The Electromagnetic Spectrum
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Microwave Communications and Radar
2/26 6.014 Lecture 14: Microwave Communications and Radar A. Overview Microwave communications and radar systems have similar architectures. They typically process the signals before and after they are transmitted through space, as suggested in Figure L14-1. Conversion of the signals to electromagnetic waves occurs at the output of a power amplifier, and conversion back to signals occurs at the detector, after reception. Guiding-wave structures connect to the transmitting or receiving antenna, which are generally one and the same in monostatic radar systems. We have discussed antennas and multipath propagation earlier, so the principal novel mechanisms we need to understand now are the coupling of these electromagnetic signals between antennas and circuits, and the intervening propagating structures. Issues we must yet address include transmission lines and waveguides, impedance transformations, matching, and resonance. These same issues also arise in many related systems, such as lidar systems that are like radar but use light beams instead, passive sensing systems that receive signals emitted by the environment either naturally (like thermal radiation) or by artifacts (like motors or computers), and data recording systems like DVD’s or magnetic disks. The performance of many systems of interest is often limited in part by our ability to couple energy efficiently from one port to another, and our ability to filter out deleterious signals. Understanding these issues is therefore an important part of such design effors. The same issues often occur in any system utilizing high-frequency signals, whether or not they are transmitted externally. B. Radar, Lidar, and Passive Systems Figure L14-2 illustrates a standard radar or lidar configuration where the transmitted power Pt is focused toward a target using an antenna with gain Gt. -
WWVB: a Half Century of Delivering Accurate Frequency and Time by Radio
Volume 119 (2014) http://dx.doi.org/10.6028/jres.119.004 Journal of Research of the National Institute of Standards and Technology WWVB: A Half Century of Delivering Accurate Frequency and Time by Radio Michael A. Lombardi and Glenn K. Nelson National Institute of Standards and Technology, Boulder, CO 80305 [email protected] [email protected] In commemoration of its 50th anniversary of broadcasting from Fort Collins, Colorado, this paper provides a history of the National Institute of Standards and Technology (NIST) radio station WWVB. The narrative describes the evolution of the station, from its origins as a source of standard frequency, to its current role as the source of time-of-day synchronization for many millions of radio controlled clocks. Key words: broadcasting; frequency; radio; standards; time. Accepted: February 26, 2014 Published: March 12, 2014 http://dx.doi.org/10.6028/jres.119.004 1. Introduction NIST radio station WWVB, which today serves as the synchronization source for tens of millions of radio controlled clocks, began operation from its present location near Fort Collins, Colorado at 0 hours, 0 minutes Universal Time on July 5, 1963. Thus, the year 2013 marked the station’s 50th anniversary, a half century of delivering frequency and time signals referenced to the national standard to the United States public. One of the best known and most widely used measurement services provided by the U. S. government, WWVB has spanned and survived numerous technological eras. Based on technology that was already mature and well established when the station began broadcasting in 1963, WWVB later benefitted from the miniaturization of electronics and the advent of the microprocessor, which made low cost radio controlled clocks possible that would work indoors. -
Understanding Infrared Light
TEACHER/PARENT ACTIVITY MANUAL Joint Polar Satellite System Understanding Infrared Light This activity educates students about the electromagnetic spectrum, or different forms of light detected by Earth observing satellites. The Joint Polar Satellite System (JPSS), a collaborative effort between NOAA and NASA, detects various wavelengths of the electromagnetic spectrum including infrared light to measure the temperature of Earth’s surface, oceans, and atmosphere. The data from these measurements provide the nation with accurate weather forecasts, hurricane warnings, wildfire locations, and much more! Provided is a list of materials that can be purchased to complete several learning activities, including simulating infrared light by constructing homemade infrared goggles. Learning Objectives Next Generation Science Standards (Grades 5–8) Performance Disciplinary Description Expectation Core Ideas 4-PS4-1 PS4.A: • Waves, which are regular patterns of motion, can be made in water Waves and Their Wave Properties by disturbing the surface. When waves move across the surface of Applications in deep water, the water goes up and down in place; there is no net Technologies for motion in the direction of the wave except when the water meets a Information Transfer beach. (Note: This grade band endpoint was moved from K–2.) • Waves of the same type can differ in amplitude (height of the wave) and wavelength (spacing between wave peaks). 4-PS4-2 PS4.B: An object can be seen when light reflected from its surface enters the Waves and Their Electromagnetic eyes. Applications in Radiation Technologies for Information Transfer 4-PS3-2 PS3.B: Light also transfers energy from place to place. -
Ultraviolet – Visible Spectroscopy for Determination of Α- and Β-Acids in Beer Hops Katharine Chau Lab Partner: Logan Bi
Ultraviolet – Visible Spectroscopy for Determination of α- and β-acids in Beer Hops Katharine Chau Lab Partner: Logan Billings TA: Kevin Fischer Date lab performed: 3/20/2018 Date report submitted: 4/9/2018 ABSTRACT: In this experiment, the content of α- and β-acids in beer hops is found through UV-Vis spectroscopic analysis. Three samples will be prepared by extracting finely grained hops through methanol and diluting with methanolic NaOH. The spectrums obtained give a constant overall shape. The experiment was done to find out the concentration of the third component from degraded α- and β-acids that is also existing in the hops samples with the help of the calculated concentrations of α- and β-acids. From the calculated results, the average concentration of the third component in all three samples was 0.061 g/L. INTRODUCTION: UV-Vis spectroscopy is a useful absorption or reflectance spectroscopy that helps determine the quantity of analytes by detecting the absorptivity or reflectance of a sample under ultra-violet to visible light wavelength range (1). In this experiment, the absorptivity of the samples were measured and the content of different components were determined from the spectrum. In this lab, UV-Vis spectroscopy was used in to obtain absorbance spectrums of α- and β- acids found in difference hops samples. The structures of α- and β-acids are shown as the Fig. 1 below. Figure 1. Structures of major α- and β-acids found in hops By understanding the content of α-acid in the hops, the bitterness flavor of beer can be controlled since the bitterness is formed by the iso-form of α-acid through isomization of α-acid. -
Relationship Between X-Ray and Ultraviolet Emission of Flares From
A&A 431, 679–686 (2005) Astronomy DOI: 10.1051/0004-6361:20041201 & c ESO 2005 Astrophysics Relationship between X-ray and ultraviolet emission of flares from dMe stars observed by XMM-Newton U. Mitra-Kraev1,L.K.Harra1,M.Güdel2, M. Audard3, G. Branduardi-Raymont1 ,H.R.M.Kay1,R.Mewe4, A. J. J. Raassen4,5, and L. van Driel-Gesztelyi1,6,7 1 Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK e-mail: [email protected] 2 Paul Scherrer Institut, Würenlingen & Villigen, 5232 Villigen PSI, Switzerland 3 Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027, USA 4 SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands 5 Astronomical Institute “Anton Pannekoek”, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands 6 Observatoire de Paris, LESIA, 92195 Meudon, France 7 Konkoly Observatory, 1525 Budapest, Hungary Received 30 April 2004 / Accepted 30 September 2004 Abstract. We present simultaneous ultraviolet and X-ray observations of the dMe-type flaring stars AT Mic, AU Mic, EV Lac, UV Cet and YZ CMi obtained with the XMM-Newton observatory. During 40 h of simultaneous observation we identify 13 flares which occurred in both wave bands. For the first time, a correlation between X-ray and ultraviolet flux for stellar flares has been observed. We find power-law relationships between these two wavelength bands for the flare luminosity increase, as well as for flare energies, with power-law exponents between 1 and 2. We also observe a correlation between the ultraviolet flare energy and the X-ray luminosity increase, which is in agreement with the Neupert effect and demonstrates that chromospheric evaporation is taking place. -
Helpful Household Energy Saving Tips
Helpful Household Energy Saving Tips When purchasing a new appliance, ask your dealer about the high-efficiency electric models. Be familiar with the Energy Guide and Energy Star Labels. Contact Waseca Utilities at 835-9718 for information on rebates available to utility customers on the purchase of energy-star rated appliances, air conditioners and LED lightbulbs. For more energy- saving tips, visit www.energystar.gov, www.energyhog.org, http://hes.lbl.gov and www.smmpa.com. Refrigerators/Freezers • Place refrigerators and freezers away from sources of heat such as stoves, clothes dryers, dishwashers, heating systems, and direct sunlight. • Replace door gaskets when they become hard or out of shape. A tight seal will minimize air leakage. • Vacuum or dust external coils at least once a year. • Defrost freezers before the ice becomes 1/4 inch thick. • Fill refrigerators and freezers to capacity, but avoid blocking air circulation. Washers/Dryers • Use hot water only for heavily soiled or greasy clothes and for sanitation purposes. • Wash only full loads or match the water level to the load size. • Use cold water in the rinse cycle. • Dry full loads of clothes and avoid over drying clothes. • Vent dryers to the outside to avoid moisture build-up inside the home. Dryers operate less efficiently when they use moist air to dry clothes. • Make sure exterior dryer vents close tightly when not in use. • Keep lint filters and exterior dryer vents clean. Dishwashers • Pre-rinse only when necessary and then use only cold water. • Operate the dishwasher only for full loads. • When time allows, air dry the dishes. -
Radar, Without Tears
Radar, without tears François Le Chevalier1 May 2017 Originally invented to facilitate maritime navigation and avoid icebergs, at the beginning of the last century, radar took off during the Second World War, especially for aerial surveillance and guidance from the ground or from aircraft. Since then, it has continued to expand its field of employment. 1 What is it, what is it for? Radar is used in the military field for surveillance, guidance and combat, and in the civilian area for navigation, obstacle avoidance, security, meteorology, and remote sensing. For some missions, it is irreplaceable: detecting flying objects or satellites, several hundred kilometers away, monitoring vehicles and convoys more than 100 kilometers round, making a complete picture of a planet through its atmosphere, measuring precipitations, marine currents and winds at long ranges, detecting buried objects or observing through walls – as many functions that no other sensor can provide, and whose utility is not questionable. Without radar, an aerial or terrestrial attack could remain hidden until the last minute, and the rain would come without warning to Roland–Garros and Wimbledon ... Curiously, to do this, the radar uses a physical phenomenon that nature hardly uses: radio waves, which are electromagnetic waves using frequencies between 1 MHz and 100 GHz – most radars operating with wavelength ( = c / f, being the wavelength, c the speed of light, 3.108 m/s, and f the frequency) between 300 m and 3 mm (actually, for most of them, between 1m and 1cm): wavelengths on a human scale ... Indeed, while the optical domain of electromagnetic waves, or even the ultraviolet and infrared domains, are widely used by animals, while the acoustic waves are also widely used by marine or terrestrial animals, there is practically no example of animal use of this vast part, known as "radioelectric", of the electromagnetic spectrum (some fish, Eigenmannia, are an exception to this rule, but they use frequencies on the order of 300 Hz, and therefore very much lower than the "radar" frequencies). -
CPG Sec. 394.500 Importation of Television Products, Microwave Ovens, and Inherent Class I Laser Products for Investigation and Evaluation During Design Development
CPG Sec. 394.500 Importation of Television Products, Microwave Ovens, and Inherent Class I Laser Products for Investigation and Evaluation during Design Development Document Effective Date: July 29, 2004 This document supersedes Compliance Policy Guide (CPG) "Sec. 394.500 Importation of Television Receivers and Microwave Ovens for Investigation and Evaluation (CPG 7133.22)" that was issued on March 1, 1984. U.S. Department of Health and Human Services Food and Drug Administration Office of Regulatory Affairs Preface Public Comment: At any time, interested persons may submit written comments regarding this document to the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852. The comments are to be identified with the title of this guidance document. Such comments will be considered when determining whether to amend the current guidance. [] Additional Copies: A copy of the guidance may be downloaded to a personal computer with access to the Internet. The guidance may be accessed at http://www.fda.gov/ora/compliance_ref/cpg/cpgdev/cpg394-500.html From 1996 CPG Manual Sec. 394.500 Importation of Television Receivers and Microwave Ovens for Investigation and Evaluation (CPG 7133.22) BACKGROUND: Federal regulations require that all imported electronic products for which applicable FDA radiation performance standards exist, shall comply with these standards and shall bear certification of such compliance. Before these products can be permitted to enter the U.S., manufacturers and importers are required to submit with each shipment certain required import entry papers through the District Director, U.S. Customs Service to the appropriate FDA district office. -
EHC 238 Front Pages Final.Fm
This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of the International Commission of Non- Ionizing Radiation Protection, the International Labour Organization, or the World Health Organization. Environmental Health Criteria 238 EXTREMELY LOW FREQUENCY FIELDS Published under the joint sponsorship of the International Labour Organization, the International Commission on Non-Ionizing Radiation Protection, and the World Health Organization. WHO Library Cataloguing-in-Publication Data Extremely low frequency fields. (Environmental health criteria ; 238) 1.Electromagnetic fields. 2.Radiation effects. 3.Risk assessment. 4.Envi- ronmental exposure. I.World Health Organization. II.Inter-Organization Programme for the Sound Management of Chemicals. III.Series. ISBN 978 92 4 157238 5 (NLM classification: QT 34) ISSN 0250-863X © World Health Organization 2007 All rights reserved. Publications of the World Health Organization can be obtained from WHO Press, World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland (tel.: +41 22 791 3264; fax: +41 22 791 4857; e- mail: [email protected]). Requests for permission to reproduce or translate WHO publications – whether for sale or for noncommercial distribution – should be addressed to WHO Press, at the above address (fax: +41 22 791 4806; e-mail: [email protected]). The designations employed and the presentation of the material in this publication do not imply the expression of any opinion whatsoever on the part of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. -
Absorption of Light Energy Light, Energy, and Electron Structure SCIENTIFIC
Absorption of Light Energy Light, Energy, and Electron Structure SCIENTIFIC Introduction Why does the color of a copper chloride solution appear blue? As the white light hits the paint, which colors does the solution absorb and which colors does it transmit? In this activity students will observe the basic principles of absorption spectroscopy based on absorbance and transmittance of visible light. Concepts • Spectroscopy • Visible light spectrum • Absorbance and transmittance • Quantized electron energy levels Background The visible light spectrum (380−750 nm) is the light we are able to see. This spectrum is often referred to as “ROY G BIV” as a mnemonic device for the order of colors it produces. Violet has the shortest wavelength (about 400 nm) and red has the longest wavelength (about 650–700 nm). Many common chemical solutions can be used as filters to demonstrate the principles of absorption and transmittance of visible light in the electromagnetic spectrum. For example, copper(II) chloride (blue), ammonium dichromate (orange), iron(III) chloride (yellow), and potassium permanganate (red) are all different colors because they absorb different wave- lengths of visible light. In this demonstration, students will observe the principles of absorption spectroscopy using a variety of different colored solutions. Food coloring will be substituted for the orange and yellow chemical solutions mentioned above. Rare earth metal solutions, erbium and praseodymium chloride, will be used to illustrate line absorption spectra. Materials Copper(II) chloride solution, 1 M, 85 mL Diffraction grating, holographic, 14 cm × 14 cm Erbium chloride solution, 0.1 M, 50 mL Microchemistry solution bottle, 50 mL, 6 Potassium permanganate solution (KMnO4), 0.001 M, 275 mL Overhead projector and screen Praseodymium chloride solution, 0.1 M, 50 mL Red food dye Water, deionized Stir rod, glass Beaker, 250-mL Tape Black construction paper, 12 × 18, 2 sheets Yellow food dye Colored pencils Safety Precautions Copper(II) chloride solution is toxic by ingestion and inhalation. -
Band Radar Models FR-2115-B/2125-B/2155-B*/2135S-B
R BlackBox type (with custom monitor) X/S – band Radar Models FR-2115-B/2125-B/2155-B*/2135S-B I 12, 25 and 50* kW T/R up X-band, 30 kW I Dual-radar/full function remote S-band inter-switching I SXGA PC monitor either CRT or color I New powerful processor with LCD high-speed, high-density gate array and I Optional ARP-26 Automatic Radar sophisticated software Plotting Aid (ARPA) on 40 targets I New cast aluminum scanner gearbox I Furuno's exclusive chart/radar overlay and new series of streamlined radiators technique by optional RP-26 VideoPlotter I Shared monitor utilization of Radar and I Easy to create radar maps PC systems with custom PC monitor switching system The BlackBox radar system FR-2115-B, FR-2125-B, FR-2155-B* and FR-2135S-B are custom configured by adding a user’s favorite display to the blackbox radar package. The package is based on a Furuno standard radar used in the FR-21x5-B series with (FURUNO) monitor which is designed to comply with IMO Res MSC.64(67) Annex 4 for shipborne radar and A.823 (19) for ARPA performance. The display unit may be selected from virtually any size of multi-sync PC monitor, either a CRT screen or flat panel LCD display. The blackbox radar system is suitable for various ships which require no specific type approval as a SOLAS compliant radar. The radar is available in a variety of configurations: 12, 25, 30 and 50* kW output, short or long antenna radiator, 24 or 42 rpm scanner, with standard Electronic Plotting Aid (EPA) and optional Automatic Radar Plotting Aid (ARPA). -
The Electromagnetic Spectrum
The Electromagnetic Spectrum Wavelength/frequency/energy MAP TAP 2003-2004 The Electromagnetic Spectrum 1 Teacher Page • Content: Physical Science—The Electromagnetic Spectrum • Grade Level: High School • Creator: Dorothy Walk • Curriculum Objectives: SC 1; Intro Phys/Chem IV.A (waves) MAP TAP 2003-2004 The Electromagnetic Spectrum 2 MAP TAP 2003-2004 The Electromagnetic Spectrum 3 What is it? • The electromagnetic spectrum is the complete spectrum or continuum of light including radio waves, infrared, visible light, ultraviolet light, X- rays and gamma rays • An electromagnetic wave consists of electric and magnetic fields which vibrates thus making waves. MAP TAP 2003-2004 The Electromagnetic Spectrum 4 Waves • Properties of waves include speed, frequency and wavelength • Speed (s), frequency (f) and wavelength (l) are related in the formula l x f = s • All light travels at a speed of 3 s 108 m/s in a vacuum MAP TAP 2003-2004 The Electromagnetic Spectrum 5 Wavelength, Frequency and Energy • Since all light travels at the same speed, wavelength and frequency have an indirect relationship. • Light with a short wavelength will have a high frequency and light with a long wavelength will have a low frequency. • Light with short wavelengths has high energy and long wavelength has low energy MAP TAP 2003-2004 The Electromagnetic Spectrum 6 MAP TAP 2003-2004 The Electromagnetic Spectrum 7 Radio waves • Low energy waves with long wavelengths • Includes FM, AM, radar and TV waves • Wavelengths of 10-1m and longer • Low frequency • Used in many