Adventures in Radio Astronomy Instrumentation and Signal Processing
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Short History of Radio Astronomy Jansky – January 1932
Short History of Radio Astronomy Jansky – January 1932 Modified Bruce Array: Harald Friis design December 1932 Jansky’s 1932 Data Grote Reber- 1937 9.5 m Parabolic Reflector! Strip Chart output From Strip Chart to Contour Plot… 1940 Ap. J. paper…barely Reber’s 160 MHz contour map published in the ApJ in 1944. This shows the northern sky in equatorial coordinates. The Reber’s 160 MHz contour map published in the ApJ in 1944. This shows the northern sky in equatorial coordinates. The Reber’s 160 MHz contour map published in the ApJ in 1944. This shows the northern sky in equatorial coordinates. The Reber’s 160 MHz contour map published in the ApJ in 1944. This shows the northern sky in equatorial coordinates. The Jan Oort & Hendrik van de Hulst Lieden Observatory 1944 Predicted HI Line Detection of Hydrogen Line …… Ewen & Purcell 21 cm HI Line (1420 MHz) Purcell HI Receiver: Doc Ewen (1951) Milky Way in Optical Origin of SETI Nature, 1959 Philip Morrison 1959 Project Ozma: April 6, 1960 Tau Ceti & Epsilon Eridani Cosmic Background: Penzias & Wilson 1965 • 20 ft Echo Horn (Sugar Scoop): • Harald Friis design Pulsars: Bell and Hewish 1967 Detection of Pulsars: ~100ft of chart/day Chart recording of the pulsar Examples of scintillating detection and an interference signal somewhat later in time. Fast chart recording of pulsar emission (LGM nomenclature is “Little Green Arecibo Message: 1974 Big Ear Radio Telescope OSU Wow! Signal, Aug. 15, 1977 Sagitarius, Chi Sagittari star group NRAO 36ft Kitt Peak Telescope The Drake Equation The Drake equation -
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. -
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 -
History of Radio Astronomy
History of Radio Astronomy Reading for High School Students Getsemary Báez Introduction form of radiation involved (soon known as electro- Radio Astronomy, a field that has strongly magnetic waves). Nevertheless, it was Oliver Heavi- evolved since the end of World War II, has become side who in conjunction with Willard Gibbs in 1884 one of the most important tools of astronomical ob- modified the equations and put them into modern servations. Radio astronomy has been responsible for vector notation. a great part of our understanding of the universe, its A few years later, Heinrich Hertz (1857- formation, composition, interactions, and even pre- 1894) demonstrated the existence of electromagnetic dictions about its future path. This article intends to waves by constructing a device that had the ability to inform the public about the history of radio astron- transmit and receive electromagnetic waves of about omy, its evolution, connection with solar studies, and 5m wavelength. This was actually the first radio the contribution the STEREO/WAVES instrument on wave transmitter, which is what we call today an LC the STEREO spacecraft will have on the study of oscillator. Just like Maxwell’s theory predicted, the this field. waves were polarized. The radiation emissions were detected using a 1mm thin circle of copper wire. Pre-history of Radio Waves Now that there is evidence of electromag- It is almost impossible to depict the most im- netic waves, the physicist Max Planck (1858-1947) portant facts in the history of radio astronomy with- was responsible for a breakthrough in physics that out presenting a sneak peak where everything later developed into the quantum theory, which sug- started, the development and understanding of the gests that energy had to be emitted or absorbed in electromagnetic spectrum. -
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. -
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. -
Table of Contents - 1 - - 2
Table of contents - 1 - - 2 - Table of Contents Foreword 5 1. The European Consortium for VLBI 7 2. Scientific highlights on EVN research 9 3. Network Operations 35 4. VLBI technical developments and EVN operations support at member institutes 47 5. Joint Institute for VLBI in Europe (JIVE) 83 6. EVN meetings 105 7. EVN publications in 2007-2008 109 - 3 - - 4 - Foreword by the Chairman of the Consortium The European VLBI Network (EVN) is the result of a collaboration among most major radio observatories in Europe, China, Puerto Rico and South Africa. The large radio telescopes hosted by these observatories are operated in a coordinated way to perform very high angular observations of cosmic radio sources. The data are then correlated by using the EVN correlator at the Joint Institute for VLBI in Europe (JIVE). The EVN, when operating as a single astronomical instrument, is the most sensitive VLBI array and constitutes one of the major scientific facilities in the world. The EVN also co-observes with the Very Long Baseline Array (VLBA) and other radio telescopes in the U.S., Australia, Japan, Russia, and with stations of the NASA Deep Space Network to form a truly global array. In the past, the EVN also operated jointly with the Japanese space antenna HALCA in the frame of the VLBI Space Observatory Programme (VSOP). The EVN plans now to co-observe with the Japanese space 10-m antenna ASTRO-G, to be launched by 2012, within the frame of the VSOP-2 project. With baselines in excess of 25.000 km, the space VLBI observations provide the highest angular resolution ever achieved in Astronomy. -
NRAO Enews Volume 12, Issue 5 • 13 June 2019
NRAO eNews Volume 12, Issue 5 • 13 June 2019 Upcoming Events NRAO Community Day at UMBC (https://science.nrao.edu/science/meetings/2019/umbc19/index) Jun 13 14, 2019 | Baltimore, MD CASCA 2019 (http://www.physics.mcgill.ca/casca2019/) Jun 17 20, 2019 | Montréal, Québec Radio/mm Astrophysical Frontiers in the Next Decade (http://go.nrao.edu/ngVLA19) Jun 25 27, 2019 | Charlottesville, VA 7th VLA Data Reduction Workshop (http://go.nrao.edu/vladrw) Oct 7 18, 2019 | Socorro, NM ALMA2019: Science Results and CrossFacility Synergies (http://www.eso.org/sci/meetings/2019/ALMA2019Cagliari.html) Oct 14 18, 2019 | Cagliari, Sardinia, Italy Semester 2019B Proposal Outcomes Lewis Ball The NRAO has completed the Semester 2019B proposal review and time allocation process (https://science.nrao.edu/observing/proposal-types/peta) for the Very Large Array (VLA) (https://science.nrao.edu/facilities/evla) and the Very Long Baseline Array (VLBA) (https://science.nrao.edu/facilities/vlba) . For the VLA a single configuration (the D array) will be available in the 19B semester and 124 new proposals were received by the 1 February 2019 submission deadline including one large and sixteen time critical (triggered) proposals. The oversubscription rate (by proposal number) was 2.5 and the proposal pressure (hours requested over hours available) was 2.1, both of which are similar to recent semesters. For the VLBA 27 new proposals were submitted, including two large proposals and one triggered proposal. The oversubscription rate was 2.1 and the proposal pressure was 2.3, both of which are similar to recent semesters. -
Pos(10Th EVN Symposium)097
La Luna: Lovell Attempts LUnar Neutrino Acquisition PoS(10th EVN Symposium)097 Ralph Spencer 1, Alan Macfarlane, Owen Mills and Lucio Piccirillo School of Physics and Astronomy, The University of Manchester Oxford Rd., Manchester M13 9PL, UK E-mail: [email protected] Recent measurements by the Pierre Auger array have found evidence for the Greisen-Zatsepin- Kuzmin (GZK) cut off in the high energy spectrum of cosmic rays. Interactions of cosmic rays with energies of greater than ~0.05 ZeV with the cosmic microwave background are expected to produce high energy neutrinos. It has been suggested that neutrino interactions in the Moon can give rise to showers of particles, which through the Askar’yan charge excess mechanism can produce Cherenkov emission in the radio, detectable from the Earth. Here we describe a preliminary experiment at 21 cm with the Lovell telescope, which produces limits comparable with those from other radio telescopes. Use of VLBI telescopes in coincidence would eliminate local impulsive RFI and also possibly be able to measure the width of the Cherenkov cone 10th European VLBI Network Symposium and EVN Users Meeting: VLBI and the new generation of radio arrays Manchester, UK September 20-24 1 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it Short title Speaker Name 1.Introduction The study of ultra-high-energy (UHE) neutrinos has the potential to be an important tool in the study of many energetic astronomical phenomena. Neutrinos with energies in excess of 10 20 eV are predicted to be produced by processes such as gamma-ray bursts, active galactic nuclei, topological defects and decays of massive relic particles [1]. -
Jodrell Bank Observatoryvisitreport
U3A Jodrell Bank Observatory Visit, March 2015 I’m sure you will all instantly recognise the equation z = a(x 2 + y 2) as that of an elliptical parabaloid. This of course, we were informed by Jodrell Bank, describes the shape of the dish of a radio-telescope, so that distant radio waves will be focussed on a receiver in the centre. And who am I to argue with them. 24 intrepid trekkers braved the rain on the 13 th March and climbed the many steps of Hednesford Travel’s coach, to arrive at the Observatory in rural Cheshire. Now part of Manchester University, it was located there on purpose, to be in a better “radio quiet” area, if that is possible these days. Switching off mobile phones was our first request on entering. The obvious landmark that greeted us was the enormous Lovell radio-telescope, 76 metres in diameter, which started receiving signals from outer space in 1957. Although we couldn’t get close enough to touch it, nor get in the control room, we did manage to get a few group photos in front of it before leaving. At least we did see it pan across the sky and rotate on its axis with quite loud grumbling noises. Well, it is an old timer now after all. Lovell managed to get the huge telescope up and running after his wartime development into radar, thinking that the receiving equipment developed could be put to other uses. During a talk from a physicist who also doubles as an educator, we were told about the parts of the electromagnetic spectrum that the Lovell telescope receives, which was from microwave frequencies upwards towards the infra-red bands. -
2020 the Pathfinder View of the Sky LEGEND Canadian Hydrogen Intensity Mapping European VLBI Experiment (CHIME) - Network (EVN) - Canada Europe
Calendar 2020 The Pathfinder View of the Sky LEGEND Canadian Hydrogen Intensity Mapping European VLBI Experiment (CHIME) - Network (EVN) - Canada Europe enhanced Multi Element Remotely NenuFAR - France Linked Interferometer Network (e-MERLIN) - United Kingdom Low Frequency Array (LOFAR) - the MeerKAT Radio Netherlands Telescope - South Africa Five-hundred-meter Aperture Spherical Australian SKA Telescope (FAST) - Pathfinder (ASKAP) - China Australia (CHIME) Giant Metrewave Murchison Widefield Radio Telescope Array (MWA) - (GMRT) - India Australia VLBI Exploration of Effelsberg 100m Members of the SKA Organisation African Partner Countries Radio Astrometry Radio Telescope - Host Countries: Australia, South Africa, United Kingdom (VERA) - Japan Germany In the lead up to the SKA, many new groundbreaking radio elusive Fast Radio Bursts. They’re also allowing engineers The 2020 SKA calendar, called The Pathfinder View of the astronomy facilities have sprung up around the world in to develop new technical solutions like aperture arrays or Sky and featuring a small selection of the results already the past 10 years. These facilities are part of a global Phased Array Feeds. In so doing, they are paving the way coming out of 12 of these telescopes, is our tribute to effort to design and build ever-more sensitive instruments for the world’s largest radio telescope, the SKA. the pathfinder family as a whole, the people who have built to detect some of the faintest signals in the universe them and the people who are using them. The knowledge These facilities are now open to the community or going and grow new scientific and technical communities while and experience they’ve accumulated will guide us through through commissioning, and already they are providing benefiting society through cutting-edge R&D. -
ASTRONET ERTRC Report
Radio Astronomy in Europe: Up to, and beyond, 2025 A report by ASTRONET’s European Radio Telescope Review Committee ! 1!! ! ! ! ERTRC report: Final version – June 2015 ! ! ! ! ! ! 2!! ! ! ! Table of Contents List%of%figures%...................................................................................................................................................%7! List%of%tables%....................................................................................................................................................%8! Chapter%1:%Executive%Summary%...............................................................................................................%10! Chapter%2:%Introduction%.............................................................................................................................%13! 2.1%–%Background%and%method%............................................................................................................%13! 2.2%–%New%horizons%in%radio%astronomy%...........................................................................................%13! 2.3%–%Approach%and%mode%of%operation%...........................................................................................%14! 2.4%–%Organization%of%this%report%........................................................................................................%15! Chapter%3:%Review%of%major%European%radio%telescopes%................................................................%16! 3.1%–%Introduction%...................................................................................................................................%16!