The Historical Development of RADAR Science and Technology I1
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Toward a Large Bandwidth Photonic Correlator for Infrared Heterodyne Interferometry a first Laboratory Proof of Concept
A&A 639, A53 (2020) Astronomy https://doi.org/10.1051/0004-6361/201937368 & c G. Bourdarot et al. 2020 Astrophysics Toward a large bandwidth photonic correlator for infrared heterodyne interferometry A first laboratory proof of concept G. Bourdarot1,2, H. Guillet de Chatellus2, and J-P. Berger1 1 Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France e-mail: [email protected] 2 Univ. Grenoble Alpes, CNRS, LIPHY, 38000 Grenoble, France Received 19 December 2019 / Accepted 17 May 2020 ABSTRACT Context. Infrared heterodyne interferometry has been proposed as a practical alternative for recombining a large number of telescopes over kilometric baselines in the mid-infrared. However, the current limited correlation capacities impose strong restrictions on the sen- sitivity of this appealing technique. Aims. In this paper, we propose to address the problem of transport and correlation of wide-bandwidth signals over kilometric dis- tances by introducing photonic processing in infrared heterodyne interferometry. Methods. We describe the architecture of a photonic double-sideband correlator for two telescopes, along with the experimental demonstration of this concept on a proof-of-principle test bed. Results. We demonstrate the a posteriori correlation of two infrared signals previously generated on a two-telescope simulator in a double-sideband photonic correlator. A degradation of the signal-to-noise ratio of 13%, equivalent to a noise factor NF = 1:15, is obtained through the correlator, and the temporal coherence properties of our input signals are retrieved from these measurements. Conclusions. Our results demonstrate that photonic processing can be used to correlate heterodyne signals with a potentially large increase of detection bandwidth. -
Electronic Warfare Fundamentals
ELECTRONIC WARFARE FUNDAMENTALS NOVEMBER 2000 PREFACE Electronic Warfare Fundamentals is a student supplementary text and reference book that provides the foundation for understanding the basic concepts underlying electronic warfare (EW). This text uses a practical building-block approach to facilitate student comprehension of the essential subject matter associated with the combat applications of EW. Since radar and infrared (IR) weapons systems present the greatest threat to air operations on today's battlefield, this text emphasizes radar and IR theory and countermeasures. Although command and control (C2) systems play a vital role in modern warfare, these systems are not a direct threat to the aircrew and hence are not discussed in this book. This text does address the specific types of radar systems most likely to be associated with a modern integrated air defense system (lADS). To introduce the reader to EW, Electronic Warfare Fundamentals begins with a brief history of radar, an overview of radar capabilities, and a brief introduction to the threat systems associated with a typical lADS. The two subsequent chapters introduce the theory and characteristics of radio frequency (RF) energy as it relates to radar operations. These are followed by radar signal characteristics, radar system components, and radar target discrimination capabilities. The book continues with a discussion of antenna types and scans, target tracking, and missile guidance techniques. The next step in the building-block approach is a detailed description of countermeasures designed to defeat radar systems. The text presents the theory and employment considerations for both noise and deception jamming techniques and their impact on radar systems. -
Understanding the Cavity Duplexer
i THE CAVITY DUPLEXER John E Portune W6NBC [email protected] rev 2019 NOTE FROM AUTHOR This book was written several years ago and based on hardware-store copper water pipe as the source of home-brew duplexer construction materials. Later I began making from spun-aluminum commercial cake pans. Both require no welding. Unfortunately the price of copper is today much higher. Cake pans, however, are still reasonably priced, readily available and very acceptable as the basis especially for VHF cavities. Because of maximum cavity size limit, copper water pipe may still be indicated for UHF and above. In any case, how a duplexer operates is basic physics. No matter what the material, or whether the duplexer is commercial or home brew, the principles herein are universal to duplexer construction, modification and tuning. This book, however, is not finished. Repeater building is no longer my primary interest in ham radio. Some subjects could be added. But as it contains the essentials, I have placed on the internet incomplete. If you reproduce it, be so kind as to give proper author’s credits. W6NBC January 2019 . ii CHAPTER OUTLINE 1. The Mysterious Duplexer • The black box everybody uses but nobody understands • Keys to understanding it • This is not a cookbook 2. Let’s Make a Cavity • Home-brew 2M aluminum cavity • Example for the entire book • The best way to learn 3. Cavities • Mechanical and electrical properties of cavities • Basic structure of a duplexer • Why use cavities • Getting energy in and out: loops, probes, taps and ports • Three cavity types: Bp, Br, Bp/Br • Creating the other types • Helical resonators for 6M and 10M duplexers 4. -
Spring 2017 Some Reflections on the History of Radar from Its Invention
newsletter OF THE James Clerk Maxwell Foundation ISSN 205 8-7503 (Print) Issue No.8 Spring 2017 ISSN 205 8-7511 (Online) Some Re flections on the History of Radar from its Invention up to the Second World War By Professor Hugh Griffiths , DSc(Eng), FIET, FIEEE, FREng, University College, London, Royal Academy of Engineering Chair of Radio Frequency Sensors Electromagnetic Waves – Maxwell and Hertz In 1927, in France, Pierre David had observed similar effects and, in 1930, had conducted further trials, leading to a deployed In his famous 1865 paper ‘ A Dynamical Theory of the Electromagnetic forward-scatter radar system to protect the naval ports of Brest, Field’ Maxwell derived theoretically his famous equations of Cherbourg, Toulon and Bizerte (Algeria). electromagnetism which showed that these equations implied that electromagnetic disturbances travelled as waves at finite speed. In 1935, in the UK, Robert Watson-Watt had a claim to be From the fact that the speed of these waves was equal (to within ‘the father of radar’ on the basis of the Daventry Experiment experimental error) to the known velocity of light, Maxwell (described later in this article) and his development of a radar detection system (Chain Home) for the R.A.F. in World War II. concluded with the immortal words: “This velocity is so nearly that of light that it seems we have strong reason But, to the author, the priority for the invention of radar should go to conclude that light itself (including radiant heat and other radiations if to a German, Christian Hülsmeyer, a young engineer who in 1904 built and demonstrated a device to detect ships. -
Detecting and Locating Electronic Devices Using Their Unintended Electromagnetic Emissions
Scholars' Mine Doctoral Dissertations Student Theses and Dissertations Summer 2013 Detecting and locating electronic devices using their unintended electromagnetic emissions Colin Stagner Follow this and additional works at: https://scholarsmine.mst.edu/doctoral_dissertations Part of the Electrical and Computer Engineering Commons Department: Electrical and Computer Engineering Recommended Citation Stagner, Colin, "Detecting and locating electronic devices using their unintended electromagnetic emissions" (2013). Doctoral Dissertations. 2152. https://scholarsmine.mst.edu/doctoral_dissertations/2152 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. DETECTING AND LOCATING ELECTRONIC DEVICES USING THEIR UNINTENDED ELECTROMAGNETIC EMISSIONS by COLIN BLAKE STAGNER A DISSERTATION Presented to the Faculty of the Graduate School of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in ELECTRICAL & COMPUTER ENGINEERING 2013 Approved by Dr. Steve Grant, Advisor Dr. Daryl Beetner Dr. Kurt Kosbar Dr. Reza Zoughi Dr. Bruce McMillin Copyright 2013 Colin Blake Stagner All Rights Reserved iii ABSTRACT Electronically-initiated explosives can have unintended electromagnetic emis- sions which propagate through walls and sealed containers. These emissions, if prop- erly characterized, enable the prompt and accurate detection of explosive threats. The following dissertation develops and evaluates techniques for detecting and locat- ing common electronic initiators. The unintended emissions of radio receivers and microcontrollers are analyzed. These emissions are low-power radio signals that result from the device's normal operation. -
Low-Noise Local Oscillator Design Techniques Using a DLL-Based Frequency Multiplier for Wireless Applications
Low-Noise Local Oscillator Design Techniques using a DLL-based Frequency Multiplier for Wireless Applications by George Chien B.S. (University of California, Los Angeles) 1993 M.S. (University of California, Berkeley) 1996 A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering-Electrical Engineering and Computer Sciences in the GRADUATE DIVISION of the UNIVERSITY OF CALIFORNIA, BERKELEY Committee in charge: Professor Paul R. Gray, Chair Professor Robert G. Meyer Professor Paul K. Wright Spring 2000 The dissertation of George Chien is approved: Professor Paul R. Gray, Chair Date Professor Robert G. Meyer Date Professor Paul K. Wright Date University of California, Berkeley Fall 1999 Low-Noise Local Oscillator Design Techniques using a DLL-based Frequency Multiplier for Wireless Applications Copyright 2000 by George Chien Abstract Low-Noise Local Oscillator Design Techniques using a DLL-based Frequency Multiplier for Wireless Applications by George Chien Doctor of Philosophy in Engineering - Electrical Engineering and Computer Sciences University of California, Berkeley Professor Paul R. Gray, Chair The fast growing demand of wireless communications for voice and data has driven recent efforts to dramatically increase the levels of integration in RF transceivers. One approach to this challenge is to implement all the RF functions in the low-cost CMOS technology, so that RF and baseband sections can be combined in a single chip. This in turn dictates an integrated CMOS implementation of the local oscillators with the same or even better phase noise performance than its discrete counterpart, generally a difficult task using conventional approaches with the available low-Q integrated inductors. -
Quantification of Bird Migration Using Doppler Weather Surveillance Radars
A Thesis entitled Quantification of Bird Migration Using Doppler Weather Surveillance Radars (NEXRAD) by Priyadarsini Komatineni Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Electrical Engineering Dr. Mohsin M. Jamali, Committee Chair Dr. Junghwan Kim, Committee Member Dr. Peter V. Gorsevski, Committee Member Dr. Patricia R. Komuniecki, Dean College of Graduate Studies The University of Toledo August 2012 Copyright 2012, Priyadarsini Komatineni This document is copyrighted material. Under copyright law, no parts of this document may be reproduced without the expressed permission of the author. An Abstract of Quantification of Bird Migration Using Doppler Weather Surveillance Radars (NEXRAD) by Priyadarsini Komatineni Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Electrical Engineering and Computer Science The University of Toledo August 2012 Wind Energy is an important renewable source in United States. Since past few years, the growth of wind farms construction has significantly increased, due to which there is an increase in number of bird deaths. Therefore, ornithologists began to study the bird’s behavior during different migration periods. So far ornithologists have used many methods to study the bird migration patterns in which the radar ornithology has been used in an innovative way. However, many studies have focused using small portable radars and recently researchers have proved that the migration events can be studied through large broad scale radars like NEXRAD. Throughout the United States, NEXRAD has 160 Doppler Weather Surveillance Radars. The advantage of NEXRAD is that it can provide bird migration movements over a broad geographical scale and can be accessed free of charge. -
Radar Applications 1
CHAPTER Radar Applications 1 William L. Melvin, Ph.D., and James A. Scheer, Georgia Institute of Technology, Atlanta, GA Chapter Outline 1.1 Introduction . .................................................... 1 1.2 Historical Perspective. ............................................ 2 1.3 Radar Measurements . ............................................ 5 1.4 Radar Frequencies................................................. 6 1.5 Radar Functions................................................... 8 1.6 U.S. Military Radar Nomenclature ..................................... 9 1.7 Topics in Radar Applications ......................................... 10 1.8 Comments . .................................................... 14 1.9 References. .................................................... 15 1.1 INTRODUCTION Radio detection and ranging (radar) involves the transmission of an electromagnetic wave to a potential object of interest, scattering of the wave by the object, receipt of the scattered energy at the receive site, and signal processing applied to the received signal to generate the desired information product. Originally developed to detect enemy aircraft during World War II, radar has through the years shown diverse application, not just for military consumers, but also for commercial customers. Radar systems are still used to detect enemy aircraft, but they also keep commercial air routes safe, detect speeding vehicles on highways, image polar ice caps, assess deforestation in rain forests from satellite platforms, and image objects under foliage or behind walls. A number of other radar applications abound. This book is the third in a series. Principles of Modern Radar: Basic Principles, appearing in 2010, discusses the fundamentals of radar operation, key radar subsystems, and basic radar signal processing [1]. Principles of Modern Radar: Advanced Techni- ques, released in 2012, primarily focuses on advanced signal processing, waveform design and analysis, and antenna techniques driving tremendous performance gains in radar system capability [2]. -
The History of Radar
The Hi st or y of Canewdon Chai n Ho me 8th September 2013 Introduction Chain Home was the UK’s World War II long range Radar System It played a major part in winning the Battle of Britain One of the radar sites was here at Canewdon And one of Canewdon’s 360’ steel transmitter towers is now located at Chelmsford Keep watching to find out about Chain Home and why one of the Canewdon towers was moved 8th September 2013 Introduction • In 1932 Stanley Baldwin gives a speech to Parliament in which he states: “The Bomber Will Always Get Through” • He was not wrong, aircraft technology was improving and for the first time bomber aircraft were faster than fighters 8th September 2013 Introduction On the 2nd August 1934 Hitler becomes Germany’s head of state. He makes no secret that he wants to expand Germany’s borders. He starts to build up Germanys armed forces which is expressly forbidden under the terms of the treaty of Versailles. No European country is able or prepared to stop Germany. Some UK politicians think war is inevitable. 8th September 2013 The UK’s Air Defense Strategy – 1930 to 1935 • Early 1930’s • UK’s Air Defence Strategy • Mainstay was Royal Observer Corps formed in 1928 • Who used Optical, Infrared and Acoustic detectors to warn of approaching aircraft • Unfortunately they all suffered from: • Poor sensitivity • Limited range and were weather dependant Acoustic Detector 8th September 2013 The UK’s Air Defense Strategy – 1930 to 1935 • Acoustic Detectors - Sound Mirrors • The Sound Mirror was at the pinnacle of Acoustic Detection, -
Phase-Locked Loop Based Oscillator Phase Noise Measurement Technique
University of Central Florida STARS Retrospective Theses and Dissertations 1986 Phase-Locked Loop Based Oscillator Phase Noise Measurement Technique Luis M. Jimenez University of Central Florida Part of the Engineering Commons Find similar works at: https://stars.library.ucf.edu/rtd University of Central Florida Libraries http://library.ucf.edu This Masters Thesis (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Jimenez, Luis M., "Phase-Locked Loop Based Oscillator Phase Noise Measurement Technique" (1986). Retrospective Theses and Dissertations. 4980. https://stars.library.ucf.edu/rtd/4980 PHASE-LOCKED LOOP BASED OSCILLATOR PHASE NOISE MEASUREMENT TECHNIQUE BY LUIS MIGUEL JIMENEZ B.S.E., University of Central Florida, 1984 THESIS Submitted in partial fulfillment of the requirements for the degree of Master of Science in the Graduate Studies Program of the College of Engineering University of Central Florida Orlando, Florida Summer Term 1986 ABSTRACT Oscillators play an important role in the performance of various radio frequency (RF) systems. The generation of stable carrier and clock frequencies is necessary at both the transmitter and receiver ends of a communication system. Phase noise is the parameter used to characterize an oscillator frequency stability. This thesis introduces a phase noise measurement technique using a phase-locked loop. A 100 MHz Colpitt's oscillator, for the phase noise source, was designed and built. The output of the oscillator was mixed down to 10 MHz, before a phase-locked loop extracted the phase noise information. -
Two-Way Radio Success
www.IntercomsOnline.com Two-Way Radio Success How to Choose Two-Way Radios and Other Wireless Communication Devices. By David Onslow Copyright 2012, IntercomsOnline.com, all rights reserved 3rd Edition v3.1 For assistance in choosing the right two-way radio or communication product for you, visit www.intercomsonline.com or email us at the following address: 2 www.IntercomsOnline.com Introduction .............................................................................................................................. 5 Types of Two-Way Radios ....................................................................................................... 5 2-Way Radio Range: How Far Can Two-Way Radios Communicate? ..................................... 6 Two-Way Radio Power ........................................................................................................ 7 Radio Frequencies ............................................................................................................... 7 UHF Radio ..........................................................................................................................10 VHF Radio ..........................................................................................................................11 Commercial Digital Two-Way Radios ..................................................................................12 Antennas ................................................................................................................................13 Channel Usage .......................................................................................................................14 -
Cavity Magnetron 1 Cavity Magnetron
Cavity magnetron 1 Cavity magnetron The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field. The 'resonant' cavity magnetron variant of the earlier magnetron tube was invented by John Randall and Harry Boot in 1940 at the University of Birmingham, England.[1] The high power of pulses from the cavity magnetron made centimeter-band radar practical, with shorter wavelength radars allowing detection of smaller objects. The compact cavity magnetron tube drastically reduced the size of radar sets[2] so that they could be installed in anti-submarine aircraft[3] and Magnetron with section removed to exhibit the escort ships.[2] At present, cavity magnetrons are commonly used in cavities. The cathode in the center is not visible. The waveguide emitting microwaves is at the left. microwave ovens and in various radar applications.[4] The magnet producing a field parallel to the long axis of the device is not shown. Construction and operation All cavity magnetrons consist of a hot cathode with a high (continuous or pulsed) negative potential created by a high-voltage, direct-current power supply. The cathode is built into the center of an evacuated, lobed, circular chamber. A magnetic field parallel to the filament is imposed by a permanent magnet. The magnetic field causes the electrons, attracted to the (relatively) positive outer part of the chamber, to spiral outward in a circular path rather, a consequence of the Lorentz force. Spaced around the rim of the chamber are cylindrical A similar magnetron with a different section cavities.