The Sodium LGS Brightness Model Over the SOR
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Sodium Guidestar Radiometry Results from the SOR's 50W Fasor
Sodium Guidestar Radiometry Results from the SOR's 50W Fasor Jack Drummond, Steve Novotny, Craig Denman, Paul Hillman, John Telle, Gerald Moore Starfire Optical Range, Directed Energy Directorate, Air Force Research Laboratory Kirtland AFB, New Mexico 87117-5776 USA Mark Eickhoff Boeing LTS, The Boeing Company, PO Box 5670, Kirtland AFB, New Mexico 87185 USA Robert Fugate New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, New Mexico 87801 USA ABSTRACT Having replaced our 20 W, 589 nm fasor (frequency-addition source of optical radiation) with a new fully computer automated 50 W fasor mounted to the azimuthal base of the 3.5m telescope, we have since produced a sodium laser guidestar (LGS) with a V1 magnitude of 5.1 for 30 W of fasor power in November 2005, when the annual peak in mesospheric sodium density occurs. This corresponds to a return flux at the top of the telescope of 7000 photons/s/cm2 through one airmass. Late in May 2006, however, a return of only 1340 ph/s/cm2 (V1=6.7) for 30 W of fasor power was obtained at the annual minimum in sodium column density. Earlier in the month, with 49 W of fasor power, the LGS was only as bright as V1=6.3 because of the minimum in column density. By measuring the LGS return flux in circular polarization from various altitudes and azimuths, we have detected the presence of the Earth's magnetic field, for the first time ever, as an enhancement in flux from the direction where the field lines are pointing at the SOR. -
A Case Study of a Sporadic Sodium Layer Observed by the ALOMAR Weber Na Lidar
Ann. Geophys., 26, 1071–1081, 2008 www.ann-geophys.net/26/1071/2008/ Annales © European Geosciences Union 2008 Geophysicae A case study of a sporadic sodium layer observed by the ALOMAR Weber Na lidar H. Nesse1,2, D. Heinrich1, B. Williams3, U.-P. Hoppe1, J. Stadsnes2, M. Rietveld4, W. Singer5, U. Blum1,6, M. I. Sandanger2, and E. Trondsen7 1Norwegian Defence Research Establishment, Kjeller, Norway 2University of Bergen, Department of Physics and Technology, Bergen, Norway 3NorthWest Research Associates/Colorado Research Associates Division, Boulder, USA 4EISCAT Scientific Association, Tromsø, Norway 5Leibniz Institute for Atmospheric Physics, Kuhlungsborn,¨ Germany 6Fraunhofer Institute for Technological Trend Analysis, Euskirchen, Germany 7University of Oslo, Department of Physics, Oslo, Norway Received: 15 December 2006 – Revised: 23 March 2007 – Accepted: 30 March 2007 – Published: 28 May 2008 Abstract. Several possible mechanisms for the production of is observed. Such layers mainly occur at altitudes between sporadic sodium layers have been discussed in the literature, 90 and 110 km (von Zahn and Hansen, 1988; Hansen and but none of them seem to explain all the accumulated obser- von Zahn, 1990). Sporadic Na layers have concentrations vations. The hypotheses range from direct meteoric input, between 2 and 20 times that of the background layer, and a to energetic electron bombardment on meteoric smoke par- typical width of less than 2 km (Clemesha, 1995). They are ticles, to ion neutralization, to temperature dependent chem- often observed to appear in a matter of minutes, but can per- istry. The varied instrumentation located on Andøya and near sist for as long as a few hours, and then disappear rapidly Tromsø in Norway gives us an opportunity to test the differ- (Gardner et al., 1995) or slowly fade into the background ent theories applied to high latitude sporadic sodium layers. -
Optimization of Cw Sodium Laser Guide Star Efficiency
A&A 510, A20 (2010) Astronomy DOI: 10.1051/0004-6361/200913108 & c ESO 2010 Astrophysics Optimization of cw sodium laser guide star efficiency R. Holzlöhner1, S. M. Rochester2, D. Bonaccini Calia1,D.Budker2,J.M.Higbie3, and W. Hackenberg1 1 Laser Systems Department, European Southern Observatory (ESO), Karl-Schwarzschild-Str. 2, 85748 Garching b. München, Germany, http://www.eso.org/sci/facilities/develop/lgsf/ e-mail: [rholzloe;dbonacci;whackenb]@eso.org 2 University of California Berkeley, Department of Physics, Berkeley, CA 94720-7300, USA e-mail: [simonr;budker]@berkeley.edu 3 Bucknell University, Department of Physics, 701 Moore Avenue, Lewisburg, PA 17837, USA e-mail: [email protected] Received 12 August 2009 / Accepted 1 October 2009 ABSTRACT Context. Sodium laser guide stars (LGS) are about to enter a new range of laser powers. Previous theoretical and numerical methods are inadequate for accurate computations of the return flux, hence for the design of the next-generation LGS systems. Aims. We numerically optimize the cw (continuous wave) laser format, in particular, the light polarization and spectrum. Methods. Using Bloch equations, we simulate the mesospheric sodium atoms, including Doppler broadening, saturation, collisional relaxation, Larmor precession, and recoil, taking all 24 sodium hyperfine states into account and 100–300 velocity groups. Results. LGS return flux is limited by “three evils”: Larmor precession due to the geomagnetic field, atomic recoil due to radiation pressure, and transition saturation. We study their impact and show that the return flux can be boosted by repumping (simultaneous excitation of the sodium D2aandD2b lines with 10−20% of the laser power in the latter). -
Sporadic Sodium Layer
https://doi.org/10.5194/acp-2020-1079 Preprint. Discussion started: 29 December 2020 c Author(s) 2020. CC BY 4.0 License. Sporadic sodium layer: A possible tracer for the conjunction between the upper and lower atmospheres Shican Qiu1,2,3, Ning Wang1,4,5, Willie Soon6, Gaopeng Lu2, Mingjiao Jia2,3, Xiankang Dou2,3 1Department of Geophysics, College of the Geology Engineering and Geomatics, Chang’an University, Xi’an, 710054, 5 China 2Key Laboratory of Geospace Environment, Chinese Academy of Sciences, University of Science & Technology of China, Hefei, Anhui, 230026, China 10 3Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China 4Gravity & Magnetic Institute of Chang’an University, Xi’an, 710054, China 15 5Key Laboratory of Western China’s Mineral Resources and Geological Engineering, China Ministry of Education, Xi’an, 710054, China 6Center for Environmental Research and Earth Sciences (CERES), Salem, Massachusetts, 01970, USA 20 Correspondence to: Shican Qiu ([email protected]) and Xiankang Dou ([email protected]) Abstract. In this research, we reveal the inter-connection between lightning strokes, reversal of the electric field, ionospheric disturbances, and a trigger of sporadic sodium layer event (NaS), based on the joint observations by three lidars, an 25 ionosonde, an atmospheric electric mill, a fluxgate magnetometer, and World Wide Lightning Location Network (WWLLN). Our results suggest that lightning strokes would probably have an influence on the ionosphere and thus give rise to the occurrence of NaS, with the overturning of electric field playing an important role. -
Four Generations of Sodium Guide Star Lasers for Adaptive Optics in Astronomy and Space Situational Awareness
From Dye Laser Factory to Portable Semiconductor Laser: Four Generations of Sodium Guide Star Lasers for Adaptive Optics in Astronomy and Space Situational Awareness Céline d’Orgeville Advanced Instrumentation and Technology Centre, Research School of Astronomy and Astrophysics, Australian National University; Space Environment Research Centre, Canberra, Australia Gregory J. Fetzer Areté Associates, Longmont, Colorado, USA ABSTRACT This paper recalls the history of sodium guide star laser systems used in astronomy and space situational awareness adaptive optics, analyzing the impact that sodium laser technology evolution has had on routine telescope operations. While it would not be practical to describe every single sodium guide star laser system developed to date, it is possible to characterize their evolution in broad technology terms. The first generation of sodium lasers used dye laser technology to create the first sodium laser guide stars in Hawaii, California, and Spain in the late 1980s and 1990s. These experimental systems were turned into the first laser guide star facilities to equip medium- to-large diameter adaptive optics telescopes, opening a new era of Laser Guide Star Adaptive Optics (LGS AO)- enabled diffraction-limited imaging from the ground. Although they produced exciting scientific results, these laser guide star facilities were large, power-hungry and messy. In the USA, a second-generation of sodium lasers was developed in the 2000s that used cleaner, yet still large and complex, solid-state laser technology. These are the systems in routine operation at the 8 to 10m-class astronomical telescopes and 4m-class satellite imaging facilities today. Meanwhile in Europe, a third generation of sodium lasers was being developed using inherently compact and efficient fiber laser technology, and resulting in the only commercially available sodium guide star laser system to date. -
Factsheets : Starfire Optical Range at Kirtland Air Force Base, New
Factsheets : Starfire Optical Range at Kirtland Air Force Base,... http://www.kirtland.af.mil/library/factsheets/factsheet.asp?id=15868 HOME NEWS PHOTOS ART LIBRARY UNITS ENVIRONMENT QUESTIONS JOIN THE AIR FORCE Library > Fact sheets > Starfire Optical Range at Kirtland Air Force Base, New Mexico Inside Kirtland AFB STARFIRE OPTICAL RANGE AT KIRTLAND AIR Search FORCE BASE, NEW MEXICO search Kirtland Posted 3/9/2012 Printable Fact Sheet View All RSS Freedom to maneuver in space is critical to meeting the United States Air Force's mission to fly, fight, and win in air, space and cyberspace. The ability to exploit the characteristics of space gives the warfighter a competitive edge in virtually all engagements. Organizations Additionally, space allows the United States to watch the entire globe on an almost "real time" basis, getting instantaneous information. To maintain space situational awareness, the Air Force conducts research in laser guide star adaptive optics, beam control, and space object identification. As satellites get smaller and the number of space objects increases dramatically, research in imaging and identification of space objects is paramount to meeting the Air Force's mission. This facility leads the industry changing technology of laser beacon adaptive optics for military uses and civilian applications such as astronomy. It is a major component of the Air Force Research Laboratory's Directed Energy Directorate. The SOR operates one of the world's premier adaptive-optics telescopes capable of tracking low-earth orbiting satellites. The telescope has a 3.5-meter (11.5 feet) diameter primary mirror and is protected by a retracting cylindrical enclosure that allows the telescope to operate in the open air. -
IAC), Adelaide, Australia, 25-29 September 2017
68th International Astronautical Congress (IAC), Adelaide, Australia, 25-29 September 2017. Copyright ©2017 by the International Astronautical Federation (IAF). All rights reserved. One or more authors of this work are employees of the government of United States, which may preclude the work from being subject to copyright in United States, in which event no copyright is asserted in that country.” IAC-17-D4.4.5 Earth to Orbit Beamed Energy Experiment Les Johnsona* and Edward E. Montgomeryb a Science and Technology Office, NASA George C. Marshall Space Flight Center, Mail Code ST03, Huntsville, Alabama 35812, [email protected] b Nexolve/Jacobs, Huntsville, AL 35812 * Corresponding Author Abstract As a means of primary propulsion, beamed energy propulsion offers the benefit of offloading much of the propulsion system mass from the vehicle, increasing its potential performance and freeing it from the constraints of the rocket equation. For interstellar missions, beamed energy propulsion is arguably the most viable in the near- to mid-term. A near-term demonstration showing the feasibility of beamed energy propulsion is necessary and, fortunately, feasible using existing technologies. Key enabling technologies are large area, low mass spacecraft and efficient and safe high power laser systems capable of long distance propagation. NASA is currently developing the spacecraft technology through the Near Earth Asteroid Scout solar sail mission and has signed agreements with the Planetary Society to study the feasibility of precursor laser propulsion experiments using their LightSail-2 solar sail spacecraft. The capabilities of Space Situational Awareness assets and the advanced analytical tools available for fine resolution orbit determination now make it possible to investigate the practicalities of an Earth-to-orbit Beamed Energy eXperiment (EBEX) – a demonstration at delivered power levels that only illuminate a spacecraft without causing damage to it. -
Lectures 10 and 11 Laser Guide Stars
Lectures 10 and 11 Laser Guide Stars Claire Max Astro 289, UC Santa Cruz February 11 and 16, 2016 Page 1 First, some images of the summit of Mauna Kea, HI • Keck 2 Subaru Page 2 • Movie of 3 lasers in operation on Mauna Kea, HI: https://vimeo.com/24338510 Page 3 Outline of lectures on laser guide stars • Why are laser guide stars needed? • Principles of laser scattering in the atmosphere – Rayleigh scattering, resonant scattering from sodium • What is the sodium layer? How does it behave? • Physics of sodium atom excitation • Lasers used in astronomical laser guide star AO • Wavefront errors for laser guide star AO Page 4 Laser guide stars: Main points • Laser guide stars are needed because there aren’t enough bright natural guide stars in the sky – Hence YOUR favorite galaxy probably won’t have a bright enough natural guide star nearby • Solution: make your own guide star using lasers – Nothing special about coherent light - could use a flashlight hanging from a “giant high-altitude helicopter” – Size on sky has to be ≲ diffraction limit of a WFS sub-aperture • Laser guide stars have pluses and minuses: – Pluses: can put them anywhere, can be bright – Minuses: NGS give better AO performance than LGS even when both are working perfectly. High-powered lasers are tricky to build and work with. Laser safety is added complication. Page 5 Two types of laser guide stars in use today: “Rayleigh” and “Sodium” • Sodium guide stars: excite atoms in “sodium layer” at ~ 95 km altitude of ~ 95 km • Rayleigh guide stars: Rayleigh scattering from air molecules sends light back into telescope, h ~ 10 km 8-12 km • Higher altitude of sodium layer is closer to sampling the same turbulence that a star from “infinity” passes Turbulence through Telescope Page 6 Reasons why laser guide stars can’t do as well as bright natural guide stars 1) Laser light is spread out by turbulence on the way up. -
A History of Anti-Satellite Programs
A History of Anti-Satellite ProgrAms January 2012 By Laura Grego, senior scientist, UCS Global Security Program ore than 5,000 satellites have been launched mainly passive support functions, satellites now play a into orbit and more than 950 still operate much more active role in “force enhancement” during wartime: today. Because these satellites provide in- other essential military support tasks such as secure and formation and other services that are in- high-volume unsecured communications, targeting and navi- Mcreasingly critical for national security, economic vitality, and gation services, weather prediction, and battle assessment. human well-being, their owners are increasingly concerned These applications are pursued largely by the United States, about keeping them safe—for as long as there have been but other countries are increasingly able to use satellites satellites there have been plans for interfering with them. for such active military support as well. Commercial satel- The act of destroying a satellite can damage the space lites have also expanded in their technical capabilities, now environment by creating dangerous amounts of space debris. offering capabilities that used to be the sole province of What’s more, the impairment or governments, such as high- loss of an important satellite, such The act of destroying a satellite resolution imagery and secure as one used for reconnaissance, can can damage the space environment by communications. quickly escalate a conflict or gen- This widening range of erate other unpredictable and dan- creating dangerous amounts of space services is now essential to our gerous consequences. And short of debris. What’s more, the impairment civilian, scientific, and eco- an actual attack on a satellite, even nomic life as well as our mili- the targeting of satellites or the or loss of an important satellite tary operations. -
Does the United States Need Space-Based Weapons?
After you have read the research report, please give us your frank opinion on the contents. All comments—large or small, complimentary or caustic—will be gratefully appreciated. Mail them to CADRE/AR, Building 1400, 401 Chennault Circle, Maxwell AFB AL 36112-6428. Does the United States Spacy Need Space-Based Weapons? Thank you for your assistance COLLEGE OF AEROSPACE DOCTRINE, RESEARCH, AND EDUCATION AIR UNIVERSITY Does the United States Need Space-Based Weapons? WILLIAM L. SPACY II Major, USAF CADRE Paper Air University Press Maxwell Air Force Base, Alabama 36112-6610 September 1999 Disclaimer Opinions, conclusions, and recommendations expressed or implied within are solely those of the author, and do not necessarily represent the views of Air University, the United States Air Force, the Department of Defense, or any other US government agency. Cleared for public release: distribution unlimited. ISBN 1-58566-070-1 ii CADRE Papers CADRE Papers are occasional publications sponsored by the Airpower Research Institute of Air University’s College of Aerospace Doctrine, Research, and Education (CADRE). Dedi- cated to promoting understanding of air and space power theory and application, these studies are published by the Air University Press and broadly distributed to the US Air Force, the Department of Defense and other governmental organiza - tions, leading scholars, selected institutions of higher learning, public policy institutes, and the media. All military members and civilian employees assigned to Air University are invited to contribute unclassified manuscripts. Manuscripts should deal with air and/or space power history, theory, doctrine or strategy, or with joint or combined service matters bearing on the application of air and/or space power. -
50 Years of Research at the Belgian Institute for Space Aeronomy
50 YEARS OF RESEARCH AT THE BELGIAN INSTITUTE FOR SPACE AERONOMY Chapter 1 1 50 YEARS OF RESEARCH AT THE BELGIAN INSTITUTE FOR SPACE AERONOMY EDITORIAL BOARD FOREWORD Direction Board Martine De Mazière, Johan De Keyser and Didier Fussen This book was written on the occasion of the 50th anniversary of the Belgisch Instituut voor Ruimte-Aeronomie - Scientific Board Institut d’Aéronomie Spatiale de Belgique (BIRA-IASB). It is intended to present a large part of the scientific studies carried Crist Amelynck, Christine Bingen, Simon Chabrillat, out during 50 years at BIRA-IASB. This is neither an exhaustive activity report nor a scientific textbook on aeronomy. Frank Daerden, Johan De Keyser, Martine De Mazière, Didier Fussen, Michel Kruglanski, Karolien Lefever, The addressed topics illustrate the historical evolution of scientific researches in the field of aeronomy since its infancy, Didier Moreau, Jean-François Müller, Eddy Neefs, in the sixties. Only a minority of topics is not reported. Viviane Pierrard, Paul C. Simon, Michel Van Roozendael and Ann Carine Vandaele. Special thanks go to all external authors: Editorial Support Guy Brasseur, Dirk Frimout, Ghislain Grégoire, William A. Lahoz, Marie-Claude Limbourg and Jean-Pierre Pommereau. Stéphanie Fratta, Sophie Robyns, Umar Sayyed and Tim Somers Their affiliation is mentioned explicitly in the book. All other authors and contributors are from BIRA-IASB or have been working there until their retirement. The authors are responsible for the content of their chapters and sections.. Responsible Editor Belgisch Instituut voor Ruimte-Aeronomie - BIRA-IASB gratefully acknowledges the financial support received for this publication from the Federal Public Planning Service institut d’aéronomie spatiale de Belgique (Bira-iasB) Science Policy, also known as Belgian Science Policy (BELSPO). -
Production of the Upper Atmospheric Sodium from Impinging Meteors
J. Geomag. Geoelectr., 36, 305-316, 1984 Production of the Upper Atmospheric Sodium from Impinging Meteors Nobuo MARUYAMA The 1st Research Center of Technical Research and Development Institute, Defense Agency, Nakameguro, Meguro-ku, Tokyo, Japan (Received January 29, 1983; Revised April 26, 1984) The temperature dependent vaporization rate for meteoric particles is ap- plied to estimate the production profile of the upper atmospheric sodium. It is shown that the earlier result estimated using a constant temperature that con- trols the vaporization process for meteoric particles leads to an underestimation of the thickness of the production profile. A typical production profile of sodium calculated by taking account of a mass distribution of the meteoric particles shows the peak height of about 93km and a thickness (10-1) of about 26km. This thickness is significantly wider than that of a usually observed sodium layer, so that effective removal process of sodium is required for shaping the sodium layer. 1. Introduction The maintenance mechanism of the upper atmospheric sodium layer discovered about half a century ago has not yet been established.The sodium layer is usual- ly observed in the height region of about 90km with a peak number density ranging from 103cm-3to 104cm-30f atomic sodium and a layer thickness(10-1) Of about 20km(GIBBON and SANDFORD,1971;MEGIE and BLAMONT,1977; SIMoNICH et al., 1979). The topside scale height of the layer is usually 1/2~1/3 of the atmospheric scale height in the same region, and a sharp cutoff of the bottomside is observed. The production source and the loss sink of atomic sodium are required to exist inside or near the sodium layer to maintain such a sharp profile.