A Saga of Radio Astronomy at TIFR, India
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Pos(Westerbork)002 Historical Introduction Historical S 4.0 International License (CC BY-NC-ND 4.0)
Historical Introduction PoS(Westerbork)002 Richard Strom ASTRON Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands E-mail: [email protected] 50 Years Westerbork Radio Observatory, A Continuing Journey to Discoveries and Innovations Richard Strom, Arnold van Ardenne, Steve Torchinsky (eds) Published with permission of the Netherlands Institute for Radio Astronomy (ASTRON) under the terms of the Creative CommonsAttribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0). Chapter 1 Historical introduction Richard Strom* rom the English longbows at the battle of Crécy (1346) to Winston Chur- chill’s world war I mobilized cannon (its true identity hidden behind the Fpseudonym “[water] tank”), warfare has always pushed technological innovation to new fronts. The second world war (WWII) was no exception. It gave us technology ranging from the dynamo-powered flashlight (a Philips invention) to jet engines, and space-capable rockets (Germany’s V2), not to mention (in a completely different realm) the mass production of Penicillin. In fact, it could be argued that WWII inventions marked the inception of the modern technological era1. In the field of electronics, the war led to innovations such as radio navigation, aircraft landing systems, and radar. It was these developments which were to * ASTRON, Univer- sity of Amsterdam, have a revolutionary impact on astronomy, initially in Britain, Australia and the The Netherlands United States. But the story begins in the US, with the electronics of the 1920s and ‘30s. Figure 1. Karl G. Jansky (c. 1933) Around 1930, there was increasing interest in the use of radio frequencies for communication. One of the main players, the Bell Telephone Laboratories in New Jersey, asked their research engineer, Karl Jansky (Figure 1), to investigate the inter- ference environment in the “short-wave” band around 20 MHz. -
Sources of Maratha History: Indian Sources
1 SOURCES OF MARATHA HISTORY: INDIAN SOURCES Unit Structure : 1.0 Objectives 1.1 Introduction 1.2 Maratha Sources 1.3 Sanskrit Sources 1.4 Hindi Sources 1.5 Persian Sources 1.6 Summary 1.7 Additional Readings 1.8 Questions 1.0 OBJECTIVES After the completion of study of this unit the student will be able to:- 1. Understand the Marathi sources of the history of Marathas. 2. Explain the matter written in all Bakhars ranging from Sabhasad Bakhar to Tanjore Bakhar. 3. Know Shakavalies as a source of Maratha history. 4. Comprehend official files and diaries as source of Maratha history. 5. Understand the Sanskrit sources of the Maratha history. 6. Explain the Hindi sources of Maratha history. 7. Know the Persian sources of Maratha history. 1.1 INTRODUCTION The history of Marathas can be best studied with the help of first hand source material like Bakhars, State papers, court Histories, Chronicles and accounts of contemporary travelers, who came to India and made observations of Maharashtra during the period of Marathas. The Maratha scholars and historians had worked hard to construct the history of the land and people of Maharashtra. Among such scholars people like Kashinath Sane, Rajwade, Khare and Parasnis were well known luminaries in this field of history writing of Maratha. Kashinath Sane published a mass of original material like Bakhars, Sanads, letters and other state papers in his journal Kavyetihas Samgraha for more eleven years during the nineteenth century. There is much more them contribution of the Bharat Itihas Sanshodhan Mandal, Pune to this regard. -
Radio Astronomy
Theme 8: Beyond the Visible I: radio astronomy Until the turn of the 17th century, astronomical observations relied on the naked eye. For 250 years after this, although astronomical instrumentation made great strides, the radiation being detected was still essentially confined to visible light (Herschel discovered infrared radiation in 1800, and the advent of photography opened up the near ultraviolet, but these had little practical significance). This changed dramatically in the mid-20th century with the advent of radio astronomy. 8.1 Early work: Jansky and Reber The atmosphere is transparent to visible light, but opaque to many other wavelengths. The only other clear “window” of transparency lies in the radio region, between 1 mm and 30 m wavelength. One might expect that the astronomical community would deliberately plan to explore this region, but in fact radio astronomy was born almost accidentally, with little if any involvement of professional astronomers. Karl Jansky (1905−50) was a radio engineer at Bell Telephone. In 1932, while studying the cause of interference on the transatlantic radio-telephone link, he discovered that part of the interference had a periodicity of one sidereal day (23h 56m), and must therefore be coming from an extraterrestrial source. By considering the time at which the interference occurred, Jansky identified the source as the Milky Way. This interesting finding was completely ignored by professional astronomers, and was followed up only by the radio engineer and amateur astronomer Grote Reber (1911−2002). Reber built a modern-looking paraboloid antenna and constructed maps of the radio sky, which also failed to attract significant professional attention. -
Probing the Universe at Low Radio Frequencies Using the GMRT
The GMRT : a look at the Past, Present and Future Yashwant Gupta & Govind Swarup National Centre for Radio Astrophysics Pune India URSI GASS Montreal 2017 The GMRT : a look at the Past, Present and Future Yashwant Gupta & Govind Swarup National Centre for Radio Astrophysics Pune India URSI GASS Montreal 2017 Overview of today’s talk . Part I : the GMRT -- a historical perspective . Part II : the GMRT -- current status . Part III : future -- the upgraded GMRT Some history . It is the early 1980s… the VLA has recently become operational . Radio astronomy has shifted from the low frequencies, where it was born, to higher frequencies (cm and higher wavelengths) -- obvious reasons . Note, however, techniques like self-cal have been shown to work . In India, the radio astronomy group at the Tata Institute, under the leadership of Govind Swarup, is looking for the next big challenge… They have already : . Built the Ooty Radio Telescope in the late 1960s – still operational & producing international quality results (in fact, currently being upgraded with new receiver system!) . Built the Ooty Synthesis Radio Telescope (1980s) – short-lived but valuable learnings . Built up considerable experience in low frequencies (metre wavelengths) Birth of the GMRT . Motivation : bridge the gap in radio astronomy facilities at low frequencies and address science problems best studied at metre wavelengths . First concept : 1984 (started with large cylinders); evolved to 34 dishes of 45 metres by 1986 . Project cleared and funding secured by 1987 . Construction started : 1990; first antenna erected : 1992 . First light observations : 1997 – 1998 . Released for world-wide use : 2002 The GMRT : turning it ON Jan 1997 : First fringes with the prototype GMRT correlator Dec 1998 : first light pulsar observation with the GMRT Dedication of the GMRT The Giant Metrewave Radio Telescope was dedicated to the World Scientific Community by the Chairman of TIFR Council, Shri Ratan Tata. -
Assessment of Agro-Tourism Potential in Junnar Tehsil, Maharashtra, India
Scholarly Research Journal for Interdisciplinary Studies, Online ISSN 2278-8808, SJIF 2016 = 6.17, www.srjis.com UGC Approved Sr. No.45269, SEPT-OCT 2017, VOL- 4/36 ASSESSMENT OF AGRO-TOURISM POTENTIAL IN JUNNAR TEHSIL, MAHARASHTRA, INDIA Thorat S. D.1 & Suryawanshi R.S.2 1PhD Research Student, Savitribai Phule Pune University, Pune-411007. E-mail - [email protected] 2Professor, Department of Geography, Abasaheb Garware College, Pune-411004, S.P.P.U. E-mail –[email protected] The present research paper is an attempt to analyse the level of development and potential of Agro- tourism in Junnar Tehsil in Pune District Maharashtra. Agro-tourism is the emerging branch of tourism in India. It helped for sustainable development in rural area. Agro-tourism give the opportunity to tourist to get aware with agricultural area, agricultural operations, local food and tradition of local area and support to economic development of farmers. The Junnar Tehsil in Pune district have many tourist destinations, but yet this Tehsil is not highlighted to large scale Agro- tourism practices. It is mainly because of lack of facilities and low development of area. The present research paper focuses on find out the potential area for agro-tourism in Junnar Tehsil. The development status of agro-tourism potential composite index is product of physiographic index and cropping pattern based on a GIS techniques. Keywords: Agro-Tourism, Composite Index and GIS technique. Scholarly Research Journal's is licensed Based on a work at www.srjis.com Introduction Tourism plays very important role in economic development on regional level. Now day’s tourism is one of the fastest growing industries in the world. -
The Ooty Wide Field Array (OWFA) Is an Upgrade to the ORT, Which Digitizes the Signals from Every 4 Dipoles Along the Feed Line
J. Astrophys. Astr. (0000) 00, 000–000 The Ooty Wide Field Array C. R. Subrahmanya1∗, P. K. Manoharan2†, Jayaram. N. Chengalur3‡ 1 Raman Research Institute, C. V. Raman Avenue, Sadashivnagar,Bengaluru 560080,India. 2 Radio Astronomy Centre, NCRA-TIFR, P. O. Box 8, Ooty 643001, India. 3 NCRA-TIFR, Pune University Campus, Ganeshkhind, Pune 411007,India. Abstract. We describe here an ongoing upgrade to the legacy Ooty Ra- dio Telescope (ORT). The ORT is a cylindrical parabolic cylinder 530mx30m in size operating at a frequency of 326.5 (or z ∼ 3.35 for the HI 21cm line). The telescope has been constructed on a north-south hill slope whose gradient is equal to the latitude of the hill, making it effectively equitorially mounted. The feed con- sists of an array of 1056 dipoles. The key feature of this upgrade is the digitisation and cross-correlation of the signals of every set of 4-dipoles. This converts the ORT into a 264 element interfer- ometer with a field of view of 2◦ × 27.4◦ cos(δ). This upgraded instrument is called the Ooty Wide Field Array (OWFA). This paper briefly describes the salient features of the upgrade, as well as its main science drivers. There are three main science drivers viz. (1) Observations of the large scale distribution of HI in the post-reionisation era (2) studies of the propagation of plasma ir- regularities through the inner heliosphere and (3) blind surveys for transient sources. More details on the upgrade, as well as on the expected science uses can be found in other papers in this special issue. -
Nominations for Different “Academy Awards/Lectures/ Medals”
The National Academy of Sciences, India (NASI) 5, Lajpatrai Road, Prayagraj – 211002 Prof. Paramjit Khurana Ph.D., FNA, FASc, FNAAS, FTWAS, FNASc Prof. Satya Deo Ph.D. (Arkansas, USA), F.N.A.Sc. General Secretaries June 15, 2021 Subject : Nominations for different “Academy Awards/Lectures/Medals” Dear Fellows, I request you to kindly send nominations for the following “Academy Awards/Lectures/Medals”– 1. Prof. Meghnad Saha Memorial Lecture Award (2021) 2. Prof. N.R. Dhar Memorial Lecture Award (2021) 3. Prof. Archana Sharma Memorial Lecture Award (2021) 4. Prof. M.G.K. Menon Lecture Award (2021) 5. Prof. M.G.K. Menon Memorial Award (2021) 6. Prof. V. P. Sharma Memorial Lecture Award (2021) 7. Prof. A.K. Sharma Memorial Lecture Award (2021) 8. Prof. Prafulla Chandra Ray Memorial Lecture Award (2021) 9. Prof. S.K. Joshi Memorial Lecture Award (2021) 10. Prof. A.C. Banerji Memorial Lecture Award (2021) 11. Dr. B.P. Pal Memorial Lecture Award (2021) 12. Dr. P. Sheel Memorial (Young Women Scientist) Lecture Award (2021) 13. Prof. B.K. Bachhawat Memorial Lecture Award (2021) 14. Prof. U.S. Srivastava Memorial Lecture Award (2021) 15. Lecture Award in the field of Biodiversity (2021) 16. NASI-Buti Foundation Lecture Award (2021) The nomination papers duly completed in all respect should be emailed to NASI on [email protected] latest by July 15, 2021. No hard copy is required for this year; kindly send the nomination on aforesaid email only (not on any other email id of NASI). The copy of Regulations regarding these Academy Awards/Lectures/Medals and the names of past recipients are enclosed. -
Messenger-No117.Pdf
ESO WELCOMES FINLANDINLAND AS ELEVENTH MEMBER STAATE CATHERINE CESARSKY, ESO DIRECTOR GENERAL n early July, Finland joined ESO as Education and Science, and exchanged which started in June 2002, and were con- the eleventh member state, following preliminary information. I was then invit- ducted satisfactorily through 2003, mak- II the completion of the formal acces- ed to Helsinki and, with Massimo ing possible a visit to Garching on 9 sion procedure. Before this event, howev- Tarenghi, we presented ESO and its scien- February 2004 by the Finnish Minister of er, Finland and ESO had been in contact tific and technological programmes and Education and Science, Ms. Tuula for a long time. Under an agreement with had a meeting with Finnish authorities, Haatainen, to sign the membership agree- Sweden, Finnish astronomers had for setting up the process towards formal ment together with myself. quite a while enjoyed access to the SEST membership. In March 2000, an interna- Before that, in early November 2003, at La Silla. Finland had also been a very tional evaluation panel, established by the ESO participated in the Helsinki Space active participant in ESO’s educational Academy of Finland, recommended Exhibition at the Kaapelitehdas Cultural activities since they began in 1993. It Finland to join ESO “anticipating further Centre with approx. 24,000 visitors. became clear, that science and technology, increase in the world-standing of ESO warmly welcomes the new mem- as well as education, were priority areas Astronomy in Finland”. In February 2002, ber country and its scientific community for the Finnish government. we were invited to hold an information that is renowned for its expertise in many Meanwhile, the optical astronomers in seminar on ESO in Helsinki as a prelude frontline areas. -
Quarterly Report, April 1
NATIONAL RADIO ASTRONOMY OBSERVATORY QUARTERLY REPORT April 1,1996 - June 30,1996 TABLE OF CONTENTS A. TELESCOPE USAGE .............................................................. 1 B. 140 FOOT OBSERVING PROGRAMS ................................................ 1 C. 12 METER TELESCOPE OBSERVING PROGRAMS .................................... 3 D. VERY LARGE ARRAY OBSERVING PROGRAMS ..................................... 7 E. VERY LONG BASELINE ARRAY OBSERVING PROGRAMS ........................... 15 F. SCIENCE HIGHLIGHTS ........................................................... 22 G. PUBLICATIONS ................................................................ 23 H. CHARLOTTESVILLE ELECTRONICS ............................................... 23 I. GREEN BANK ELECTRONICS .................................................... 25 J. TUCSON ELECTRONICS ......................................................... 26 K. SOCORRO ELECTRONICS........................................................ 27 L. COMPUTING AND AIPS.......................................................... 30 M . AIPS++ .................................................... .................... 32 N. GREEN BANK TELESCOPE PROJECT ............................................... 32 O. PERSONNEL .................................................................... 33 APPENDIX A. PREPRINTS A. TELESCOPE USAGE The following telescopes have been scheduled for research and maintenance in the following manner during the second quarter of 1996. 140 Foot 12 Meter VLA VLBA Scheduled Observing -
A Real-Time Coherent Dedispersion Pipeline for the Giant Metrewave Radio Telescope
Experimental Astronomy manuscript No. (will be inserted by the editor) A Real-time Coherent Dedispersion Pipeline for the Giant Metrewave Radio Telescope Kishalay De · Yashwant Gupta Received: date / Accepted: date Abstract A fully real-time coherent dedispersion system has been developed for the pulsar back-end at the Giant Metrewave Radio Telescope (GMRT). The dedispersion pipeline uses the single phased array voltage beam produced by the existing GMRT software back-end (GSB) to produce coherently dedispersed intensity output in real time, for the currently operational bandwidths of 16 MHz and 32 MHz. Provision has also been made to coherently dedisperse voltage beam data from observations recorded on disk. We discuss the design and implementation of the real-time coherent dedispersion system, describing the steps carried out to optimise the performance of the pipeline. Presently functioning on an Intel Xeon X5550 CPU equipped with a NVIDIA Tesla C2075 GPU, the pipeline allows dispersion free, high time resolution data to be ob- tained in real-time. We illustrate the significant improvements over the existing in- coherent dedispersion system at the GMRT, and present some preliminary results obtained from studies of pulsars using this system, demonstrating its potential as a useful tool for low frequency pulsar observations. We describe the salient features of our implementation, comparing it with other recently developed real-time coherent dedispersion systems. This implementation of a real-time coherent dedispersion pipeline for a large, low frequency array instrument like the GMRT, will enable long-term observing programs using coherent dedisper- sion to be carried out routinely at the observatory. -
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. -
NATIONAL ACADEMIES of SCIENCES and ENGINEERING NATIONAL RESEARCH COUNCIL of the UNITED STATES of AMERICA
NATIONAL ACADEMIES OF SCIENCES AND ENGINEERING NATIONAL RESEARCH COUNCIL of the UNITED STATES OF AMERICA UNITED STATES NATIONAL COMMITTEE International Union of Radio Science National Radio Science Meeting 4-8 January 2000 Sponsored by USNC/URSI University of Colorado Boulder, Colorado U.S.A. United States National Committee INTERNATIONAL UNION OF RADIO SCIENCE PROGRAM AND ABSTRACTS National Radio Science Meeting 4-8 January 2000 Sponsored by USNC/URSI NOTE: Programs and Abstracts of the USNC/URSI Meetings are available from: USNC/URSI National Academy of Sciences 2101 Constitution Avenue, N.W. Washington, DC 20418 at $5 for 1983-1999 meetings. The full papers are not published in any collected format; requests for them should be addressed to the authors who may have them published on their own initiative. Please note that these meetings are national. They are not organized by the International Union, nor are the programs available from the International Secretariat. ii MEMBERSHIP United States National Committee INTERNATIONAL UNION OF RADIO SCIENCE Chair: Gary Brown* Secretary & Chair-Elect: Umran S. !nan* Immediate Past Chair: Susan K. Avery* Members Representing Societies, Groups, and Institutes: American Astronomical Society Thomas G. Phillips American Geophysical Union Donald T. Farley American Meteorological Society vacant IEEE Antennas and Propagation Society Linda P.B. Katehi IEEE Geosciences and Remote Sensing Society Roger Lang IEEE Microwave Theory and Techniques Society Arthur A. Oliner Members-at-Large: Amalia Barrios J. Richard Fisher Melinda Picket-May Ronald Pogorzelski W. Ross Stone Richard Ziolkowski Chairs of the USNC/URSI Commissions: Commission A Moto Kanda Commission B Piergiorgio L. E. Uslenghi Commission C Alfred 0.