DOCSLIB.ORG

Radio Astronomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read 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. In twelve chapters and five Appendices, the Handbook introduces the reader to radio astronomy viewed as a radiocommunication service for the purpose of frequency coordination. It starts with a preamble on radio astronomy and society, outlining the role and benefits of radio astronomy to society, often extending beyond astronomy. The Handbook then covers areas such as the characteristics of radio astronomy, preferred frequency bands for observations, special radio astronomy applications, vulnerability to radio frequency interference (RFI) from other services, and issues associated with sharing the radio spectrum with other services. Additional chapters have been included in this third edition of the Handbook on techniques for mitigating the effects of RFI, on the establishment and characteristics of Radio Quiet Zones (RQZ), on the searches for extraterrestrial intelligence (SETI) and on ground-based radar astronomy. New Appendices have been added to explain the use of units and the dB scale in radio astronomy, and an extensive list of acronyms. Almost ten years have passed since the second edition of the Handbook – Radio Astronomy was published. In the meantime ITU has held three World Radiocommunication Conferences (WRC-2003, WRC-2007 and WRC-2012). In this period, there has been a virtual explosion in the development of communication services, and wireless services are now all pervasive in our multi-connected society. In parallel, technological developments in radio astronomy have enabled observations over very wide frequency bands, often not covered by the ITU allocations. Such developments present a challenge for the protection of radio astronomy and new methods had to be explored. New techniques on RFI mitigation are under continuous development, and RQZ have been defined to provide unique places on the planet where radio astronomy can proceed with minimal interference. Such developments have been covered within ITU with new and extensive ITU-R Reports. Radio astronomy is now also operating in bands above 275 GHz, with the ALMA observatory in South America, which commenced operations in 2013. These bands are not covered by the formal ITU allocations, but WRC-2012 clarified the usage of such bands by the passive services without precluding the development of active services. Studies have shown that sharing between services would be relatively easy at such high frequencies. Just before WRC-2012, ITU-R Working Party 7D (WP 7D) started to revise the Handbook, and this work continued over two years. WP 7D is the section within ITU-R Study Group 7 (Science services) that is responsible for radio astronomy, SETI, and radar astronomy. In parallel with the necessary revision and expansion of the Handbook, WP 7D had to revise relevant ITU-R Recommendations and Reports to protect the radio astronomy service. The third edition of the Handbook successfully incorporates the results of these efforts by the Working Party members. Radio Astronomy Introduction - iv - I wish to acknowledge the considerable effort of a small group of people without whose involvement the Handbook could not have materialized. I am particularly indebted to the following WP 7D members (in alphabetical order): – Dr. W. Baan (Netherlands), Dr. S. H. Chung (Korea), Dr. A. Clegg (United States of America), – Dr. M. Davis (United States of America), Dr. T. Gergely (United States of America), Dr. A. Jessner (Germany), – Dr. G. Langston (United States of America), Dr. B. Lewis (United States of America), Dr. H. Liszt (United States of America), – Dr. M. Ohishi (Japan), Dr. P. Thomasson (United Kingdom), Dr. W. van Driel (France). Other contributors were: Dr. J. Romney from USA, who extensively re-wrote the sections on very long baseline interferometry (VLBI), Dr. J. Lovell from Australia for the section on geodetic VLBI, and Dr. K. Tapping (Canada) for revising the section on solar astronomy. The ITU-R Secretariat provided considerable help and in particular the Study Group 7 Counsellor Mr. Vadim Nozdrin and the Secretariat led by Mrs. Elizabeth Mostyn-Jones. Finally I would like to express my sincere appreciation to the Chairman of Study Group 7, Dr. Vincent Meens and the vice-Chair responsible for the Handbooks Dr. John Zuzek, for their continuing encouragement and support during this work. I thank all contributors and wish the ITU-R Handbook – Radio Astronomy every success. Anastasios Tzioumis Chairman, ITU-R Working Party 7D Introduction Radio Astronomy - v - PREFACE The Handbook on Radio Astronomy has been developed by experts of Working Party 7D of ITU-R Study Group 7 (Science services), under the chairmanship of Dr. A. Tzioumis (Australia), Chairman, Working Party 7D. Radio astronomy plays a key role in the study of problems in fundamental physics and cosmology. Many of the phenomena studied cannot be studied in other parts of the electromagnetic spectrum. To cite but a few examples: the emission line of neutral atomic hydrogen; cosmic microwave background radiation and its angular structure, which is of immense significance in cosmology; the huge regions of synchrotron radiation associated with radio galaxies; and regions of star formation that are hidden by dust in optical frequencies. Using radio frequencies, it is possible to achieve the highest angular resolution and the most precise measurement of angular positions and of spectral lines and their Doppler shifts. For this reason, radio astronomy, far from being a mere adjunct to traditional optical methods, plays a leading role in research carried out in many areas of astronomy and astrophysics. Apart from this, radio astronomy, like any fundamental science, stimulates development in other branches. It is to radio astronomy that we owe the development of low-noise receivers and antennas that enable us to use a single antenna to capture signals of differing polarisations. Methods developed in radio astronomy to combat radio echo are now being used successfully in WiFi-type mobile communication systems. The foundations of radionavigation theory that are used today in a range of systems were developed and confirmed in radio astronomy. The need to process huge quantities of data in radio astronomy has resulted in major improvements in automated data processing, including the development of methods for parallel data processing and new programming languages. In the medical sphere, radio astronomy has led to the introduction of X-ray diagnostics and computerized tomography. All the above indicate the importance of the international recognition and protection of spectrum used by radioastronomy. This Handbook gives the reader a very useful source of information relevant to the management of radio spectrum usage in order to minimize the interference caused to this valuable service. François Rancy Director Radiocommunication Bureau Radio Astronomy Preface - vii - TABLE OF CONTENTS Page Introduction to the third edition by the Chairman of ITU-R Working Party 7D (Radio Astronomy) ..... iii PREFACE ......................................................................................................................................... v PREAMBLE Radio Astronomy and Society ......................................................................................... 1 0.1 Introduction to astronomy ..................................................................................................... 1 0.2 The role of radio astronomy .................................................................................................. 1 0.3 Economic and societal value ................................................................................................. 4 0.3.1 Introduction ................................................................................................................ 4 0.3.2 Economic and societal value of radio astronomy research ........................................
Load more

Recommended publications
  • 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]
  • Astronomy 114 Problem Set # 2 Due: 16 Feb 2007 Name
    Astronomy 114 Problem Set # 2 Due: 16 Feb 2007 Name: SOLUTIONS As we discussed in class, most angles encountered in astronomy are quite small so degrees are often divded into 60 minutes and, if necessary, minutes in 60 seconds. Therefore to convert an angle measured in degrees to minutes, multiply by 60. To convert minutes to seconds, multiply by 60. To use trigonometric formulae, angles might have to be written in terms of radians. Recall that 2π radians = 360 degrees. Therefore, to convert degrees to radians, multiply by 2π/360. 1 The average angular diameter of the Moon is 0.52 degrees. What is the angular diameter of the moon in minutes? The goal here is to change units from degrees to minutes. 0.52 degrees 60 minutes = 31.2 minutes 1 degree 2 The mean angular diameter of the Sun is 32 minutes. What is the angular diameter of the Sun in degrees? 32 minutes 1 degrees =0.53 degrees 60 minutes 0.53 degrees 2π =0.0093 radians 360 degrees Note that the angular diameter of the Sun is nearly the same as the angular diameter of the Moon. This similarity explains why sometimes an eclipse of the Sun by the Moon is total and sometimes is annular. See Chap. 3 for more details. 3 Early astronomers measured the Sun’s physical diameter to be roughly 109 Earth diameters (1 Earth diameter is 12,750 km). Calculate the average distance to the Sun using trigonometry. (Hint: because the angular size is small, you can make the approximation that sin α = α but don’t forget to express α in radians!).
    [Show full text]
  • Lecture 5. Interstellar Dust: Optical Properties
    Lecture 5. Interstellar Dust: Optical Properties 1. Introduction 2. Extinction 3. Mie Scattering 4. Dust to Gas Ratio 5. Appendices References Spitzer Ch. 7, Osterbrock Ch. 7 DC Whittet, Dust in the Galactic Environment (IoP, 2002) E Krugel, Physics of Interstellar Dust (IoP, 2003) B Draine, ARAA, 41, 241, 2003 1. Introduction: Brief History of Dust Nebular gas long accepted but existence of absorbing interstellar dust controversial. Herschel (1738-1822) found few stars in some directions, later extensively demonstrated by Barnard’s photos of dark clouds. Trumpler (PASP 42 214 1930) conclusively demonstrated interstellar absorption by comparing luminosity distances & angular diameter distances for open clusters: • Angular diameter distances are systematically smaller • Discrepancy grows with distance • Distant clusters are redder • Estimated ~ 2 mag/kpc absorption • Attributed it to Rayleigh scattering by gas Some of the Evidence for Interstellar Dust Extinction (reddening of bright stars, dark clouds) Polarization of starlight Scattering (reflection nebulae) Continuum IR emission Depletion of refractory elements from the gas Dust is also observed in the winds of AGB stars, SNRs, young stellar objects (YSOs), comets, interplanetary Dust particles (IDPs), and in external galaxies. The extinction varies continuously with wavelength and requires macroscopic absorbers (or “dust” particles). Examples of the Effects of Dust Extinction B68 Scattering - Pleiades Extinction: Some Definitions Optical depth, cross section, & efficiency: ext ext ext τ λ = ∫ ndustσ λ ds = σ λ ∫ ndust 2 = πa Qext (λ) Ndust nd is the volumetric dust density The magnitude of the extinction Aλ : ext I(λ) = I0 (λ) exp[−τ λ ] Aλ =−2.5log10 []I(λ)/I0(λ) ext ext = 2.5log10(e)τ λ =1.086τ λ 2.
    [Show full text]
  • Seasonal and Spatial Variations in the Attenuation of Light in the North Atlantic Ocean
    JEFFREY H. SMART SEASONAL AND SPATIAL VARIATIONS IN THE ATTENUATION OF LIGHT IN THE NORTH ATLANTIC OCEAN This article examines seasonal and spatial vanatlOns in the average depth profiles of the diffuse attenuation coefficient, Kd, for visible light propagating downward from the ocean surface at wavelengths of 490 and 532 nm. Profiles of the depth of the nth attenuation length are also shown. Spring, summer, and fall data from the northwestern and north central Atlantic Ocean and winter data from the northeastern Atlantic Ocean are studied. Variations in the depth-integrated Kd profiles are important because they are related to the depth penetration achievable by an airborne active optical antisubmarine warfare system. INTRODUCTION Numerous investigators have tried to characterize the the geographic areas and seasons indicated in Table 1 and diffuse attenuation coefficient (hereafter denoted as Kd) Figure 1. Despite the incomplete spatial and temporal for various ocean areas and for the different seasons. Platt coverage across the North Atlantic Ocean, this article and Sathyendranath 1 generated numerical fits to averaged should serve as a useful resource to estimate the optical profiles from coastal and open-ocean regions, and they characteristics in the areas studied. divided the North Atlantic into provinces that extended The purpose of this article is to characterize the sea­ from North America to Europe and over large ranges sonal and spatial variations in diffuse attenuation at 490 in latitude (e.g. , from 10.0° to 37.00 N and from 37.0° to and 532 nm. Because Kd frequently changes with depth, 50.00 N). In addition, numerous papers have attempted profiles of depth versus number of attenuation lengths are to model chlorophyll concentrations (which are closely required to characterize the attenuation of light as it correlated with Kd ) using data on available sunlight as a propagates from the surface downward into the water function of latitude and season, nutrient concentrations, column.
    [Show full text]
  • Square Kilometre Array Computational Challenges
    Square Kilometre Array Computational Challenges Paul Alexander Paul Alexander SKA Computational Challenges What is the Square Kilometre Array (SKA) • Next Generation radio telescope – compared to best current instruments it is ... E-MERLIN • ~100 times sensitivity • ~ 106 times faster imaging the sky • More than 5 square km of collecting area on sizes 3000km eVLA 27 27m dishes Longest baseline 30km GMRT 30 45m dishes Longest baseline 35 km Paul Alexander SKA Computational Challenges What is the Square Kilometre Array (SKA) • Next Generation radio telescope – compared to best current instruments it is ... • ~100 times sensitivity • ~ 106 times faster imaging the sky • More than 5 square km of collecting area on sizes 3000km • Will address some of the key problems of astrophysics and cosmology (and physics) • Builds on techniques developed in Cambridge • It is an interferometer • Uses innovative technologies... • Major ICT project • Need performance at low unit cost Paul Alexander SKA Computational Challenges Dishes Paul Alexander SKA Computational Challenges Phased Aperture array Paul Alexander SKA Computational Challenges also a Continental sized Radio Telescope • Need a radio-quiet site • Very low population density • Large amount of space • Possible sites (decision 2012) • Western Australia • Karoo Desert RSA Paul Alexander SKA Computational Challenges Sensitivity comparison 12,000 Sensitivity Comparison 10,000 1 - K 2 8,000 SKA2 6,000 SKA2 SKA1 MeerKAT LOFAR ASKAP 4,000 Sensitivity: Aeff/Tsys m Sensitivity:Aeff/Tsys eVLA SKA1 2,000
    [Show full text]
  • 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
    [Show full text]
  • Introduction to Radio Astronomy
    Introduction to Radio Astronomy Greg Hallenbeck 2016 UAT Workshop @ Green Bank Outline Sources of Radio Emission Continuum Sources versus Spectral Lines The HI Line Details of the HI Line What is our data like? What can we learn from each source? The Radio Telescope How do we actually detect this stuff? How do we get from the sky to the data? I. Radio Emission Sources The Electromagnetic Spectrum Radio ← Optical Light → A Galaxy Spectrum (Apologies to the radio astronomers) Continuum Emission Radiation at a wide range of wavelengths ❖ Thermal Emission ❖ Bremsstrahlung (aka free-free) ❖ Synchrotron ❖ Inverse Compton Scattering Spectral Line Radiation at a wide range of wavelengths ❖ The HI Line Categories of Emission Continuum Emission — “The Background” Radiation at a wide range of wavelengths ❖ Thermal Emission ❖ Synchrotron ❖ Bremsstrahlung (aka free-free) ❖ Inverse Compton Scattering Spectral Lines — “The Spikes” Radiation at specific wavelengths ❖ The HI Line ❖ Pretty much any element or molecule has lines. Thermal Emission Hot Things Glow Emit radiation at all wavelengths The peak of emission depends on T Higher T → shorter wavelength Regulus (12,000 K) The Sun (6,000 K) Jupiter (100 K) Peak is 250 nm Peak is 500 nm Peak is 30 µm Thermal Emission How cold corresponds to a radio peak? A 3 K source has peak at 1 mm. Not getting any colder than that. Synchrotron Radiation Magnetic Fields Make charged particles move in circles. Accelerating charges radiate. Synchrotron Ingredients Strong magnetic fields High energies, ionized particles. Found in jets: ❖ Active galactic nuclei ❖ Quasars ❖ Protoplanetary disks Synchrotron Radiation Jets from a Protostar At right: an optical image.
    [Show full text]
  • Atmospheric Anisotrophy and Its Effect on the Delay Power Spectra of Tropospheric Scatter Radio Signals Hosny Mohammed Ibrahim Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1982 Atmospheric anisotrophy and its effect on the delay power spectra of tropospheric scatter radio signals Hosny Mohammed Ibrahim Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Electrical and Electronics Commons Recommended Citation Ibrahim, Hosny Mohammed, "Atmospheric anisotrophy and its effect on the delay power spectra of tropospheric scatter radio signals " (1982). Retrospective Theses and Dissertations. 7507. https://lib.dr.iastate.edu/rtd/7507 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity.
    [Show full text]
  • Project Cyclops : a Design Study of a System for Detecting
    ^^^^m•i.j . --f'v.i^ "^y^-!^ A Design Study of a System for Detecting Extraterrestrial Intelligent Life '• >..-, i,C%' PREPARED UNDER STANFORD /NASA /AMES RESEARCH CENTER >J^1t> 1971 SUMMER FACULTY FELLOWSHIP PROGRAM IN ENGINEERING SYSTEMS DESIGr CR 114445 (Revised Edition 7/73) Available to the public rB' ^ A Design Study of a System for Detecting Extraterrestrial Intelligent Life PREPARED UNDER STANFORD/ NASA/AMES RESEARCH CENTER 1971 SUMMER FACULTY FELLOWSHIP PROGRAM IN ENGINEERING SYSTEMS DESIGN Further copies of this report may be obtained by writing to Dr. John Billingham NASA/ Ames Research Center, Code LT Moffett Field, California 94035 weixesunr colligc LWRART CYCLOPS PEOPLE Co-Directors: Bernard M. Oliver Stanford University (Summer appointment) John Billingham Ames Research Center, NASA System Design and Advisory Group: James Adams Stanford University Edwin L. Duckworth San Francisco City College Charles L. Seeger New Mexico State University George Swenson University of Illinois Antenna Structures Group: Lawrence S. Hill California State College L.A. John Minor New Mexico State University Ronald L. Sack University of Idaho Harvey B. Sharfstein San Jose State College Pennsylvania Alan 1. Soler University of Receiver Group: Washington Ward J. Helms University of William Hord Southern Illinois University Pierce Johnson University of Missouri C. ReedPredmore Rice University Transmission and Control Group: Marvin Siegel Michigan State University Jon A. Soper Michigan Technological University Henry J. Stalzer, Jr. Cooper Union Signal Processing Group: Jonnie B. Bednar University of Tulsa Douglas B. Brumm Michigan Technological University James H. Cook Cleveland State University Robert S. Dixon Ohio State University Johnson Luh Purdue University Francis Yu Wayne State University /./ la J C, /o ) •»• < .
    [Show full text]
  • Essay on Optics
    Essay on Optics by Émilie du Châtelet translated, with notes, by Bryce Gessell published by LICENSE AND CITATION INFORMATION 2019 © Bryce Gessell This work is licensed by the copyright holder under a Creative Commons Attribution-NonCommercial 4.0 International License. Published by Project Vox http://projectvox.org How to cite this text: Du Châtelet, Emilie. Essay on Optics. Translated by Bryce Gessell. Project Vox. Durham, NC: Duke University Libraries, 2019. http://projectvox.org/du-chatelet-1706-1749/texts/essay-on-optics This translation is based on the copy of Du Châtelet’s Essai sur l’Optique located in the Universitätsbibliothek Basel (L I a 755, fo. 230–265). The original essay was transcribed and edited in 2017 by Bryce Gessell, Fritz Nagel, and Andrew Janiak, and published on Project Vox (http://projectvox.org/du-chatelet-1706-1749/texts/essai-sur-loptique). 2 This work is governed by a CC BY-NC 4.0 license. You may share or adapt the work if you give credit, link to the license, and indicate changes. You may not use the work for commercial purposes. See creativecommons.org for details. CONTENTS License and Citation Information 2 Editor’s Introduction to the Essay and the Translation 4 Essay on Optics Introduction 7 Essay on Optics Chapter 1: On Light 8 Essay on Optics Chapter 2: On Transparent Bodies, and on the Causes of Transparence 11 Essay on Optics Chapter 3: On Opacity, and on Opaque Bodies 28 Essay on Optics Chapter 4: On the Formation of Colors 37 Appendix 1: Figures for Essay on Optics 53 Appendix 2: Daniel II Bernoulli’s Note 55 Appendix 3: Figures from Musschenbroek’s Elementa Physicae (1734) 56 Appendix 4: Figures from Newton’s Principia Mathematica (1726) 59 3 This work is governed by a CC BY-NC 4.0 license.
    [Show full text]
  • Natural and Enhanced Attenuation of Soil and Ground Water At
    LMS/MON/S04243 Office of Legacy Management Natural and Enhanced Attenuation of Soil and Groundwater at Monument Valley, Arizona, and Shiprock, New Mexico, DOE Legacy Waste Sites 2007 Pilot Study Status Report June 2008 U.S. Department OfficeOffice ofof LegacyLegacy ManagementManagement of Energy Work Performed Under DOE Contract No. DE–AM01–07LM00060 for the U.S. Department of Energy Office of Legacy Management. Approved for public release; distribution is unlimited. This page intentionally left blank LMS/MON/S04243 Natural and Enhanced Attenuation of Soil and Groundwater at Monument Valley, Arizona, and Shiprock, New Mexico, DOE Legacy Waste Sites 2007 Pilot Study Status Report June 2008 This page intentionally left blank Contents Acronyms and Abbreviations ....................................................................................................... vii Executive Summary....................................................................................................................... ix 1.0 Introduction......................................................................................................................1–1 2.0 Monument Valley Pilot Studies.......................................................................................2–1 2.1 Source Containment and Removal..........................................................................2–1 2.1.1 Phreatophyte Growth and Total Nitrogen...................................................2–1 2.1.2 Causes and Recourses for Stunted Plant Growth........................................2–5
    [Show full text]