DOCSLIB.ORG

Annual Report 1955 National Bureau of Standards

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Annual Report 1955 National Bureau of Standards Annual Report 1955 National Bureau of Standards U. S. Department of Commerce UNITED STATES DEPARTMENT OF COMMERCE Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS A. V. Astin, Director Annual Report 1955 National Bureau of Standards Miscellaneous Publication 217 For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 55 cents Contents Page General Review 1 1.1. Introduction 1 1.2. Technical Activities 2 1.3. Administrative Activities 9 1.4. Publications 11 Research and Development Program 12 2.1. Electricity and Electronics 12 Fundamental electrical units 13, Electrochemistry 14, Improve- ments in measuring techniques 14, Resistor noise 15, Electron tubes 15, Research on electric spark discharge 16, Pole-top failure 16, Design of mutual inductance transducers 16, Marine weather station 16, Special electronic devices 17, Preferred circuits 17, Mechanized production of electronics 18. 2.2. Optics and Metrology 19 Intercomparison of standards 20, Determination of color dif- ferences 20, Glass color standards 21, Spectacle lenses 22, Aviation lighting 23, Refractometry of synthetic crystals 24. 2.3. Heat and Power 24 Temperature standards 25, Low-temperature research 26, Properties of air and related substances 28, Thermodynamic properties of metals and salts 29, Mechanical degradation of polymers 29, Combustion in engines 30. 2.4. Atomic and Radiation Physics 31 Velocity of light redetermined 31, Radiation balance 32, X-ray calorimeter 32, Electron beam extractor 33, New radiochem- istry laboratory 33, Attenuation of gamma rays at oblique incidence 34, Zone melting apparatus 35, International inter- comparison of radiation standards 36, Negative ion research 36. 2.5. Chemistry 37 Colloidal dispersions 37, Titanium compounds 38, Labeled sugars 38, Research in analytical chemistry 39, Electrodeposi- tion of metals from organic solutions and fused salts 40, Advances in physical chemistry 41, Evaluation of scientific data 42, Special investigations and devices 42. iii .6. Mechanics . t Measurement of hearing 44, Jet noise 44, Architectural acoustics 44, Measurement on material substances with sound 45, Analysis of sound 45, Measurement of high pressures 46, Aerological and flight test instruments 47, Water-wave research 47, Density current research 48, Boundary layer transition 48, Surface roughness 49, Vibration standards for the calibration of pickups 50, Thermal stresses 51, Fatigue strength of aircraft structures 51, Airplane design 52, One thousand-pound balance 53, Densities of alcohol-water mix- tures 54, Combustion in high-velocity air 54, Fuel accessories for aircraft 54. .7. Organic and Fibrous Materials Crystallization phenomena in polymers 55, Behavior of "pure gum" rubber vulcanizates in tension 56, Effect of atmospheric contaminants on textiles 57, Effect of light on coated ground- wood papers 57, Accelerated aging of record papers 58, Amino acid analysis of collagen 58, Micropore structure of leather 59, Temperature of tires 60, High-temperature polymers 60, Blood plasma expanders 61, Dielectric studies 62, Multiaxial stretching of plastic glazing material 62, Infrared spectra of insoluble organic materials 62, Mechanism of rain erosion 63, Panographic dental X-ray machine 64, Gallium alloys 65. .8. Metallurgy Constitution diagrams 65, Properties and behavior ot alloys 66, Mechanisms of the deformation of metals 67, Titanium 69, Fatigue of metals 69, Corrosion 70. .9. Mineral Products Thermal decomposition of crystalline materials 72, Structure and properties of glass 72, Ceramic transducers 73, Ceramics containing uranium dioxide 73, Mechanism of deformation in ceramics 74, Electrical conductance in vitreous ceramics 75, Thermochemistry of inorganic materials 75, Crystal structure of the phosphates 76, Standard X-ray diffraction patterns 76, Phase studies of the system lime-silica-water 76, High-tem- perature, ceramic-metal strain gages 77, Phase equilibrium studies on portland cement 77, Effect of ceramic coatings on the creep of alloys 78, Reaction of portland cement with car- bon dioxide 79, Refractory concrete for jet aircraft aprons 79, Properties of glass fibers 80, Special optical glasses 80. Page 2.10. Building Technology 81 Instrumentation and measurement 82, Control of cracking in reinforced concrete 82, Flame spread test method 83, Aircraft fire detection 84, Water usage for drinking water coolers 84, Effect of moisture on rcof deck insulation 85, Performance of air cleaners 86, A study of a ceiling panel heating system 86, Asphalt roofing 87, Roof maintenance manual 87. 2.11. Applied Mathematics 87 Numerical analysis 88, Digital computation 89, Statistical en- gineering 91, Mathematical physics 92. 2.12. Data Processing Systems 94 SEAC 95, Analog computers 95, Development of new com- puters 96, Computer circuitry packaging 96, Diode amplifier 96, Cold cathode gas diodes 96, Other diode studies 97, Mag- netic core investigations 97, Rotating reading head 97, High- density magnetic tape recording 98. 2.13. Cryogenic Engineering 99 Cryogenic equipment 99, Cryogenic processes 100, Low-tem- perature properties of materials 101, Liquefaction of gases 102. 2.14. Radio Propagation Physics 103 Oblique incidence studies 104, Low-frequency propagation 105, Cosmic noise 105, Arctic radio propagation 106, Interna- tional Geophysical Year 106, Speed of light 107. 2.15. Radio Propagation Engineering 107 Radio noise studies and noise predictions 108, Tropospheric forward scatter propagation 109, Phase stability of VHF and UHF transmissions 110, Obstacle enhancement of signals 110. 2.16. Radio Standards 110 Power measurements 111, Voltage standards 111, Attenuation standards 112, Coaxial resonance line for microwave imped- ance measurements 112, Precision microwave interferometer 112, Dielectric and magnetic materials 113, Microwave spectroscopy of gases at high pressure 114, Atomic standards of frequency and time 115, Frequency standards and stand- ard frequency broadcasts 115. 2.17. Basic Instrumentation 117 Specific instrument developments 118, Instrument reference service 119, Indexing system 120, Instrument surveys 121, Studies on shock and vibration 121. V Page 3. Calibration, Testing, and Standard Samples 122 3.1. Calibration Center 123 3.2. Making Standards Available for Practical Use 123 Time and frequency 123, Clinical thermometers 124, Dental materials 126. 3.3. Calibration Requests Show Industry Trends 126 3.4. New Standard Samples 127 3.5. Testing for Government Purchase 128 3.6. Services in Other Areas 130 4. Cooperative Activities 132 Federal specifications 133, Methods of test 134, Industry spec- ifications 134, Building and safety codes 135, Radiation pro- tection 136, Weights and measures 136, Research associate program 137, Optics 139, Heat and power 140, Building tech- nology 140, Data processing 141, Radio propagation 142, Dental materials 144, Metals, mineral products, and other materials 144, Acoustics 145, Smog 146, Highway truck weighing 146, Educational program 146, International 147. 5. Appendices 149 5.1. Organization 149 5.2. Fiscal Data on NBS Program 154 5.3. Advisory Committees 155 5.4. Awards and Honors 157 5.5. List of Publications 158 vi 1. General Review 1.1. Introduction During the past year, the major effort of the National Bureau of Standards has been devoted to the strengthening of its basic programs. With the assistance of scientific advisory committees, the Bureau is seeking: to develop a balanced technical program bv increasing the level of research, especially basic research, in those fields for which the Bureau has an assigned responsibility. An effective standards research program must at all times remain at the forefront of science. It must continually push to the frontiers in order to provide the new standards needed bv scientists in their studies of new materials and newly understood phenomena. Standards are important to scientific inquiry. They are the results of meticulous investigation themselves. They are intimately associated with the basic units of measurement or comparison by which experiments may be properly described and verified. Research associated with the development of standards helps to unravel some of the puzzling results obtained with new experiments and leads scientists and engineers to the best avenues for the solution of their special technical problems. Thus, it pro- vides clues for effective applied research and helps to eliminate false starts in development work. By virtue of its responsibility for the custody, maintenance, and establishment of the Nation's primary standards of physical measurement, the National Bureau of Standards serves Govern- ment, science, and industry. The Bureau is the source for physical standards used in mass production and in the development of interchangeable parts—so vital to our modern economy. For industry and science, the Bureau also performs critical calibrations of working standards and distributes standard samples for use in production and research. For Government, the Bureau develops methods for the acceptance testing of materials in procurement and helps to devise codes and specifications. In addition, the scientific staff of the Bureau provides technical advice to various scientific and Government groups and undertakes a large variety of studies to meet the special needs of other Government agencies. Obviously, the work of the National Bureau of Standards is quite broad. The scope of this responsibility is such that the Bureau I must continually adjust
Load more

Recommended publications
  • Spectrum Management Technical Handbook
    NTIA TN 89-2 SPECTRUM MANAGEMENT TECHNICAL HANDBOOK TECHNICAL NOTE SERIES NTIA TECHNICAL NOTE 89-2 SPECTRUM MANAGEMENT TECHNICAL HANDBOOK l U.S. DEPARTMENT OF COMMERCE Robert A. Mosbacher, Secretary Alfred C. Sikes, Assistant Secretary for Communications and Information JULY 1989 ACKNOWLEDGEMENT NT IA acknowledges the efforts of Mark Schellhammer in the completion of Phase I of this handbook (Sections 1-3). Other portions will be added as resources are available. ABSTRACT This handbook is a compilation of the procedures, definitions, relationships and conversions essential to electromagnetic compatibility analysis. It is intended as a reference for NTIA engineers. KEY WORDS CONVERSION FACTORS COUPLING EQUATIONS DEFINITIONS ·TECHNICAL RELATIONSHIPS iii TABLE OF CONTENTS Subsection Page SECTION 1 TECHNICAL TERMS:DEFINITIONS AND NOTATION TERMS AND DEFINITIONS . .. .. 1-1 GLOSSARY OF STANDARD NOTATION . .. 1-13 SECTION 2 TECHNICAL RELATIONSHIPS AND CONVERSION FACTORS INTRODUCTION . .. .. .. 2-1 TRANSMISSION LOSS FOR RADIO LINKS . �. .. .. 2-1 Propagation Loss . .. .. .. 2-1 Transmission Loss ........................................ 2-2 Free-Space Basic Transmission Loss .......................... 2-2 Basic Transmission Loss .................................... 2-2 Loss Relative to Free-Space .................................. 2-2 System Loss . .. 2-3 ; Total Loss . .. .. 2-3 ANTENNA CHARACTERISTICS . .. 2-3 Antenna Directivity ........................................ 2-3 Antenna Gain and Efficiency .................................. 2-3 I
    [Show full text]
  • C:\Documents and Settings\Owner
    A Multi-Media Guide to Shopping, Dining, Lodging, Recreation, Entertainment, Art & Historic Points of Interest for The American Heritage Tourist EVENTS... 4 INDEX OF CITIES... 6-7 ON THE ROAD... 27 Establish Your Community as a GREAT AMERICAN DESTINATION FALL / WINTER 2017-2018 (for less than a dime a day per lister) www.AmericanAntiquities.com See inside front cover 2 / AMERICAN JOURNAL Volume 25, FALL/WINTER 2017-18 AMERICAN ANTIQUITIES JOURNAL Volume 25, FALL/WINTER 2017-18/ 3 Enjoy your next road trip to one of our 500+ client cities. Let this be your guide for AboutAbout thethe CoCovverer shopping, dining, lodging, recreation, entertainment & historic points of interest for the AMERICAN HERITAGE TOURIST www.AmericanAntiquities.com Depression glass is clear or a specified number of colored translucent magazine subscriptions, thus glassware. It was produced in making its way into almost a multitude of colors, ranging every American home. from the deep colors of purple, Depression glass started one black, cobalt, and red to the of the largest collecting trends pastels of pink, yellow, green, ever, from collectors to amber, and blue which nostalgia hunters. Over created to bring a bright note 100,000 eager collectors now into the otherwise drab times seek this prized glass, of the depression. Most of this whether to complete a glassware was made in the handed-down family set of Ohio River Valley of the United dishes, or to find the highly States, where access to raw sought and elusive rare materials and power made pieces. manufacturing inexpensive. Depression glass is More than twenty becoming more scarce on the manufacturers made more open market.
    [Show full text]
  • Ira Sprague Bowen Papers, 1940-1973
    http://oac.cdlib.org/findaid/ark:/13030/tf2p300278 No online items Inventory of the Ira Sprague Bowen Papers, 1940-1973 Processed by Ronald S. Brashear; machine-readable finding aid created by Gabriela A. Montoya Manuscripts Department The Huntington Library 1151 Oxford Road San Marino, California 91108 Phone: (626) 405-2203 Fax: (626) 449-5720 Email: [email protected] URL: http://www.huntington.org/huntingtonlibrary.aspx?id=554 © 1998 The Huntington Library. All rights reserved. Observatories of the Carnegie Institution of Washington Collection Inventory of the Ira Sprague 1 Bowen Papers, 1940-1973 Observatories of the Carnegie Institution of Washington Collection Inventory of the Ira Sprague Bowen Paper, 1940-1973 The Huntington Library San Marino, California Contact Information Manuscripts Department The Huntington Library 1151 Oxford Road San Marino, California 91108 Phone: (626) 405-2203 Fax: (626) 449-5720 Email: [email protected] URL: http://www.huntington.org/huntingtonlibrary.aspx?id=554 Processed by: Ronald S. Brashear Encoded by: Gabriela A. Montoya © 1998 The Huntington Library. All rights reserved. Descriptive Summary Title: Ira Sprague Bowen Papers, Date (inclusive): 1940-1973 Creator: Bowen, Ira Sprague Extent: Approximately 29,000 pieces in 88 boxes Repository: The Huntington Library San Marino, California 91108 Language: English. Provenance Placed on permanent deposit in the Huntington Library by the Observatories of the Carnegie Institution of Washington Collection. This was done in 1989 as part of a letter of agreement (dated November 5, 1987) between the Huntington and the Carnegie Observatories. The papers have yet to be officially accessioned. Cataloging of the papers was completed in 1989 prior to their transfer to the Huntington.
    [Show full text]
  • A Novel Ship Target Detection Algorithm Based on Error Self-Adjustment Extreme Learning Machine and Cascade Classifier
    Cognitive Computation (2019) 11:110–124 https://doi.org/10.1007/s12559-018-9606-5 A Novel Ship Target Detection Algorithm Based on Error Self-adjustment Extreme Learning Machine and Cascade Classifier Wandong Zhang1,2 · Qingzhong Li1 · Q. M. Jonathan Wu2 · Yimin Yang3 · Ming Li1 Received: 30 June 2018 / Accepted: 10 October 2018 / Published online: 24 October 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract High-frequency surface wave radar (HFSWR) has a vital civilian and military significance for ship target detection and tracking because of its wide visual field and large sea area coverage. However, most of the existing ship target detection methods of HFSWR face two main difficulties: (1) the received radar signals are strongly polluted by clutter and noises, and (2) it is difficult to detect ship targets in real-time due to high computational complexity. This paper presents a ship target detection algorithm to overcome the problems above by using a two-stage cascade classification structure. Firstly, to quickly obtain the target candidate regions, a simple gray-scale feature and a linear classifier were applied. Then, a new error self-adjustment extreme learning machine (ES-ELM) with Haar-like input features was adopted to further identify the target precisely in each candidate region. The proposed ES-ELM includes two parts: initialization part and updating part. In the former stage, the L1 regularizer process is adopted to find the sparse solution of output weights, to prune the useless neural nodes and to obtain the optimal number of hidden neurons. Also, to ensure an excellent generalization performance by the network, in the latter stage, the parameters of hidden layer are updated through several iterations using L2 regularizer process with pulled back error matrix.
    [Show full text]
  • Transmitter T (X) Channel E (X) Receiver R
    Analog Communication ( 10EC53 ) Introduction The function of the communication system is to make available at the destination a signal originating at a distant point. This signal is called the desired signal. Unfortunately, during the passage of the signal through the channel and front-end of the receiver, this desired signal gets corrupted by a number of undesired signals. This is referred to as Noise. Noise is any unknown or unwanted signal. Noise is the static you hear in the speaker when you tune any AM or FM receiver to any position between stations. It is also the snow or confetti that is visible on a TV screen. The received signal is modeled as r (t) = s (t) + n (t) Where s (t) is the transmitted/desired signal n (t) is the additive noise/unwanted signal The signal n (t) gets added at the channel. It disturbs the transmission and processing of signal in Communication System. Over which one cannot have a control. In general term it is an unwanted signal that affects a wanted signal. It is a random signal that cannot be represented with a simple equation. But some time can be deterministic components (power supply hum, certain oscillations).Deterministic Components can be eliminated by proper shielding and introduction of notch filters. If their were no noise perfect communication would be possible with minimum transmitted power. At the receiver only amplification of the signal power to the desired level is required. If R (x)=T (x) then e (x)=0 Transmitter Receiver T (x) R (x) If R (x) ≠ T (x) then e (x) ≠ 0.The received signal is corrupted.
    [Show full text]
  • Demodulation, Bit-Error Probability and Diversity Arrangements
    RADIO SYSTEMS – ETIN15 Lecture no: 6 Demodulation, bit-error probability and diversity arrangements Anders J Johansson, Department of Electrical and Information Technology [email protected] 5 April 2017 1 Contents • Receiver noise calculations [Covered briefly in Chapter 3 of textbook!] • Optimal receiver and bit error probability – Principle of maximum-likelihood receiver – Error probabilities in non-fading channels – Error probabilities in fading channels • Diversity arrangements – The diversity principle – Types of diversity – Spatial (antenna) diversity performance 5 April 2017 2 RECEIVER NOISE 5 April 2017 3 Receiver noise Noise sources The noise situation in a receiver depends on several noise sources Noise picked up Wanted by the antenna signal Output signal Analog Detector with requirement circuits on quality Thermal noise 5 April 2017 4 Receiver noise Equivalent noise source To simplify the situation, we replace all noise sources with a single equivalent noise source. Wanted How do we determine Noise free signal N from the other sources? N Output signal C Analog Detector with requirement circuits on quality Noise free Same “input quality”, signal-to-noise ratio, C/N in the whole chain. 5 April 2017 5 Receiver noise Examples • Thermal noise is caused by random movements of electrons in circuits. It is assumed to be Gaussian and the power is proportional to the temperature of the material, in Kelvin. • Atmospheric noise is caused by electrical activity in the atmosphere, e.g. lightning. This noise is impulsive in its nature and below 20 MHz it is a dominating. • Cosmic noise is caused by radiation from space and the sun is a major contributor.
    [Show full text]
  • The Depression Era Pdf, Epub, Ebook
    CENTRAL GLASS WORKS: THE DEPRESSION ERA PDF, EPUB, EBOOK Tim Schmidt | 192 pages | 01 Jun 2004 | Schiffer Publishing Ltd | 9780764320163 | English | Atglen, United States Central Glass Works: The Depression Era PDF Book Comic Books. To find a value for your vintage glassware, shop around. Nonetheless, stock prices continued to rise, and by the fall of that year had reached stratospheric levels that could not be justified by expected future earnings. Answer: When we think of Depression Glass, we usually think of the popular dishware manufactured during that period. Lorraine — Also known as pattern No. Model Trains. The early history of the companies and operations which became the Indiana Glass Company are confusing, convoluted and not terribly well documented! And those relief programs for which blacks were eligible on paper were rife with discrimination in practice, since all relief programs were administered locally. Feel the heft of it. Princess is often found in pink and green, followed by yellow and occasionally in light blue. Jobs available to women paid less, but were more stable during the banking crisis: nursing, teaching and domestic work. Many cookie jars were made in colors not originally associated with Mayfair, but the pink and light blue versions can be troublesome for new collectors. It went over to mass production in the s. Consignment shops also must collect a percentage of the sold price. Pyramid — also known as pattern No. For instance, English Hobnail and Miss America can look very similar with just a cursory inspection. Most often found in pink and monax. Lincoln's Depression. Cookie jars and shot glasses have been reproduced in the Mayfair pattern.
    [Show full text]
  • Signal to Noise Ratio (SNR Or S/N) SNR Is the Ratio of the Signal Power to Noise Power
    JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY KAKINADA KAKINADA – 533 001 , ANDHRA PRADESH GATE Coaching Classes as per the Direction of Ministry of Education GOVERNMENT OF ANDHRA PRADESH Analog Communication 26-05-2020 to 06-07-2020 Prof. Ch. Srinivasa Rao Dept. of ECE, JNTUK-UCE Vizianagaram Analog Communication-Day 7, 01-06-2020 Presentation Outline Noise: • Noise and its types • Thermal Noise • Parameters of Noise • Noise in Baseband Communication systems • Gaussian process and NB Noise • Problems 02-06-2020 Prof.Ch.Srinivasa Rao, JNTUK UCEV 2 Learning Outcomes • At the end of this Session, Student will be able to: • LO 1 : Fundamental aspects of Noise • LO 2 : Different Noise types and its Paraneters • LO 3 : Gaussian Process and ND Noise 02-06-2020 Prof.Ch.Srinivasa Rao, JNTUK UCEV 3 Noise Definitions of Noise: • Noise is unwanted signal that affects wanted signal. • Noise can broadly be defined as any unknown signal that affects the recovery of the desired signal. • Noise is an unwanted signal, which interferes with the original message signal and corrupts the parameters of the message signal. This alteration in the communication process, leads to the message getting altered. It most likely enters at the channel or the receiver. Effect of noise • Degrades system performance (Analog and digital) • Receiver cannot distinguish signal from noise • Efficiency of communication system reduces Most common examples of noise are: • Hiss sound in radio receivers • Buzz sound amidst of telephone conversations • Flicker in television receivers, Noise Sources External Internal Noise Noise Atmospheric Industrial Extraterrestrial Solar Noise Cosmic Noise External Noise : • It is due to Man- made and natural resources • Sources over which we have no control such as thunders, snow fall, lightning etc.
    [Show full text]
  • The Public Need and the Role of the Inventor
    " lationsl Buresm 01 v »< JUL 1 0 1974 7HO160 The Public Need and the Role of the Inventor 1% Proceedings of a Conference held in Monterey, California June 11-14, 1973 Edited by Florence Essers and Jacob Rabinow Office of Invention and Innovation Institute for Applied Technology National Bureau of Standards Washington, D.C. 20234 3%% U.S. DEPARTMENT OF COMMERCE, Frederick B. Dent, Secretary NATIONAL BUREAU OF STANDARDS, Richard W. Roberts, Director Issued May 1974 Library of Congress Catalog Number: 73-600324 National Bureau of Standards Special Publication 388 Nat. Bur. Stand. (U.S.), Spec. Publ. 388, 215 pages (May 1974) CODEN: XNBSAV U.S. GOVERNMENT PRINTING OFFICE WASHINGTON: 1974 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 (Order by SD Catalog No. C 13. 10: 388). Price $5.55. Stock Number 0303-01261 Abstract This book presents the proceedings of the Conference on the Public Need and the Role of the Inven- tor, held at Monterey, Calif., on June 11-14, 1973. The conference, based on a recommendation of the National Inventors Council, was sponsored by the Office of Invention and Innovation, Institute for Ap- plied Technology, under a grant from the Experimental Technology Incentives Program, NBS. The pur- pose of the conference was to study the climate for invention and how to make it one in which America's inventors can flourish for the common good. Eighteen invited papers were presented. In addition, the proceedings includes statements from the chairmen of the three sessions: Charles S. Draper, Jacob Rabinow, and Myron Coler.
    [Show full text]
  • CALIFORNIA STATE UNIVERSITY, NORTHRIDGE SPACE COMMUNICATION THEORY and PRACTICE a Graduate Project Submitted in Partial Satisfac
    CALIFORNIA STATE UNIVERSITY, NORTHRIDGE SPACE COMMUNICATION THEORY AND PRACTICE A graduate project submitted in partial satisfaction of the requirements for the degree of the Masterr of Science 1n Engineering by Kristine Patricia Maine January, 1983 The project of Kristine Patricia Maine is approved: CDr. Ste~en A. Gad~ski) (Dr. ~y H. Pettit, Chair) California State University, Northridge ii ACKNOWLEDGEMENTS A deep sense of gratitude is expressed to my academic advisor, Dr. Ray Pettit, for his invaluable counsel and advisement during the course of this study. In addition, I express thanks to The Aerospace Corporation for the use of their facilities and personnel for the completion of this document. iii TABLE OF CONTENTS Title Page Acknowledgement iii Table of Figures v List of Tables vii List of Symbols viii Abstract xi I. Introduction 1 II. Space Communication System Components 2 III. Theory of Link Analysis 8 IV. Applications of Link Analysis 21 v. Summary 41 Appendix A--Signal Losses 45 Appendix B--Space Shuttle Design Model 54 Appendix C--Communication Satellite Systems 62 Footnotes 67 Bi biliography 70 iv TABLE OF FIGURES Figure Number Title 1 Simplified Transponder Block Diagram 3 Showing a Single Channel Transponder 2 TWT Characteristics 4 3 Typical Antenna Beamwidth Pattern 7 4 Satellite Communication System 9 5 Uplink Model 10 6 Downlink Model 13 7 Satellite Communication Transmitter­ 16 to-Receiver with Typical Loss and Noise Sources 8 Zenith Attenuation Values Expected to 18 be Exceeded 2% of the Year at Mid­ latitudes 9 Probability
    [Show full text]
  • Annual Report 1956 National Bureau of Standards
    Annual Report 1956 National Bureau of Standards U. S. Department of Commerce UNITED STATES DEPARTMENT OF COMMERCE Sinclair Weeks, Secretary NATIONAL BUREAU OF STANDARDS A. V. Astin, Director Annual Report 1956 National Bureau of Standards Miscellaneous Publication 220 For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 60 cents ii - Contents Page General Review 1 1.1. Introduction 1 1.2. Technical Activities 2 1.3. Administrative Activities 10 1.4. Publications 12 Research and Development Program 12 2.1. Electricity and Electronics 13 Fundamental electrical units 13, Electrochemistry 14, Electromotive force series for solid and molten chlorides 15, EMF -temperature hysteresis studies 15, Gassing of dry cells 15, Improvements in measuring techniques 16, Automatic microimage file 16, Microfilm - to-punched-card conveter 16, Magnetic -core transducer 16, Mech- anized production of electronics 16, Electronic miniaturization techniques 17, Miniaturized receiver 17, Preferred circuits 17, Re- search on electric spark discharge 17. 2.2. Optics and Metrology 18 Intercomparison of length standards 18, New standards 19, Precision liquid light niters for photographic sensitometry 19, Size of color differences 19, Dictionary of color names 20, Interlaboratory photo- metric intercomparisons 20, Refractometry 20, Photogrammetry 20, Image evaluation 21, Waviness of mica 21, Aerial reconnais- sance photography 21, Aviation lighting 21. 2.3. Heat and Power 22 Temperature standards 22, Low-temperature research 24, Thermo- dynamics 25, Lubrication 27, Engine fuels 28, Pneumatic systems 29. 2.4. Atomic and Radiation Physics 30 Spectroscopic research 30, Standards of isotopic abundance 30, Semiconducting materials 31, Field-emission X-ray microscope 32, Electron -optical studies of low-pressure gases 32, Microwave ab- sorption 32, Radioactivity 33, X-ray standards 33, High-energy accelerator research 34, Reciprocity laws for X-rays 35, Medical X-ray rooms 35, National photoneutrons standard 36, Low-energy electron scatter 36.
    [Show full text]
  • Dr. Dharmendra Kumar Assistant Professor Department of Electronics and Communication Engineering MMM University of Technology, Gorakhpur–273010
    Dr. Dharmendra Kumar Assistant Professor Department of Electronics and Communication Engineering MMM University of Technology, Gorakhpur–273010. Content of Unit-3 Noise: Source of Noise, Frequency domain, Representation of noise, Linear Filtering of noise, Noise in Amplitude modulation system, Noise in SSB-SC,DSB and DSB-C, Noise Ratio, Noise Comparison of FM and AM, Pre- emphasis and De-emphasis, Figure of Merit. Claude E. Shannon conceptualized the communication theory model in the late 1940s. It remains central to communication study today. Noise is random signal that exists in communication systems Channel is the main source of noise in communication systems Transmitter or Receiver may also induce noise in the system There are mainly 2-types of noise sources Internal noise source (are mainly internal to the communication system) External noise source Noise is an inconvenient feature which affects the system performance. Following are the effects of noise Degrade system performance for both analog and digital systems Noise limits the operating range of the systems Noise indirectly places a limit on the weakest signal that can be amplified by an amplifier. The oscillator in the mixer circuit may limit its frequency because of noise. A system’s operation depends on the operation of its circuits. Noise limits the smallest signal that a receiver is capable of processing The receiver can not understand the sender the receiver can not function as it should be. Noise affects the sensitivity of receivers: Sensitivity is the minimum amount of input signal necessary to obtain the specified quality output. Noise affects the sensitivity of a receiver system, which eventually affects the output.
    [Show full text]