DOCSLIB.ORG

Radio Telescopes and Interferometers in the World

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Radio Telescopes and Interferometers in the World Radio Telescopes and Interferometers in the World 澤田-佐藤 聡子 사와다-사토우 사토코 Satoko SAWADA-SATOH (山口大学, 야마구치대학, Yamaguchi University) Second Asian Radio Astronomy School Aug 18-22, 2008 at ASIAA, Taipei World Radio Telescope Tour ! (...but not in East Asia) 1. Big Antenna 2. Interferometry 3. VLBI Big Antenna ~ Towards higher sensitivity Arecibo (National Astronomy and Ionosphere Center ) • The largest single aperture ~ 73000 m2 • Diameter : 305 m • Location : Puerto Rico • Band : 50 MHz to 10 GHz • Maximum Angular Resolution : 30'' RATAN-600 (Special Astrophysics Observatory) • The world's largest radio telescope • 576 meter diameter of circular antenna with tilt-able curved and flat reflectors • Location : Zelenchukskaya, Russia • Aperture : ~15000 m2 • Band : 600 MHz to 30 GHz • Maximum Angular Resolution : 2'' Effelsberg Telescope (Max Planck Institut) • The 100-m diameter alt-azimuth mounted antenna • The largest fully steerable radio telescope for 30 years • Location : Effelsberg, near Bonn, Germany • Aperture : 7854 m2 • Band : 800 MHz to 96 GHz • Maximum Angular Resolution : 60'' Green Bank Telescope (NRAO) • Parabolic off axis reflector • The world's largest fully steerable radio telescope – 100 m x 110 m diameter • Location : Green Bank, West Virginia, USA • Band : 300 MHz to 50 GHz • Maximum Angular Resolution : 120'' Lovell Telescope (Jodrell Bank Observatory) • A 76-m alt-azimuth mounted parabolic dish antenna • Location : Cheshire, in the north-west of England • Band : Up to ~ 5 GHz • Maximum Angular Resolution : 160'' Tidbinbilla (Canberra Deep Space Communication Complex) • The largest steerable radio telescope in the southern hemisphere (70-m diameter) • a part of Deep Space Network run by NASA's Jet Propulsin Laboratory (JPL) • Location : near canberra, Australia • Band : 1.6 to 24 GHz • Maximum Angular Resolution : 40 '' Interferometry ~ to get higher angular resolution VLA (NRAO) • Consist of twenty seven 25-m diameter antennas • Location : New Mexico, USA • Band : 74 MHz to 50 GHz • Baseline : up to 36 km • Angular Resolution : 0.04'' GMRT (National Centre for Radio Astrophysics) • The world's largest array of radio telescopes at meter wavelengths. • Consist of thirty 45-m antennas • Location : Pune, India • Band : 50 to 1500 MHz • Angular Resolution : up to 1.6'' WSRT (ASTRON) • Consist of fourteen 25-m antennas • Location : Westerbork, Netherlands • Band : 120 MHz to 8.3 GHz • Baseline : 2.7 km East-West linear array • Angular Resolution : 2.8 '' ATCA (Australia Telescope National Facility) • Consist of six 22-m diameter antennas • Currently, the only one interferometer in south hemisphere • Location : Narrabri, Australia • Bands : 1.2 to 106 Ghz – up to millimeter wave length • Baseline : up to 6 km • Angular Resolution : up to 0.5'' PdBI (IRAM) • consist of six 15-m diameter antennas • Millimeter Interferometer • Location : Plateau de Bure, at 2550 m altitude in the French Alps • Band : 80 to 267 Ghz • Baseline : up to 730 m • Angular Resolution : up to 0.35'' SMA (SAO/ASIAA) • consist of eight 6-m antennas • The first submilimeter interferometer • Location : Mauna Kea, Hawaii, USA • Band : 186 to 696 Ghz • Baseline : up to 508 m • Angular Resolution : up to 0.15'' VLBI ~ Challenge to the ultimate angular resolution VLBA (NRAO) • ten 25-m antennas in US territories, span ~8600 km • the largest dedicated full-time VLBI array • Angular Resolution : up to 72 micro arcsec • Correlator : Array Operations Center at Socorro, US – singal is recorded in tapes at each antenna – the tapes are shipped to the correlator • Band : 0.3 to 90 Ghz EVN (Joint Institute for VLBI in Europe; JIVE) • operate 18 individual antennas spread throughout Europe and beyond (~ 10000 km) • Angular Resolution : up to 0.15 mas • Correlator : The EVN Mark IV at JIVE as the default • Band : 0.3 to 43 Ghz LBA (Australia Telescope National Facility) • 7 sites in Australia, 1 site in South Africa • The only one VLBI facility in south hemisphere • Correlator : The DiFX software correlator – Data is recorded on disks – Correlated on the DiFX software correlator • Baseline : up to ~9800 km • Band : 1.4 to 22 GHz You can access • Most of those antennas and interferometories open their observing time to scientists world wide. • Some antennas or interferometories open parcially. • All of them have their websites to show their documentations and users' guides. .
Load more

Recommended publications
  • Jodrell Bank Observatory
    UK Tentative List of Potential Sites for World Heritage Nomination: Application form Please save the application to your computer, fill in and email to: [email protected] The application form should be completed using the boxes provided under each question, and, where possible, within the word limit indicated. Please read the Information Sheets before completing the application form. It is also essential to refer to the accompanying Guidance Note for help with each question, and to the relevant paragraphs of UNESCO’s Operational Guidelines for the Implementation of the World Heritage Convention, (OG) available at: http://whc.unesco.org/en/guidelines Applicants should provide only the information requested at this stage. Further information may be sought in due course. (1) Name of Proposed World Heritage Site Jodrell Bank Observatory (2) Geographical Location Name of country/region United Kingdom Grid reference to centre of site SJ 798708 Please enclose a map preferably A4-size, a plan of the site, and 6 photographs, preferably electronically. page 1 (3) Type of Site Please indicate category: Natural Cultural Mixed Cultural Landscape (4) Description Please provide a brief description of the proposed site, including the physical characteristics. 200 words The Jodrell Bank Observatory, which is part of the University of Manchester’s School of Physics and Astronomy, is dominated by the monumental Lovell Telescope, the first large fully steerable radio telescope in the world - which still operates as the 3rd largest on the planet. The telescope, which is a Grade 1 listed structure, is 76m in diameter and stands 89m high. Despite its age (53 years in 2010), it is now more powerful than ever and remains at the forefront of Astrophysics research, working 24 hours a day, 365 days a year to observe distant galaxies and objects such as Pulsars and Quasars, far out across the Universe.
    [Show full text]
  • Meerkat Commissioning & NRAO in South Africa
    MeerKAT Commissioning & NRAO in South Africa Deb Shepherd NRAO & SKA Africa 10 Nov 2010 Radio telescopes around the World: Very Large Array (VLA), NM Very Long Baseline Array Green Bank Telescope (VLBA) , USA (GBT), WV Sub-Millimeter Array (SMA), Mauna Kea Owens Valley Radio Observatory (OVRO) + Berkeley-Illinois-Maryland Array (BIMA) = CARMA, CA http://www.ska.ac.za MeerKAT! QuickTime™ and a YUV420 codec decompressor are needed to see this picture. MeerKAT & the SKA 3000-4000 antennas MeerKAT: 64 - 13.5m Offset Gregorian antennas The MeerKAT Team MeerKAT Precursor Array MPA (or KAT-7) Today 2 1 3 4 5 Commissioning Accomplishments To Date • March 2010 - Regular commissioning activity began, tipping scans, pointing determination, gain curves. • April 2010 - First demonstration single dish image made (Centaurus A) • May 2010 - First demonstration interferometric image (4 antennas, warm receivers) • July 2010 - Holography system built and demonstrated on XDM and KAT antennas 5 & 6. • July 2010 - Noise diode calibration and Tsys determination for antennas 1-4 completed. Preliminary single dish commissioning evaluation complete for antennas 1-4 with warm receivers. • Aug/Sept 2010 - Commissioning paused; RFI measurement campaign • Nov 2010 - First cold feed installed on antenna 5 Tipping Curves • Antennas 1-4: tipping curve, warm receivers 1694-1960 MHz Tipping curve shape compares well with theoretical predictions, including spillover model provided by EMSS. AfriStar Pointing Determination • Antennas 1-4: pointing determination, warm receivers 1822 MHz center frequency All sky coverage 1.5’ RMS using all sources 0.76’ RMS using only 6 brightest sources Gain Curves • Antennas 1-4: Gain curve determination, warm receivers 1694-1950 MHz Preliminary gain, aperture efficiency, Tsys and SFED as a function of elevation.
    [Show full text]
  • Astro2020 APC White Paper Panel on Radio
    Astro2020 APC White Paper Panel on Radio, Millimeter, and Submillimeter Observations from the Ground The Case for a Fully Funded Green Bank Telescope Brief Description [350 character limit]: The NSF has reduced its funding for peer-reviewed use on the GBT to ~3900 hours/year, 60% of available science time. This greatly increases the telescope pressure & fragments the schedule, making it very difficult to allocate time for even the highest rated projects planned for the next decade. Here we seek funding for 1500 more hours annually. Principal Author: K. O’Neil (Green Bank Observatory; [email protected]) Co-authors: Felix J Lockman (Green Bank Observatory), Filippo D'Ammando (INAF-IRA Bologna), Will Armentrout (Green Bank Observatory), Shami Chatterjee (Cornell University), Jim Cordes (Cornell University), Martin Cordiner (NASA GSFC), David Frayer (Green Bank Observatory), Luke Zoltan Kelley (Northwestern University), Natalia Lewandowska (West Virginia University), Duncan Lorimer (WVU), Brian Mason (NRAO), Maura McLaughlin (West Virginia University), Tony Mroczkowski (European Southern Observatory), Hooshang Nayyeri (UC Irvine), Eric Perlman (Florida Institute of Technology), Bindu Rani (NASA Goddard Space Flight Center), Dominik Riechers (Cornell University), Martin Sahlan (Uppsala University), Ian Stephens (CfA/SAO), Patrick Taylor (Lunar and Planetary Institute), Francisco Villaescusa- Navarro (Center for Computational Astrophysics, Flatiron Institute) Endosers: Esteban D. Araya (Western Illinois University), Hector Arce (Yale
    [Show full text]
  • 50 Years of the Lovell Telescope Transcript
    50 years of the Lovell telescope Transcript Date: Wednesday, 5 December 2007 - 12:00AM 50 YEARS OF THE LOVELL TELESCOPE Professor Ian Morison The Early days at Jodrell Bank In late 1945 Dr Bernard Lovell (as he then was) returned to Manchester University after working on the development of radar during the war years. His aim was to continue his researches into cosmic rays - highly energetic particles that enter the Earth's atmosphere from outer space. He had the idea that sporadic echoes sometimes received by military radars might be the result of cosmic rays entering the atmosphere and thus radar observations might provide a new way to continue his researches. Radar observations were not practical in the centre of Manchester so he took his ex-army radar system out to the University's Botanical Grounds at Jodrell Bank, some 20 miles to the south. By the middle of December 1945, the system was operating and his team was soon able to prove that the echoes were coming not from cosmic rays but from ionized meteor trails left behind when small particles, released from comets, are burnt up in the upper atmosphere of the Earth. Radar Antenna in the Botany Grounds. The Jodrell Bank Experimental Station. The observations continued and, to house the expanding staff and equipment, the Jodrell Bank Experimental Station was built in the field next to the Botanic Grounds. Lovell realised that a much more sensitive radio telescope would be required to detect cosmic rays and so, in 1947, the researchers built a large parabolic reflector, 66-m across, pointing upwards to observe the sky passing overhead.
    [Show full text]
  • The Lovell Telescope … Through Its Surfaces Simon Garrington, JBO/University of Manchester
    The Lovell Telescope … through its surfaces Simon Garrington, JBO/University of Manchester • Original design & redesign: 1950-1957 • Radical modification & new surface: 1971 • Replacement of surface: 2001 • Replacement of original Picture A. Holloway surface: 2018 • Other consequences: foundations O1 Original MkI proposal and changes • Concept & proposals: 1950-1 • Lovell-Husband Sep 1949 • Radio Astronomy Cttee 1950 • rail track; towers, cradle, 4-inch mesh • 2-inch mesh/5-in profile by 20 Mar 1951 submission • Design changes • 21cm line discovered (Ewen 25 Mar 1951) • Inner 100’ mesh 1x2-in ‘at no cost’ ? Sep 1952 • Interest from Air Ministry: 10cm radar • March 1954: 3/4-in mesh -> stronger cradle … but Air Ministry step back O2 Original MkI proposal and changes • Concept & proposals: 1950-1 • Lovell-Husband Sep 1949 • Radio Astronomy Cttee 1950 • rail track; towers, cradle, 4-inch mesh • 2-inch mesh/5-in profile by 20 Mar 1951 submission • Design changes • 21cm line discovered (Ewen 25 Mar 1951) • Inner 100’ mesh 1x2-in ‘at no cost’ ? Sep 1952 • Interest from Air Ministry: 10cm radar • March 1954: 3/4-in mesh -> stronger cradle … but Air Ministry step back O3 Original MkI proposal and changes • Concept & proposals: 1950-1 • Lovell-Husband Sep 1949 • Radio Astronomy Cttee 1950 • rail track; towers, cradle, 4-inch mesh • 2-inch mesh/5-in profile by 20 Mar 1951 submission • Design changes • 21cm line discovered (Ewen 25 Mar 1951) • Inner 100’ mesh 1x2-in ‘at no cost’ ? Sep 1952 • Interest from Air Ministry: 10cm radar • March 1954: 3/4-in
    [Show full text]
  • CORF Comments on RM11713 (00724414).DOC
    Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D.C. 20554 In the Matter of ) ) Battelle Memorial Institute, Inc. ) RM-11713 ) Petition for Rulemaking to Adopt Service Rules ) for the 102-109.5 GHz Band ) COMMENTS OF THE NATIONAL ACADEMY OF SCIENCES’ COMMITTEE ON RADIO FREQUENCIES The National Academy of Sciences, through the National Research Council's Committee on Radio Frequencies (hereinafter, CORF), hereby submits its comments in response to the Commission's February 24, 2014, Public Notice regarding the above- captioned Petition for Rulemaking.1 In these Comments, CORF discusses the potential impact on radio astronomy from the proposals in the Petition for Rulemaking (Petition) filed by Battelle Memorial Institute, Inc. (Battelle) that led to the initiation of this proceeding, as well as the ways to minimize that impact. CORF does not oppose fixed commercial use of the sort proposed in the Petition, as long as the Commission’s rules provide for appropriate frequency coordination sufficient to protect Radio Astronomy Service (RAS) observations.2 1 CORF hereby moves for leave to file these comments after the filing deadline. The public interest would be served by accepting the comments, since Battelle’s proposal would directly impact radio astronomy observatories, and no other parties in this proceeding have filed any information regarding that impact or the proposals to limit that impact. Thus, these comments will provide information important for the Commission’s consideration in this proceeding. Further, no parties will be harmed by the acceptance of these comments, as further rounds of comments are anticipated if the Commission grants the Battelle Petition and initiates a rulemaking proceeding.
    [Show full text]
  • Astro2020 APC White Paper
    Astro2020 APC White Paper Argus+: Wide-Field, High Resolution 3mm Molecular Imaging Type of Activity: Ground Based Project Space Based Project Infrastructure Activity Technological Development Activity State of the Profession Consideration Other Panel: Radio, Millimeter, and Submillimeter Observations from the Ground. Principal Author: Name: David T. Frayer Institution: Green Bank Observatory (GBO) Email: [email protected] Phone: 304-456-2223 Co-authors: Felix J. Lockman (GBO), Paul Goldsmith (JPL), Andrew I. Harris (Univ. of Maryland), Kieran A. Cleary (Caltech), Joshua O. Gundersen (Univ. of Miami), Laura Jensen (GBO), Alvaro Hacar (Leiden University), Che-Yu Chen (Univ. of Virginia), Will Armentrout (GBO), Natalie Butterfield (GBO), Larry Morgan (GBO), Amanda Kepley (NRAO), Jialu Li (Univ. of Maryland), Ian Stephens (CfA/SAO), Sarah Sadavoy (CfA/SAO), Kevin Harrington (Univ. of Bonn, AIfA), Jaime Pineda (Max-Planck), Zhi-Yun Li (Univ. of Virginia), Anthony Readhead (Caltech), Sarah Church (Stanford), Steven White (GBO), Randy McCullough (GBO), Galen Watts (GBO), Dennis Egan (GBO), Martin Bloss (GBO) Project Endorsers: Loren Anderson (West Virginia Univ.), Hector´ G. Arce (Yale Univ.), Tracy Becker (Southwest Research Institute), Robert Benjamin (U. Wisconsin-Whitewater), Alberto Bolatto (Univ. of Maryland), Amber Bonsall (GBO), Sara Cazzoli (Instituto de Astrofisica de Andalucia), Suchetana Chatterjee (Presidency University), Chian-Chou Chen (T.C.) (ESO), Claudia Cicone (INAF, University of Oslo), Martin Cordiner (NASA GSFC), Simon Dicker
    [Show full text]
  • Radio Astronomy
    Edition of 2013 HANDBOOK ON RADIO ASTRONOMY International Telecommunication Union Sales and Marketing Division Place des Nations *38650* CH-1211 Geneva 20 Switzerland Fax: +41 22 730 5194 Printed in Switzerland Tel.: +41 22 730 6141 Geneva, 2013 E-mail: [email protected] ISBN: 978-92-61-14481-4 Edition of 2013 Web: www.itu.int/publications Photo credit: ATCA David Smyth HANDBOOK ON RADIO ASTRONOMY Radiocommunication Bureau Handbook on Radio Astronomy Third Edition EDITION OF 2013 RADIOCOMMUNICATION BUREAU Cover photo: Six identical 22-m antennas make up CSIRO's Australia Telescope Compact Array, an earth-rotation synthesis telescope located at the Paul Wild Observatory. Credit: David Smyth. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. - iii - Introduction to the third edition by the Chairman of ITU-R Working Party 7D (Radio Astronomy) It is an honour and privilege to present the third edition of the Handbook – Radio Astronomy, and I do so with great pleasure. The Handbook is not intended as a source book on radio astronomy, but is concerned principally with those aspects of radio astronomy that are relevant to frequency coordination, that is, the management of radio spectrum usage in order to minimize interference between radiocommunication services. Radio astronomy does not involve the transmission of radiowaves in the frequency bands allocated for its operation, and cannot cause harmful interference to other services. On the other hand, the received cosmic signals are usually extremely weak, and transmissions of other services can interfere with such signals.
    [Show full text]
  • Structure in the Radio Counterpart to the 2004 Dec 27 Giant Flare From
    SLAC-PUB-11623 astro-ph/0511214 Structure in the radio counterpart to the 2004 Dec 27 giant flare from SGR 1806-20 R. P. Fender1⋆, T.W.B. Muxlow2, M.A. Garrett3, C. Kouveliotou4, B.M. Gaensler5, S.T. Garrington2, Z. Paragi3, V. Tudose6,7, J.C.A. Miller-Jones6, R.E. Spencer2, R.A.M. Wijers6, G.B. Taylor8,9,10 1 School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ, UK 2 University of Manchester, Jodrell Bank Observatory, Cheshire, SK11 9DL, UK 3 Joint Institute for VLBI in Europe, Postbus 2, NL-7990 AA Dwingeloo, The Netherlands 4 NASA / Marshall Space Flight Center, NSSTC, XD-12, 320 Sparkman Drive, Huntsville, AL 35805, USA 5 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 6 Astronomical Institute ‘Anton Pannekoek’, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands 7 Astronomical Institute of the Romanian Academy, Cutitul de Argint 5, RO-040557 Bucharest, Romania 8 Kavli Institute of Particle Astrophysics and Cosmology, Menlo Park, CA 94025 USA 9 National Radio Astronomy Observatory, Socorro, NM 87801, USA 10Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131, USA 8 November 2005 ABSTRACT On Dec 27, 2004, the magnetar SGR 1806-20 underwent an enormous outburst resulting in the formation of an expanding, moving, and fading radio source. We report observations of this radio source with the Multi-Element Radio-Linked Interferometer Network (MERLIN) and the Very Long Baseline Array (VLBA). The observations confirm the elongation and expansion already reported based on observations at lower angular resolutions, but suggest that at early epochs the structure is not consistent with the very simplest models such as a smooth flux distribution.
    [Show full text]
  • Adventures in Radio Astronomy Instrumentation and Signal Processing
    Adventures in Radio Astronomy Instrumentation and Signal Processing by Peter Leonard McMahon Submitted to the Department of Electrical Engineering in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering at the University of Cape Town July 2008 Supervisor: Professor Michael Inggs Co-supervisors: Dr Dan Werthimer, CASPER1, University of California, Berkeley Dr Alan Langman, Karoo Array Telescope arXiv:1109.0416v1 [astro-ph.IM] 2 Sep 2011 1Center for Astronomy Signal Processing and Electronics Research Abstract This thesis describes the design and implementation of several instruments for digi- tizing and processing analogue astronomical signals collected using radio telescopes. Modern radio telescopes have significant digital signal processing demands that are typically best met using custom processing engines implemented in Field Pro- grammable Gate Arrays. These demands essentially stem from the ever-larger ana- logue bandwidths that astronomers wish to observe, resulting in large data volumes that need to be processed in real time. We focused on the development of spectrometers for enabling improved pulsar2 sci- ence on the Allen Telescope Array, the Hartebeesthoek Radio Observatory telescope, the Nan¸cay Radio Telescope, and the Parkes Radio Telescope. We also present work that we conducted on the development of real-time pulsar timing instrumentation. All the work described in this thesis was carried out using generic astronomy pro- cessing tools and hardware developed by the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California, Berkeley. We successfully deployed to several telescopes instruments that were built solely with CASPER technology, which has helped to validate the approach to developing radio astronomy instruments that CASPER advocates.
    [Show full text]
  • High Resolution Radio Astronomy Using Very Long Baseline Interferometry
    IOP PUBLISHING REPORTS ON PROGRESS IN PHYSICS Rep. Prog. Phys. 71 (2008) 066901 (32pp) doi:10.1088/0034-4885/71/6/066901 High resolution radio astronomy using very long baseline interferometry Enno Middelberg1 and Uwe Bach2 1 Astronomisches Institut, Universitat¨ Bochum, 44801 Bochum, Germany 2 Max-Planck-Institut fur¨ Radioastronomie, Auf dem Hugel¨ 69, 53121 Bonn, Germany E-mail: [email protected] and [email protected] Received 3 December 2007, in final form 11 March 2008 Published 2 May 2008 Online at stacks.iop.org/RoPP/71/066901 Abstract Very long baseline interferometry, or VLBI, is the observing technique yielding the highest-resolution images today. Whilst a traditionally large fraction of VLBI observations is concentrating on active galactic nuclei, the number of observations concerned with other astronomical objects such as stars and masers, and with astrometric applications, is significant. In the last decade, much progress has been made in all of these fields. We give a brief introduction to the technique of radio interferometry, focusing on the particularities of VLBI observations, and review recent results which would not have been possible without VLBI observations. This article was invited by Professor J Silk. Contents 1. Introduction 1 2.9. The future of VLBI: eVLBI, VLBI in space and 2. The theory of interferometry and aperture the SKA 10 synthesis 2 2.10. VLBI arrays around the world and their 2.1. Fundamentals 2 capabilities 10 2.2. Sources of error in VLBI observations 7 3. Astrophysical applications 11 2.3. The problem of phase calibration: 3.1. Active galactic nuclei and their jets 12 self-calibration 7 2.4.
    [Show full text]
  • Newsletter February 2011
    Newsletter February 2011 1 First HartRAO-KAT-7 VLBI fringes First HartRAO-KAT-7 VLBI JASPER HORREL, fringes signal new capability signal new capability MEERKAT PROJECT OFFICE, CAPE TOWN 2 MeerKAT engineers launch A milestone has been achieved in South Africa the mechanics and electronics. The HartRAO new ROACH board with the successful detection of “fringes” in a antenna recorded the data to a Mark5A VLBI recorder, while the KAT engineers constructed 3 joint very long baseline interferometry (VLBI) a new and flexible data recorder system (using MeerKAT Science – observation performed using one of the seven ROACH-1; graphics processing units and other the Large Survey Projects 12 m dishes of the KAT-7 radio telescope, near Carnarvon in the Northern Cape, together with high-end PC components) to perform the job. 4 the 26 m dish of the Hartebeesthoek Radio The HartRAO antenna makes use of a hydro - More power and connectivity Astronomy Observatory (HartRAO) near Pretoria. gen maser as the master clock, while a GPS- milestones for Karoo disciplined rubidium oscillator was used in the VLBI is a well established technique, where the Karoo. 5 signals recorded by widely separated radio MeerKAT Karoo Express – telescopes, simultaneously observing the same To produce the detection, the signals were flying to the MeerKAT site part of the sky, are brought together to produce jointly recorded, the data were transported to 6 a very high resolution radio picture of that region Cape Town and converted to the same format, SKA South Africa and NRAO of the sky. While HartRAO has been involved in a so-called “fringe stopping” correction was to deepen collaboration in 2011 VLBI observations for many years with telescopes applied to the data (a correction for the earth’s around the world, this is the first time that a rotation, using the accurately known antenna Technician team deployed at KAT-7 antenna has been used and the first time and radio source positions) and the data were KAT-7 in Karoo that all the data processing has been done in correlated to produce a “lag plot”.
    [Show full text]