiating sources are provided as illustrative examples.

  10. Calibration of a cylindrical RF capacitance probe. [for ionospheric plasma effects on Radio Astronomy Explorer 1 antenna

    NASA Technical Reports Server (NTRS)

    Mosier, S. R.; Kaiser, M. L.

    1975-01-01

    Ambient electron concentrations derived from observations with the Radio Astronomy Explorer 1 antenna capacitance probe have been compared with upper hybrid resonance measurements from the same spacecraft. From this comparison an empirical correction factor for the capacitance probe measurements has been derived. The differences between the two types of measurements is attributed to sheath effects.

  11. Albrecht Unsöld: his role in the interpretation of the origin of cosmic radio emission and in the beginning of radio astronomy in Germany

    NASA Astrophysics Data System (ADS)

    Wielebinski, Richard

    2013-03-01

    Albrecht Unsöld's career spanned over 50 years at the beginning of the 20th century. In this period atomic physics made great advances and Unsöld applied this to astrophysical questions. He came in contact with the early radio astronomy observations and devoted part of his career to the interpretation of the origin of cosmic radio waves. Although hampered by the post-war situation, Unsöld's contributions to the interpretation of cosmic radio waves were important.

  12. A Low-Frequency Distributed Aperture Array for Radio Astronomy in Space

    NASA Astrophysics Data System (ADS)

    Boonstra, Albert-Jan; Saks, Noah; Falcke, Heino; Klein-Wolt, Marc; Bentum, Ark; Thilak Rajan, Raj; Wijnholds, Ir. Stefan J.; Arts, Michel; van-T Klooster, Kees; Belien, Frederik

    The frequency band below 30 MHz is one of the last unexplored bands in radio astronomy. This band is well suited for studying the early cosmos at high hydrogen redshifts, the so-called dark ages, extragalactic surveys, (extra) solar planetary bursts, and high energy particle physics. In addition, space research such as space weather tomography, are also areas of scientific interest. Due to ionospheric scintillation (below 30MHz) and its opaqueness (below 15MHz), earth-bound radio astronomy observations in these bands are either severely limited in sensitivity and spatial resolution or entirely impossible. A radio telescope in space obviously would not be hampered by the Earth's ionosphere. In the past, several (limited) studies have been conducted to explore possibilities for such an array in space. These studies considered aperture synthesis arrays in space, at the back-side of the Moon, or a satellite constellation operating in a coherent mode. In 2009 an ESA project, Distributed Aperture Array for Radio Astronomy in Space (DARIS), set out to investigate the space-based radio telescope concept. The focus of this feasibility study is on a moderate size three-dimensional satellite constellation operating as a coherent large aperture synthesis array. This aperture synthesis array would consist of 5 to 50 antennas (satellites) having a maximum separation of 100 km. This study considers the main aspects of such a distributed system in more detail than previous studies. This conference contribution aims at presenting an overview of the DARIS project and at discussing the main results. The project selected extra-galactic surveys and the search for transient radio sources as the best suited science cases within the DARIS concept, and it investigated the scientific and technical requirements for such an array. Several antenna concepts were considered and simulated. An active antenna dipole array concept would be well suited, and a moderate 5 m tip-tip antenna system would

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Landon, Jonathan C.

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

  15. Next Generation Very Large Array: Centimeter Radio Astronomy in the 2020s

    NASA Astrophysics Data System (ADS)

    Hughes, A. Meredith; Beasley, Anthony; Carilli, Christopher

    2015-08-01

    We discuss the future scientific discovery and technical challenges for cm radio studies, presenting calculations and simulations of the science of a next generation VLA (ngVLA), an array with vastly improved resolution and sensitivity relative to ALMA and JVLA, operating from ~1 GHz to 115 GHz, with an enhanced ability to image thermal objects on milliarcsecond scales, spanning thermal and non-thermal radio astronomy and bridging SKA and ALMA capabilities.Key areas of astrophysics where ngVLA can make new contributions include:- Probing deep into dusty protoplanetary disks, revealing terrestrial planet formation on AU-scales — regions that are opaque at shorter wavelengths. Observations in this wavelength range are critically required to study the poorly understood growth of dust into rocks.- Providing a census and imaging at kpc-scale resolution, of the cool molecular gas in distant galaxies. The ngVLA will be able to observe the lower order molecular transitions in high redshift, normal star forming galaxies, a key diagnostic for understanding the fuel driving the star formation history of the Universe.- Enabling an unprecedented, wide field imaging capability for nearby galaxies, over the cm frequency range covering key astrochemical tracers, including both thermal/non-thermal radio continuum emission.- Exploring the otherwise-unobservable deep atmospheres of the giant planets. In addition, the subsurfaces of other solar system bodies (e.g. icy satellites, TNOs, comets, asteroids) can be probed via thermal emission and radar remote sensing.- Allowing major improvements in synoptic, astrometric and transient/time-domain measurements at cm wavelengths of a wide variety of active sources, including Fast Radio Bursts, AGNs, pulsars and x-ray binaries.Led by NRAO, work to address the technical challenges for the ngVLA is underway. Areas currently under investigation include: low cost antennas, ultra-wide band feeds and receivers, broad band data transmission, and

  16. National Radio Astronomy Observatory: The early history and development of the observatory at Green Bank, West Virginia, are reviewed.

    PubMed

    Emberson, R M

    1959-11-13

    The existence of the National Radio Astronomy Observatory and the researches already accomplished there are the result of the foresight and wisdom of United States scientists, the National Science Board, and the Congress, who joined forces to make possible this new national asset. Continued effort will be needed td insure that the observatory will always have the finest possible research instruments and that the site will be a haven of radio quiet. Visiting scientists in some instances may wish to bring equipment with them for studying special problems. Within its means, the observatory will provide supporting facilities, including receivers and other electronic devices, computers, laboratories and shops, and housing. Scientists interested in more details concerning arrangements for visitors should direct their inquiries to the National Radio Astronomy Observatory, P. O. Box 2, Green Bank, West Virginia. PMID:17753091

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

    NASA Astrophysics Data System (ADS)

    1998-12-01

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

  18. 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

  19. Estimate of Interference from the Aeronautical Mobile Services of the Cities of Glendale and Pasadena to Goldstone Radio Astronomy Stations at 4.9 Gigahertz

    NASA Astrophysics Data System (ADS)

    Ho, C.; Sue, M.; Manshadi, F.

    2006-05-01

    The Federal Communications Commission (FCC) recently allocated the 4.9-GHz band to public safety telecommunications services. Radio Astronomy Services (RAS) also has been using this frequency. NASA will primarily use Deep Space Station 28 (DSS 28) at Goldstone, California, for radio astronomy services that are sensitive to radio-frequency interference (RFI). This study is to determine the RFI potential of airborne transmission from two cities to radio astronomy sites in Goldstone. Propagation losses over the terrain between both cities and Goldstone are estimated using the Trans-Horizon Interference Propagation Loss (THIPL) software recently developed at JPL and high-resolution terrain data. The necessary coordination area for protecting the Goldstone radio astronomy station has been defined based on the minimum propagation loss required. Study results and suggestions for modification to the airborne areas proposed by both cities' police departments are presented.

  20. Designing a new Geodetic Research Data Management System for the Hartebeesthoek Radio Astronomy Observatory

    NASA Astrophysics Data System (ADS)

    Coetzer, Glend Lorraine

    2015-08-01

    The Hartebeesthoek Radio Astronomy Observatory (HartRAO) participates in astronomic, astrometric and geodetic Very Long Baseline Interferometry (VLBI) observations using both 26- and 15-m diameter radio telescopes. Geodetic data from a Satellite Laser Ranger (SLR), Global Navigation Satellite System (GNSS), Met4 weather stations and a new seismic vault network must be stored at HartRAO and made available to the scientific community. Some data are e-transferred to correlators, analysis centres and space geodesy data providers, while some data are processed locally to produce basic data products. The new South African co-located seismology network of seismic and GNSS instrumentation will generate large volumes of raw data to be stored and archived at HartRAO. The current data storage systems are distributed and outdated, and management systems currently being used will also not be able to handle the additional large volumes of data. This necessitates the design and implementation of a new, modern research data management system which combines all the datasets into one database, as well as cater for current and future data volume requirements. The librarian’s expertise and knowledge will be used in the design and implementation of the new HartRAO Geodetic Research Data Management System (GRDMS). The librarian’s role and involvement in the design and implementation of the new GRDMS are presented here. Progress to date will also be discussed.

  1. Instrumental and Observational Studies in Radio Astronomy, Low Noise Amplifier Design and Methanol Maser Research

    NASA Astrophysics Data System (ADS)

    Minier, V.

    1998-10-01

    ``Radio astronomy is the study of the universe by observing electromagnetic radiation after it has been amplified. The use of amplifiers that preserve the oscillatory character of radiation - the phase information - is the mark of Radio astronomy.'' Thus, the development of low noise amplifiers for microwave and millimeter wavelengths is a major part of Radio astronomy as important as the observations themselves. This technical report involves those two aspects of Radio astronomy, the observational and technical aspects. In the first part, observations of methanol masers in massive star forming regions using Very Long Baseline Interferometry (VLBI) are presented. The second part concerns the realization of low noise amplifiers using in a radio camera. Recent observations have confirmed that the methanol masers are powerful tools for probing the regions of massive star formation. The methanol masers fall in two distinct classes related to their location in the star forming regions. Class I methanol masers are observed offset far away from the UC HII region emission peak. They are certainly collisionally pumped and may occur in the interface between high velocity gas outflows and the ambient molecular material. Class II methanol masers coincide with the UC HII region emission. They may be radiatively pumped by FIR radiation from the dust grains and reside either in spherical layers surrounding the UC HII regions or in circumstellar discs. The maser spots are usually compact (~1-10 AU) and lie in region of physical conditions n(H)~104-108 cm-3 and T=100-1000 K. CH3OH may be produced by hydrogenation of CO on the surface of the icy mantles of the dust grains . The methanol is then injected in the molecular gas by evaporation of the ice (n(H)=106 cm-3, T=100-300 K). In this report we present VLBI observations of 6.7 and 12.2 GHz methanol masers in the star forming regions NGC7538, W75N and S252. Our results show the existence of two groups of masers in NGC7538. The

  2. 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

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

    NASA Astrophysics Data System (ADS)

    Sane, N.; Ford, J.; Harris, A. I.; Bhattacharyya, S. S.

    2012-05-01

    There is a growing trend toward using high-level tools for design and implementation of radio astronomy digital signal processing (DSP) systems. Such tools, for example, those from the Collaboration for Astronomy Signal Processing and Electronics Research (CASPER), are usually platform-specific, and lack high-level, platform-independent, portable, scalable application specifications. This limits the designer's ability to experiment with designs at a high-level of abstraction and early in the development cycle. We address some of these issues using a model-based design approach employing dataflow models. We demonstrate this approach by applying it to the design of a tunable digital downconverter (TDD) used for narrow-bandwidth spectroscopy. Our design is targeted toward an FPGA platform, called the Interconnect Break-out Board (IBOB), that is available from the CASPER. We use the term TDD to refer to a digital downconverter for which the decimation factor and center frequency can be reconfigured without the need for regenerating the hardware code. Such a design is currently not available in the CASPER DSP library. The work presented in this paper focuses on two aspects. First, we introduce and demonstrate a dataflow-based design approach using the dataflow interchange format (DIF) tool for high-level application specification, and we integrate this approach with the CASPER tool flow. Secondly, we explore the trade-off between the flexibility of TDD designs and the low hardware cost of fixed-configuration digital downconverter (FDD) designs that use the available CASPER DSP library. We further explore this trade-off in the context of a two-stage downconversion scheme employing a combination of TDD or FDD designs.

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

    NASA Astrophysics Data System (ADS)

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

    2000-12-01

    In recent years, Composite Optics, Inc. (COI) has made significant advances in the use of graphite fiber reinforced composite (GFRC) materials for astronomical instrument applications. The inherent low density, high stiffness, and thermal stability makes GFRC a natural candidate for many astronomy applications. In order to reap these inherent benefits in astronomical applications, basic research has focused on material and process improvement. This has been accompanied by the design, fabrication, and test of several prototype reflectors that cover a broad wavelength spectrum of astronomical interests. The results of, and applications for, these efforts are summarized in the following list. X-Ray Carrier Shell: Innovative composite process yields accuracy and moisture stability. Demonstrated by vacuum optical test of 6" Wolter-I shell. Applicable to Con-X, etc. Lightweight Mirror Substrate for Visible Astronomy: Composite/glass hybrid design. Areal density < 15 kg/m2. Demonstrated by cryo-optical test (to 35K) of 1.6m NMSD mirror. Applicable to NGST, etc. Polishable Composite Facesheet: Glass-like coating applied to composite. Polishable by conventional methods. Multiple six-inch substrates polished to 20 angstroms. Technology will enable future 5 kg/m2 visible to UV optics. 10 kg/m2 Submillimeter Reflector: Apertures to 5m possible with economical, all-composite mirror design, diffraction limited at 80 microns. Demonstrated with cryo-optical test (to 70K) of FIRST 2-meter prototype mirror. Applicable to FIRST and other IR astronomy. Large, Ultra-Stable Optical Support Structure: Uniform and near-zero CTE over broad dimensions. Demonstrated with cryo-optical test of 2-meter FIRST prototype. Applicable to NGST, SIM, LISSA. Ground Based Radio Telescope Reflector: Low-cost, accurate, stable, durable all-composite design for support structure & reflective surface. Demonstrated via fab & test of 3m adjustable and 5m static prototypes. Applicable to LMT, ALMA, etc. These

  5. Applicability of radio astronomy techniques to the processing and interpretation of aperture synthesis passive millimetre-wave applications

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    This PhD programme is contributing to the development of Passive Millimetre-Wave Imagers (PMMWI) using the principles of interferometric aperture synthesis and digital signal processing. The principal applications are security screening, all-weather flight aids and earth observation. To enhance the cost-effectiveness of PMMWI systems the number of collecting elements must be minimised whilst maintaining adequate image fidelity. A wide range of techniques have been developed by the radio astronomy community for improving the fidelity of sparse interferometric array imagery. This paper brings to the attention of readers these techniques and discusses how they may be applied to imaging using software packages publicly available from the radio astronomy community. The intention of future work is to adapt these algorithms to process experimental data from a range of realistic simulations and real-world targets.

  6. The radio astronomy experiment on Helios A and B /E 5c/. [using dipole antenna-preamplifier-radiometer system

    NASA Technical Reports Server (NTRS)

    Weber, R. R.

    1975-01-01

    The NASA Goddard Space Flight Center radio astronomy experiment on Helios, identified as Experiment 5c, has sixteen observing frequencies over the range of 26.5 to 3000 kHz. The antenna consists of two extendible 15-m booms, forming an electric dipole, two high-impedance preamplifiers located at the root of the booms, and the 16-channel radiometer. Important information about propagation conditions, such as absorption, scattering and refraction, are expected from observations of radio emission regions at distances between 1 and 0,3 AU.

  7. The beginnings of decameter radio astronomy: pioneering works of Semen Ya. Braude and his followers in Ukraine

    NASA Astrophysics Data System (ADS)

    Vavilova, I. B.; Konovalenko, A. A.; Megn, A. V.

    2007-06-01

    S.Ya. Braude (1911-2003) was the well-known radio astronomer, one of the founders of low-frequency astronomical research in the world, in particular in the former Soviet Union. He began to work in this field of science in 1957, in Kharkiv city (Ukraine), from the design and manufacturing small decameter interferometer ID-1 and ID-2. Since that time Braude and his team have developed more sophisticated radio decameter telescopes as UTR-1 and UTR-2 (the largest in the world till now) as well as the first decameter VLBI network URAN. They have obtained some important pioneering results about low-frequency radio emission of objects in our Solar system, Galaxy and Metagalaxy by means of these telescopes. In this paper the key events of early history of decameter radio astronomy research in the former USSR are mentioned with emphasizing the role of S. Braude. For the period of 1957-1962, the quotations of Braude's Personal Diary (2003) are first laying open to the public. The most important results obtained by S.Ya. Braude and his followers as well as perspectives of decameter radio astronomy in Ukraine and in the world are highlighted briefly.

  8. A Collision of Interests - Protecting Radio Astronomy from Interference in a Free-Market Environment

    NASA Astrophysics Data System (ADS)

    Vanden Bout, P. A.

    2004-05-01

    The protection of radio astronomy (RA) from radio frequency interference (RFI) is becoming increasingly difficult. Established mechanisms for the management of spectrum in the United States and throughout the world have provided a degree of protection from RFI by assigning certain bands to RA on an exclusive or shared use basis. Explosive growth in commercial spectrum use has created spectrum crowding outside the RA bands, especially at lower frequencies below 3 GHz. Constellations of low-earth-orbit satellites are a particular problem to RA in that they always have transmitters above the horizon and these transmitters can spill unwanted emissions into the RA bands from their adjacent operating bands. The desire to study the early Universe presents a new challenge for RA with respect to RFI. The RA protected bands were selected for frequencies of important spectral lines. For objects in the distant, redshifted Universe, these lines can appear at all frequencies below the rest frequency and observations may be needed where the RA bands offer no protection. The growing needs of RA occur at the same time that commercial demand for spectrum is driving the Federal Communications Commission and the International Telecommuncations Union to consider entirely new approaches to spectrum management. These approaches would favor intensive commercial use of spectrum over scientific use in that decisions would be largely based on economic and efficient use considerations. It has even been proposed by some proponents of change in spectrum management policy that the entire spectrum be sold to the highest bidders in one global auction. While this is unlikely to happen, it is indicative of the climate in which RA spectrum managers currently work.

  9. Detection of dust impacts by the Voyager planetary radio astronomy experiment

    NASA Technical Reports Server (NTRS)

    Evans, David R.

    1993-01-01

    The Planetary Radio Astronomy (PRA) instrument detected large numbers of dust particles during the Voyager 2 encounter with Neptune. The signatures of these impacts are analyzed in some detail. The major conclusions are described. PRA detects impacts from all over the spacecraft body, not just the PRA antennas. The signatures of individual impacts last substantially longer than was expected from complementary Plasma Wave Subsystem (PWS) data acquired by another Voyager experiment. The signatures of individual impacts demonstrate very rapid fluctuations in signal strength, so fast that the data are limited by the speed of response of the instrument. The PRA detects events at a rate consistently lower than does the Plasma Wave subsystem. Even so, the impact rate is so great near the inbound crossing of the ring plane that no reliable estimate of impact rate can be made for this period. The data are consistent with the presence of electrons accelerated by ions within an expanding plasma cloud from the point of impact. An ancillary conclusion is that the anomalous appearance of data acquired at 900 kHz appears to be due to an error in processing the PRA data prior to their delivery rather than due to overload of the PRA instrument.

  10. The Evolution of the National Radio Astronomy Observatory into a User Based Observatory

    NASA Astrophysics Data System (ADS)

    Kellerman, Kenneth I.; Bouton, E.

    2006-12-01

    The NRAO was conceived in the mid 1950s as a state-of-the-art facility to allow the United States to compete in the exciting radio astronomy discoveries then taking place in the U.K., the Netherlands and Australia. Otto Struve, the first NRAO director in Green Bank, was chosen to lead the Observatory research program. During Struve's tenure as director, nearly all of the research was carried out by NRAO staff members resident at the Green Bank Observatory. However, under Dave Heeschen, who served as NRAO Director from 1961 to 1978, the number of visitor programs gradually increased; the NRAO scientific staff become more involved in visitor support than in doing their own research, and users became more dependent on instruments and techniques developed by NRAO, often not even coming to the Observatory for their observations. Currently, about half of the observing time on NRAO facilities is allocated to observers from foreign institutions -institutions with which NRAO was built to compete.

  11. FANATIC: an SIS radiometer for radio astronomy from 660 to 695 GHz

    NASA Astrophysics Data System (ADS)

    Harris, A. I.; Schuster, K.-F.; Genzel, R.; Plathner, B.; Gundlach, K.-H.

    1994-09-01

    FANATIC is a compact radiometer optimized for radio astronomy from about 660 to 695 GHz (lambda 455 - 432 micron). We observed a large number of molecular and atomic spectral lines from galactic and extragalactic sources during FANATIC's first run on the James Clerk Maxwell Telescope in early March 1994. Double sideband receiver temperatures during observations were about 800 K (25 h nu/k). The heart of the receiver is a two-junction Nb/AlO(x)/Nb SIS array fed by a sandwiched V-antenna. The junction array and antenna are fabricated together at IRAM's Grenoble SIS laboratory. Each junction has a normal resistance of Rn approximately 10 Ohm, an area of approximately 2 sq micron, an individual radial stub circuit to resonate the capacitance, and a lambda/4 transformer to match to the antenna. The solid-state local oscillator is a mm-wave Gunn oscillator followed by a doubler and tripler. The LO diplexer is a Martin-Puplett interferometer, which insures that there is always abundant LO power for operation and speedy tuning. The receiver and telescope coupling optics, LO, dewar, and calibration system fit on an 0.6 x 0.8 m optical breadboard.

  12. FANATIC: An SIS Radiometer for Radio Astronomy in the 660-690 GHz Band

    NASA Astrophysics Data System (ADS)

    Harris, A. I.; Schuster, K.-F.; Gundlach, K.-H.; Plathner, B.

    1994-05-01

    FANATIC is a compact radiometer optimized for radio astronomy from about 660 to 690 GHz (455-435 micron). We observed a large number of molecular and atomic spectral lines from galactic and extragalactic sources during FANATIC's first run on the James Clerk Maxwell Telescope in early March 1994. Double sideband receiver temperatures during observations were about 800 K (25 hv/k). The heart of the receiver is a two-junction Nb/AlOx/Nb SIS array fed by a sandwiched V-Antenna. The junction array and antenna are fabricated together at IRAM's Grenoble SIS laboratory. Each junction has a normal resistance of Rn~10 ohm, an area of ~2 um^2 , an individual radial stub circuit to resonate the capacitance, and a 1/4-wavelength transformer to match to the antenna. The solid-state local oscillator is a mm-wave Gunn oscillator followed by a doubler and tripler. The LO diplexer is a Martin-Puplett interferometer, which insures that there is always abundant LO power for operation and speedy tuning. The receiver and telescope coupling optics, LO, dewar, and calibration system fit on an 0.6 x 0.8 m optical breadboard.

  13. 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.

  14. Ambient and Cryogenic, Decade Bandwidth, Low Noise Receiving System for Radio Astronomy Using Sinuous Antenna

    NASA Astrophysics Data System (ADS)

    Gawande, Rohit Sudhir

    Traditionally, radio astronomy receivers have been limited to bandwidths less than an octave, and as a result multiple feeds and receivers are necessary to observe over a wide bandwidth. Next generation of instruments for radio astronomy will benefit greatly from reflector antenna feeds that demonstrate very wide instantaneous bandwidth, and exhibit low noise behavior. There is an increasing interest in wideband systems from both the cost and science point of view. A wideband feed will allow simultaneous observations or sweeps over a decade or more bandwidth. Instantaneous wide bandwidth is necessary for detection of short duration pulses. Future telescopes like square kilometer array (SKA), consisting of 2000 to 3000 coherently connected antennas and covering a frequency range of 70 MHz to 30 GHz, will need decade bandwidth single pixel feeds (SPFs) along with integrated LNAs to achieve the scientific objectives in a cost effective way. This dissertation focuses on the design and measurement of a novel decade bandwidth sinuous-type, dual linear polarized, fixed phase center, low loss feed with an integrated LNA. A decade bandwidth, low noise amplifier is specially designed for noise match to the higher terminal impedance encountered by this antenna yielding an improved sensitivity over what is possible with conventional 50 O amplifiers. The self-complementary, frequency independent nature of the planar sinuous geometry results in a nearly constant beam pattern and fixed phase center over more than a 10:1 operating frequency range. In order to eliminate the back-lobe response over such a wide frequency range, we have projected the sinuous pattern onto a cone, and a ground plane is placed directly behind the cone's apex. This inverted, conical geometry assures wide bandwidth operation by locating each sinuous resonator a quarter wavelength above the ground plane. The presence of a ground plane near a self complementary antenna destroys the self complementary nature

  15. 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.

  16. 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.

  17. The history of early low frequency radio astronomy in Australia. 3: Ellis, Reber and the Cambridge field station near Hobart

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

    Low frequency radio astronomy in Tasmania began with the arrival of Grote Reber to the State in 1954. After analysing ionospheric data from around the world, he concluded that Tasmania would be a very suitable place to carry out low frequency observations. Communications with Graeme Ellis in Tasmania, who had spent several years studying the ionosphere, led to a collaboration between the two in 1955 during which year they made observations at Cambridge, near Hobart. Their observations took place at four frequencies between 2.13 MHz and 0.52 MHz inclusive, with the results at the higher frequencies revealing a clear celestial component

  18. Image Reconstruction in Radio Astronomy with Non-Coplanar Synthesis Arrays

    NASA Astrophysics Data System (ADS)

    Goodrick, L.

    2015-03-01

    Traditional radio astronomy imaging techniques assume that the interferometric array is coplanar, with a small field of view, and that the two-dimensional Fourier relationship between brightness and visibility remains valid, allowing the Fast Fourier Transform to be used. In practice, to acquire more accurate data, the non-coplanar baseline effects need to be incorporated, as small height variations in the array plane introduces the w spatial frequency component. This component adds an additional phase shift to the incoming signals. There are two approaches to account for the non-coplanar baseline effects: either the full three-dimensional brightness and visibility model can be used to reconstruct an image, or the non-coplanar effects can be removed, reducing the three dimensional relationship to that of the two-dimensional one. This thesis describes and implements the w-projection and w-stacking algorithms. The aim of these algorithms is to account for the phase error introduced by non-coplanar synthesis arrays configurations, making the recovered visibilities more true to the actual brightness distribution model. This is done by reducing the 3D visibilities to a 2D visibility model. The algorithms also have the added benefit of wide-field imaging, although w-stacking supports a wider field of view at the cost of more FFT bin support. For w-projection, the w-term is accounted for in the visibility domain by convolving it out of the problem with a convolution kernel, allowing the use of the two-dimensional Fast Fourier Transform. Similarly, the w-Stacking algorithm applies a phase correction in the image domain to image layers to produce an intensity model that accounts for the non-coplanar baseline effects. This project considers the KAT7 array for simulation and analysis of the limitations and advantages of both the algorithms. Additionally, a variant of the Högbom CLEAN algorithm was used which employs contour trimming for extended source emission flagging. The

  19. Indexing data cubes for content-based searches in radio astronomy

    NASA Astrophysics Data System (ADS)

    Araya, M.; Candia, G.; Gregorio, R.; Mendoza, M.; Solar, M.

    2016-01-01

    Methods for observing space have changed profoundly in the past few decades. The methods needed to detect and record astronomical objects have shifted from conventional observations in the optical range to more sophisticated methods which permit the detection of not only the shape of an object but also the velocity and frequency of emissions in the millimeter-scale wavelength range and the chemical substances from which they originate. The consolidation of radio astronomy through a range of global-scale projects such as the Very Long Baseline Array (VLBA) and the Atacama Large Millimeter/submillimeter Array (ALMA) reinforces the need to develop better methods of data processing that can automatically detect regions of interest (ROIs) within data cubes (position-position-velocity), index them and facilitate subsequent searches via methods based on queries using spatial coordinates and/or velocity ranges. In this article, we present the development of an automatic system for indexing ROIs in data cubes that is capable of automatically detecting and recording ROIs while reducing the necessary storage space. The system is able to process data cubes containing megabytes of data in fractions of a second without human supervision, thus allowing it to be incorporated into a production line for displaying objects in a virtual observatory. We conducted a set of comprehensive experiments to illustrate how our system works. As a result, an index of 3% of the input size was stored in a spatial database, representing a compression ratio equal to 33:1 over an input of 20.875 GB, achieving an index of 773 MB approximately. On the other hand, a single query can be evaluated over our system in a fraction of second, showing that the indexing step works as a shock-absorber of the computational time involved in data cube processing. The system forms part of the Chilean Virtual Observatory (ChiVO), an initiative which belongs to the International Virtual Observatory Alliance (IVOA) that

  20. An antenna, a radio and a microprocessor: which kinds of observation are possible in meteor radio astronomy?

    NASA Astrophysics Data System (ADS)

    Barbieri, L.

    2016-01-01

    Radio meteors are usually investigated by professional radars. Amateur astronomers cannot have transmitters, so usually they can only listen to sounds generated by a radio tuned to a TV or military transmitter. Until recently, this kind of observation has not produced good data. The experience of "RAMBo" (Radar Astrofilo Meteorico Bolognese) shows which data can be extracted from an amateur meteor scatter observatory and the results which can be achieved.

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  2. The Contribution of the Division of Radiophysics Murraybank Field Station to International Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Wendt, Harry; Orchiston, Wayne; Slee, Bruce

    During the 1950s Australia was one of the world's foremost astronomical nations owing primarily to the work of the dynamic radio astronomy group within the Commonwealth Scientific and Industrial Research Organisation's Division of Radiophysics. Most of the observations were made at the network of field stations maintained by the Division in or near Sydney, and one of these field stations was Murraybank in the north-western suburbs of Sydney. GVaucouleursDe1954The Magellanic Clouds and the GalaxyThe Observatory7423311954Obs....74...23DDe Vaucouleurs, G., 1954a. The Magellanic Clouds and the Galaxy. The Observatory, 74, 23-31. GVaucouleursDe1954The Magellanic Clouds and the Galaxy, IIThe Observatory741581641954Obs....74..158DDe Vaucouleurs, G., 1954b. The Magellanic Clouds and the Galaxy, II. The Observatory, 74, 158-164. GVaucouleursDe1961Classification and radial velocities of bright southern galaxiesMemoirs of the Royal Astronomical Society68

  3. Highlighting the history of French radio astronomy. 2: The solar eclipse observations of 1949-1954

    NASA Astrophysics Data System (ADS)

    Orchiston, Wayne; Steinberg, Jean-Louis

    2007-03-01

    During the 1940s and early 1950s radio astronomers from a number of nations used observations of total and partial solar eclipses to investigate the positions of radio-emitting regions and to determine the distribution of radio emission across the solar disk. Between 1949 and 1954 French radio astronomers from the Ecole Normale Supérieure and the Institute of Astrophysics between them mounted four successful eclipse expeditions to Africa and northern Europe. This short paper lists the personnel involved, discusses their instrumentation, describes the observations made, and evaluates the significance of these observations in an international context.

  4. The history of early low frequency radio astronomy in Australia. 4: Kerr, Shain, Higgins and the Hornsby Valley field station near Sydney

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    Between 1949 and 1952 the CSIR's Division of Radiophysics was a world leader in low frequency radio astronomy, through research conducted mainly by Alex Shain and Charlie Higgins at their Hornsby Valley field station near Sydney. In this paper we discuss the personnel, radio telescopes and research programs (mainly conducted at 9.15 and 18.3 MHz) associated with the Hornsby Valley site.

  5. 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.

  6. Highlighting the history of French radio astronomy. 1: Nordmann's attempt to observe solar radio emission in 1901

    NASA Astrophysics Data System (ADS)

    Débarbat, Suzanne; Lequeux, James; Orchiston, Wayne

    2007-03-01

    Soon after the discovery of radio waves by Hertz in 1886 the idea that the Sun must emit this radiation was suggested. A number of scientists from different nations then attempted to detect this emission, and one of these was the French astronomer, Charles Nordmann. This paper provides biographical Information an Nordmann before discussing his attempt to detect solar emisson in 1901 and the reasons he was unsuccessful.

  7. The Center for Advanced Radio Astronomy: Graduates, Undergraduates and High School Students Engaged in the Exploration of Astrophysics

    NASA Astrophysics Data System (ADS)

    Miller, Andy; Jenet, F. A.

    2014-01-01

    The Center for Advanced Radio Astronomy (CARA) is a part of the University of Texas system located in Brownsville, Texas. Under the umbrella of CARA is the Arecibo Remote Command Center (ARCC). The ARCC is a virtual control room where researchers and students (graduate, undergraduate, and local high school students) control and take data utilizing the Arecibo Observatory, the Green Bank Telescope, and the Long Wavelength Array. This poster presents a general outline of CARA programs and recent accomplishments—including on-going pulsar discoveries, the expansion of the Low Frequency All Sky Monitor (LoFASM) to four sites across North America, and the graduation of our second cohort of ARCC Scholars.

  8. 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.

  9. 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.; Kaiser, M.; Kassim, N.; Kuiper, T.; MacDowall, R.; Mahoney, M.; Perley, R.; Preston, R.; Reiner, M.; Rodriguez, P.; Stone, R.; Unwin, S.; Weiler, K.; Woan, G.; Woo, R.

    1999-01-01

    A radio interferometer array in space providing high dynamic range images with unprecedented angular resolution over the broad frequency range from 0.030 - 30 MHz will open new vistas in solar, terrestial, galactic, and extragalactic astrophysics.

  10. Source counts at 5 gigahertz from the MG survey. [radio astronomy

    NASA Technical Reports Server (NTRS)

    Bennett, C. L.; Lawrence, C. R.; Burke, B. F.

    1985-01-01

    The MIT-Green Bank (MG) radio survey (reported by Bennett and colleagues in 1984 and 1985) is the largest 5 GHz survey to date. In this paper the source counts from the MG survey are examined. They are consistent with past measurements, but due to the large size of the MG survey the Poisson errors have been reduced. Radio source evolution models (such as that reported by Condon in 1984) are consistent with these new measurements.