Chapter 20: Height Finding and 3D Radar
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Design and Testing of Collimators for Use in Measuring X-Ray Attenuation
DESIGN AND TESTING OF COLLIMATORS FOR USE IN MEASURING X-RAY ATTENUATION By RAJESH PANTHI Master of Science (M.Sc.) in Physics Tribhuvan University Kathmandu, Nepal 2009 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE December, 2017 DESIGN AND TESTING OF COLLIMATORS FOR USE IN MEASURING X-RAY ATTENUATION Thesis Approved: Dr. Eric R. Benton Thesis Adviser and Chair Dr. Eduardo G. Yukihara Dr. Mario F. Borunda ii ACKNOWLEDGEMENTS I would like to express the deepest appreciation to my thesis adviser As- sociate Professor Dr. Eric Benton of the Department of Physics at Oklahoma State University for his vigorous guidance and help in the completion of this work. He provided me all the academic resources, an excellent lab environment, financial as- sistantship, and all the lab equipment and materials that I needed for this project. I am grateful for many skills and knowledge that I gained from his classes and personal discussion with him. I would like to thank Adjunct Profesor Dr. Art Lucas of the Department of Physics at Oklahoma State University for guiding me with his wonderful experience on the Radiation Physics. My sincere thank goes to the members of my thesis committee: Professor Dr. Eduardo G. Yukihara and Assistant Professor Dr. Mario Borunda of the Department of Physics at Oklahoma State University for generously offering their valuable time and support throughout the preparation and review of this document. I would like to thank my colleague Mr. Jonathan Monson for helping me to access the Linear Accelerators (Linacs) in St. -
Repeating Fast Radio Bursts Caused by Small Bodies Orbiting a Pulsar Or a Magnetar Fabrice Mottez1, Philippe Zarka2, and Guillaume Voisin3,1
A&A 644, A145 (2020) Astronomy https://doi.org/10.1051/0004-6361/202037751 & c F. Mottez et al. 2020 Astrophysics Repeating fast radio bursts caused by small bodies orbiting a pulsar or a magnetar Fabrice Mottez1, Philippe Zarka2, and Guillaume Voisin3,1 1 LUTH, Observatoire de Paris, PSL Research University, CNRS, Université de Paris, 5 Place Jules Janssen, 92190 Meudon, France e-mail: [email protected] 2 LESIA, Observatoire de Paris, PSL Research University, CNRS, Université de Paris, Sorbonne Université, 5 Place Jules Janssen, 92190 Meudon, France 3 Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester M19 9PL, UK Received 16 February 2020 / Accepted 1 October 2020 ABSTRACT Context. Asteroids orbiting into the highly magnetized and highly relativistic wind of a pulsar offer a favorable configuration for repeating fast radio bursts (FRB). The body in direct contact with the wind develops a trail formed of a stationary Alfvén wave, called an Alfvén wing. When an element of wind crosses the Alfvén wing, it sees a rotation of the ambient magnetic field that can cause radio-wave instabilities. In the observer’s reference frame, the waves are collimated in a very narrow range of directions, and they have an extremely high intensity. A previous work, published in 2014, showed that planets orbiting a pulsar can cause FRBs when they pass in our line of sight. We predicted periodic FRBs. Since then, random FRB repeaters have been discovered. Aims. We present an upgrade of this theory with which repeaters can be explained by the interaction of smaller bodies with a pulsar wind. -
A High Power Microwave Zoom Antenna with Metal Plate Lenses Julie Lawrance
University of New Mexico UNM Digital Repository Electrical and Computer Engineering ETDs Engineering ETDs 1-28-2015 A High Power Microwave Zoom Antenna With Metal Plate Lenses Julie Lawrance Follow this and additional works at: https://digitalrepository.unm.edu/ece_etds Recommended Citation Lawrance, Julie. "A High Power Microwave Zoom Antenna With Metal Plate Lenses." (2015). https://digitalrepository.unm.edu/ ece_etds/151 This Dissertation is brought to you for free and open access by the Engineering ETDs at UNM Digital Repository. It has been accepted for inclusion in Electrical and Computer Engineering ETDs by an authorized administrator of UNM Digital Repository. For more information, please contact [email protected]. Julie Lawrance Candidate Electrical Engineering Department This dissertation is approved, and it is acceptable in quality and form for publication: Approved by the Dissertation Committee: Dr. Christos Christodoulou , Chairperson Dr. Edl Schamilaglu Dr. Mark Gilmore Dr. Mahmoud Reda Taha i A HIGH POWER MICROWAVE ZOOM ANTENNA WITH METAL PLATE LENSES by JULIE LAWRANCE B.A., Physics, Occidental College, 1985 M.S. Electrical Engineering, 2010 DISSERTATION Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Engineering The University of New Mexico Albuquerque, New Mexico December, 2014 ii A HIGH POWER MICROWAVE ZOOM ANTENNA WITH METAL PLATE LENSES by Julie Lawrance B.A., Physics, Occidental College, 1985 M.S., Electrical Engineering, University of New Mexico, 2010 Ph.D., Engineering, University of New Mexico, 2014 ABSTRACT A high power microwave antenna with true zoom capability was designed and constructed with the use of metal plate lenses. Proof of concept was achieved through experiment as well as simulation. -
Before the Federal Communications Commission Washington DC 20554
Before the Federal Communications Commission Washington DC 20554 In the Matter of ) ) Unlicensed Use of the 6 GHz Band ) ET Docket No. 18-295 ) Expanding Flexible Use of the Mid-Band ) GN Docket No. 17-183 Spectrum Between 3.17 and 24 GHz ) COMMENTS OF THE FIXED WIRELESS COMMUNICATIONS COALITION Cheng-yi Liu Mitchell Lazarus FLETCHER, HEALD & HILDRETH, P.L.C. 1300 North 17th Street, 11th Floor Arlington, VA 22209 703-812-0400 Counsel for the Fixed Wireless February 15, 2019 Communications Coalition TABLE OF CONTENTS A. Summary .................................................................................................................................. 1 B. 6 GHz FS Bands and the Public Interest ................................................................................. 6 C. Fallacies on RLAN/FS Interference ........................................................................................ 9 1. High-off-the-ground FS antennas .................................................................................... 9 2. Indoor operation ............................................................................................................. 10 3. Statistical interference prediction .................................................................................. 10 D. Automatic Frequency Control Using Exclusion Zones ......................................................... 13 E. Multipath Fading and Fade Margin ....................................................................................... 15 1. Momentary interference -
Laser Collimated Beam Sensor LA SERIES ■■General Terms and Conditions
1053 Laser Collimated Beam Sensor LA SERIES ■ General terms and conditions ........... F-17 ■ Sensor selection guide ................. P.967~ FIBER Related Information SENSORS ■ About laser beam........................ P.1403~ ■ General precautions ..................... P.1405 LASER SENSORS PHOTOELECTRIC SENSORS Conforming to Conforming to FDA regulations EMC Directive MICRO (LA-511 only) PHOTOELECTRIC SENSORS AREA SENSORS LIGHT CURTAINS PRESSURE / FLOW SENSORS INDUCTIVE PROXIMITY SENSORS PARTICULAR USE SENSORS SENSOR LA-510 is classified as OPTIONS a Class 1 Laser Product SIMPLE in IEC / JIS standards. WIRE-SAVING LA-511 is a Class I Laser UNITS Product in FDA regulations WIRE-SAVING 21 CFR 1040.10. SYSTEMS Do not look at the laser MEASUREMENT beam through optical SENSORS panasonic-electric-works.net/sunx system such as a lens. STATIC CONTROL DEVICES ENDOSCOPE LASER “Class 1” laser beam sensor safe for your eyes MARKERS PLC / TERMINALS BASIC PERFORMANCE FUNCTIONS HUMAN MACHINE INTERFACES Safe laser beam LA-510 Easy laser beam alignment ENERGY CONSUMPTION VISUALIZATION This laser collimated beam sensor conforms to the Four monitoring LEDs help you to easily align the emitter COMPONENTS Class 1 laser stipulated in IEC 60825-1 and JIS C 6802. and the receiver. FA COMPONENTS Hence, safety measures such as protective gear are not necessary. MACHINE VISION Receiver front face SYSTEMS Precise sensing in wide area “DOWN” lights up UV CURING SYSTEMS Sensing area: 15 × 500 mm 0.591 × 19.685 in Minimum sensing object: ø0.1 mm ø0.004 in “LEFT” lights up The monitoring Repeatability: 10 µm 0.394 mil or less system checks whether the incident Sensing range beam falls evenly on Selection Emitter 500 mm 19.685 in Receiver “RIGHT” lights up Guide all the four receiving Laser “UP” lights up elements in the Displacement receiver window. -
Beam Expander Basics: Not All Spots Are Created Equal
LEARNING – UNDERSTANDING – INTRODUCING – APPLYING Beam Expander Basics: Not All Spots Are Created Equal APPLICATION NOTES www.edmundoptics.com BEAM EXPANDERS A laser beam expander is designed to increase the diameter from well-established optical telescope fundamentals. In such of a collimated input beam to a larger collimated output beam. systems, the object rays, located at infinity, enter parallel to Beam expanders are used in applications such as laser scan- the optical axis of the internal optics and exit parallel to them ning, interferometry, and remote sensing. Contemporary laser as well. This means that there is no focal length to the entire beam expander designs are afocal systems that developed system. THEORY: TELESCOPES Optical telescopes, which have classically been used to view eye, or image created, is called the image lens. distant objects such as celestial bodies in outer space, are di- vided into two types: refracting and reflecting. Refracting tele- A Galilean telescope consists of a positive lens and a negative scopes utilize lenses to refract or bend light while reflecting lens that are also separated by the sum of their focal length telescopes utilize mirrors to reflect light. (Figure 2). However, since one of the lenses is negative, the separation distance between the two lenses is much shorter Refracting telescopes fall into two categories: Keplerian and than in the Keplerian design. Please note that using the Effec- Galilean. A Keplerian telescope consists of positive focal length tive Focal Length of the two lenses will give a good approxima- lenses that are separated by the sum of their focal lengths (Fig- tion of the total length, while using the Back Focal Length will ure 1). -
Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers Including Near-Field Coupling Analysis
UNIVERSITY OF CALIFORNIA Los Angeles Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers including Near-field Coupling Analysis A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Electrical Engineering by Ilkyu Kim 2012 c Copyright by Ilkyu Kim 2012 ABSTRACT OF THE DISSERTATION Design of a Class of Antennas Utilizing MEMS, EBG and Septum Polarizers including Near-field Coupling Analysis by Ilkyu Kim Doctor of Philosophy in Electrical Engineering University of California, Los Angeles, 2012 Professor Yahya Rahmat-Samii, Chair Recent developments in mobile communications have led to an increased appearance of short-range communications and high data-rate signal transmission. New technologies provides the need for an accurate near-field coupling analysis and novel antenna designs. An ability to effectively estimate the coupling within the near-field region is required to realize short-range communications. Currently, two common techniques that are applicable to the near-field coupling problem are 1) integral form of coupling formula and 2) generalized Friis formula. These formulas are investigated with an emphasis on straightforward calculation and accuracy for various distances between the two antennas. The coupling formulas are computed for a variety of antennas, and several antenna configurations are evaluated through full-wave simulation and indoor measurement in order to validate these techniques. In addition, this research aims to design multi- functional and high performance antennas based on MEMS (Microelectromechanical ii Systems) switches, EBG (Electromagnetic Bandgap) structures, and septum polarizers. A MEMS switch is incorporated into a slot loaded patch antenna to attain frequency reconfigurability. -
A Gaussian Beam Shooting Algorithm for Radar Propagation Simulations Ihssan Ghannoum, Christine Letrou, Gilles Beauquet
A Gaussian beam shooting algorithm for radar propagation simulations Ihssan Ghannoum, Christine Letrou, Gilles Beauquet To cite this version: Ihssan Ghannoum, Christine Letrou, Gilles Beauquet. A Gaussian beam shooting algorithm for radar propagation simulations. RADAR 2009 : International Radar Conference ’Surveillance for a safer world’, Oct 2009, Bordeaux, France. hal-00443752 HAL Id: hal-00443752 https://hal.archives-ouvertes.fr/hal-00443752 Submitted on 4 Jan 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A GAUSSIAN BEAM SHOOTING ALGORITHM FOR RADAR PROPAGATION SIMULATIONS Ihssan Ghannoum and Christine Letrou Gilles Beauquet Lab. SAMOVAR (UMR CNRS 5157) Surface Radar Institut TELECOM SudParis THALES Air Systems S.A. 9 rue Charles Fourier, 91011 Evry Cedex, France Hameau de Roussigny, 91470 Limours, France Emails: [email protected] Email: [email protected] [email protected] Abstract— Gaussian beam shooting is proposed as an al- ternative to the Parabolic Equation method or to ray-based techniques, in order to compute backscattered fields in the context of Non-Line-of-Sight ground-based radar. Propagated fields are represented as a superposition of Gaussian beams, which are launched from the emitting antenna and transformed through successive interactions with obstacles. -
Observation and Modeling of Solar Jets
Observation and Modeling of Solar Jets rspa.royalsocietypublishing.org 1 Yuandeng Shen 1 Invited Review Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650216, China The solar atmosphere is full of complicated transients manifesting the reconfiguration of solar magnetic Article submitted to journal field and plasma. Solar jets represent collimated, beam-like plasma ejections; they are ubiquitous in the solar atmosphere and important for the Subject Areas: understanding of solar activities at different scales, Solar Physics, Plasma Physics, magnetic reconnection process, particle acceleration, Space Science coronal heating, solar wind acceleration, as well as other related phenomena. Recent high spatiotemporal Keywords: resolution, wide-temperature coverage, spectroscopic, Flares, Coronal Mass Ejections, and stereoscopic observations taken by ground-based and space-borne solar telescopes have revealed many Magnetic Fields, valuable new clues to restrict the development of Filaments/Prominences, Solar theoretical models. This review aims at providing the Energetic Particles, Magnetic reader with the main observational characteristics of Reconnection, solar jets, physical interpretations and models, as well Magnetohydrodynamic Simulation as unsolved outstanding questions in future studies. Author for correspondence: Yuandeng Shen 1. Introduction e-mail: [email protected] The dynamic solar atmosphere hosts many jetting phenomena that manifest as collimated plasma beams with a width ranging from several hundred to few times 5 10 km [1–5]; they are frequently accompanied by micro- flares, photospheric magnetic flux cancellations, and type III radio bursts, and can occur in all types of solar regions including active regions, coronal holes, and quiet-Sun regions. Since these jetting activities continuously supply mass and energy into the upper atmosphere, they are thought to be one of the important source for heating coronal plasma and accelerating solar wind [1,6–9]. -
Laser Safety
Laser Safety The George Washington University Office of Laboratory Safety Ross Hall, Suite B05 202-994-8258 LASER LASER stands for: Light Amplification by the Stimulated Emission of Radiation Laser Light Laser light – is monochromatic, unlike ordinary light which is made of a spectrum of many wavelengths. Because the light is all of the same wavelength, the light waves are said to be synchronous. – is directional and focused so that it does not spread out from the point of origin. Asynchronous, multi-directional Synchronous, light. monochromatic, directional light waves Uses of Lasers • Lasers are used in industry, communications, military, research and medical applications. • At GW, lasers are used in both research and medical procedures. How a Laser Works A laser consists of an optical cavity, a pumping system, and a lasing medium. – The optical cavity contains the media to be excited with mirrors to redirect the produced photons back along the same general path. – The pumping system uses various methods to raise the media to the lasing state. – The laser medium can be a solid (state), gas, liquid dye, or semiconductor. Source: OSHA Technical Manual, Section III: Chapter 6, Laser Hazards. Laser Media 1. Solid state lasers 2. Gas lasers 3. Excimer lasers (a combination of the terms excited and dimers) use reactive gases mixed with inert gases. 4. Dye lasers (complex organic dyes) 5. Semiconductor lasers (also called diode lasers) There are different safety hazards associated with the various laser media. Types of Lasers Lasers can be described by: • which part of the electromagnetic spectrum is represented: – Infrared – Visible Spectrum – Ultraviolet • the length of time the beam is active: – Continuous Wave – Pulsed – Ultra-short Pulsed Electromagnetic Spectrum Laser wavelengths are usually in the Ultraviolet, Visible or Infrared Regions of the Electromagnetic Spectrum. -
Repeating Fast Radio Bursts Caused by Small Bodies Orbiting a Pulsar Or a Magnetar Fabrice Mottez, Philippe Zarka, Guillaume Voisin
Repeating fast radio bursts caused by small bodies orbiting a pulsar or a magnetar Fabrice Mottez, Philippe Zarka, Guillaume Voisin To cite this version: Fabrice Mottez, Philippe Zarka, Guillaume Voisin. Repeating fast radio bursts caused by small bodies orbiting a pulsar or a magnetar. Astronomy and Astrophysics - A&A, EDP Sciences, 2020. hal- 02490705v3 HAL Id: hal-02490705 https://hal.archives-ouvertes.fr/hal-02490705v3 Submitted on 3 Jul 2020 (v3), last revised 2 Dec 2020 (v4) HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Astronomy & Astrophysics manuscript no. 2020˙FRB˙small˙bodies˙revision˙3-GV-PZ˙referee c ESO 2020 July 3, 2020 Repeating fast radio bursts caused by small bodies orbiting a pulsar or a magnetar Fabrice Mottez1, Philippe Zarka2, Guillaume Voisin3,1 1 LUTH, Observatoire de Paris, PSL Research University, CNRS, Universit´ede Paris, 5 place Jules Janssen, 92190 Meudon, France 2 LESIA, Observatoire de Paris, PSL Research University, CNRS, Universit´ede Paris, Sorbonne Universit´e, 5 place Jules Janssen, 92190 Meudon, France. 3 Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester M19 9PL, UK July 3, 2020 ABSTRACT Context. -
Beamforming in 5G Mm-Wave Radio Networks Importance of Frequency Multiplexing for Users in Urban Macro Environments
UPTEC E 20002 Examensarbete 30 hp Mars 2020 Beamforming in 5G mm-wave radio networks Importance of frequency multiplexing for users in urban macro environments Carl Lutnaes Abstract Beamforming in 5G mm-wave radio networks Carl Lutnaes Teknisk- naturvetenskaplig fakultet UTH-enheten 5G brings a few key technological improvements compared to previous generations in telecommunications. These include, but are not limited to, greater speeds, Besöksadress: increased capacity and lower latency. These improvements are in part due to using Ångströmlaboratoriet Lägerhyddsvägen 1 high band frequencies, where increased capacity is found. By advancements in Hus 4, Plan 0 various technologies, mobile broadband traffic has become increasingly chatty, i.e. more small packets are being sent. From a capacity standpoint this Postadress: characteristic poses a challenge for early 5G millimeter-wave advanced antenna Box 536 751 21 Uppsala systems. This thesis investigates if network performance of 5G millimetre-wave systems can be improved by increasing the utilisation of the bandwidth by using Telefon: adaptive beamforming. Two adaptive codebook approaches are proposed; a single- 018 – 471 30 03 beam and a multi-beam approach. The simulations are performed in an outdoor urban Telefax: macro scenario. The results show that for a small packet scenario with good 018 – 471 30 00 coverage the ability to frequency multiplex users is important for good network performance. Hemsida: http://www.teknat.uu.se/student Handledare: Erik Larsson Ämnesgranskare: Steffi Knorn Examinator: Tomas Nyberg ISSN: 1654-7616, UPTEC E 20002 Popul¨arvetenskaplig sammanfattning 5G ¨arn¨astagenerations telekommunikationsstandard. Nya 5G–n¨atverksprodukter kommer att ha ¨okad kapacitet vilket leder till snabbare data¨overf¨oringaroch mindre f¨ordr¨ojningarf¨orenheter i n¨atverken, exempelvis mobiler.