DOCSLIB.ORG

Seeber · Satellite Geodesy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Seeber · Satellite Geodesy Seeber · Satellite Geodesy Günter Seeber Satellite Geodesy 2nd completely revised and extended edition ≥ Walter de Gruyter · Berlin · New York 2003 Author Günter Seeber,Univ. Prof. Dr.-Ing. Institut für Erdmessung Universität Hannover Schneiderberg 50 30167 Hannover Germany 1st edition 1993 This book contains 281 figures and 64 tables. Țȍ Printed on acid-free paper which falls within the guidelines of the ANSI to ensure permanence and durability. Library of Congress Cataloging-in-Publication Data Seeber,Günter,1941 Ϫ [Satellitengeodäsie. English] Satellite geodesy : foundations,methods,and applications / Gün- ter Seeber. Ϫ 2nd completely rev. and extended ed. p. cm. Includes bibliographical references and index. ISBN 3-11-017549-5 (alk. paper) 1. Satellite geodesy. I. Title. QB343 .S4313 2003 526Ј.1Ϫdc21 2003053126 ISBN 3-11-017549-5 Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data is available in the Internet at Ͻhttp://dnb.ddb.deϾ. Ą Copyright 2003 by Walter de Gruyter GmbH & Co. KG,10785 Berlin All rights reserved,including those of translation into foreign languages. No part of this book may be reproduced or transmitted in any form or by any means,electronic or mechanical,including photocopy,recording,or any information storage and retrieval system,without permission in writing from the publisher. Printed in Germany Cover design: Rudolf Hübler,Berlin Typeset using the authors TEX files: I. Zimmermann,Freiburg Printing and binding: Hubert & Co. GmbH & Co. Kg,Göttingen To the memory of my grandson Johannes Preface Methods of satellite geodesy are increasingly used in geodesy, surveying engineering, and related disciplines. In particular, the modern development of precise and opera- tional satellite based positioning and navigation techniques have entered all fields of geosciences and engineering. A growing demand is also evident for fine-structured gravity field models from new and forthcoming satellite missions and for the monitor- ing of Earth’s rotation in space. For many years I have had the feeling that there is a definite need for a systematic textbook covering the whole subject, including both its foundations and its applications. It is my intention that this book should, at least in part, help to fulfill this requirement. The material presented here is partly based on courses taught at the University of Hannover since 1973 and on guest lectures given abroad. It is my hope that this mate- rial can be used at other universities for similar courses. This book is intended to serve as a text for advanced undergraduates and for graduates, mainly in geodesy, survey- ing engineering, photogrammetry, cartography and geomatics. It is also intended as a source of information for professionals who have an interest in the methods and results of satellite geodesy and who need to acquaint themselves with new developments. In addition, this book is aimed at students, teachers, professionals and scientists from related fields of engineering and geosciences, such as terrestrial and space navigation, hydrography, civil engineering, traffic control, GIS technology, geography, geology, geophysics and oceanography. In line with this objective, the character of the book falls somewhere between that of a textbook and that of a handbook. The background required is an undergraduate level of mathematics and elementary mathematical statis- tics. Because of rapid and continuous developments in this field, it has been necessary to be selective, and to give greater weight to some topics than to others. Particular importance has been attached to the fundamentals and to the applications, especially to the use of artificial satellites for the determination of precise positions. A compre- hensive list of references has been added for further reading to facilitate deeper and advanced studies. The first edition of this book was published in 1993 as an English translation and update of the book “Satellitengeodäsie”, that was printed in the German language in 1989. The present edition has been completely revised and significantly extended. The fundamental structure of the first edition has been maintained to facilitate continuity of teaching; however, outdated material has been removed and new material has been included. All chapters have been updated and some have been re-written. The overall status is autumn 2002 but some of the most recent technological developments to March 2003 have been included. Extensions and updates mainly pertain to reference coordinate systems and refer- ence frames [2.2], signal propagation [2.3], directions with CCD technology [5.2], the Global Positioning System (GPS) and GNSS [7], satellite laser ranging [8], satellite viii Preface altimetry [9], gravity field missions [10] and applications [12]. In particular, the chap- ter on GPS and GNSS [7] has been almost completely re-written and now covers about 200 pages. Together with chapters [2], [3], and [12], it forms a comprehensive GPS manual on its own. New technological developments of the space and user segment are included, as is the current state of data analysis and error budget. Differential GPS and permanent reference networks are now treated in a comprehensive section of their own [7.5]. GLONASS and the forthcoming GALILEO are included in a new section on GNSS [7.7]. Gravity field missions like CHAMP, GRACE and GOCE, because of their increas- ing importance, are dealt with in a new chapter [10]. VLBI, together with the new inclusion of interferometric SAR, form another new chapter [11]. Coverage of histor- ical techniques like photographic camera observations [5] and Transit Doppler [6] has been considerably reduced. The basic principles, however, are still included because of their historical importance and because they are shared by new technologies like CCD cameras [5.2] and DORIS [6.7]. The geodetic history of Transit Doppler tech- niques, in addition, is an excellent source for understanding the evolution and basic concepts of the GPS. The chapter on applications, now renumbered [12], has been updated to include modern developments and a new section on the combination of geodetic space techniques [12.5]. International services of interest to satellite geodesy have been included, namely the IGS [7.8.1], the ILRS [8.5.1], the IVS [11.1.3], and the IERS [12.4]. The bibliography has been updated and expanded considerably by adding an in- creased number of English language references. The total number of references is now reaching 760, about half of which are new in this edition. Many of the examples within this book are based on field projects and research work carried out in collaboration with my graduate students, doctorate candidates and scientific colleagues at the University of Hannover over more than 20 years. I would like to thank all these individuals for their long standing cooperation and the many fruitful discussions I have had with them. In addition, the help of the staff at the Institut für Erdmessung is gratefully acknowledged. Most figures have been redrawn by cand. geod. Anke Daubner and Dipl.-Ing. Wolfgang Paech. My sincere thanks for checking and correcting the English language go to Dr. Graeme Eagles of the Alfred Wegener Institut für Polar- und Meeresforschung, Bremerhaven. I should also like to thank the many colleagues from all over the world who helped to improve the book through their comments on the first edition, and the individuals and organizations who provided illustrations. Finally my gratitude goes to my wife Gisela for her never ending support and under- standing. The publisher remained excellently cooperative throughout the preparation of this book. My cordial thanks go to Dr. Manfred Karbe, Dr. Irene Zimmermann, and the staff at Walter de Gruyter. Hannover, May 2003 Günter Seeber Contents Preface vii Abbreviations xvii 1 Introduction 1 1.1 Subject of Satellite Geodesy ...................... 1 1.2 Classification and Basic Concepts of Satellite Geodesy ........ 3 1.3 Historical Development of Satellite Geodesy .............. 5 1.4 Applications of Satellite Geodesy .................... 7 1.5 Structure and Objective of the Book .................. 9 2 Fundamentals 10 2.1 Reference Coordinate Systems ..................... 10 2.1.1 Cartesian Coordinate Systems and Coordinate Transformations 10 2.1.2 Reference Coordinate Systems and Frames in Satellite Geodesy 12 2.1.2.1 Conventional Inertial Systems and Frames ..... 13 2.1.2.2 Conventional Terrestrial Systems and Frames .... 15 2.1.2.3 Relationship between CIS and CTS ......... 17 2.1.3 Reference Coordinate Systems in the Gravity Field of Earth . 21 2.1.4 Ellipsoidal Reference Coordinate Systems ........... 23 2.1.5 Ellipsoid, Geoid and Geodetic Datum ............. 25 2.1.6 World Geodetic System 1984 (WGS 84) ............ 28 2.1.7 Three-dimensional Eccentricity Computation ......... 30 2.2Time................................... 31 2.2.1 Basic Considerations ...................... 31 2.2.2 Sidereal Time and Universal Time ............... 32 2.2.3 Atomic Time .......................... 35 2.2.4 Ephemeris Time, Dynamical Time, Terrestrial Time ...... 37 2.2.5 Clocks and Frequency Standards ................ 39 2.3 Signal Propagation ........................... 42 2.3.1 Some Fundamentals of Wave Propagation ........... 43 2.3.1.1 Basic Relations and Definitions ........... 43 2.3.1.2 Dispersion, Phase Velocity and Group Velocity . 45 2.3.1.3 Frequency Domains ................. 46
Load more

Recommended publications
  • Smiths 0 N U N Ins Ti Tu Tion Astrophysical Observatory
    SMITHS0 NUN INS TITU TION ASTROPHYSICAL OBSERVATORY OPTICAL SATELLITE- TRACKING PROGRAM Grant Number NGR 09-015-002 Semiannual Progress Report No. 20 1 January 1969 to 30 June 1969 Project Director: Fred L. Whipple Prepared for National Aeronautics and Space Administration Washington, D. C. 20546 Smithsonian Institution Astrophysical Observatory Cambridge, Massachusetts 021 38 SMITHSONIAN INS TITU TION ASTROPHYSICAL OBSERVATORY OPTICAL SATELLITE- TRACKING PROGRAM Grant Number NGR 09-015-002 Semiannual Progress Report No. 20 1 January 1969 to 30 June 1969 Project Director: Fred L. Whipple Prepared for National Ae r onauti cs and Space Administration Washington, D. C. 20546 Smithsonian Institution A s t r o phy s i cal Ob s e rvatory Cambridge, Massachusetts 021 38 908-2 TABLE OF CONTENTS Page INTRODUCTION .................................. 1 RESEARCHPROGRAMS ............................. .2 GEODETIC INVESTIGATIONS ...................... 3 ATMOSPHERIC INVESTIGATIONS ................... 6 DATAACQUISITION ............................... 8 SATELLITE- TRACKING AND DATA-ACQUISITION DEPARTMENT ................................ 9 COMMUNICATIONS ............................. 21 DATAPROCESSING ................................ 23 DATA PROCESSING ............................. 24 PHOTOREDUCTION DIVISION ...................... 27 PROGRAMMING DIVISION. ........................ 29 EDITORIAL AND PUBLICATIONS. ...................... 31 ii INTRODUCTION In support of the scientific and operational requirements under the Satellite- Tracking Program grant, the
    [Show full text]
  • UCGE Reports Ionosphere Weighted Global Positioning System Carrier
    UCGE Reports Number 20155 Ionosphere Weighted Global Positioning System Carrier Phase Ambiguity Resolution (URL: http://www.geomatics.ucalgary.ca/links/GradTheses.html) Department of Geomatics Engineering By George Chia Liu December 2001 Calgary, Alberta, Canada THE UNIVERSITY OF CALGARY IONOSPHERE WEIGHTED GLOBAL POSITIONING SYSTEM CARRIER PHASE AMBIGUITY RESOLUTION by GEORGE CHIA LIU A THESIS SUBMITTED TO THE FACULTY OF GRADUATE STUDIES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE DEPARTMENT OF GEOMATICS ENGINEERING CALGARY, ALBERTA OCTOBER, 2001 c GEORGE CHIA LIU 2001 Abstract Integer Ambiguity constraint is essential in precise GPS positioning. The perfor- mance and reliability of the ambiguity resolution process are being hampered by the current culmination (Y2000) of the eleven-year solar cycle. The traditional approach to mitigate the high ionospheric effect has been either to reduce the inter-station separation or to form ionosphere-free observables. Neither is satisfactory: the first restricts the operating range, and the second no longer possesses the ”integerness” of the ambiguities. A third generalized approach is introduced herein, whereby the zero ionosphere weight constraint, or pseudo-observables, with an appropriate weight is added to the Kalman Filter algorithm. The weight can be tightly fixed yielding the model equivalence of an independent L1/L2 dual-band model. At the other extreme, an infinite floated weight gives the equivalence of an ionosphere-free model, yet perserves the ambiguity integerness. A stochastically tuned, or weighted, model provides a compromise between the two ex- tremes. The reliability of ambiguity estimates relies on many factors, including an accurate functional model, a realistic stochastic model, and a subsequent efficient integer search algorithm.
    [Show full text]
  • Geodesy in the 21St Century
    Eos, Vol. 90, No. 18, 5 May 2009 VOLUME 90 NUMBER 18 5 MAY 2009 EOS, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION PAGES 153–164 geophysical discoveries, the basic under- Geodesy in the 21st Century standing of earthquake mechanics known as the “elastic rebound theory” [Reid, 1910], PAGES 153–155 Geodesy and the Space Era was established by analyzing geodetic mea- surements before and after the 1906 San From flat Earth, to round Earth, to a rough Geodesy, like many scientific fields, is Francisco earthquakes. and oblate Earth, people’s understanding of technology driven. Over the centuries, it In 1957, the Soviet Union launched the the shape of our planet and its landscapes has developed as an engineering discipline artificial satellite Sputnik, ushering the world has changed dramatically over the course because of its practical applications. By the into the space era. During the first 5 decades of history. These advances in geodesy— early 1900s, scientists and cartographers of the space era, space geodetic technolo- the study of Earth’s size, shape, orientation, began to use triangulation and leveling mea- gies developed rapidly. The idea behind and gravitational field, and the variations surements to record surface deformation space geodetic measurements is simple: Dis- of these quantities over time—developed associated with earthquakes and volcanoes. tance or phase measurements conducted because of humans’ curiosity about the For example, one of the most important between Earth’s surface and objects in Earth and because of geodesy’s application to navigation, surveying, and mapping, all of which were very practical areas that ben- efited society.
    [Show full text]
  • Solar Radiation Pressure Models for Beidou-3 I2-S Satellite: Comparison and Augmentation
    remote sensing Article Solar Radiation Pressure Models for BeiDou-3 I2-S Satellite: Comparison and Augmentation Chen Wang 1, Jing Guo 1,2 ID , Qile Zhao 1,3,* and Jingnan Liu 1,3 1 GNSS Research Center, Wuhan University, 129 Luoyu Road, Wuhan 430079, China; [email protected] (C.W.); [email protected] (J.G.); [email protected] (J.L.) 2 School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK 3 Collaborative Innovation Center of Geospatial Technology, Wuhan University, 129 Luoyu Road, Wuhan 430079, China * Correspondence: [email protected]; Tel.: +86-027-6877-7227 Received: 22 December 2017; Accepted: 15 January 2018; Published: 16 January 2018 Abstract: As one of the most essential modeling aspects for precise orbit determination, solar radiation pressure (SRP) is the largest non-gravitational force acting on a navigation satellite. This study focuses on SRP modeling of the BeiDou-3 experimental satellite I2-S (PRN C32), for which an obvious modeling deficiency that is related to SRP was formerly identified. The satellite laser ranging (SLR) validation demonstrated that the orbit of BeiDou-3 I2-S determined with empirical 5-parameter Extended CODE (Center for Orbit Determination in Europe) Orbit Model (ECOM1) has the sun elongation angle (# angle) dependent systematic error, as well as a bias of approximately −16.9 cm. Similar performance has been identified for European Galileo and Japanese QZSS Michibiki satellite as well, and can be reduced with the extended ECOM model (ECOM2), or by using the a priori SRP model to augment ECOM1. In this study, the performances of the widely used SRP models for GNSS (Global Navigation Satellite System) satellites, i.e., ECOM1, ECOM2, and adjustable box-wing model have been compared and analyzed for BeiDou-3 I2-S satellite.
    [Show full text]
  • Geomatics Guidance Note 3
    Geomatics Guidance Note 3 Contract area description Revision history Version Date Amendments 5.1 December 2014 Revised to improve clarity. Heading changed to ‘Geomatics’. 4 April 2006 References to EPSG updated. 3 April 2002 Revised to conform to ISO19111 terminology. 2 November 1997 1 November 1995 First issued. 1. Introduction Contract Areas and Licence Block Boundaries have often been inadequately described by both licensing authorities and licence operators. Overlaps of and unlicensed slivers between adjacent licences may then occur. This has caused problems between operators and between licence authorities and operators at both the acquisition and the development phases of projects. This Guidance Note sets out a procedure for describing boundaries which, if followed for new contract areas world-wide, will alleviate the problems. This Guidance Note is intended to be useful to three specific groups: 1. Exploration managers and lawyers in hydrocarbon exploration companies who negotiate for licence acreage but who may have limited geodetic awareness 2. Geomatics professionals in hydrocarbon exploration and development companies, for whom the guidelines may serve as a useful summary of accepted best practice 3. Licensing authorities. The guidance is intended to apply to both onshore and offshore areas. This Guidance Note does not attempt to cover every aspect of licence boundary definition. In the interests of producing a concise document that may be as easily understood by the layman as well as the specialist, definitions which are adequate for most licences have been covered. Complex licence boundaries especially those following river features need specialist advice from both the survey and the legal professions and are beyond the scope of this Guidance Note.
    [Show full text]
  • PRINCIPLES and PRACTICES of GEOMATICS BE 3200 COURSE SYLLABUS Fall 2015
    PRINCIPLES AND PRACTICES OF GEOMATICS BE 3200 COURSE SYLLABUS Fall 2015 Meeting times: Lecture class meets promptly at 10:10-11:00 AM Mon/Wed in438 Brackett Hall and lab meets promptly at 12:30-3:20 PM Wed at designated sites Course Basics Geomatics encompass the disciplines of surveying, mapping, remote sensing, and geographic information systems. It’s a relatively new term used to describe the science and technology of dealing with earth measurement data that includes collection, sorting, management, planning and design, storage, and presentation of the data. In this class, geomatics is defined as being an integrated approach to the measurement, analysis, management, storage, and presentation of the descriptions and locations of spatial data. Goal: Designed as a "first course" in the principles of geomeasurement including leveling for earthwork, linear and area measurements (traversing), mapping, and GPS/GIS. Description: Basic surveying measurements and computations for engineering project control, mapping, and construction layout. Leveling, earthwork, area, and topographic measurements using levels, total stations, and GPS. Application of Mapping via GIS. 2 CT2: This course is a CT seminar in which you will not only study the course material but also develop your critical thinking skills. Prerequisite: MTHSC 106: Calculus of One Variable I. Textbook: Kavanagh, B. F. Surveying: Principles and Applications. Prentice Hall. 2010. Lab Notes: Purchase Lab notes at Campus Copy Shop [REQUIRED]. Materials: Textbook, Lab Notes (must be brought to lab), Field Book, 3H/4H Pencil, Small Scale, and Scientific Calculator. Attendance: Regular and punctual attendance at all classes and field work is the responsibility of each student.
    [Show full text]
  • GLONASS Spacecraft
    INNO V AT IO N The task of designing and developing the GLONASS GLONASS spacecraft fell to the Scientific Production Association of Applied Mechan­ ics (Nauchno Proizvodstvennoe Ob"edinenie Spacecraft Prikladnoi Mekaniki or NPO PM) , located near Krasnoyarsk in Siberia. This major aero­ Nicholas L. Johnson space industrial complex was established in 1959 as a division of Sergei Korolev 's Kaman Sciences Corporation Expe1imental Design Bureau (Opytno Kon­ struktorskoe Byuro or OKB). (Korolev , among other notable achievements , led the Fourteen years after the launch of the effort to develop the Soviet Union's first first test spacecraft, the Russian Global Nav­ launch vehicle - the A launcher - which igation Satellite System (Global 'naya Navi­ placed Sputnik 1 into orbit.) The founding gatsionnaya Sputnikovaya Sistema or and current general director and chief GLONASS) program remains viable and designer is Mikhail Fyodorovich Reshetnev, essentially on schedule despite the economic one of only two still-active chief designers and political turmoil surrounding the final from Russia's fledgling 1950s-era space years of the Soviet Union and the emergence program. of the Commonwealth of Independent States A closed facility until the early 1990s, (CIS). By the summer of 1994, a total of 53 NPO PM has been responsible for all major GLONASS spacecraft had been successfully Russian operational communications, navi­ Despite the significant economic hardships deployed in nearly semisynchronous orbits; gation, and geodetic satellite systems to associated with the breakup of the Soviet Union of the 53 , nearly 12 had been normally oper­ date. Serial (or assembly-line) production of and the transition to a modern market economy, ational since the establishment of the Phase I some spacecraft, including Tsikada and Russia continues to develop its space programs, constellation in 1990.
    [Show full text]
  • Geodetic Position Computations
    GEODETIC POSITION COMPUTATIONS E. J. KRAKIWSKY D. B. THOMSON February 1974 TECHNICALLECTURE NOTES REPORT NO.NO. 21739 PREFACE In order to make our extensive series of lecture notes more readily available, we have scanned the old master copies and produced electronic versions in Portable Document Format. The quality of the images varies depending on the quality of the originals. The images have not been converted to searchable text. GEODETIC POSITION COMPUTATIONS E.J. Krakiwsky D.B. Thomson Department of Geodesy and Geomatics Engineering University of New Brunswick P.O. Box 4400 Fredericton. N .B. Canada E3B5A3 February 197 4 Latest Reprinting December 1995 PREFACE The purpose of these notes is to give the theory and use of some methods of computing the geodetic positions of points on a reference ellipsoid and on the terrain. Justification for the first three sections o{ these lecture notes, which are concerned with the classical problem of "cCDputation of geodetic positions on the surface of an ellipsoid" is not easy to come by. It can onl.y be stated that the attempt has been to produce a self contained package , cont8.i.ning the complete development of same representative methods that exist in the literature. The last section is an introduction to three dimensional computation methods , and is offered as an alternative to the classical approach. Several problems, and their respective solutions, are presented. The approach t~en herein is to perform complete derivations, thus stqing awrq f'rcm the practice of giving a list of for11111lae to use in the solution of' a problem.
    [Show full text]
  • GNSS Performance Monitoring
    GNSS PERFORMANCE Monitoring SiS AVAILABILITY PARAMETER DEfiNITION AND EVALUATION M. DE Groot Master THESIS Geoscience & Remote Sensing GNSS Performance Monitoring SiS availability parameter definition and evaluation by M. de Groot to obtain the degree of Master of Science at the Delft University of Technology, to be defended publicly on Wednesday September 27, 2017 Student number: 4089456 Project duration: May 1, 2016 – July 1, 2017 Thesis committee: Prof. dr. ir. R. F.Hanssen, TU Delft Graduation supervisor Dr. ir. H. van der Marel, TU Delft Daily supervisor Ir. A. van den Berg, CGI Daily supervisor Ir. W. J. F. Simons, TU Delft Co-reader An electronic version of this thesis is available at http://repository.tudelft.nl/. Preface This thesis forms the end of my period at the TU Delft. I enjoyed studying the bachelor of civil engineering and the master track of geoscience & remote sensing. The track contained several interesting topics in which GNSS had my attention from the start. Many people make use of GNSS on a daily basis without actually knowing how it works. Position, velocity and timing results are obtained using satellites at 20000 kilometres above the Earth. Good performance is usually taken for granted, but performance monitoring is essential for any system. Using a monitoring tool with substantiated parameters can give the system more trust and can lead to new insights. I would like to thank my daily supervisors, Axel van den Berg and Hans van der Marel, for introducing me to this topic. Both were really helpful with all their knowledge, experience and feedback. I would also like to thank the people of the space department of CGI the Netherlands with their input and for giving me a place to work on the project.
    [Show full text]
  • GPS and the Search for Axions
    GPS and the Search for Axions A. Nicolaidis1 Theoretical Physics Department Aristotle University of Thessaloniki, Greece Abstract: GPS, an excellent tool for geodesy, may serve also particle physics. In the presence of Earth’s magnetic field, a GPS photon may be transformed into an axion. The proposed experimental setup involves the transmission of a GPS signal from a satellite to another satellite, both in low orbit around the Earth. To increase the accuracy of the experiment, we evaluate the influence of Earth’s gravitational field on the whole quantum phenomenon. There is a significant advantage in our proposal. While the geomagnetic field B is low, the magnetized length L is very large, resulting into a scale (BL)2 orders of magnitude higher than existing or proposed reaches. The transformation of the GPS photons into axion particles will result in a dimming of the photons and even to a “light shining through the Earth” phenomenon. 1 Email: [email protected] 1 Introduction Quantum Chromodynamics (QCD) describes the strong interactions among quarks and gluons and offers definite predictions at the high energy-perturbative domain. At low energies the non-linear nature of the theory introduces a non-trivial vacuum which violates the CP symmetry. The CP violating term is parameterized by θ and experimental bounds indicate that θ ≤ 10–10. The smallness of θ is known as the strong CP problem. An elegant solution has been offered by Peccei – Quinn [1]. A global U(1)PQ symmetry is introduced, the spontaneous breaking of which provides the cancellation of the θ – term. As a byproduct, we obtain the axion field, the Nambu-Goldstone boson of the broken U(1)PQ symmetry.
    [Show full text]
  • Orbital Debris: a Chronology
    NASA/TP-1999-208856 January 1999 Orbital Debris: A Chronology David S. F. Portree Houston, Texas Joseph P. Loftus, Jr Lwldon B. Johnson Space Center Houston, Texas David S. F. Portree is a freelance writer working in Houston_ Texas Contents List of Figures ................................................................................................................ iv Preface ........................................................................................................................... v Acknowledgments ......................................................................................................... vii Acronyms and Abbreviations ........................................................................................ ix The Chronology ............................................................................................................. 1 1961 ......................................................................................................................... 4 1962 ......................................................................................................................... 5 963 ......................................................................................................................... 5 964 ......................................................................................................................... 6 965 ......................................................................................................................... 6 966 ........................................................................................................................
    [Show full text]
  • World Geodetic System 1984
    World Geodetic System 1984 Responsible Organization: National Geospatial-Intelligence Agency Abbreviated Frame Name: WGS 84 Associated TRS: WGS 84 Coverage of Frame: Global Type of Frame: 3-Dimensional Last Version: WGS 84 (G1674) Reference Epoch: 2005.0 Brief Description: WGS 84 is an Earth-centered, Earth-fixed terrestrial reference system and geodetic datum. WGS 84 is based on a consistent set of constants and model parameters that describe the Earth's size, shape, and gravity and geomagnetic fields. WGS 84 is the standard U.S. Department of Defense definition of a global reference system for geospatial information and is the reference system for the Global Positioning System (GPS). It is compatible with the International Terrestrial Reference System (ITRS). Definition of Frame • Origin: Earth’s center of mass being defined for the whole Earth including oceans and atmosphere • Axes: o Z-Axis = The direction of the IERS Reference Pole (IRP). This direction corresponds to the direction of the BIH Conventional Terrestrial Pole (CTP) (epoch 1984.0) with an uncertainty of 0.005″ o X-Axis = Intersection of the IERS Reference Meridian (IRM) and the plane passing through the origin and normal to the Z-axis. The IRM is coincident with the BIH Zero Meridian (epoch 1984.0) with an uncertainty of 0.005″ o Y-Axis = Completes a right-handed, Earth-Centered Earth-Fixed (ECEF) orthogonal coordinate system • Scale: Its scale is that of the local Earth frame, in the meaning of a relativistic theory of gravitation. Aligns with ITRS • Orientation: Given by the Bureau International de l’Heure (BIH) orientation of 1984.0 • Time Evolution: Its time evolution in orientation will create no residual global rotation with regards to the crust Coordinate System: Cartesian Coordinates (X, Y, Z).
    [Show full text]