WorldWideScience

Sample records for geodesy

  1. Intrinsic Geodesy

    Science.gov (United States)

    1952-03-01

    of Curves and Surfaces on Vectorial Basis), Zurich, Orell-Fussl.i, 1947 2. BAESCHLIN, q. F., Iohbuch der G*Wdsie (A Treatise on Geodesy), Zurich...Pavia, Mattei, 1912 6. BURGATTI, P., BOGGIO, T., and BURALI-FORTI, C., Analisi vettoriale Renerale ed applicazioni° Geometria differenziale (General

  2. Physical Geodesy

    Science.gov (United States)

    Hofmann-Wellenhof, Bernhard; Moritz, Helmut

    "Physical Geodesy" by Heiskanen and Moritz, published in 1967, has for a long time been considered as the standard introduction to its field. The enormous progress since then, however, required a complete reworking. While basic material could be retained other parts required a complete update.This concerns, above all, the adaptation to the fact that the geometry can now be precisely determined by methods such as GPS, and that new satellite methods, combined with terrestrial methods, also make a detailed determination of the earth's gravitational field a possibility and a necessity.

  3. Seafloor Geodesy

    Science.gov (United States)

    Bürgmann, Roland; Chadwell, David

    2014-05-01

    Seafloor geodetic techniques allow for measurements of crustal deformation over the ˜70% of Earth's surface that is inaccessible to the standard tools of tectonic geodesy. Precise underwater measurement of position, displacement, strain, and gravity poses technical, logistical, and cost challenges. Nonetheless, acoustic ranging; pressure sensors; underwater strain-, tilt- and gravimeters; and repeat multibeam sonar and seismic measurements are able to capture small-scale or regional deformation with approximately centimeter-level precision. Pioneering seafloor geodetic measurements offshore Japan, Cascadia, and Hawaii have substantially contributed to advances in our understanding of the motion and deformation of oceanic tectonic plates, earthquake cycle deformation in subduction zones, and the deformation of submarine volcanoes. Nontectonic deformation related to down-slope mass movement and underwater extraction of hydrocarbons or other resources represent other important targets. Recent technological advances promise further improvements in precision as well as the development of smaller, more autonomous, and less costly seafloor geodetic systems.

  4. Theoretical geodesy

    Directory of Open Access Journals (Sweden)

    Borkowski Andrzej

    2015-12-01

    Full Text Available The paper presents a summary of research activities concerning theoretical geodesy performed in Poland in the period of 2011-2014. It contains the results of research on new methods of the parameter estimation, a study on robustness properties of the M-estimation, control network and deformation analysis, and geodetic time series analysis. The main achievements in the geodetic parameter estimation involve a new model of the M-estimation with probabilistic models of geodetic observations, a new Shift-Msplit estimation, which allows to estimate a vector of parameter differences and the Shift-Msplit(+ that is a generalisation of Shift-Msplit estimation if the design matrix A of a functional model has not a full column rank. The new algorithms of the coordinates conversion between the Cartesian and geodetic coordinates, both on the rotational and triaxial ellipsoid can be mentioned as a highlights of the research of the last four years. New parameter estimation models developed have been adopted and successfully applied to the control network and deformation analysis.

  5. Theoretical geodesy

    Science.gov (United States)

    Borkowski, Andrzej; Kosek, Wiesław

    2015-12-01

    The paper presents a summary of research activities concerning theoretical geodesy performed in Poland in the period of 2011-2014. It contains the results of research on new methods of the parameter estimation, a study on robustness properties of the M-estimation, control network and deformation analysis, and geodetic time series analysis. The main achievements in the geodetic parameter estimation involve a new model of the M-estimation with probabilistic models of geodetic observations, a new Shift-Msplit estimation, which allows to estimate a vector of parameter differences and the Shift-Msplit(+) that is a generalisation of Shift-Msplit estimation if the design matrix A of a functional model has not a full column rank. The new algorithms of the coordinates conversion between the Cartesian and geodetic coordinates, both on the rotational and triaxial ellipsoid can be mentioned as a highlights of the research of the last four years. New parameter estimation models developed have been adopted and successfully applied to the control network and deformation analysis. New algorithms based on the wavelet, Fourier and Hilbert transforms were applied to find time-frequency characteristics of geodetic and geophysical time series as well as time-frequency relations between them. Statistical properties of these time series are also presented using different statistical tests as well as 2nd, 3rd and 4th moments about the mean. The new forecasts methods are presented which enable prediction of the considered time series in different frequency bands.

  6. Geodesy and cartography

    Science.gov (United States)

    Batson, R.; Arthur, D.

    1976-01-01

    Geodesy and cartography provide the geometric framework on which most investigations of planets are ultimately based. Specifically, the products of these disciplines provide information on the following: (1) the dimensions of the planet, (2) a mathematical figure of reference for the planet, (3) the orientation of the body in the celestial coordinate system, (4) the rotational constants, (5) a defined system of coordinates, (6) the location of surface points in the defined coordinate system, (7) the gravity potential expressed in spherical harmonics, (8) topographic and thematic maps, and (9) surface albedo in various wavelengths. The relevance of geodesy and cartography to planetology is discussed, and the requirements of data acquisition and mission design are considered.

  7. The gravimetric geodesy investigation

    Science.gov (United States)

    Siry, J. W.

    1971-01-01

    The Gravimetric Geodesy Investigation which will utilize altimeter and satellite-to-satellite tracking data from GEOS-C, ATS-F, and other spacecraft as appropriate to improve our knowledge of the earth's gravitational field is discussed. This investigation is interrelated with the study of oceanographic phenomena such as those associated with tides and currents, hence the latter are considered together with gravitational effects in the analysis of the data. The oceanographic effects, each of the order of a meter or two in amplitude and with still smaller uncertainties does not seriously hamper the altimeter gravimetric studies at the five meter level. Laser and satellite-to-satellite tracking data, when combined with the altimeter results, should provide the basis for such studies over wide areas of the ocean surface. Laser and conventional geodetic tracking data from ISAGEX and succeeding campaigns will provide a valuable framework for these analyses.

  8. Relativistic GLONASS and geodesy

    Science.gov (United States)

    Mazurova, E. M.; Kopeikin, S. M.; Karpik, A. P.

    2016-12-01

    GNSS technology is playing a major role in applications to civil, industrial and scientific areas. Nowadays, there are two fully functional GNSS: American GPS and Russian GLONASS. Their data processing algorithms have been historically based on the Newtonian theory of space and time with only a few relativistic effects taken into account as small corrections preventing the system from degradation on a fairly long time. Continuously growing accuracy of geodetic measurements and atomic clocks suggests reconsidering the overall approach to the GNSS theoretical model based on the Einstein theory of general relativity. This is essentially more challenging but fundamentally consistent theoretical approach to relativistic space geodesy. In this paper, we overview the basic principles of the relativistic GNSS model and explain the advantages of such a system for GLONASS and other positioning systems. Keywords: relativistic GLONASS, Einstein theory of general relativity.

  9. Advances and Applications for Geodesy

    Science.gov (United States)

    Calais, Eric; Schwartz, Susan; Arrowsmith, Ramon

    2010-07-01

    2010 UNAVCO Science Workshop; Boulder, Colorado, 8-11 March 2010; Geodesy's reach has expanded rapidly in recent years as EarthScope and international data sets have grown and new disciplinary applications have emerged. To explore advances in geodesy and its applications in geoscience research and education, approximately 170 scientists (representing 11 countries: Colombia, Denmark, Ecuador, France, Japan, Lebanon, Mexico, New Zealand, Russia, Spain, and the United States), including 15 students, gathered at the 2010 UNAVCO Science Workshop in Colorado. UNAVCO is a nonprofit membership-governed consortium that facilitates geoscience research and education using geodesy. Plenary sessions integrated discovery with broad impact and viewed geodesy through three lenses: (1) pixel-by-pixel geodetic imaging where various remote sensing methodologies are revealing fine-scale changes in the near-surface environment and the geologic processes responsible for them; (2) epoch-by-epoch deformation time series measured in seconds to millennia, which are uncovering ephemeral processes associated with the earthquake cycle and glacial and groundwater flow; and (3) emerging observational powers from advancing geodetic technologies. A fourth plenary session dealt with geodesy and water, a new strategic focus on the hydrosphere, cryosphere, and changing climate. Keynotes included a historical perspective by Bernard Minster (Scripps Institution of Oceanography) on space geodesy and its applications to geophysics, and a summary talk by Susan Eriksson (UNAVCO) on the successes of Research Experience in Solid Earth Science for Students (RESESS) and its 5-year follow-on with opportunities to mentor the next generation of geoscientists through cultivation of diversity.

  10. Recent developments in seismological geodesy

    Institute of Scientific and Technical Information of China (English)

    Caijun Xu; Zheng Gong; Jieming Niu

    2016-01-01

    With the advanced development of the modern geodetic techniques,the geodetic observations have been proved to be more powerful to uncover the geophysical phenomena,especially the seismic one,than that in the past time.The recent developments and achievements in the seismological geodesy are summarised here.Several popular geodetic techniques,such as high-rate GNSS,InSAR and Satellite Gravimetry,are introduced first to present their recent contributions in studying the seismic deformations.The developments of the joint inversion of the seismic source parameters from multiple observations are then highlighted.Some outlooks in seismological geodesy are presented in the end.

  11. Engineering Geodesy - Definition and Core Competencies

    Science.gov (United States)

    Kuhlmann, Heiner; Schwieger, Volker; Wieser, Andreas; Niemeier, Wolfgang

    2014-11-01

    This article summarises discussions concerning the definition of "engineering geodesy" within the German Geodetic Commission. It is noted that engineering geodesy by means of its tasks, methods and characteristics is an application-oriented science whose research questions often arise from observed phenomena or from unsolved practical problems. In particular it is characterised by the professional handling of geometry-related problems in a cost-effective manner that includes comprehensive quality assessment at all phases of the problem solution - from planning through measurement to data processing and interpretation. The current methodical developments are primarily characterised by the increasing integration of the measurement and analysis into challenging construction, production and monitoring processes as well as by the transition to spatially continuous methods. A modern definition of engineering geodesy is proposed at the end of this article.

  12. Chronometric Geodesy and Fundamental Physics

    Science.gov (United States)

    Delva, P.; Puchades, N.; Lodewyck, J.

    2016-12-01

    Atomic clocks are today essential for several daily life applications, such as the building of the International Atomic Time (TAI) or Global Navigation Satellite Systems (GNSS). With the new generation of optical clocks, they reach such accuracy and stability that they are now considered in practical applications for the measurement of gravitational potential differences, thanks to the Einstein effect, or gravitational redshift. Several projects explored the possibilities of using clocks in geodesy or geophysical applications and research. This context offers a fantastic opportunity to use atomic clocks to test fundamental physics. In this talk I will present two such studies for testing the gravitational redshift and Lorentz invariance.The first project is the "Galileo gravitational Redshift test with Eccentric sATellites" (GREAT), funded by the European Space Agency (ESA). Here we use the on-board atomic clocks of the Galileo satellites 5 and 6 to look for violations of general relativity theory. These two satellites were launched on August, 30th 2014 and, because of a technical problem, the launcher brought them on an elliptic orbit. An elliptic orbit induces a periodic modulation of the gravitational redshift while the good stability of recent GNSS clocks allows to test this periodic modulation to a very good level of accuracy. The Galileo 5 and 6 satellites, with their large eccentricity and on-board H-maser clocks, are hence perfect candidates to perform this test.In the second study we propose a test of special relativity theory using a network of distant optical lattice clocks located in France, Germany and Great-Britain. By exploiting the difference between the velocities of each clock in the inertial geocentric frame, due to their different positions on the surface of the Earth, we can test the time dilation effect. The connection between these clocks, achieved with phase-compensated optical fibers, allows for an unprecedented level of statistical

  13. Reference Ellipsoid and Geoid in Chronometric Geodesy

    OpenAIRE

    Kopeikin, Sergei M.

    2016-01-01

    Chronometric geodesy applies general relativity to study the problem of the shape of celestial bodies including the earth, and their gravitational field. The present paper discusses the relativistic problem of construction of a background geometric manifold that is used for describing a reference ellipsoid, geoid, the normal gravity field of the earth and for calculating geoid's undulation (height). We choose the perfect fluid with an ellipsoidal mass distribution uniformly rotating around a ...

  14. Physical applications of GPS geodesy: a review

    Science.gov (United States)

    Bock, Yehuda; Melgar, Diego

    2016-10-01

    Geodesy, the oldest science, has become an important discipline in the geosciences, in large part by enhancing Global Positioning System (GPS) capabilities over the last 35 years well beyond the satellite constellation’s original design. The ability of GPS geodesy to estimate 3D positions with millimeter-level precision with respect to a global terrestrial reference frame has contributed to significant advances in geophysics, seismology, atmospheric science, hydrology, and natural hazard science. Monitoring the changes in the positions or trajectories of GPS instruments on the Earth’s land and water surfaces, in the atmosphere, or in space, is important for both theory and applications, from an improved understanding of tectonic and magmatic processes to developing systems for mitigating the impact of natural hazards on society and the environment. Besides accurate positioning, all disturbances in the propagation of the transmitted GPS radio signals from satellite to receiver are mined for information, from troposphere and ionosphere delays for weather, climate, and natural hazard applications, to disturbances in the signals due to multipath reflections from the solid ground, water, and ice for environmental applications. We review the relevant concepts of geodetic theory, data analysis, and physical modeling for a myriad of processes at multiple spatial and temporal scales, and discuss the extensive global infrastructure that has been built to support GPS geodesy consisting of thousands of continuously operating stations. We also discuss the integration of heterogeneous and complementary data sets from geodesy, seismology, and geology, focusing on crustal deformation applications and early warning systems for natural hazards.

  15. 25 Years of Reports on Geodesy and Geoinformatics

    OpenAIRE

    Siemiątkowska Jadwiga

    2016-01-01

    The article presents an outline of the 25-year history of the journal “Reports on Geodesy and Geoinformatics”. The source of information was mainly the journal issues themselves. Attention was drawn to changes that the journal underwent over a quarter of a century and its relationship with the Institute of Geodesy and Geodetic Astronomy and later the Department of Geodesy and Geodetic Astronomy. Many issues were dedicated to materials from Polish conferences - those organised by the Institute...

  16. Reference ellipsoid and geoid in chronometric geodesy

    Directory of Open Access Journals (Sweden)

    Sergei M Kopeikin

    2016-02-01

    Full Text Available Chronometric geodesy applies general relativity to study the problem of the shape of celestial bodies including the earth, and their gravitational field. The present paper discusses the relativistic problem of construction of a background geometric manifold that is used for describing a reference ellipsoid, geoid, the normal gravity field of the earth and for calculating geoid's undulation (height. We choose the perfect fluid with an ellipsoidal mass distribution uniformly rotating around a fixed axis as a source of matter generating the geometry of the background manifold through the Einstein equations. We formulate the post-Newtonian hydrodynamic equations of the rotating fluid to find out the set of algebraic equations defining the equipotential surface of the gravity field. In order to solve these equations we explicitly perform all integrals characterizing the interior gravitational potentials in terms of elementary functions depending on the parameters defining the shape of the body and the mass distribution. We employ the coordinate freedom of the equations to choose these parameters to make the shape of the rotating fluid configuration to be an ellipsoid of rotation. We derive expressions of the post-Newtonian mass and angular momentum of the rotating fluid as functions of the rotational velocity and the parameters of the ellipsoid including its bare density, eccentricity and semi-major axes. We formulate the post-Newtonian Pizzetti and Clairaut theorems that are used in geodesy to connect the parameters of the reference ellipsoid to the polar and equatorial values of force of gravity. We expand the post-Newtonian geodetic equations characterizing the reference ellipsoid into the Taylor series with respect to the eccentricity of the ellipsoid, and discuss the small-eccentricity approximation. Finally, we introduce the concept of relativistic geoid and its undulation with respect to the reference ellipsoid, and discuss how to calculate it

  17. National Report for the International Association of Geodesy of the International Union of Geodesy and Geophysics 2011-2014

    CERN Document Server

    Savinykh, V P; Malkin, Z; Pobedinsky, G; Stoliarov, I A; Sermiagin, R; Zotov, L; Gorshkov, V; Shestakov, N; Steblov, G; Dokukin, P; Ustinov, A

    2015-01-01

    In this National Report are given major results of researches conducted by Russian geodesists in 2011-2014 on the topics of the International Association of Geodesy (IAG) of the International Union of Geodesy and Geophysics (IUGG). This report is prepared by the Section of Geodesy of the National Geophysical Committee of Russia. In the report prepared for the XXVI General Assembly of IUGG (Czhech Republic, Prague, 22 June - 2 July 2015), the results of principal researches in geodesy, geodynamics, gravimetry, in the studies of geodetic reference frame creation and development, Earth's shape and gravity field, Earth's rotation, geodetic theory, its application and some other directions are briefly described. For some objective reasons not all results obtained by Russian scientists on the problems of geodesy are included in the report.

  18. 25 Years of Reports on Geodesy and Geoinformatics

    Directory of Open Access Journals (Sweden)

    Siemiątkowska Jadwiga

    2016-06-01

    Full Text Available The article presents an outline of the 25-year history of the journal “Reports on Geodesy and Geoinformatics”. The source of information was mainly the journal issues themselves. Attention was drawn to changes that the journal underwent over a quarter of a century and its relationship with the Institute of Geodesy and Geodetic Astronomy and later the Department of Geodesy and Geodetic Astronomy. Many issues were dedicated to materials from Polish conferences - those organised by the Institute and the international ones attended by the employees of the Institute, which was indicated in the section on the history of the journal.

  19. Geodesy and cartography. [of planet Mars surface

    Science.gov (United States)

    Davies, Merton E.; Batson, Raymond M.; Wu, Sherman S. C.

    1992-01-01

    An overview of geodesy and cartography of Mars over the past century is presented. The modern exploration began with the Mariner 4, 6, and 7 flyby missions, followed by the Mariner 9 and Viking missions that mapped the entire surface of Mars. The primary modern changes to the coordinate system have led to improved measurements of the rotational period, the direction of the spin axis, and the size and shape of Mars. Planimetric mapping based on Mariner 9 pictures began with a 1:25-M-scale sheet and 30 1:5-M-scale sheets that covered the entire Martian surface. The quality of the Viking Orbiter pictures was greatly improved over Mariner 9 and led to the publication of 140 controlled photomosaic sheets at a scale of 1:2 M. Two digital data bases have been compiled for Mars - the digital image model and the digital terrain model.

  20. Mathematical foundation of geodesy selected papers of Torben Krarup

    CERN Document Server

    Borre, K

    2006-01-01

    This volume contains selected papers by Torben Krarup, one of the most important geodesists of the 20th century. The collection includes the famous booklet "A Contribution to the Mathematical Foundation of Physical Geodesy" from 1969, the unpublished "Molodenskij letters" from 1973, the final version of "Integrated Geodesy" from 1978, "Foundation of a Theory of Elasticity for Geodetic Networks" from 1974, as well as trend-setting papers on the theory of adjustment.

  1. National Report for the International Association of Geodesy of the International Union of Geodesy and Geophysics 2007-2010

    CERN Document Server

    Boyarsky, E A; Gerasimenko, M D; Demianov, G V; Kaufman, M B; Kaftan, V I; Mazurova, E M; Malkin, Z M; Molodenskii, S M; Neyman, Yu M; Pevnev, A K; Savinykh, V P; Steblov, G M; Tatevian, S K; Tolchel'nikova, S A; Shestakov, N V

    2015-01-01

    This report submitted to the International Association of Geodesy (IAG) of the International Union of Geodesy and Geophysics (IUGG) contains results obtained by Russian geodesists in 2007-2010. In the report prepared for the XXV General Assembly of IUGG (Australia, Melbourne, 28 June - 7 July 2011), the results of principal researches in geodesy, geodynamics, gravimetry, in the studies of geodetic reference frame creation and development, Earth's shape and gravity field, Earth's rotation, geodetic theory, its application and some other directions are briefly described. The period from 2007 to 2010 was still difficult for Russian geodesy mainly due to the permanent reformation of state geodetic administration as well as state education structure and organization. The report is organized as a sequence of abstracts of principal publications and presentations for symposia, conferences, workshops, etc. Each of the report paragraphs includes a list of scientific papers published in 2007-2010 including those prepare...

  2. Recent Developments in Space Geodesy Data Discovery at the CDDIS

    Science.gov (United States)

    Noll, C. E.; Michael, B. P.; Pollack, N.

    2014-12-01

    The Crustal Dynamics Data Information System (CDDIS) supports data archiving and distribution activities for the space geodesy and geodynamics community. The main objectives of the system are to store space geodesy and geodynamics related data products in a central data bank, to maintain information about the archival of these data, and to disseminate these data and information in a timely manner to a global scientific research community. The archive consists of GNSS, laser ranging, VLBI, and DORIS data sets and products derived from these data. The CDDIS is one of NASA's Earth Observing System Data and Information System (EOSDIS) distributed data centers; EOSDIS data centers serve a diverse user community and are tasked to provide data discovery tools to search and access science data and products. The CDDIS data system and its archive is a key component in several of the operational services within the International Association of Geodesy (IAG) and its project the Global Geodetic Observing System (GGOS), including the IGS, the International DORIS Service (IDS), the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), and the International Earth Rotation Service (IERS). Several applications have recently been developed at the CDDIS to aid users in data discovery, both within the international space geodesy community and beyond. This poster will include background information about the system and its user communities, archive contents and updates, enhancements for data discovery, new system architecture, and future plans.

  3. Hybrid Atom Electrostatic System for Satellite Geodesy

    Science.gov (United States)

    Zahzam, Nassim; Bidel, Yannick; Bresson, Alexandre; Huynh, Phuong-Anh; Liorzou, Françoise; Lebat, Vincent; Foulon, Bernard; Christophe, Bruno

    2017-04-01

    for a future geodesy space mission with theoretical and experimental work.

  4. InSAR Geodesy: The Next Phase

    Science.gov (United States)

    Simons, M.

    2016-12-01

    Published in 1993, the first prominent geophysical applications of repeat pass Interferometric Synthetic Aperture Radar (InSAR) demonstrated spatially continuous imaging of the velocity of a remote ice stream in Antarctica and the ground displacement from a large earthquake in California. These studies heralded comprehensive assessments of rapid changes in the ice sheets and novel perspectives on earthquake source physics, all enabled by a new era in geodetic imaging with sub-centimeter sensitivity, meter-scale spatial resolution and expansive coverage. Since 1993, the promise of InSAR has been to provide deformation measurements "everywhere and all the time". Indeed, the new generation of satellites are already providing shorter revisit times and the gradual move to constellations of nearly identical satellites allows sub-weekly revisits at selected radar frequencies for many regions of interest. This increase in temporal sampling has prompted the geodetic community to develop a variety of InSAR time series methods and corrections techniques to mitigate the impact of path delays accrued in the atmosphere, all while inferring one or more components of the 3D time-dependent motions of Earth's solid surface. We illustrate these capabilities with recent studies that include detection of shallow aseismic slip transients on a major strike slip fault, dynamics of a subglacial eruption, the signature of aquifer management, mapping of rapid aseismic fault slip following a major earthquake and the long-distance response of ice stream motion to ocean tides. The increased sampling rate of observations allows us to improve our sensitivity to small amplitude deformation processes, separate overlapping physical processes by their different spatio-temporal signatures, and increase the general utility of imaging geodesy for rapid disaster response. At the same time, we need to rethink how data is managed for users with different capabilities - a critical challenge as we aim for a

  5. Geodetic and Geodynamic Studies at Department of Geodesy and Geodetic Astronomy Wut

    Directory of Open Access Journals (Sweden)

    Brzeziński Aleksander

    2016-06-01

    Full Text Available The article presents current issues and research work conducted in the Department of Geodesy and Geodetic Astronomy at the Faculty of Geodesy and Cartography at Warsaw University of Technology. It contains the most important directions of research in the fields of physical geodesy, satellite measurement techniques, GNSS meteorology, geodynamic studies, electronic measurement techniques and terrain information systems.

  6. Advancing geodesy in the U.S. Midcontinent: workshop report

    Science.gov (United States)

    Hamburger, Michael W.; Boyd, Oliver S.; Calais, Eric; King, Nancy E.; Stein, Seth A.

    2014-01-01

    The workshop on “Advancing Geodesy in the U.S. Midcontinent” was held from October 31 to November 1, 2012, at Northwestern University in Evanston, Illinois. The workshop included 28 participants from academia, government, and private-sector organizations that are involved in research on geodesy and earthquake hazards in the seismically active areas of the U.S. midcontinent (the region of relatively undeformed crust roughly between the Great Plains and Appalachian Mountains). The workshop was intended to provide guidance to the U.S. Geological Survey’s internal and external Earthquake Hazards research programs in the U.S. midcontinent. The 2012 workshop was developed as a follow-up to the “Workshop on New Madrid Geodesy and Understanding Intraplate Earthquakes,” held in Norwood, Massachusetts, in March 2011. The goal of the 2012 workshop was to provide specific recommendations to the U.S. Geological Survey on priorities for infrastructure and research investments related to geodesy in the U.S. midcontinent.

  7. 25 Years of Reports on Geodesy and Geoinformatics

    Science.gov (United States)

    Siemiątkowska, Jadwiga

    2016-06-01

    The article presents an outline of the 25-year history of the journal "Reports on Geodesy and Geoinformatics". The source of information was mainly the journal issues themselves. Attention was drawn to changes that the journal underwent over a quarter of a century and its relationship with the Institute of Geodesy and Geodetic Astronomy and later the Department of Geodesy and Geodetic Astronomy. Many issues were dedicated to materials from Polish conferences - those organised by the Institute and the international ones attended by the employees of the Institute, which was indicated in the section on the history of the journal. The second part of the article concerns the current activity and importance of the journal. Attention was paid to visibility of "Reports on Geodesy and Geoinformatics" in the domestic and foreign databases. Polish databases where the journal is indexed have been identified and briefly described. A separate issue is the evaluation of the journal, which forms a measure of its popularity among consumers. For this purpose, various parameters and biometrics indicators are used. The article used the Web of Science, Google Scholar and the Ministerial List databases for the assessment of the journal.

  8. Geodesy introduction to geodetic datum and geodetic systems

    CERN Document Server

    Lu, Zhiping; Qiao, Shubo

    2014-01-01

    A full introduction to geodetic data and systems written by well-known experts in their respective fields, this book is an ideal text for courses in geodesy and geomatics covering everything from coordinate and gravimetry data to geodetic systems of all types.

  9. Post-Newtonian reference-ellipsoid for relativistic geodesy

    CERN Document Server

    Kopeikin, Sergei; Mazurova, Elena

    2015-01-01

    We apply general relativity to construct the post-Newtonian background manifold that serves as a reference level surface in relativistic geodesy for conducting calculation of geoid's undulation. We chose the perfect homogeneous fluid uniformly rotating around a fixed axis as a source of the background manifold. We, then, reformulate and extend rotating-fluid calculations done by a number of previous researchers for astrophysical applications to the realm of relativistic geodesy to find out the algebraic equation of the post-Newtonian reference-ellipsoid. We explicitly perform all integrals characterizing gravitational potentials inside the fluid body and represent them in terms of elementary functions depending on the body's eccentricity. We fully explore the coordinate freedom of the equations describing the post-Newtonian ellipsoid and demonstrate that the fractional deviation of the post-Newtonian level surface from the Maclaurin ellipsoid can be made much smaller than the previously anticipated estimate a...

  10. Geodesy Students in Slovenia and Information & Communication Technology

    OpenAIRE

    Istenič Starčič, Andreja; Turk, Žiga

    2010-01-01

    The implementation of information and communication technologies (ICT) in university curricula is important for the development of graduates' competences and their preparation for the labour market. ICT use encourages the development of collaboration, creativity, leadership, and other generic and subject-specific competences. In this paper, the results of a survey among Slovene geodesy students conducted in 2009 are presented. The survey focuses on the modes in which students use ICT in learn...

  11. Observing and understanding the Earth system variations from space geodesy

    OpenAIRE

    Jin, Shuanggen; van Dam, Tonie; Wdowinski, Shimon

    2013-01-01

    The interaction and coupling of the Earth system components that include the atmosphere, hydrosphere, cryosphere, lithosphere, and other fluids in Earth's interior, influence the Earth's shape, gravity field and its rotation (the three pillars of geodesy). The effects of global climate change, such as sea level rise, glacier melting, and geoharzards, also affect these observables. However, observations and models of Earth's system change have large uncertainties due to the lack of direct high...

  12. Preface - Scientific applications of DORIS in space geodesy

    Science.gov (United States)

    Lemoine, F. G.; Schrama, E. J. O.

    2016-12-01

    As part of its responsibilities as an International Association of Geodesy (IAG) service, for the second time the International DORIS Service (IDS) has prepared a technique contribution to the development of improved realization of the International Terrestrial Reference Frame (ITRF), in this case ITRF2014. In order to prepare their contributions, the IDS community undertook a systematic reanalysis of all DORIS data from 1993 to 2015.0, and examined in-depth issues that produced systematic errors, or limited the accuracy of DORIS data products. As a result the IDS contribution to ITRF2014 is a landmark achievement for the IDS. The efforts of the different groups provide the main impetus for this special issue in Advances in Space Research "Scientific Applications of DORIS in Space Geodesy". For the third time the DORIS community has realized a special issue devoted to scientific analysis and products developed from DORIS data. The previous two special issues were published in the Journal of Geodesy (2006), and in Advances in Space Research (two volumes, 2010).

  13. Friedrich Robert Helmert, founder of modern geodesy, on the occasion of the centenary of his death

    Science.gov (United States)

    Ihde, Johannes; Reinhold, Andreas

    2017-08-01

    Friedrich Robert Helmert died in Potsdam in 1917 at the age of 74 after serving for over 30 years as director of the Royal Prussian Geodetic Institute and of the Central Bureau of the Internationale Erdmessung, the forerunner of today's International Association of Geodesy. He dedicated his life and his scientific career to the field of geodesy. His teachings on theoretical and physical geodesy were incorporated into university curricula around the world and hence into international endeavours to measure planet Earth. The purpose of this article is to illustrate the impact he has had on the development of modern geodesy and on the related sciences.

  14. Post-Newtonian reference ellipsoid for relativistic geodesy

    Science.gov (United States)

    Kopeikin, Sergei; Han, Wenbiao; Mazurova, Elena

    2016-02-01

    We apply general relativity to construct the post-Newtonian background manifold that serves as a reference spacetime in relativistic geodesy for conducting a relativistic calculation of the geoid's undulation and the deflection of the plumb line from the vertical. We chose an axisymmetric ellipsoidal body made up of a perfect homogeneous fluid uniformly rotating around a fixed axis, as a source generating the reference geometry of the background manifold through Einstein's equations. We then reformulate and extend hydrodynamic calculations of rotating fluids done by a number of previous researchers for astrophysical applications to the realm of relativistic geodesy to set up algebraic equations defining the shape of the post-Newtonian reference ellipsoid. To complete this task, we explicitly perform all integrals characterizing gravitational field potentials inside the fluid body and represent them in terms of the elementary functions depending on the eccentricity of the ellipsoid. We fully explore the coordinate (gauge) freedom of the equations describing the post-Newtonian ellipsoid and demonstrate that the fractional deviation of the post-Newtonian level surface from the Maclaurin ellipsoid can be made much smaller than the previously anticipated estimate based on the astrophysical application of the coordinate gauge advocated by Bardeen and Chandrasekhar. We also derive the gauge-invariant relations of the post-Newtonian mass and the constant angular velocity of the rotating fluid with the parameters characterizing the shape of the post-Newtonian ellipsoid including its eccentricity, a semiminor axis, and a semimajor axis. We formulate the post-Newtonian theorems of Pizzetti and Clairaut that are used in geodesy to connect the geometric parameters of the reference ellipsoid to the physically measurable force of gravity at the pole and equator of the ellipsoid. Finally, we expand the post-Newtonian geodetic equations describing the post-Newtonian ellipsoid to

  15. Acceleration Noise Considerations for Drag-free Satellite Geodesy Missions

    Science.gov (United States)

    Hong, S. H.; Conklin, J. W.

    2016-12-01

    The GRACE mission, which launched in 2002, opened a new era of satellite geodesy by providing monthly mass variation solutions with spatial resolution of less than 200 km. GRACE proved the usefulness of a low-low satellite-to-satellite tracking formation. Analysis of the GRACE data showed that the K-Band ranging system, which is used to measure the range between the two satellites, is the limiting factor for the precision of the solution. Consequently, the GRACE-FO mission, schedule for launch in 2017, will continue the work of GRACE, but will also test a new, higher precision laser ranging interferometer compared with the K-Band ranging system. Beyond GRACE-FO, drag-free systems are being considered for satellite geodesy missions. GOCE tested a drag-free attitude control system with a gravity gradiometer and showed improvements in the acceleration noise compensation compared to the electrostatic accelerometers used in GRACE. However, a full drag-free control system with a gravitational reference sensor has not yet been applied to satellite geodesy missions. More recently, this type of drag-free system was used in LISA Pathfinder, launched in 2016, with an acceleration noise performance two orders of magnitude better than that of GOCE. We explore the effects of drag-free performance in satellite geodesy missions similar to GRACE-FO by applying three different residual acceleration noises from actual space missions: GRACE, GOCE and LISA Pathfinder. Our solutions are limited to degree 60 spherical harmonic coefficients with biweekly time resolution. Our analysis shows that a drag-free system with acceleration noise performance comparable to GOCE and LISA-Pathfinder would greatly improve the accuracy of gravity solutions. In addition to these results, we also present the covariance shaping process used in the estimation. In the future, we plan to use actual acceleration noise data measured using the UF torsion pendulum. This apparatus is a ground facility at

  16. WEGENER: World Earthquake GEodesy Network for Environmental Hazard Research

    Science.gov (United States)

    Ozener, Haluk; Zerbini, Susanna; Bastos, Luisa; Becker, Matthias; Meghraoui, Mustapha; Reilinger, Robert

    2013-04-01

    WEGENER is originally the acronym for Working Group of European Geoscientists for the Establishment of Networks for Earth-science Research. It was founded in March 1981 in response to an appeal delivered at the Journées Luxembourgeoises de Geodynamique in December 1980 to respond with a coordinated European proposal to a NASA Announcement of Opportunity inviting participation in the Crustal Dynamics and Earthquake Research Program. WEGENER, during the past 32 years, has always kept a close contact with the Agencies and Institutions responsible for the development and maintenance of the global space geodetic networks with the aim to make them aware of the scientific needs and outcomes of the project which might have an influence on the general science policy trends. WEGENER was serving as Inter-commission Project 3.2, between Commission 1 and Commission 3, of the International Association of Geodesy (IAG) until 2012. Since then, WEGENER project has became the Sub-commission 3.5 of IAG commission 3, namely Tectonics and Earthquake Geodesy. In this study, we briefly review the accomplishments of WEGENER as originally conceived and outline and justify the new focus of the WEGENER consortium. The remarkable and rapid evolution of the present state of global geodetic monitoring in regard to the precision of positioning capabilities (and hence deformation) and global coverage, the development of InSAR for monitoring strain with unprecedented spatial resolution, and continuing and planned data from highly precise satellite gravity and altimetry missions, encourage us to shift principal attention from mainly monitoring capabilities by a combination of space and terrestrial geodetic techniques to applying existing observational methodologies to the critical geophysical phenomena that threaten our planet and society. Our new focus includes developing an improved physical basis to mitigate earthquake, tsunami, and volcanic risks, and the effects of natural and anthropogenic

  17. Use of Very Stable Clocks in Satellite Geodesy

    Science.gov (United States)

    Hugentobler, Urs; Romanyuk, Tetyana

    2016-07-01

    Time and frequency play an essential role in satellite geodesy and navigation. Global Navigation Satellite Systems (GNSS) rely on precise measurements of signal travel times. The satellite and receiver clocks involved in measuring this time interval need to be synchronized at the picosecond level. The concept of GNSS allows for an epoch-wise synchronization of space and ground clocks, a feature which is consequently used in satellite geodesy by estimating epoch-wise clock corrections for all clocks in the system, either explicitly or implicitly by forming double differences. Ultra-stable clocks allow to estimate only few parameters for each clock, e.g., offset and drift. The much reduced number of parameters should stabilize GNSS solutions, e.g., tracking network station coordinates. On the other hand systematic errors, e.g., from troposphere or orbit modeling deficiencies or temperature induced hardware delay variations may systematically affect the solutions. The presentation shows trade-offs of modelling higly stable clocks and negative impact of error sources based on simulations.

  18. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

    Mass transports occurring in the atmosphere-hydrosphere-cryosphere-solid Earth-core system (the 'global geophysical fluids') are important geophysical phenomena. They occur on all temporal and spatial scales. Examples include air mass and ocean circulations, oceanic and solid tides, hydrological water and idsnow redistribution, mantle processes such as post-glacial rebound, earthquakes and tectonic motions, and core geodynamo activities. The temporal history and spatial pattern of such mass transport are often not amenable to direct observations. Space geodesy techniques, however, have proven to be an effective tool in monitorihg certain direct consequences of the mass transport, including Earth's rotation variations, gravitational field variations, and the geocenter motion. Considerable advances have been made in recent years in observing and understanding of these geodynamic effects. This paper will use several prominent examples to illustrate the triumphs in research over the past years under a 'Moore's law' in space geodesy. New space missions and projects promise to further advance our knowledge about the global mass transports. The latter contributes to our understanding of the geophysical processes that produce and regulate the mass transports, as well as of the solid Earth's response to such changes in terms of Earth's mechanical properties.

  19. NASA space geodesy program: Catalogue of site information

    Science.gov (United States)

    Bryant, M. A.; Noll, C. E.

    1993-01-01

    This is the first edition of the NASA Space Geodesy Program: Catalogue of Site Information. This catalogue supersedes all previous versions of the Crustal Dynamics Project: Catalogue of Site Information, last published in May 1989. This document is prepared under the direction of the Space Geodesy and Altimetry Projects Office (SGAPO), Code 920.1, Goddard Space Flight Center. SGAPO has assumed the responsibilities of the Crustal Dynamics Project, which officially ended December 31, 1991. The catalog contains information on all NASA supported sites as well as sites from cooperating international partners. This catalog is designed to provde descriptions and occupation histories of high-accuracy geodetic measuring sites employing space-related techniques. The emphasis of the catalog has been in the past, and continues to be with this edition, station information for facilities and remote locations utilizing the Satellite Laser Ranging (SLR), Lunar Laser Ranging (LLR), and Very Long Baseline Interferometry (VLBI) techniques. With the proliferation of high-quality Global Positioning System (GPS) receivers and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) transponders, many co-located at established SLR and VLBI observatories, the requirement for accurate station and localized survey information for an ever broadening base of scientists and engineers has been recognized. It is our objective to provide accurate station information to scientific groups interested in these facilities.

  20. Geodesy, a Bibliometric Approach for 2000-2006

    Science.gov (United States)

    Vazquez, G.; Landeros, C. F.

    2007-12-01

    In recent years, bibliometric science has been frequently applied in the development and evaluation of scientific research. This work presents a bibliometric analysis for the research work performed in the field of geodesy "science of the measurement and mapping of the earth surface including its external gravity field". The objective of this work is to present a complete overview of the generated research on this field to assemble and study the most important publications occurred during the past seven years. The analysis was performed including the SCOPUS and WEB OF SCIENCE databases for all the geodetic scientific articles published between 2000 and 2006. The search profile was designed considering a strategy to seek for titles and article descriptors using the terms geodesy and geodetic and some other terms associated with the topics: geodetic surfaces, vertical measurements, reference systems and frames, modern space-geodetic techniques and satellite missions. Some preliminary results had been achieved specifically Bradford law of distribution for journals and education institutes, and Lotka's law for authors that also includes the cooperation between countries in terms of writing together scientific articles. In the particular case of distributions, the model suggested by Egghe (2002) was adopted for determining the cores.

  1. International VLBI Service for Geodesy and Astrometry: General Meeting Proceedings

    Science.gov (United States)

    Vandenberg, Nancy R. (Editor); Baver, Karen D. (Editor)

    2002-01-01

    This volume contains the proceedings of the second General Meeting of the International VLBI Service for Geodesy and Astrometry (IVS), held in Tsukuba, Japan, February 4-7, 2002. The contents of this volume also appear on the IVS Web site at http://ivscc.gsfc.nasa.gov/publications/gm2002. The key-note of the second GM was prospectives for the future, in keeping with the re-organization of the IAG around the motivation of geodesy as 'an old science with a dynamic future' and noting that providing reference frames for Earth system science that are consistent over decades on the highest accuracy level will provide a challenging role for IVS. The goal of the meeting was to provide an interesting and informative program for a wide cross section of IVS members, including station operators, program managers, and analysts. This volume contains 72 papers and five abstracts of papers presented at the GM. The volume also includes reports about three splinter meetings held in conjunction with the GM: a mini-TOW (Technical Operations Workshop), the third IVS Analysis Workshop and a meeting of the analysis working group on geophysical modeling.

  2. Surveying co-located space geodesy techniques for ITRF computation

    Science.gov (United States)

    Sarti, P.; Sillard, P.; Vittuari, L.

    2003-04-01

    We present a comprehensive operational methodology, based on classical geodesy triangulation and trilateration, that allows the determination of reference points of the five space geodesy techniques used in ITRF computation (i.e.: DORIS, GPS, LLR, SLR, VLBI). Most of the times, for a single technique, the reference point is not accessible and measurable directly. Likewise, no mechanically determined ex-center with respect to an external and measurable point is usually given. In these cases, it is not possible to directly measure the sought reference points and it is even less straightforward to obtain the statistical information relating these points for different techniques. We outline the most general practical surveying methodology that permits to recover the reference points of the different techniques regardless of their physical materialization. We also give a detailed analytical approach for less straightforward cases (e.g.: non geodetic VLBI antennae and SLR/LLR systems). We stress the importance of surveying instrumentation and procedure in achieving the best possible results and outline the impact of the information retrieved with our method in ITRF computation. In particular, we will give numerical examples of computation of the reference point of VLBI antennae (Ny Aalesund and Medicina) and the ex-centre vector computation linking co-located VLBI and GPS techniques in Medicina (Italy). A special attention was paid to the rigorous derivation of statistical elements. They will be presented in an other presentation.

  3. International VLBI Service for Geodesy and Astrometry 2012 Annual Report

    Science.gov (United States)

    Baver, Karen D.; Behrend, Dirk; Armstrong, Kyla L.

    2013-01-01

    This volume of reports is the 2012 Annual Report of the International VLBI Service for Geodesy and Astrometry (IVS). The individual reports were contributed by VLBI groups in the international geodetic and astrometric community who constitute the permanent components of IVS. The IVS 2012 Annual Report documents the work of the IVS components for the calendar year 2012, our fourteenth year of existence. The reports describe changes, activities, and progress ofthe IVS. Many thanks to all IVS components who contributed to this Annual Report. With the exception of the first section and parts of the last section (described below), the contents of this Annual Report also appear on the IVS Web site athttp:ivscc.gsfc.nasa.gov/publications/ar2012

  4. Geodesy constraints on the interior structure and composition of Mars

    Science.gov (United States)

    Rivoldini, A.; Van Hoolst, T.; Verhoeven, O.; Mocquet, A.; Dehant, V.

    2011-06-01

    Knowledge of the interior structure of Mars is of fundamental importance to the understanding of its past and present state as well as its future evolution. The most prominent interior structure properties are the state of the core, solid or liquid, its radius, and its composition in terms of light elements, the thickness of the mantle, its composition, the presence of a lower mantle, and the density of the crust. In the absence of seismic sounding only geodesy data allow reliably constraining the deep interior of Mars. Those data are the mass, moment of inertia, and tides. They are related to Mars' composition, to its internal mass distribution, and to its deformational response to principally the tidal forcing of the Sun. Here we use the most recent estimates of the moment of inertia and tidal Love number k2 in order to infer knowledge about the interior structure of the Mars. We have built precise models of the interior structure of Mars that are parameterized by the crust density and thickness, the volume fractions of upper mantle mineral phases, the bulk mantle iron concentration, and the size and the sulfur concentration of the core. From the bulk mantle iron concentration and from the volume fractions of the upper mantle mineral phases, the depth dependent mineralogy is deduced by using experimentally determined phase diagrams. The thermoelastic properties at each depth inside the mantle are calculated by using equations of state. Since it is difficult to determine the temperature inside the mantle of Mars we here use two end-member temperature profiles that have been deduced from studies dedicated to the thermal evolution of Mars. We calculate the pressure and temperature dependent thermoelastic properties of the core constituents by using equations state and recent data about reference thermoelastic properties of liquid iron, liquid iron-sulfur, and solid iron. To determine the size of a possible inner core we use recent data on the melting temperature of

  5. Geodesy in the 21st Century: new Applications and Education

    Science.gov (United States)

    Eriksson, S. C.; Wdowinski, S.

    2008-12-01

    The UNAVCO community is developing curricular materials incorporating use of data with web-based educational tools highlighting current and new advances in application of space geodesy to issues of climate change such as sea level change, glacial melting, and coastal subsidence. One of the major scientific challenges for our community is to characterize the processes that control natural hazards within the lithosphere, cryosphere and atmosphere, including earthquakes, tsunamis, volcanic eruptions, and long term changes in climate, ice mass, global sea level, and coastal subsidence. Space geodetic technologies (positioning techniques, Global Navigation Satellite Systems (GNNS), altimetry, Interferometric Syntheic Aperture Radar (InSAR) and gravity missions ) yield sub-centimeter accuracy allowing detection of small movements of the Earth's solid, hydrosphere and cryosphere surfaces. For example, the global coverage of altimetry satellites allow decadal observations of global sea level changes, complementing 100-year long terrestrial measurements, but better reflecting sea surface changes within the entire ocean basins, not limited to coastal areas where tide-gauges are located. In addition, GPS measurements help improve the terrestrial relative sea level change record by monitoring the subsidence/uplift of gauge stations, decoupling the relative movement of sea and land. UNAVCO has a program for faculty teaching general education, introductory geoscience courses and in- service teachers of Earth Science. We are further developing this program from using "traditional" solid earth data such as GPS to include other geodetic data that impact natural hazard mitigation, the effects of global warming, and optimum use of water resources, all major study areas for space geodesy. Other products include posters, an expanded websites, and papers in an array of geoscience journals that reach broad audiences.

  6. Turtles to Terabytes: The Ongoing Revolution in Volcano Geodesy

    Science.gov (United States)

    Dzurisin, D.

    2015-12-01

    Volcano geodesy is in the midst of a revolution. GPS and InSAR, together with extensive ground-based sensor networks, have enabled major advances in understanding how and why volcanoes deform. Surveying techniques that produced a few bytes of information per benchmark per year have been replaced by continuously operating deformation networks and imaging radar satellites that generate terabytes of data at resolutions unattainable only a few decades ago. These developments have enabled more detailed assessments of volcano hazards, more accurate forecasts of volcanic activity, and better insights into how volcanoes behave over a variety of spatial and temporal scales. Forty years ago, repeated leveling surveys showed that the floor of the Yellowstone caldera had risen more than 70 cm in the past 5 decades. Today a network of GPS stations tracks surface movements continuously with millimeter-scale accuracy and the entire deformation field is imaged frequently by a growing number of SAR satellites, revealing a far more complex style of deformation than was recognized previously. At Mount St. Helens, the 1980-1986 eruption taught us that a seemingly quiescent volcano can suddenly become overtly restless, and that accurate eruption predictions are possible at least in some limited circumstances given sufficient observations. The lessons were revisited during the volcano's 2004-2008 eruption, during which a new generation of geodetic sensors and methods detected a range of co-eruptive changes that enabled new insights into the volcano's magma storage and transport system. These examples highlight volcano deformation styles and scales that were unknown just a few decades ago but now have been revealed by a growing number of data types and modeling methods. The rapid evolution that volcano geodesy is currently experiencing provides an ongoing challenge for geodesists, while also demonstrating that geodetic unrest is common, widespread, and illuminating. Vive la révolution!

  7. Research and Development Work Carried out by the Chair of Engineering Geodesy and Measurement and Control Systems, Faculty of Geodesy and Cartography WUT - Thematic Scope and Achievements

    Science.gov (United States)

    Nowak, Edward; Malarski, Ryszard; Prószyński, Witold; Sadowska, Alicja; Woźniak, Marek; Zaczek-Peplinska, Janina

    2016-06-01

    Geodetic engineering surveys are an important part of the works carried out by the Faculty of Geodesy and Cartography, Warsaw University of Technology. These works concern measurement techniques as well as advanced result analysis methods applied in precise industrial surveys and in processes controlling object's behaviour over time. The thematic scope of research realised by Chair of Engineering Geodesy and Control-Measuring Systems shows that article related to geodetic engineering measurements and geodetic monitoring is carried out with high intensity, resulting in technological advancement and implementation of new or improved measurement solutions and methods of measurement result development.

  8. 3rd Course of the International School of Advanced Geodesy

    CERN Document Server

    Sansò, Fernando

    1985-01-01

    During the period April 25th to May 10th, 1984 the 3rd Course of the International School of Advanced Geodesy entitled "Optimization and Design of Geodetic Networks" took place in Erice. The main subject of the course is clear from the title and consisted mainly of that particular branch of network analysis, which results from applying general concepts of mathematical optimization to the design of geodetic networks. As al­ ways when dealing with optimization problems, there is an a-priori choice of the risk (or gain) function which should be minimized (or maximized) according to the specific interest of the "designer", which might be either of a scientific or of an economic nature or even of both. These aspects have been reviewed in an intro­ ductory lecture in which the particular needs arising in a geodetic context and their analytical representations are examined. Subsequently the main body of the optimization problem, which has been conven­ tionally divided into zero, first, second and third order desi...

  9. Linear homotopy solution of nonlinear systems of equations in geodesy

    Science.gov (United States)

    Paláncz, Béla; Awange, Joseph L.; Zaletnyik, Piroska; Lewis, Robert H.

    2010-01-01

    A fundamental task in geodesy is solving systems of equations. Many geodetic problems are represented as systems of multivariate polynomials. A common problem in solving such systems is improper initial starting values for iterative methods, leading to convergence to solutions with no physical meaning, or to convergence that requires global methods. Though symbolic methods such as Groebner bases or resultants have been shown to be very efficient, i.e., providing solutions for determined systems such as 3-point problem of 3D affine transformation, the symbolic algebra can be very time consuming, even with special Computer Algebra Systems (CAS). This study proposes the Linear Homotopy method that can be implemented easily in high-level computer languages like C++ and Fortran that are faster than CAS by at least two orders of magnitude. Using Mathematica, the power of Homotopy is demonstrated in solving three nonlinear geodetic problems: resection, GPS positioning, and affine transformation. The method enlarging the domain of convergence is found to be efficient, less sensitive to rounding of numbers, and has lower complexity compared to other local methods like Newton-Raphson.

  10. Research-related intercultural higher education in satellite geodesy

    Science.gov (United States)

    Mayer, M.; Heck, B.; Krueger, C. P.

    2009-04-01

    In order to improve the education of young researchers (master degree, PhD, PostDocs) a cooperation between the Department of Geomatics (DGEOM), Federal University of Paraná (UFPR), Curitiba (Brazil) and the Geodetic Institute (GIK), University Karlsruhe (TH), Karlsruhe (Germany) was established which now exists since more than five years. The joint venture is actually called "PROBRAL: Precise positioning and height determination by means of GPS: Modeling of errors and transformation into physical heights" and focuses on research and education within the field of satellite geodesy. PROBRAL is funded by the Brazilian academic exchange service CAPES and the German academic exchange service DAAD. The geodetic aim of the research project is to validate and improve the quality of 3d positions derived from observations related to satellite navigation systems like GPS. In order to fulfill this ambitious goal sustainably, research has to be carried out in close cooperation. At the same time, e.g. to guarantee continuous success, a coordinated education has to be ensured. Besides technical education aspects key competences (e.g. language, capacity for teamwork, project management skills) are trained. Within the presentation the lessons which were learned from this project are discussed in detail.

  11. Seafloor geodesy: Measuring surface deformation and strain-build up

    Science.gov (United States)

    Kopp, Heidrun; Lange, Dietrich; Hannemann, Katrin; Petersen, Florian

    2017-04-01

    Seafloor deformation is intrinsically related to tectonic processes, which potentially may evolve into geohazards, including earthquakes and tsunamis. The nascent scientific field of seafloor geodesy provides a way to monitor crustal deformation at high resolution comparable to the satellite-based GPS technique upon which terrestrial geodesy is largely based. The measurements extract information on stress and elastic strain stored in the oceanic crust. Horizontal seafloor displacement can be obtained by acoustic/GPS combination to provide absolute positioning or by long-term acoustic telemetry between different beacons fixed on the seafloor. The GeoSEA (Geodetic Earthquake Observatory on the SEAfloor) array uses acoustic telemetry for relative positioning at mm-scale resolution. The transponders within an array intercommunicate via acoustic signals for a period of up to 3.5 years. The seafloor acoustic transponders are mounted on 4 m high tripod steel frames to ensure clear line-of-sight between the stations. The transponders also include high-precision pressure sensors to monitor vertical movements and dual-axis inclinometers in order to measure their level as well as any tilt of the seafloor. Sound velocity sensor measurements are used to correct for water sound speed variations. A further component of the network is GeoSURF, a self-steering autonomous surface vehicle (Wave Glider), which monitors system health and is able to upload the seafloor data to the sea surface and to transfer it via satellite. The GeoSEA array is capable of both continuously monitoring horizontal and vertical ground displacement rates along submarine fault zones and characterizing their behavior (locked or aseismically creeping). Seafloor transponders are currently installed along the Siliviri segment of the North Anatolian Fault offshore Istanbul for measurements of strain build-up along the fault. The first 18 month of baseline ranging were analyzed by a joint-least square inversion

  12. A Feasibility Study of Space VLBI for Geodesy and Geodynamics

    Science.gov (United States)

    Kulkarni, Madhav Narayan

    1992-01-01

    Space Very Long Baseline Interferometry (VLBI) is an extension of the ground based VLBI to the space. With the launching of two or more Space VLBI satellites in the future, Space VLBI observations will be available for astrometric, geodetic and geodynamic applications. This new technique holds potential for various important applications including monitoring Earth rotation and interconnection of the reference frames used in geodesy and geodynamics. The aim of this feasibility study has been to investigate the possibility of precise estimation of geodetic parameters, with emphasis on the Earth rotation parameters (ERP's), from Space VLBI observations. A brief description of the Space VLBI technique, it's possible applications, and the Space VLBI missions being planned has been given. Estimability analysis to investigate the estimability of geodetic parameters from Space VLBI observations has been carried out and a simplified mathematical model is derived in terms of estimable parameters. Results of sensitivity analysis carried out to study the sensitivity of the Space VLBI observables to the geodetic parameters of interest, including the number of these parameters and random errors in their a priori values, have been presented. Some of the dominant systematic effects including atmospheric refraction, solar radiation pressure and relativistic effects have also been investigated. Simulation studies have been carried out to study the influence of these systematic effects and a priori information on the estimation of the Earth rotation parameters. The results from the simulation studies indicate that it may be possible to use the Space VLBI technique for monitoring Earth rotation and polar motion, only if the orbital systematic effects can be modeled to a high degree of accuracy (or the satellites can be tracked, with high accuracy, independently), and precise a priori information on station coordinates from other sources is used. A brief description of the Space VLBI

  13. Geodesy and the UNAVCO Consortium: Three Decades of Innovations

    Science.gov (United States)

    Rowan, L. R.; Miller, M. M.; Meertens, C. M.; Mattioli, G. S.

    2015-12-01

    UNAVCO, a non-profit, university consortium that supports geoscience research using geodesy, began with the ingenious recognition that the nascent Global Positioning System constellation (GPS) could be used to investigate earth processes. The consortium purchased one of the first commercially available GPS receivers, Texas Instrument's TI-4100 NAVSTAR Navigator, in 1984 to measure plate deformation. This early work was highlighted in a technology magazine, GPSWorld, in 1990. Over a 30-year period, UNAVCO and the community have helped advance instrument design for mobility, flexibility, efficiency and interoperability, so research could proceed with higher precision and under ever challenging conditions. Other innovations have been made in data collection, processing, analysis, management and archiving. These innovations in tools, methods and data have had broader impacts as they have found greater utility beyond research for timing, precise positioning, safety, communication, navigation, surveying, engineering and recreation. Innovations in research have expanded the utility of geodetic tools beyond the solid earth science through creative analysis of the data and the methods. For example, GPS sounding of the atmosphere is now used for atmospheric and space sciences. GPS reflectrometry, another critical advance, supports soil science, snow science and ecological research. Some research advances have had broader impacts for society by driving innovations in hazards risk reduction, hazards response, resource management, land use planning, surveying, engineering and other uses. Furthermore, the geodetic data is vital for the design of space missions, testing and advancing communications, and testing and dealing with interference and GPS jamming. We will discuss three decades (and counting) of advances by the National Science Foundation's premiere geodetic facility, consortium and some of the many geoscience principal investigators that have driven innovations in

  14. Trajectory models and reference frames for crustal motion geodesy

    Science.gov (United States)

    Bevis, Michael; Brown, Abel

    2014-03-01

    We sketch the evolution of station trajectory models used in crustal motion geodesy over the last several decades, and describe some recent generalizations of these models that allow geodesists and geophysicists to parameterize accelerating patterns of displacement in general, and postseismic transient deformation in particular. Modern trajectory models are composed of three sub-models that represent secular trends, annual oscillations, and instantaneous jumps in coordinate time series. Traditionally the trend model invoked constant station velocity. This can be generalized by assuming that position is a polynomial function of time. The trajectory model can also be augmented as needed, by including one or more logarithmic transients in order to account for typical multi-year patterns of postseismic transient motion. Many geodetic and geophysical research groups are using general classes of trajectory model to characterize their crustal displacement time series, but few if any of them are using these trajectory models to define and realize the terrestrial reference frames (RFs) in which their time series are expressed. We describe a global GPS reanalysis program in which we use two general classes of trajectory model, tuned on a station by station basis. We define the network trajectory model as the set of station trajectory models encompassing every station in the network. We use the network trajectory model from the each global analysis to assign prior position estimates for the next round of GPS data processing. We allow our daily orbital solutions to relax so as to maintain their consistency with the network polyhedron. After several iterations we produce GPS time series expressed in a RF similar to, but not identical with ITRF2008. We find that each iteration produces an improvement in the daily repeatability of our global time series and in the predictive power of our trajectory models.

  15. Eventual Participation in GMES of Institute of Geodesy and Geoinformation

    Science.gov (United States)

    Balodis, J.; Janpaule, I.; Rubans, A.; Zarinjsh, A.; Abele, M.; Ubelis, A.; Cekule, M.

    2012-04-01

    The new project has been commenced at the University of Latvia (LU) - "Fotonika-LV". Three institutes, namely institute of Atomphysics and Spectroscopy, Institute of Astronomy and Institute of Geodesy and Geoinformation have succeeded to receive the sources for proposed development of photonics in applied research. Several highly advanced partner institutions have agreed to establish partnership in planned research activities. The photonics plays an important role at the R&D of the Institute of Geodesy and Geoinformation of the University of Latvia (LU GGI). The Institute applies the space related technologies for the environmental studies in Latvia. Photonics has been applied in satellite laser ranging systems. The small size modern satellite laser ranging system (SLR) and its control software has been developed at the Institute recently. SLR will be used for the regular observations of low Earth orbiters (LAGEOS, GOCE, GRACE, ERS2, ENVISAT, CRYOSAT, etc.) within the framework of ILRS. The test observations have proved the results of high quality. Sentinel mission satellites could be observed as well if they will have the laser retroreflectors. The developed SLR is a small size. It could be improved for the mobility applications in variety of sites if needed. Another SLR machine is under construction with planned application for remote sensing satellite calibration by using the white laser beam. Additionally it could be used for Galileo and LAGEOS observation. However, in order to use the SLR for Galileo and other higher orbit satellites the most sensitive photonics are needed. From other side the proper optical devices are needed for SLR observations at the daylight. Additionally, the sky in the Baltic region is frequently covered by the thin clouds which make the satellite observations very complicated and less productive. The optimal choice of photonics in each case is needed and best solutions are required. The CCD matrices combination with especially made

  16. Geodesy Data and Metadata Integration Strategies for Collaborative Global Research Infrastructures

    Science.gov (United States)

    Boler, Fran; Meertens, Charles

    2017-04-01

    Through multiple pathways, UNAVCO is collaborating with US and international partners to integrate geodesy-related research infrastructures. One of the earliest of UNAVCO's efforts at an integrated research infrastructure for geodesy was the Geodesy Seamless Archive Centers (GSAC) software, a web services-based data and metadata search and access system that was pioneered by UNAVCO and collaborators at Scripps and NASA. GSAC was adopted as an enabling technology in the early phases of the European Plate Observing System through the CoopEUS European and US initiative. GSAC is also a core piece of the infrastructure used in Dataworks for GNSS (Global Navigation Satellite System), a UNAVCO effort to build integrated GNSS data system components. In addition to GSAC, Dataworks has components that facilitate data download from a network of GNSS receivers, and data and metadata management. Dataworks has been deployed for capacity building in the Caribbean. The web services approach continues to be a major focus for UNAVCO and has been implemented within the NSF EarthCube Building Block project GeoWS, which takes the web services concept from an inter-domain infrastructure capability (across institutions but within geodesy) to the next level as a cross-domain (geodesy, seismology, marine geophysics) infrastructure capability through definition of common, standards-based vocabularies and exchange formats. In a separate effort focused on metadata, UNAVCO is working under the Data Centers Working Group of the International GNSS Service to establish metadata formats and exchange mechanisms using standards via the GeodesyML effort of Geosciences Australia and others for Open Geospatial Consortium web services for metadata.

  17. GPS-Acoustic Seafloor Geodesy using a Wave Glider

    Science.gov (United States)

    Chadwell, C. D.

    2013-12-01

    The conventional approach to implement the GPS-Acoustic technique uses a ship or buoy for the interface between GPS and Acoustics. The high cost and limited availability of ships restricts occupations to infrequent campaign-style measurements. A new approach to address this problem uses a remote controlled, wave-powered sea surface vehicle, the Wave Glider. The Wave Glider uses sea-surface wave action for forward propulsion with both upward and downward motions producing forward thrust. It uses solar energy for power with solar panels charging the onboard 660 W-h battery for near continuous operation. It uses Iridium for communication providing command and control from shore plus status and user data via the satellite link. Given both the sea-surface wave action and solar energy are renewable, the vehicle can operate for extended periods (months) remotely. The vehicle can be launched from a small boat and can travel at ~ 1 kt to locations offshore. We have adapted a Wave Glider for seafloor geodesy by adding a dual frequency GPS receiver embedded in an Inertial Navigation Unit, a second GPS antenna/receiver to align the INU, and a high precision acoustic ranging system. We will report results of initial testing of the system conducted at SIO. In 2014, the new approach will be used for seafloor geodetic measurements of plate motion in the Cascadia Subduction Zone. The project is for a three-year effort to measure plate motion at three sites along an East-West profile at latitude 44.6 N, offshore Newport Oregon. One site will be located on the incoming plate to measure the present day convergence between the Juan de Fuca and North American plates and two additional sites will be located on the continental slope of NA to measure the elastic deformation due to stick-slip behavior on the mega-thrust fault. These new seafloor data will constrain existing models of slip behavior that presently are poorly constrained by land geodetic data 100 km from the deformation front.

  18. Method for the numerical integration of equations of perturbed satellite motion in problems of space geodesy

    Science.gov (United States)

    Plakhov, Iu. V.; Mytsenko, A. V.; Shel'Pov, V. A.

    A numerical integration method is developed that is more accurate than Everhart's (1974) implicit single-sequence approach for integrating orbits. This method can be used to solve problems of space geodesy based on the use of highly precise laser observations.

  19. Drag-free Small Satellite Platforms for Future Geodesy Missions

    Science.gov (United States)

    Conklin, J. W.; Hong, S.; Nguyen, A.; Serra, P.; Balakrishnan, K.; Buchman, S.; De Bra, D. B.; Hultgren, E.; Zoellner, A.

    2013-12-01

    Continuous satellite geodesy measurements lasting into the foreseeable future are critical for the understanding of our changing planet. It is therefore imperative that we explore ways to reduce costs, while maintaining science return. Small satellite platforms represent a promising path forward if ways can be found to reduce the size, weight, and power of the necessary instrumentation. One key enabling technology is a precision small-scale drag-free system under development at the University of Florida and Stanford University. A drag-free satellite (a) contains and shields a free-floating test mass from all non-gravitational forces, and (b) precisely measures the position of the test mass inside the satellite. A feedback control system commands thrusters to fly the 'tender' spacecraft with respect to the test mass. Thus, both test mass and spacecraft follow a pure geodesic in spacetime. By tracking the relative positions of low Earth orbiting drag-free satellites, using laser interferometry for example, the detailed shape of geodesics, and through analysis, the higher order harmonics of the Earth's geopotential can be determined. Drag-free systems can be orders of magnitude more accurate that accelerometer-based systems because they fundamentally operate at extremely low acceleration levels, and are therefore not limited by dynamic range like accelerometers. Since no test mass suspension force is required, larger gaps between the test mass and satellite are possible, which reduces the level of unwanted disturbing forces produced by the satellite itself. The small satellite platform also enables cost-effective constellations, which can increase the temporal resolution of gravity field maps by more-frequently observing given locations on the Earth. Mixed-orbit constellations can also markedly enhance observational strength, decorrelate gravity coefficient estimates, and help address the fundamental aliasing problem that exists with previous missions. The

  20. New Collaboration Among Geodesy Data Centers in Europe and the US Facilitates Data Discovery and Access

    Science.gov (United States)

    Boler, Fran; Wier, Stuart; D'Agostino, Nicola; Fernandes, Rui R. M.; Ganas, Athanassios; Bruyninx, Carine; Ofeigsson, Benedikt

    2014-05-01

    COOPEUS, the European Union project to strengthen the cooperation between the US and the EU in the field of environmental research infrastructures, is linking the US NSF-supported geodesy Facility at UNAVCO with the European Plate Observing System (EPOS) in joint research infrastructure enhancement activities that will ultimately advance international geodesy data discovery and access. (COOPEUS also links a broad set of additional EU and US based Earth, oceans, and environmental science research entities in joint research infrastructure enhancement activities.) The UNAVCO Data Center in Boulder, Colorado, archives for preservation and distributes geodesy data and products, including hosting GNSS data from 2,500 continuously operating stations around the globe. UNAVCO is only one of several hundred data centers worldwide hosting GNSS data, which are valuable for scientific research, education, hazards assessment and monitoring, and emergency management. However, the disparate data holdings structures, metadata encodings, and infrastructures at these data centers represent a significant obstacle to use by scientists, government entities, educators and the public. Recently a NASA-funded project at UNAVCO and two partner geodesy data centers in the US (CDDIS and SOPAC) has successfully designed and implemented software for simplified data search and access called the Geodesy Seamless Archive Centers (GSAC). GSAC is a web services based technology that is intended to be simple to install and run for most geodesy data centers. The GSAC services utilize a repository layer and a service layer to identify and present both the required metadata elements along with any data center-specific services and capabilities. In addition to enabling web services and related capabilities at the data center level, GSAC repository code can be implemented to federate two or more GSAC-enabled data centers wishing to present a unified search and access capability to their user community. In

  1. Application of artificial intelligence in Geodesy - A review of theoretical foundations and practical examples

    Science.gov (United States)

    Reiterer, Alexander; Egly, Uwe; Vicovac, Tanja; Mai, Enrico; Moafipoor, Shahram; Grejner-Brzezinska, Dorota A.; Toth, Charles K.

    2010-12-01

    Artificial Intelligence (AI) is one of the key technologies in many of today's novel applications. It is used to add knowledge and reasoning to systems. This paper illustrates a review of AI methods including examples of their practical application in Geodesy like data analysis, deformation analysis, navigation, network adjustment, and optimization of complex measurement procedures. We focus on three examples, namely, a geo-risk assessment system supported by a knowledge-base, an intelligent dead reckoning personal navigator, and evolutionary strategies for the determination of Earth gravity field parameters. Some of the authors are members of IAG Sub-Commission 4.2 - Working Group 4.2.3, which has the main goal to study and report on the application of AI in Engineering Geodesy.

  2. Participation of Employees and Students of the Faculty of Geodesy and Cartography in Polar Research

    Science.gov (United States)

    Pasik, Mariusz; Adamek, Artur; Rajner, Marcin; Kurczyński, Zdzisław; Pachuta, Andrzej; Woźniak, Marek; Bylina, Paweł; Próchniewicz, Dominik

    2016-06-01

    This year the Faculty of Geodesy and Cartography, Warsaw University of Technology celebrates its 95th jubilee, which provides an opportunity to present the Faculty's rich traditions in polar research. Employees and students of the faculty for almost 60 years have taken part in research expeditions to the polar circle. The article presents various studies typical of geodesy and cartography, as well as miscellany of possible measurement applications and geodetic techniques used to support interdisciplinary research. Wide range of geodetic techniques used in polar studies includes classic angular and linear surveys, photogrammetric techniques, gravimetric measurements, GNSS satellite techniques and satellite imaging. Those measurements were applied in glaciological, geological, geodynamic, botanical researches as well as in cartographic studies. Often they were used in activities aiming to ensure continuous functioning of Polish research stations on both hemispheres. This study is a short overview of thematic scope and selected research results conducted by our employees and students.

  3. Project for the Space Science in Moscow State University of Geodesy and Cartography (MIIGAiK)

    Science.gov (United States)

    Semenov, M.; Oberst, J.; Malinnikov, V.; Shingareva, K.; Grechishchev, A.; Karachevtseva, I.; Konopikhin, A.

    2012-04-01

    Introduction: Based on the proposal call of the Government of Russian Federation 40 of international scientists came to Russia for developing and support-ing research capabilities of national educational institutions. Moscow State University of Geodesy and Cartography (MIIGAiK) and invited scientist Prof. Dr. Jurgen Oberst were awarded a grant to establish a capable research facility concerned with Planetary Geodesy, Cartography and Space Exploration. Objectives: The goals of the project are to build laboratory infrastructure, and suitable capability for MIIGAiK to participate in the planning, execution and analyses of data from future Russian planetary mis-sions and also to integrate into the international science community. Other important tasks are to develop an attractive work place and job opportunities for planetary geodesy and cartography students. For this purposes new MIIGAiK Extraterrestrial Laboratory (MExLab) was organized. We involved professors, researchers, PhD students in to the projects of Moon and planets exploration at the new level of Russian Space Science development. Main results: MExLab team prepare data for upcom-ing Russian space missions, such as LUNA-GLOB and LUNA-RESOURSE. We established cooperation with Russian and international partners (IKI, ESA, DLR, and foreign Universities) and actively participated in international conferences and workshops. Future works: For the future science development we investigated the old Soviet Archives and received the access to the telemetry data of the Moon rovers Lunokhod-1 and Lunokhod-2. That data will be used in education purposes and could be the perfect base for the analysis, development and support in new Russian and international missions and especially Moon exploration projects. MExLab is open to cooperate and make the consortiums for science projects for the Moon and planets exploration. Acknowledgement: Works are funded by the Rus-sian Government (Project name: "Geodesy, cartography and the

  4. Reference-ellipsoid and the normal gravity field in post-Newtonian geodesy

    Science.gov (United States)

    Kopeikin, Sergei; Mazurova, Elena

    2016-07-01

    We apply general relativity to construct the post-Newtonian background manifold that serves as a reference spacetime in relativistic geodesy for conducting relativistic calculation of the geoid undulation and the deflection of the plumb line from the vertical. We chose an axisymmetric ellipsoidal body made up of a perfect homogeneous fluid uniformly rotating around a fixed axis, as a source generating the reference geometry. We reformulate and extend hydrodynamic calculations of rotating fluids done by previous researchers to the realm of relativistic geodesy to set up the algebraic equations defining the shape of the post-Newtonian reference ellipsoid. We explicitly perform all integrals characterizing gravitational field inside and outside the fluid body and represent them in terms of the elementary functions depending on its eccentricity. We fully explore the coordinate freedom of the equations describing the post-Newtonian ellipsoid and evaluate the deviation of the post-Newtonian level surface from the Newtonian (Maclaurin) ellipsoid. We also derive the post-Newtonian normal gravity field of the rotating fluid in terms of the parameters characterizing the post-Newtonian ellipsoid including relativistic mass, angular velocity and eccentricity. We formulate the post-Newtonian theorems of Pizzetti and Clairaut that are used in geodesy to connect the geometric parameters of the Earth figure to physically measurable force of gravity at its pole and equator.

  5. Monitoring Shallow Water Vertical Seafloor Displacement: a Challenge for Seafloor Geodesy

    Science.gov (United States)

    Iannaccone, G.; De Martino, P.; Chierici, F.; Pignagnoli, L.; Guardato, S.; Malservisi, R.; Beranzoli, L.; Donnarumma, G. P.

    2016-12-01

    Vertical displacement measurement in shallow seafloor poses a unique challenge for geodesy, as neither traditional land geodesy nor classical deep water marine geodesy provide valid techniques for accurate evaluations. Vertical displacement monitoring is of paramount importance in submarine volcanic areas, in marine oil extraction fields, in the study of coseismic ground movements in seismogenic areas. Sea bottom measurement of hydrostatic pressure variations could be the base to measure the vertical ground displacements. Although bottom Pressure Recorders (BPR) are affected by intrinsic limitations such as the signal drift, and shallow water are particularly affected by tides and other oceanographic effects, or rapid and sharp variations of physical properties of the sea water (e.g. temperature and salinity), BPR can be effective tools to evaluate sea bottom vertical deformation. We present unprecedented vertical displacement assessment of the marine sector of Campi Flegrei volcanic area (Southern Italy). These new results come from the integration of new GPS buoy, BPR and tide gauges measurements provided by the integrated monitoring system of Campi Flegrei. The multiparametric marine systems are operational since spring 2016 and consist of three geodetic buoys equipped with seafloor multisensor modules. The new data show on-going seafloor uplift of the submerged part of the Campi Flegrei caldera and provide new contributions to the regional deformation assessment. The methodology adopted for the data processing can significantly improve our ability to understand the volcanic process extending our monitoring capabilities offshore.

  6. UNAVCO: A Decade Supporting EarthScope - Three Decades of Supporting Geodesy for Science Innovation

    Science.gov (United States)

    Miller, M.

    2013-12-01

    UNAVCO supports research that establishes Earth's reference frame, enabling mapping of the planet's shape and mass; determines changes in the distribution of ice, water resources, and sea level; characterizes processes that contribute to natural and man-made hazards; and recognizes land-use changes (including subsidence, soil moisture, and health of wetlands). UNAVCO began as an investigator cooperative in 1984 - with the goal of sharing equipment and technologies that were expensive, rapidly changing, and extraordinarily powerful. Today as NSF's National Earth Science Geodetic Facility, on the eve of our 30th anniversary, we are excited to highlight a decade of support for major components of EarthScope, especially the Plate Boundary Observatory (PBO). Innovations by UNAVCO and the UNAVCO community have supported steady advancement towards millimeter-level global geodesy. Modern space geodesy provides new observational capability for contemporary deformation and magmatism in active convergent margin systems that operate over a spectrum of temporal and spatial scales, especially the PBO. Time scales vary from seconds to millennia, and spatial scales from borehole nanostrains to the global plate circuit. High-precision strain or 3-D point observations with borehole strainmeter or Global Positioning System (GPS) observations and geodetic imaging with SAR and LiDAR are used in combination to reveal these complex systems. GPS now combines with strong ground motion accelerometer time series to provide important enhancements to conventional seismology. The resulting 3-D fully georeferenced dynamic positioning time series are free of ambiguities associated with seismometer tilt and displacement. Geodesy constrains plate kinematics for convergence rate and direction, co-seismic deformation during great and moderate earthquakes, episodic tremor and slip events and related transient deformation, tectono-magmatic interactions, and the possible triggering effects of

  7. The Geodesy of the Outer Solar System Bodies from Precise Spacecraft Tracking

    Science.gov (United States)

    Iess, L.; Asmar, S.; Anabtawi, A.

    2014-12-01

    Gravity is at the same time the main force acting on spacecraft and an essential tool to investigate the interior structure of planetary bodies. The large infrastructure of NASA's Deep Space Network (DSN), developed to support telecommunications and navigation of deep space probes, became therefore also a crucial instrument in planetary geodesy and geophysics. This dual role of the DSN was especially important in the Cassini mission, where the precise navigation of the spacecraft throughout the many flybys of Titan and the icy satellites of the Saturnian system was unavoidably entangled with the determination of the gravity fields and the ephemerides of those bodies. Thanks to precise range rate measurements enabled by the DSN and the onboard radio system, Cassini has been able to determine the density and the moment of inertia of Titan, and the presence of large tidal deformations indicating the presence of a global, internal, ocean. Gravity-topography correlations have also been used to infer the thickness and the rigidity of the satellite's icy shell. Recently, Doppler data acquired during three Enceladus flybys revealed the presence of a gravity anomaly in the southern polar region that is compatible with a regional sea at a depth of about 40 km. This sea is the likely source of the Enceladus's water plumes. Although current planetary geodesy experiments exploited tracking systems at X band (7.1-8.5 GHz), much improved range rate measurements can be attained with Ka band radio links (32.5-34 GHz), because of their larger immunity to plasma noise. This advanced system, available at the DSS 25 tracking antenna in Goldstone (CA), has been already used in the Cassini cruise phase to carry out an accurate test of general relativity, and will be exploited again by Juno in 2016 to determine the gravity field of Jupiter. Additional uses of the DSN Ka band system have been proposed in several precise geodesy experiments with future planetary missions, both with orbiters

  8. Education of geodesy and cartography at the School of Higher Education In National Economy In Kutno, Poland.

    Science.gov (United States)

    Sledzinski, Janusz

    2013-04-01

    School of Higher (university degree) Education in National Economy in Kutno is one of the rather younger university schools in Poland that were established in the last years of the XX century. It was founded in 1998, but the convenient location of Kutno in Central Poland seems to be a good opportunity for students coming from all parts of Poland. The School is continuously developed, number of faculties and new study directions and specialisations are steadily growing. The offer of the School include studies in the stationary, extra-mural and post-graduate systems in two Engineering (or licenciate) and M.Sc. levels. At the moment the geodesy and cartography is a part of the Faculty of Technical Sciences; students can chose one of three specialisations: 1.Economic geodesy, property and estate management, 2. Rural (agriculture) geodesy and property engineering and 3. Geoinformatic sciences.

  9. NASA Space Geodesy Program: GSFC data analysis, 1993. VLBI geodetic results 1979 - 1992

    Science.gov (United States)

    Ma, Chopo; Ryan, James W.; Caprette, Douglas S.

    1994-01-01

    The Goddard VLBI group reports the results of analyzing Mark 3 data sets acquired from 110 fixed and mobile observing sites through the end of 1992 and available to the Space Geodesy Program. Two large solutions were used to obtain site positions, site velocities, baseline evolution for 474 baselines, earth rotation parameters, nutation offsets, and radio source positions. Site velocities are presented in both geocentric Cartesian and topocentric coordinates. Baseline evolution is plotted for the 89 baselines that were observed in 1992 and positions at 1988.0 are presented for all fixed stations and mobile sites. Positions are also presented for quasar radio sources used in the solutions.

  10. The Earth's gravity field from satellite geodesy: A 30 year adventure

    Science.gov (United States)

    Rapp, Richard H.

    1991-12-01

    The history of research in the Earth's gravity field from satellite geodesy is described and limitations of existing geopotential models are indicated. Although current solutions have made outstanding achievements, their limited accuracy restricts their use for some oceanographic applications. An example is discussed where there appears to be an incompatibility of the long wavelength geoid undulation obtained through satellite analysis with independent estimates that have become available. The future Aristoteles mission is seen as providing a significant leap in Earth gravity field knowledge improvement.

  11. Role of WEGENER (World Earthquake GEodesy Network for Environmental Hazard Research) in monitoring natural hazards (Invited)

    Science.gov (United States)

    Ozener, H.; Zerbini, S.; Bastos, M. L.; Becker, M. H.; Meghraoui, M.; Reilinger, R. E.

    2013-12-01

    WEGENER was originally the acronym for Working Group of European Geoscientists for the Establishment of Networks for Earth-science Research. It was founded in March 1981 in response to an appeal delivered at the Journées Luxembourgeoises de Geodynamique in December 1980 to respond with a coordinated European proposal to a NASA Announcement of Opportunity inviting participation in the Crustal Dynamics and Earthquake Research Program. WEGENER, during the past 33 years, has always kept a close contact with the Agencies and Institutions responsible for the development and maintenance of the global space geodetic networks with the aim to make them aware of the scientific needs and outcomes of the project which might have an influence on the general science policy trends. WEGENER served as Inter-commission Project 3.2, between Commission 1 and Commission 3, of the International Association of Geodesy (IAG) until 2012. Since then, WEGENER project has become the Sub-commission 3.5 of IAG commission 3, namely Tectonics and Earthquake Geodesy. In this presentation, we briefly review the accomplishments of WEGENER as originally conceived and outline and justify the new focus of the WEGENER consortium. The remarkable and rapid evolution of the present state of global geodetic monitoring in regard to the precision of positioning capabilities (and hence deformation) and global coverage, the development of InSAR for monitoring strain with unprecedented spatial resolution, and continuing and planned data from highly precise satellite gravity and altimetry missions, encourage us to shift principal attention from mainly monitoring capabilities by a combination of space and terrestrial geodetic techniques to applying existing observational methodologies to the critical geophysical phenomena that threaten our planet and society. Our new focus includes developing an improved physical basis to mitigate earthquake, tsunami, and volcanic risks, and the effects of natural and

  12. Multi-disciplinary contributions of HartRAO to global geodesy and geodynamics

    Science.gov (United States)

    Combrinck, Ludwig

    2015-04-01

    The Hartebeesthoek Radio Astronomy Observatory (South Africa) supports global initiatives in both geodesy and geodynamics through an active programme of science platform provision in Africa, the Atlantic Ocean, Indian Ocean and Antarctica. Our involvement ranges from the installation of tide gauges, Global Navigation Satellite Systems stations, seismometers and accelerometers on remote islands to the installation of radar reflectors in Antarctica which enable accurate, geo-referenced maps of the Antarctic coast line to be made. Currently we also participate in the African VLBI Network (AVN), with the aim to densify not only astronomical observatories in Africa, but to improve the geometry and distribution of advanced geodetic and geophysical equipment to facilitate development of research platforms in Africa, which can be used for geodynamics and related sciences, supporting international projects such as the WEGENER initiative. We present our multi-disciplinary activities during the last decade and sketch the way forward. Participation of Africa in the global arena of astronomy, geodesy, geodynamics and related fields will receive a major boost during the next decade. This is partially due to the development of a component of the Square Kilometre Array (SKA) in Africa but also due to the Global Geodetic Observing System (GGOS) project and the international objectives of higher geodetic accuracies and more stable reference frames. Consequent spinoffs into many disciplines relying on global reference frames and sub-cm positional accuracies stand to benefit and Africa can play a major role in improving both science and network geometries.

  13. ROMY - The First Large 3D Ring Laser Structure for Seismology and Geodesy

    Science.gov (United States)

    Schreiber, Karl Ulrich; Igel, Heiner; Wassermann, Joachim; Lin, Chin-Jen; Gebauer, André; Wells, Jon-Paul

    2016-04-01

    Large ring laser gyroscopes have matured to the point that they can routinely observe rotational motions from geophysical processes that can be used in geodesy and seismology. The ring lasers used for this purpose enclose areas between 16 and 800 square meters and have in common that they can only measure rotations around the vertical axis because the structures are horizontally placed on the floor. With the ROMY project we have embarked on the construction of a full 3-dimensional rotation sensor. The actual apparatus consists of four individual triangular ring lasers arranged in the shape of a tetrahedron with 12 m of length on each side. At each corner of the tetrahedron three of the ring lasers are rigidly tied together to the same mechanical reference. The overall size of the installation provides a promising compromise between sensor stability on one side and sensor resolution on the other side. This talk introduces the technical concept of the ROMY ring laser installation and will also briefly outline the requirements for applications in space geodesy.

  14. Theoretical Tools for Relativistic Gravimetry, Gradiometry and Chronometric Geodesy and Application to a Parameterized Post-Newtonian Metric

    Directory of Open Access Journals (Sweden)

    Pacôme Delva

    2017-03-01

    Full Text Available An extensive review of past work on relativistic gravimetry, gradiometry and chronometric geodesy is given. Then, general theoretical tools are presented and applied for the case of a stationary parameterized post-Newtonian metric. The special case of a stationary clock on the surface of the Earth is studied.

  15. Contribution of GNSS CORS Infrastructure to the Mission of Modern Geodesy and Status of GNSS CORS in Thailand

    Directory of Open Access Journals (Sweden)

    Chalermchon Satirapod

    2011-01-01

    Full Text Available Geodesy is the science of measuring and mapping the geometry, orientation and gravity field of the Earth including the associated variations with time. Geodesy has also provided the foundation for high accuracy surveying and mapping. Modern Geodesy involves a range of space and terrestrial technologies that contribute to our knowledge of the solid earth, atmosphere and oceans. These technologies include: Global Positioning System/Global Navigation Satellite Systems (GPS/GNSS, Satellite Laser Ranging (SLR, Very Long Baseline Interferometry (VLBI, Satellite Altimetry, Gravity Mapping Missions such as GRACE, CHAMP and GOCE, satelliteborne Differential Interferometric Synthetic Aperture Radar (DInSAR, Absolute and Relative Gravimetry, and Precise Terrestrial Surveying (Levelling and Traversing. A variety of services have been established in recent years to ensure high accuracy and reliable geodetic products to support geoscientific research. The reference frame defined by Modern Geodesy is now the basis for most national and regional datums. Furthermore, the GPS/GNSS technology is a crucial geopositioning tool for both Geodesy and Surveying. There is therefore a blurring of the distinction between geodetic and surveying GPS/GNSS techniques, and increasingly the ground infrastructure of continuously operating reference stations (CORS receivers attempts to address the needs of both geodesists and other positioning professionals. Yet Geodesy is also striving to increase the level of accuracy by a factor of ten over the next decade in order to address the demands of “global change” studies. The Global Geodetic Observing System (GGOS is an important component of the International Association of Geodesy. GGOS aims to integrate all geodetic observations in order to generate a consistent high quality set of geodetic parameters for monitoring the phenomena and processes within the “System Earth”. Integration implies the inclusion of all relevant

  16. Probabilistic and deterministic aspects of linear estimation in geodesy. Ph.D. Thesis

    Science.gov (United States)

    Dermanis, A.

    1976-01-01

    Recent advances in observational techniques related to geodetic work (VLBI, laser ranging) make it imperative that more consideration should be given to modeling problems. Uncertainties in the effect of atmospheric refraction, polar motion and precession-nutation parameters, cannot be dispensed with in the context of centimeter level geodesy. Even physical processes that have generally been previously altogether neglected (station motions) must now be taken into consideration. The problem of modeling functions of time or space, or at least their values at observation points (epochs) is explored. When the nature of the function to be modeled is unknown. The need to include a limited number of terms and to a priori decide upon a specific form may result in a representation which fails to sufficiently approximate the unknown function. An alternative approach of increasing application is the modeling of unknown functions as stochastic processes.

  17. Application of the Allan Variance to Time Series Analysis in Astrometry and Geodesy: A Review

    CERN Document Server

    Malkin, Zinovy

    2016-01-01

    The Allan variance (AVAR) was introduced 50 years ago as a statistical tool for assessing of the frequency standards deviations. For the past decades, AVAR has increasingly being used in geodesy and astrometry to assess the noise characteristics in geodetic and astrometric time series. A specific feature of astrometric and geodetic measurements, as compared with the clock measurements, is that they are generally associated with uncertainties; thus, an appropriate weighting should be applied during data analysis. Besides, some physically connected scalar time series naturally form series of multi-dimensional vectors. For example, three station coordinates time series $X$, $Y$, and $Z$ can be combined to analyze 3D station position variations. The classical AVAR is not intended for processing unevenly weighted and/or multi-dimensional data. Therefore, AVAR modifications, namely weighted AVAR (WAVAR), multi-dimensional AVAR (MAVAR), and weighted multi-dimensional AVAR (WMAVAR), were introduced to overcome these ...

  18. PENENTUAN BATAS WILAYAH LAUT PROVINSI JAWA TENGAH DAN JAWA BARAT MENGGUNAKAN DATUM GEODESI NASIONAL

    Directory of Open Access Journals (Sweden)

    Sutomo Kahar

    2012-08-01

    Full Text Available According to Minister of Internal Affair regulation which is Permendagri No.1 Tahun 2006, Peta LingkunganLaut Indonesia (LLN must be utilized to define boundaries of province sea jurisdiction. Unfortunately, PetaLingkunan Laut Indonesia still applies Indonesia Datum 1974 instead of Datum Geodesi Nasional 1995. It iscontrary with Permendagri No 76 Tahun 2012 and UU No.4 Tahun 2011 which declare the urgency of singlereference datum for Indonesia region. To fit the requirement, Peta Lingkungan Laut Indonesia must betransformed into official datum. This research applied two transformation formulae. There was LaufTransformations to accomodate 2 Dimension Transformation. Computation of transformation parameters andapplication of those parameters were tested at North Coast of Java from Kendal regency to Brebes regency. Ascalculated in MatLab software, this research concluded that Lauf transformation was good for transformingLingkungan Laut Indonesia from ID74 to DGN95.

  19. Ten-year progress of Chinese polar geodesy:1996-2006

    Institute of Scientific and Technical Information of China (English)

    Oongchen E; Shengkai ZHANG; Chunxia ZHOU

    2008-01-01

    The ten-year progress of Chinese polar geodesy from 1996 to 2006 is summarized.Research on plate motion,crustal movement,orbit determination,and atmospheric monitoring,including the ionosphere and troposphere,were performed using GPS data of the Great Wall Station,Zhongshan Station and Yellow River Station.GPS was also applied in the Amery Ice Shelf,Grove Mountains and Dome A expeditions to study ice dynamics.During the 2004/2005 austral summer season,the absolute gravity and relative gravity were measured at the Great Wall Station with precision within + 3 × 10-8 ms-2 and + 10×10-8 ms-2 respectively.The tide gauge,which was set up in Zhongshan Station to monitor sea level change in 2000,recorded the 2004 Indian Ocean tsunami.SAR interferometry was applied to build the DEM of ice sheet and monitor ice flow in the polar region.

  20. Proceedings of the Sixth General Meeting of the International VLBI Service for Geodesy and Astrometry

    Science.gov (United States)

    Behrend, Dirk (Editor); Baver, Karen D. (Editor)

    2010-01-01

    This volume is the proceedings of the sixth General Meeting of the International VLBI Service for Geodesy and Astrometry (IVS), held in Hobart, Tasmania, Australia, February 7-13, 2010. The contents of this volume also appear on the IVS Web site at http://ivscc.gsfc.nasa.gov/publications/gm2010. The keynote of the sixth GM was the new perspectives of the next generation VLBI system under the theme "VLBI2010: From Vision to Reality". The goal of the meeting was to provide an interesting and informative program for a wide cross-section of IVS members, including station operators, program managers, and analysts. This volume contains 88 papers. All papers were edited by the editors for usage of the English language, form, and minor content-related issues.

  1. Round-Trip System Available to Measure Path Length Variation in Korea VLBI System for Geodesy

    Science.gov (United States)

    Oh, Hongjong; Kondo, Tetsuro; Lee, Jinoo; Kim, Tuhwan; Kim, Myungho; Kim, Suchul; Park, Jinsik; Ju, Hyunhee

    2010-01-01

    The construction project of Korea Geodetic VLBI officially started in October 2008. The construction of all systems will be completed by the end of 2011. The project was named Korea VLBI system for Geodesy (KVG), and its main purpose is to maintain the Korea Geodetic Datum. In case of the KVG system, an observation room with an H-maser frequency standard is located in a building separated from the antenna by several tens of meters. Therefore KVG system will adopt a so-called round-trip system to transmit reference signals to the antenna with reduction of the effect of path length variations. KVG s round-trip system is designed not only to use either metal or optical fiber cables, but also to measure path length variations directly. We present this unique round trip system for KVG.

  2. The Crustal Dynamics Data Information System: A Resource to Support Scientific Analysis Using Space Geodesy

    Science.gov (United States)

    Noll. Carey E.

    2010-01-01

    Since 1982. the Crustal Dynamics Data Information System (CDDIS) has supported the archive and distribution of geodetic data products acquired by the National Aeronautics and Space Administration (NASA) as well as national and international programs. The CDDIS provides easy, timely, and reliable access to a variety of data sets, products, and information about these data. These measurements. obtained from a global network of nearly 650 instruments at more than 400 distinct sites, include DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), GNSS (Global Navigation Satellite System), SLR and LLR (Satellite and Lunar Laser Ranging), and VLBI (Very Long Baseline Interferometry). The CDDIS data system and its archive have become increasingly important to many national and international science communities, particularly several of the operational services within the International Association of Geodesy (IAG) and its observing system the Global Geodetic Observing System (GGOS), including the International DORIS Service (IDS), the International GNSS Service (IGS). the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS). and the International Earth rotation and Reference frame Service (IERS), Investigations resulting from the data and products available through the CDDIS support research in many aspects of Earth system science and global change. Each month, the CDDIS archives more than one million data and derived product files totaling over 90 Gbytes in volume. In turn. the global user community downloads nearly 1.2 TBytes (over 10.5 million files) of data and products from the CDDIS each month. The requirements of analysts have evolved since the start of the CDDIS; the specialized nature of the system accommodates the enhancements required to support diverse data sets and user needs. This paper discusses the CDDIS. including background information about the system and its. user communities

  3. The crustal dynamics data information system: A resource to support scientific analysis using space geodesy

    Science.gov (United States)

    Noll, Carey E.

    2010-06-01

    Since 1982, the Crustal Dynamics Data Information System (CDDIS) has supported the archive and distribution of geodetic data products acquired by the National Aeronautics and Space Administration (NASA) as well as national and international programs. The CDDIS provides easy, timely, and reliable access to a variety of data sets, products, and information about these data. These measurements, obtained from a global network of nearly 650 instruments at more than 400 distinct sites, include DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite), GNSS (Global Navigation Satellite System), SLR and LLR (Satellite and Lunar Laser Ranging), and VLBI (Very Long Baseline Interferometry). The CDDIS data system and its archive have become increasingly important to many national and international science communities, particularly several of the operational services within the International Association of Geodesy (IAG) and its observing system the Global Geodetic Observing System (GGOS), including the International DORIS Service (IDS), the International GNSS Service (IGS), the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), and the International Earth rotation and Reference frame Service (IERS). Investigations resulting from the data and products available through the CDDIS support research in many aspects of Earth system science and global change. Each month, the CDDIS archives more than one million data and derived product files totaling over 90 Gbytes in volume. In turn, the global user community downloads nearly 1.2 Tbytes (over 10.5 million files) of data and products from the CDDIS each month. The requirements of analysts have evolved since the start of the CDDIS; the specialized nature of the system accommodates the enhancements required to support diverse data sets and user needs. This paper discusses the CDDIS, including background information about the system and its user communities

  4. Reforma studija geodezije na Odsjeku za geodeziju Građevinskog fakulteta Univerziteta u Sarajevu : Reform of the study of geodesy at the Department of geodesy of Faculty of Civil Engineering, University of Sarajevo

    Directory of Open Access Journals (Sweden)

    Džanina Omićević

    2011-12-01

    Full Text Available U ovom radu prikazane su aktivnosti i ciljevi vezani uz implementaciju Bolonjskog procesa na Odsjeku za geodeziju Građevinskog fakulteta Univerziteta u Sarajevu. Prvi puta su predstavljeni novi programi studija geodezije organizovana u tri ciklusa: dodiplomski, diplomski i doktorski studij. Cilj je da sažeto iznesemo osnovne informacije o reformskom procesu, koji je u toku, a koji bi trebalo da dugoročno promijeni evropski visokoškolski sistem. : This paper presents activities and goals related with the implementation of the Bologna process at the Department of Geodesy of Civil Engineering, University of Sarajevo. For the first time, new curricula study of geodesy which are organized into three cycles: bachelor, master and postgraduete doctoral study are presented. The goal of this paper is to present basic informacion about ongoing reform proces, and that should change the long-term European university system.

  5. Astronomy, Geodesy and Map-Drawing in Moldova Since the Middle Ages Till the World War I

    Science.gov (United States)

    Gaina, A.

    A short outline of the history of astronomy, astronomical navigation, geodesy and map-drawing in Moldova since the Middle Ages till the World War I is presented. The contribution of Rudjer Bošković to the determination of geographical coordinates of Galati and Iasi and the triangulation of Montenegro in 1879-1880 by Russian military geodesists has been discussed as well.

  6. Geodetic Imaging: Expanding the Boundaries of Geodesy in the 21st Century

    Science.gov (United States)

    Fernandez Diaz, J. C.; Carter, W. E.; Shrestha, R. L.; Glennie, C. L.

    2013-12-01

    High resolution (sub-meter) geodetic images covering tens to thousands of square kilometers have extended the boundaries of geodesy into related areas of the earth sciences, such as geomorphology and geodynamics, during the past decade, to archaeological exploration and site mapping during the past few years, and are now poised to transform studies of flora and fauna in the more remote regions of the world. Geodetic images produced from airborne laser scanning (ALS), a.k.a. airborne light detection and ranging (LiDAR) have proven transformative to the modern practice of geomorphology where researchers have used decimeter resolution digital elevation models (DEMs) to determine the spatial frequencies of evenly spaced features in terrain, and developed models and mathematical equations to explain how the terrain evolved to its present state and how it is expected to change in the future (Perron et al., 2009). In geodynamics researchers have used ';before' and ';after' geodetic images of the terrain near earthquakes, such as the 2010 El Mayor-Cucapah Earthquake, to quantify surface displacements and suggest models to explain the observed deformations (Oskin et. al., 2012). In archaeology, the ability of ALS to produce ';bare earth' DEMs of terrain covered with dense vegetation, including even tropical rain forests, has revolutionized the study of archaeology in highly forested areas, finding ancient structures and human modifications of landscapes not discovered by archaeologists working at sites for decades (Chase et al., 2011 & Evans et al., 2013), and finding previously unknown ruins in areas that ground exploration has not been able to penetrate since the arrival of the conquistadors in the new world in the 17th century (Carter et al., 2012). The improved spatial resolution and ability of the third generation ALS units to obtain high resolution bare earth DEMs and canopy models in areas covered in dense forests, brush, and even shallow water (steams, lakes, and

  7. Engaging students in geodesy: A quantitative InSAR module for undergraduate tectonics and geophysics classes

    Science.gov (United States)

    Taylor, H.; Charlevoix, D. J.; Pritchard, M. E.; Lohman, R. B.

    2013-12-01

    In the last several decades, advances in geodetic technology have allowed us to significantly expand our knowledge of processes acting on and beneath the Earth's surface. Many of these advances have come as a result of EarthScope, a community of scientists conducting multidisciplinary Earth science research utilizing freely accessible data from a variety of instruments. The geodetic component of EarthScope includes the acquisition of synthetic aperture radar (SAR) images, which are archived at the UNAVCO facility. Interferometric SAR complements the spatial and temporal coverage of GPS and allows monitoring of ground deformation in remote areas worldwide. However, because of the complex software required for processing, InSAR data are not readily accessible to most students. Even with these challenges, exposure at the undergraduate level is important for showing how geodesy can be applied in various areas of the geosciences and for promoting geodesy as a future career path. Here we present a module focused on exploring the tectonics of the western United States using InSAR data for use in undergraduate tectonics and geophysics classes. The module has two major objectives: address topics concerning tectonics in the western U.S. including Basin and Range extension, Yellowstone hotspot activity, and creep in southern California, and familiarize students with how imperfect real-world data can be manipulated and interpreted. Module questions promote critical thinking skills and data literacy by prompting students to use the information given to confront and question assumptions (e.g. 'Is there a consistency between seismic rates and permanent earthquake deformation? What other factors might need to be considered besides seismicity?'). The module consists of an introduction to the basics of InSAR and three student exercises, each focused on one of the topics listed above. Students analyze pre-processed InSAR data using MATLAB, or an Excel equivalent, and draw on GPS and

  8. Basic Radar Altimetry Toolbox: Tools to Use Radar Altimetry for Geodesy

    Science.gov (United States)

    Rosmorduc, V.; Benveniste, J. J.; Bronner, E.; Niejmeier, S.

    2010-12-01

    Radar altimetry is very much a technique expanding its applications and uses. If quite a lot of efforts have been made for oceanography users (including easy-to-use data), the use of those data for geodesy, especially combined witht ESA GOCE mission data is still somehow hard. ESA and CNES thus had the Basic Radar Altimetry Toolbox developed (as well as, on ESA side, the GOCE User Toolbox, both being linked). The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data. The software is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason-1, Envisat, Jason- 2, CryoSat and the future Saral missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data and additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. It is an opportunity to teach remote sensing with practical training. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. About 1200 people downloaded it (Summer 2010), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been

  9. Theoretical and Applied Research in the Field of Higher Geodesy Conducted in Rzeszow

    Science.gov (United States)

    Kadaj, Roman; Świętoń, Tomasz

    2016-06-01

    Important qualitative changes were taking place in polish geodesy in last few years. It was related to application of new techniques and technologies and to introduction of European reference frames in Poland. New reference stations network ASG-EUPOS, together with Internet services which helps in precise positioning was created. It allows to fast setting up precise hybrid networks. New, accurate satellite networks became the basis of new definitions in the field of reference systems. Simultaneously arise the need of new software, which enables to execute the geodetic works in new technical conditions. Authors had an opportunity to participate in mentioned undertakings, also under the aegis of GUGiK, by creation of methods, algorithms and necessary software tools. In this way the automatic postprocessing module (APPS) in POZGEO service, a part of ASG-EUPOS system came into being. It is an entirely polish product which works in Trimble environment. Universal software for transformation between PLETRF89, PL-ETRF2000, PULKOWO'42 reference systems as well as defined coordinate systems was created (TRANSPOL v. 2.06) and published as open product. An essential functional element of the program is the quasi-geoid model PL-geoid-2011, which has been elaborated by adjustment (calibration) of the global quasi-geoid model EGM2008 to 570 geodetic points (satellite-leveling points). Those and other studies are briefly described in this paper.

  10. Mercury's interior structure constrained by geodesy and present-day thermal state

    Science.gov (United States)

    Rivoldini, Attilio; Van Hoolst, Tim; Beuthe, Mikael; Deproost, Marie-Hélène

    2016-10-01

    Recent measurements of Mercury's spin state and gravitational field strongly constrain Mercury's core radius and core density, but provide little information on the size of its inner core. Both a fully molten liquid core and a core differentiated into a large solid inner core and a liquid outer part are consistent with the observations, although the observed tides seem to exclude an extremely large inner core. The observed global magnetic field could be generated even without a growing inner core, since remelting of iron snow inside the core might produce a sufficiently large buoyancy flux to drive magnetic field generation by compositional convection.Further constraints on Mercury's internal structure can be obtained by studying its thermal state. The inner core radius depends mainly on the thermal state and on the light elements present in the core. Secular cooling and subsequent formation of an inner core lead to the global contraction of the planet, estimated to be about 7 km.In this study we combine geodesy data (88 day libration amplitude, polar moment of inertia, and tidal Love number) with the recent estimate of the radial contraction of Mercury and thermal evolution calculations in order to constrain its interior structure and in particular its inner core. We consider bulk compositions that are in agreement with the reducing formation conditions suggested by remote sensing data of Mercury's surface.

  11. Deformations between African and Euroasian plates estimated by methods of space geodesy - new result

    Science.gov (United States)

    Zeman, A.; Holesovsky, J.; Novotny, Z.; Hassan, K. A.; Abd El Monem, M. S.; Kostelecky, J.

    2009-12-01

    The contribution concerns with analysis of detailed information from the results of space geodesy (GPS) in the region of Mediterranean sea enclosing the results of till now not processed and published observations in quasipermanent network of the sites in Egypt. (It was made possible by agreement between the National Research Institute of Astronomy and Geophysics in Egypt and the Research Center of Earth Dynamics in Czech Republic). A main topic in WEGENER's project activities is observation of geodynamic processes of the European-Mediterranean region, northern Africa and Asia Minor, by (space) geodetic techniques. The geodynamic setting of the region is formed by the convergence of the three major lithosphere plates (Eurasia, Africa and Arabia). In the plate boundary zones a variety of subduction and collision processes are active. The cotribution contains actual results of processing of the observations in Egypt together with selected sites of permanent EPN network in region of eastern part of Mediterranean sea. Results of analyses confirm model presumption of mutual activities between African, Arabic and Euroasian plates.

  12. Potential contributions to space geodesy from the IridiumNEXT constellation

    Science.gov (United States)

    Gunter, B. C.; Encarnação, J.; Ditmar, P.; Klees, R.

    2012-12-01

    The IridiumNEXT constellation will soon replace the existing Iridium satellite telecommunication network, with initial launches set to start in 2015. In addition to the primary task of providing global telecommunication services, each IridiumNEXT satellite will also carry a hosted payload that will provide both private and public institutions the opportunity to place an instrument suite on one or all of constellation's satellites. This creates the possibility to gather continuous, global observations of Earth over the entire 15 year projected mission lifetime. Access to such a platform creates the potential to investigate many of Earth's highly dynamic processes at a spatiotemporal resolution that is simply not possible from single-satellite missions. Space geodesy is one the numerous fields that would benefit from such a mission. Precise orbits of the IridiumNEXT satellites derived through an on-board GNSS receiver (plus accelerometers and star cameras) have the potential to observe the large-scale, high-frequency variations in Earth's gravity field at time scales as short as one day. Additional positioning data from ground-based laser ranging stations would help improve the orbit determination, in addition to providing the necessary link to improve estimates of geocenter motion and reference frames. In this presentation, we will analyze the expected geodetic science returns from such a mission and will discuss the instrumental requirements needed to achieve these objectives.

  13. Theoretical and Applied Research in the Field of Higher Geodesy Conducted in Rzeszow

    Directory of Open Access Journals (Sweden)

    Kadaj Roman

    2016-06-01

    Full Text Available Important qualitative changes were taking place in polish geodesy in last few years. It was related to application of new techniques and technologies and to introduction of European reference frames in Poland. New reference stations network ASG-EUPOS, together with Internet services which helps in precise positioning was created. It allows to fast setting up precise hybrid networks. New, accurate satellite networks became the basis of new definitions in the field of reference systems. Simultaneously arise the need of new software, which enables to execute the geodetic works in new technical conditions. Authors had an opportunity to participate in mentioned undertakings, also under the aegis of GUGiK, by creation of methods, algorithms and necessary software tools. In this way the automatic postprocessing module (APPS in POZGEO service, a part of ASG-EUPOS system came into being. It is an entirely polish product which works in Trimble environment. Universal software for transformation between PLETRF89, PL-ETRF2000, PULKOWO’42 reference systems as well as defined coordinate systems was created (TRANSPOL v. 2.06 and published as open product. An essential functional element of the program is the quasi-geoid model PL-geoid-2011, which has been elaborated by adjustment (calibration of the global quasi-geoid model EGM2008 to 570 geodetic points (satellite-leveling points. Those and other studies are briefly described in this paper.

  14. Geodesy and cartography methods of exploration of the outer planetary systems: Galilean satellites and Enceladus

    Science.gov (United States)

    Zubarev, Anatoliy; Kozlova, Natalia; Kokhanov, Alexander; Oberst, Jürgen; Nadezhdina, Irina; Patraty, Vyacheslav; Karachevtseva, Irina

    Introduction. While Galilean satellites have been observed by different spacecrafts, including Pioneer, Voyager-1 and -2, Galileo, New Horizons, and Enceladus by Cassini and Voyager-2, only data from Galileo, Cassini and the two Voyagers are useful for precise mapping [1, 2]. For purposes of future missions to the system of outer planets we have re-computed the control point network of the Io, Ganymede and Enceladus to support spacecraft navigation and coordinate knowledge. Based on the control networks, we have produced global image mosaics and maps. Geodesy approach. For future mission Laplace-P we mainly focused on Ganymede which coverage is nearly complete except for polar areas (which includes multispectral data). However, large differences exist in data resolutions (minimum global resolution: 30 km/pixel). Only few areas enjoy coverage by highest resolution images, so we suggest to obtain regional Digital Elevation Models (DEMs) from stereo images for selected areas. Also using our special software, we provide calculation of illumination conditions of Ganymede surface in various representations [3]. Finally, we propose a careful evaluation of all available data from the previous Voyager and Galileo missions to re-determine geodetic control and rotation model for other Galilean satellites - Callisto and Europe. Mapping. Based on re-calculated control point networks and global mosaics we have prepared new maps for Io, Ganymede and Enceladus [4]. Due to the difference in resolution between the images, which were also taken from different angles relative to the surface, we can prepare only regional high resolution shape models, so for demonstrating of topography and mapping of the satellites we used orthographic projection with different parameters. Our maps, which include roughness calculations based on our GIS technologies [5], will also be an important tool for studies of surface morphology. Conclusions. Updated data collection, including new calculation of

  15. Super-large optical gyroscopes for applications in geodesy and seismology: state-of-the-art and development prospects

    Energy Technology Data Exchange (ETDEWEB)

    Velikoseltsev, A A; Luk' yanov, D P [St. Petersburg Electrotechnical University ' ' LETI' ' , St. Petersburg (Russian Federation); Vinogradov, V I [OJSC Tambov factory Elektropribor (Russian Federation); Shreiber, K U [Forschungseinrichtung Satellitengeodaesie, Technosche Universitaet Muenchen, Geodaetisches Observatorium Wettzell, Sackenrieder str. 25, 93444 Bad Koetzting (Germany)

    2014-12-31

    A brief survey of the history of the invention and development of super-large laser gyroscopes (SLLGs) is presented. The basic results achieved using SLLGs in geodesy, seismology, fundamental physics and other fields are summarised. The concept of SLLG design, specific features of construction and implementation are considered, as well as the prospects of applying the present-day optical technologies to laser gyroscope engineering. The possibilities of using fibre-optical gyroscopes in seismologic studies are analysed and the results of preliminary experimental studies are presented. (laser gyroscopes)

  16. Gravity field recovery in the framework of a Geodesy and Time Reference in Space (GETRIS)

    Science.gov (United States)

    Hauk, Markus; Schlicht, Anja; Pail, Roland; Murböck, Michael

    2017-04-01

    The study ;Geodesy and Time Reference in Space; (GETRIS), funded by European Space Agency (ESA), evaluates the potential and opportunities coming along with a global space-borne infrastructure for data transfer, clock synchronization and ranging. Gravity field recovery could be one of the first beneficiary applications of such an infrastructure. This paper analyzes and evaluates the two-way high-low satellite-to-satellite-tracking as a novel method and as a long-term perspective for the determination of the Earth's gravitational field, using it as a synergy of one-way high-low combined with low-low satellite-to-satellite-tracking, in order to generate adequate de-aliasing products. First planned as a constellation of geostationary satellites, it turned out, that an integration of European Union Global Navigation Satellite System (Galileo) satellites (equipped with inter-Galileo links) into a Geostationary Earth Orbit (GEO) constellation would extend the capability of such a mission constellation remarkably. We report about simulations of different Galileo and Low Earth Orbiter (LEO) satellite constellations, computed using time variable geophysical background models, to determine temporal changes in the Earth's gravitational field. Our work aims at an error analysis of this new satellite/instrument scenario by investigating the impact of different error sources. Compared to a low-low satellite-to-satellite-tracking mission, results show reduced temporal aliasing errors due to a more isotropic error behavior caused by an improved observation geometry, predominantly in near-radial direction within the inter-satellite-links, as well as the potential of an improved gravity recovery with higher spatial and temporal resolution. The major error contributors of temporal gravity retrieval are aliasing errors due to undersampling of high frequency signals (mainly atmosphere, ocean and ocean tides). In this context, we investigate adequate methods to reduce these errors. We

  17. Spreading the usage of NAPEOS, the ESA tool for satellite geodesy.

    Science.gov (United States)

    Springer, T. A.; Otten, M.; Flohrer, C.

    2012-04-01

    Over the recent years the Navigation Package for Earth Orbiting Satellites, NAPEOS, has evolved to a great tool for satellite geodesy. It is developed and maintained at the European Space Operations Centre (ESOC) of the European Space Agency (ESA) NAPEOS is capable of processing data from all GNSS systems, all DORIS, and all SLR observations. And, NAPEOS is used for generating state of the art products for all three satellite-geodetic techniques and there corresponding services: IGS, IDS, and ILRS. ESA owned software is in general available free of charge to any entity in the ESA member states as the developments have been paid by public funding. Thus NAPEOS is, in principle, available free of charge but under a strict license agreement with ESA. However, ESA does not provide any support on how to use the software. And like most research oriented packages learning such software from scratch is at the very least an "adventure". In 2009 we therefore started a company, called PosiTim, with the prime focus on delivering services and support for the NAPEOS software package. PosiTim currently offers the following services and support for NAPEOS: • Distribution of the NAPEOS software through a sub-license agreement with ESA. • Detailed step by step installation guide. The installation procedure includes the execution of some data processing to test and validate the installation. • Detailed user manual describing and discussing a few key processing examples. • Software installation support including compiler/platform dependent bug-fixing. • Software development collaboration. PosiTim provides access to its version controlled software repository, which allows for sharing the latest software developments. • Annual (target bi-annual) NAPEOS training course. • Technical support, e.g., answer questions by e-mail. • Collaboration with universities to "tailor" NAPEOS to their (research) needs. In our presentation we will start with a brief overview of the NAPEOS

  18. Inter-satellite links: A versatile tool for geodesy and planetary and interplanetary navigation

    Science.gov (United States)

    Schlicht, Anja; Hugentobler, Urs; Hauk, Markus; Murböck, Michael; Pail, Roland

    2016-07-01

    ) synchronized from ground. We now want to get a step further and design a versatile concept for the use of this synergy in a satellite constellation based on existing and future planned ESA infrastructure and highlight the benefits in different disciplines from geodesy to interplanetary ranging, with emphasis on gravity field recovery.

  19. Analytical solution of perturbed relative motion: an application of satellite formations to geodesy

    Science.gov (United States)

    Wnuk, Edwin

    In the upcoming years, several space missions will be operated using a number of spacecraft flying in formation. Clusters of spacecraft with a carefully designed orbits and optimal formation geometry enable a wide variety of applications ranging from remote sensing to astronomy, geodesy and basic physics. Many of the applications require precise relative navigation and autonomous orbit control of satellites moving in a formation. For many missions a centimeter level of orbit control accuracy is required. The GRACE mission, since its launch in 2002, has been improving the Earth's gravity field model to a very high level of accuracy. This mission is a formation flying one consisting of two satellites moving in coplanar orbits and provides range and range-rate measurements between the satellites in the along-track direction. Future geodetic missions probably will employ alternative architectures using additional satellites and/or performing out-of-plane motion, e.g cartwheel orbits. The paper presents an analytical model of a satellite formation motion that enables propagation of the relative spacecraft motion. The model is based on the analytical theory of satellite relative motion that was presented in the previous our papers (Wnuk and Golebiewska, 2005, 2006). This theory takes into account the influence of the following gravitational perturbation effects: 1) zonal and tesseral harmonic geopotential coefficients up to arbitrary degree and order, 2) Lunar gravity, 3) Sun gravity. Formulas for differential perturbations were derived with any restriction concerning a plane of satellite orbits. They can be applied in both: in plane and out of plane cases. Using this propagator we calculated relative orbits and future relative satellite positions for different types of formations: in plane, out of plane, cartwheel and others. We analyzed the influence of particular parts of perturbation effects and estimated the accuracy of predicted relative spacecrafts positions

  20. The Phobos Atlas and Geo-portal: geodesy and cartography approach for planetary exploration

    Science.gov (United States)

    Karachevtseva, Irina; Kozlova, Natalia; Kokhanov, Alexander; Oberst, Jürgen; Zubarev, Anatoliy; Nadezhdina, Irina; Patraty, Vyacheslav; Konopikhin, Anatoliy; Garov, Andrey

    New Phobos mapping. Methods of image processing and modern GIS technologies provide the opportunity for high quality planetary mapping. The new Phobos DTM and global orthomosaic have been used for developing a geodatabase (Karachevtseva et al., 2012) which provides data for various surface spatial analyses: statistics of crater density, as well as studies of gravity field, geomorphology, and photometry. As mapping is the best way to visualize results of research based on spatial context we created the Phobos atlas. The new Phobos atlas includes: control points network which were calculated during photogrammetry processing of SRC images (Zubarev et al., 2012) and fundamental body parameters as a reference basis for Phobos research as well as GIS analyses of surface objects and geomorphologic studies. According to the structure of the atlas we used various scales and projections based on different coordinate system, including three-axial ellipsoid which parameters (a=13.24 km, b=11.49 km, c=9.48 km) derived from new Phobos shape model (Nadezhdina and Zubarev, 2014). The new Phobos atlas includes about 30 thematic original maps that illustrate the surface of the small body based on Mars Express data (Oberst et al., 2008) and illustrates results of various studies of Phobos:, geomorphology parameters of craters (Basilevsky et al., 2014), morphometry studies (Koknanov et al., 2012), statistics of crater size-frequency distributions based on multi-fractal approach (Uchaev Dm. et al., 2012). Phobos Geo-portal. The spatial data products which used for preparing maps for the Phobos atlas are available at the planetary data storage with access via Geo-portal (http://cartsrv.mexlab.ru/geoportal/), based on modern spatial and web-based technologies (Karachevtseva et al., 2013). Now we are developing Geodesy and Cartography node which can integrate various types of information not only for Phobos data, but other planets and their satellites, and it can be used for geo

  1. Undergraduate teaching modules featuring geodesy data applied to critical social topics (GETSI: GEodetic Tools for Societal Issues)

    Science.gov (United States)

    Pratt-Sitaula, B. A.; Walker, B.; Douglas, B. J.; Charlevoix, D. J.; Miller, M. M.

    2015-12-01

    The GETSI project, funded by NSF TUES, is developing and disseminating teaching and learning materials that feature geodesy data applied to critical societal issues such as climate change, water resource management, and natural hazards (serc.carleton.edu/getsi). It is collaborative between UNAVCO (NSF's geodetic facility), Mt San Antonio College, and Indiana University. GETSI was initiated after requests by geoscience faculty for geodetic teaching resources for introductory and majors-level students. Full modules take two weeks but module subsets can also be used. Modules are developed and tested by two co-authors and also tested in a third classroom. GETSI is working in partnership with the Science Education Resource Center's (SERC) InTeGrate project on the development, assessment, and dissemination to ensure compatibility with the growing number of resources for geoscience education. Two GETSI modules are being published in October 2015. "Ice mass and sea level changes" includes geodetic data from GRACE, satellite altimetry, and GPS time series. "Imaging Active Tectonics" has students analyzing InSAR and LiDAR data to assess infrastructure earthquake vulnerability. Another three modules are in testing during fall 2015 and will be published in 2016. "Surface process hazards" investigates mass wasting hazard and risk using LiDAR data. "Water resources and geodesy" uses GRACE, vertical GPS, and reflection GPS data to have students investigating droughts in California and the High Great Plains. "GPS, strain, and earthquakes" helps students learn about infinitesimal and coseismic strain through analysis of horizontal GPS data and includes an extension module on the Napa 2014 earthquake. In addition to teaching resources, the GETSI project is compiling recommendations on successful development of geodesy curricula. The chief recommendations so far are the critical importance of including scientific experts in the authorship team and investing significant resources in

  2. Marine geodesy a multipurpose approach to solve oceanic problems. [including submersible navigation under iced seas, demarcation and determination of boundaries in deep ocean, tsunamis, and ecology

    Science.gov (United States)

    Saxena, N.

    1974-01-01

    Various current and future problem areas of marine geodesy are identified. These oceanic problem areas are highly diversified and include submersible navigation under ice seas, demarcation and determination of boundaries in deep ocean, tsunamis, ecology, etc., etc. Their achieved as well as desired positional accuracy estimates, based upon publications and discussions, are also given. A multipurpose approach to solve these problems is described. An optimum configuration of an ocean-bottom control-net unit is provided.

  3. New geoscience techniques for Earth and planetary studies developed in Moscow State University of Geodesy and Cartography (MIIGAiK)

    Science.gov (United States)

    Mayorov, Andrey; Karachevtseva, Irina; Oberst, Jürgen

    2015-04-01

    The University was established in 1779 and for all these years it has been the centre of higher geodetic education in Russia, the largest specialized educational institution of this profile in Europe. The great historical past, long pedagogical and scientific traditions developed throughout almost the two and a half centuries' history of the University, importance of geodetic sciences and land survey branch for many fields of knowledge and national economy, a wide range of specialties in which MIIGAiK trains specialists have given the University the leading position as a specialized higher educational institution [1]. Now, the University is a large educational-and-scientific and production complex including six faculties of full-time training, a faculty of distance learning, a Training Centre for teachers of high schools and retraining of experts, postgraduate and doctoral courses, educational specialized laboratories in various directions of geodesy, cartography and remote sensing. In the University structure, there are also research-and-production centers Geodynamics, Geomonitoring, a Center for satellite technologies in geodesy, a Cartographic centre, Geodesy and Air Photography Journal Publishing House, two educational test fields, computing centers, an educational-and-geodetic museum and a library. New MIIGAiK Extraterrestrial Laboratory (MExLab) [2], which was established in 2010 under the leadership of invited scientist Prof. Dr. Jürgen Oberst (DLR, TUB, Germany), studies of characteristics of Solar System bodies with geodetic and cartographic methods. The several celestial bodies are chosen as subjects for new planetary project: Europa, Ganymede, Callisto (Galilean satellites of Jupiter), and Enceladus (a satellite of Saturn), as well as the Moon, Mars, its satellite Phobos, and Mercury. The significance of the project objectives is defined both by necessity of gaining fundamental knowledge about properties of the Solar System bodies, and practical needs

  4. Seafloor Geodesy usi­ng Wave Gliders to study Earthquake and Tsunami Hazards at Subduction Zones

    Science.gov (United States)

    Sathiakumar, S.; Barbot, S.; Hill, E.; Peng, D.; Zerucha, J.; Suhaimee, S.; Chia, G.; Salamena, G. G.; Syahailatua, A.

    2016-12-01

    Land-based GNSS networks are now in place to monitor most subduction zones of the world. These provide valuable information about the amount of­ geodetic strain accumulated in the region, which in turn gives insight into the seismic potential. However, it is usually impossible to resolve activity on the megathrust near the trench using land-based GNSS data alone, given typical signal-to-noise ratios. Ship-based seafloor geodesy is being used today to fill this observation gap. However, surveys using ships are very expensive, tedious and impractical due to the large areas to be covered. Instead of discrete missions using ships, continuous monitoring of the seafloor using autonomous marine robots would aid in understanding the tectonic setting of the seafloor better at a potentially lower cost, as well as help in designing better warning systems. Thus, we are developing seafloor geodesy capabilities using Wave Gliders, a new class of wave-propelled, persistent marine autonomous vehicle using a combination of acoustic and GNSS technologies. We use GNSS/INS to position the platform, and acoustic ranging to locate the seafloor. The GNSS/INS system to be integrated with the Wave Gliders has stringent requirements of low power, light weight, and high accuracy. All these factors are equally important due to limited power and space in the Wave Gliders and the need for highly accurate and precise measurements. With this hardware setup, a limiting factor is the accuracy of measurement of the sound velocity in the water column. We plan to obtain precise positioning of seafloor by exploring a measurement setup that minimizes uncertainties in sound velocity. This will be achieved by making fine-resolution measurements of the two-way travel time of the acoustic waves underwater using the Wave Gliders, and performing statistical signal processing on this data to obtain more reliable sound velocity measurement. This enhanced seafloor geodetic technique using Wave Gliders should

  5. Project of the planetary terrain analogs research for technology development and education in geodesy and image processing.

    Science.gov (United States)

    Semenov, Mikhail; Gavrushin, Nikolay; Bataev, Mikhail; Kruzhkov, Maxim; Oberst, Juergen

    2013-04-01

    The MIIGAiK Extraterrestrial Laboratory (MExLab) is currently finalizing the development the robotic mobile science platform MExRover, designed for simulating rover activities on the surface of earth-type planets and satellites. In the project, we develop a hardware and software platform for full rover operation and telemetry processing from onboard instruments, as a means of training undergraduate and postgraduate students and young scientists working in the field of planetary exploration. 1. Introduction The main aim of the project is to provide the research base for image processing development and geodesy survey. Other focus is the development of research programs with participation of students and young scientists of the University, for digital terrain model creation for macro- and microrelief surveying. MExRover would be a bridge from the old soviet Lunokhod experience to the new research base for the future rover technology development support. 2. Rover design The design of the rover and its instrument suite allows acquiring images and navigation data satisfying the requirements for photogrammetric processing. The high-quality color panoramas as well as DTMs (Digital Terrain Models) will be produced aboard and could be used for the real-time track correction and environment analysis. A local operator may control the rover remotely from a distance up to 3 km and continuously monitor all systems. The MExRover has a modular design, which provides maximum flexibility for accomplishing different tasks with different sets of additional equipment weighing up to 15 kg. The framework can be easily disassembled and fit into 3 transport boxes, which allows transporting them on foot, by car, train or plane as a the ordinary luggage. The imaging system included in the present design comprises low resolution video cameras, high resolution stereo camera, microphone and IR camera. More instruments are planned to be installed later as auxiliary equipment, such as

  6. A Blind Test Experiment in Volcano Geodesy: a Benchmark for Inverse Methods of Ground Deformation and Gravity Data

    Science.gov (United States)

    D'Auria, Luca; Fernandez, Jose; Puglisi, Giuseppe; Rivalta, Eleonora; Camacho, Antonio; Nikkhoo, Mehdi; Walter, Thomas

    2016-04-01

    The inversion of ground deformation and gravity data is affected by an intrinsic ambiguity because of the mathematical formulation of the inverse problem. Current methods for the inversion of geodetic data rely on both parametric (i.e. assuming a source geometry) and non-parametric approaches. The former are able to catch the fundamental features of the ground deformation source but, if the assumptions are wrong or oversimplified, they could provide misleading results. On the other hand, the latter class of methods, even if not relying on stringent assumptions, could suffer from artifacts, especially when dealing with poor datasets. In the framework of the EC-FP7 MED-SUV project we aim at comparing different inverse approaches to verify how they cope with basic goals of Volcano Geodesy: determining the source depth, the source shape (size and geometry), the nature of the source (magmatic/hydrothermal) and hinting the complexity of the source. Other aspects that are important in volcano monitoring are: volume/mass transfer toward shallow depths, propagation of dikes/sills, forecasting the opening of eruptive vents. On the basis of similar experiments already done in the fields of seismic tomography and geophysical imaging, we have devised a bind test experiment. Our group was divided into one model design team and several inversion teams. The model design team devised two physical models representing volcanic events at two distinct volcanoes (one stratovolcano and one caldera). They provided the inversion teams with: the topographic reliefs, the calculated deformation field (on a set of simulated GPS stations and as InSAR interferograms) and the gravity change (on a set of simulated campaign stations). The nature of the volcanic events remained unknown to the inversion teams until after the submission of the inversion results. Here we present the preliminary results of this comparison in order to determine which features of the ground deformation and gravity source

  7. Geodesy- and geology-based slip-rate models for the Western United States (excluding California) national seismic hazard maps

    Science.gov (United States)

    Petersen, Mark D.; Zeng, Yuehua; Haller, Kathleen M.; McCaffrey, Robert; Hammond, William C.; Bird, Peter; Moschetti, Morgan; Shen, Zhengkang; Bormann, Jayne; Thatcher, Wayne

    2014-01-01

    The 2014 National Seismic Hazard Maps for the conterminous United States incorporate additional uncertainty in fault slip-rate parameter that controls the earthquake-activity rates than was applied in previous versions of the hazard maps. This additional uncertainty is accounted for by new geodesy- and geology-based slip-rate models for the Western United States. Models that were considered include an updated geologic model based on expert opinion and four combined inversion models informed by both geologic and geodetic input. The two block models considered indicate significantly higher slip rates than the expert opinion and the two fault-based combined inversion models. For the hazard maps, we apply 20 percent weight with equal weighting for the two fault-based models. Off-fault geodetic-based models were not considered in this version of the maps. Resulting changes to the hazard maps are generally less than 0.05 g (acceleration of gravity). Future research will improve the maps and interpret differences between the new models.

  8. Analytical continuation in physical geodesy constructed by means of tools and formulas related to an ellipsoid of revolution

    Science.gov (United States)

    Holota, Petr; Nesvadba, Otakar

    2014-05-01

    In physical geodesy mathematical tools applied for solving problems of potential theory are often essentially associated with the concept of the so-called spherical approximation (interpreted as a mapping). The same holds true for the method of analytical (harmonic) continuation which is frequently considered as a means suitable for converting the ground gravity anomalies or disturbances to corresponding values on the level surface that is close to the original boundary. In the development and implementation of this technique the key role has the representation of a harmonic function by means of the famous Poisson's formula and the construction of a radial derivative operator on the basis of this formula. In this contribution an attempt is made to avoid spherical approximation mentioned above and to develop mathematical tools that allow implementation of the concept of analytical continuation also in a more general case, in particular for converting the ground gravity anomalies or disturbances to corresponding values on the surface of an oblate ellipsoid of revolution. The respective integral kernels are constructed with the aid of series of ellipsoidal harmonics and their summation, but also the mathematical nature of the boundary date is discussed in more details.

  9. International VLBI Service for Geodesy and Astrometry - Delivering high-quality products and embarking on observations of the next generation

    Science.gov (United States)

    Nothnagel, A.; Artz, T.; Behrend, D.; Malkin, Z.

    2016-09-01

    The International VLBI Service for Geodesy and Astrometry (IVS) regularly produces high-quality Earth orientation parameters from observing sessions employing extensive networks or individual baselines. The master schedule is designed according to the telescope days committed by the stations and by the need for dense sampling of the Earth orientation parameters (EOP). In the pre-2011 era, the network constellations with their number of telescopes participating were limited by the playback and baseline capabilities of the hardware (Mark4) correlators. This limitation was overcome by the advent of software correlators, which can now accommodate many more playback units in a flexible configuration. In this paper, we describe the current operations of the IVS with special emphasis on the quality of the polar motion results since these are the only EOP components which can be validated against independent benchmarks. The polar motion results provided by the IVS have improved continuously over the years, now providing an agreement with IGS results at the level of 20-25 μ as in a WRMS sense. At the end of the paper, an outlook is given for the realization of the VLBI Global Observing System.

  10. International VLBI Service for Geodesy and Astrometry. Delivering high-quality products and embarking on observations of the next generation

    Science.gov (United States)

    Nothnagel, A.; Artz, T.; Behrend, D.; Malkin, Z.

    2017-07-01

    The International VLBI Service for Geodesy and Astrometry (IVS) regularly produces high-quality Earth orientation parameters from observing sessions employing extensive networks or individual baselines. The master schedule is designed according to the telescope days committed by the stations and by the need for dense sampling of the Earth orientation parameters (EOP). In the pre-2011 era, the network constellations with their number of telescopes participating were limited by the playback and baseline capabilities of the hardware (Mark4) correlators. This limitation was overcome by the advent of software correlators, which can now accommodate many more playback units in a flexible configuration. In this paper, we describe the current operations of the IVS with special emphasis on the quality of the polar motion results since these are the only EOP components which can be validated against independent benchmarks. The polar motion results provided by the IVS have improved continuously over the years, now providing an agreement with IGS results at the level of 20-25 μas in a WRMS sense. At the end of the paper, an outlook is given for the realization of the VLBI Global Observing System.

  11. GEodesy Tools for Societal Issues (GETSI): Undergraduate curricular modules that feature geodetic data applied to critical social topics

    Science.gov (United States)

    Douglas, B. J.; Pratt-Sitaula, B.; Walker, B.; Miller, M. S.; Charlevoix, D.

    2014-12-01

    The GETSI project is a three-year NSF funded project to develop and disseminate teaching and learning materials that feature geodesy data applied to critical societal issues such as climate change, water resource management, and natural hazards (http://serc.carleton.edu/getsi). GETSI was born out of requests from geoscience faculty for more resources with which to educate future citizens and future geoscience professionals on the power and breadth of geodetic methods to address societally relevant topics. Development of the first two modules started at a February 2014 workshop and initial classroom testing begins in fall 2014. The Year 1 introductory module "Changing Ice and Sea Level" includes geodetic data such as gravity, satellite altimetry, and GPS time series. The majors-level Year 1 module is "Imaging Active Tectonics" and it has students analyzing InSAR and LiDAR data to assess infrastructure vulnerability to demonstratively active faults. Additional resources such as animations and interactive data tools are also being developed. The full modules will take about two weeks of class time; module design will permit portions of the material to be used as individual projects or assignments of shorter duration. Ultimately a total of four modules will be created and disseminated, two each at the introductory and majors-levels. GETSI is working in tight partnership with the Science Education Resource Center's (SERC) InTeGrate project on the module development, assessment, and dissemination to ensure compatibility with the growing number of resources for geoscience education. This will allow for an optimized module development process based on successful practices defined by these earlier efforts.

  12. Preface to the Special Issue on "Geophysical and Climate Change Studies in Tibet, Xinjiang, and Siberia (TibXS from Satellite Geodesy"

    Directory of Open Access Journals (Sweden)

    Cheinway Hwang

    2013-01-01

    Full Text Available This special issue publishes papers on recent results in geophysical and climate change studies over Tibet, Xinjiang and Siberia (TibXS based upon some of the key sensors used in satellite geodesy, including satellite gravimetric sensors (GRACE and GOCE, satellite altimeters (TOPEX, Jason-1 and -2, and ENVISAT, and Global Positioning System satellites. Results from ground- and airborne-based geodetic observations, notably those based on airborne gravimeter, superconducting gravimeter (SG and seismometers are also included in the special issue. In all, 22 papers were submitted for this special issue; 17 papers were accepted.

  13. A new laser-ranged satellite for General Relativity and space geodesy: I. An introduction to the LARES2 space experiment

    Science.gov (United States)

    Ciufolini, Ignazio; Paolozzi, Antonio; Pavlis, Erricos C.; Sindoni, Giampiero; Koenig, Rolf; Ries, John C.; Matzner, Richard; Gurzadyan, Vahe; Penrose, Roger; Rubincam, David; Paris, Claudio

    2017-08-01

    We introduce the LARES 2 space experiment recently approved by the Italian Space Agency (ASI). The LARES 2 satellite is planned for launch in 2019 with the new VEGA C launch vehicle of ASI, ESA and ELV. The orbital analysis of LARES 2 experiment will be carried out by our international science team of experts in General Relativity, theoretical physics, space geodesy and aerospace engineering. The main objectives of the LARES 2 experiment are gravitational and fundamental physics, including accurate measurements of General Relativity, in particular a test of frame-dragging aimed at achieving an accuracy of a few parts in a thousand, i.e., aimed at improving by about an order of magnitude the present state-of-the-art and forthcoming tests of this general relativistic phenomenon. LARES 2 will also achieve determinations in space geodesy. LARES 2 is an improved version of the LAGEOS 3 experiment, proposed in 1984 to measure frame-dragging and analyzed in 1989 by a joint ASI and NASA study.

  14. Bernese Developments in Planetary Geodesy: our Latest Solution of Moon Gravity Field and Tides and an Outlook on Future Projects

    Science.gov (United States)

    Bertone, S.; Arnold, D.; Jaeggi, A.; Hosseini, A.

    2016-12-01

    -induced gravity.Our latest developments and the experience gained with GRAIL open the way to further research projects in planetary geodesy at AIUB. We present an overview of future applications of the Bernese GNSS Software in planetary research and of our ongoing collaborations, including BepiColombo orbit simulations and altimetry studies.

  15. Geodezija od Mesopotamije do Globalnog geodetskog opažačkog sistema : Geodesy from Mesopotamie to Global Geodetic Observing System

    Directory of Open Access Journals (Sweden)

    Medžida Mulić

    2015-12-01

    Full Text Available Tokom šest milenijuma postojanja civilizacije na Zemlji, geodetske tehnike su doživjele teško sagledive promjene. Definicija i uloga geodezije su se mijenjale u skladu s tim promijenila. Geodezija (viša je evoluirala od svoje originalne klasične definicije da „proučava kretanja nebeskih tijela, oblik i dimenzije Zemlje“ u „znanost koja osim naprijed rečenog, proučava njene promjene i kompleksne dinamičke procese, koji djeluju unutar Zemlje, na njenoj površini i iznad njene površine, kao i u svemiru koji je okružuje. Rad predstavlja detaljan pregled geodetskih tehnika, instrumenata, katastra i kartografije kod starih civilizacija: Mesopotamije, starog Egipta, antičke Grčke, starog Rima, pa sve do Evropljana, između 17. stoljeća do modernog doba. Posebno su opisani geodetski radovi u Bosni i Hercegovini, od doba osmanlija, austro-ugarskog premjera, do savremenih dostignuća u polju premjera i primjene satelitskih modernih tehnika. Globalni geodetski opažački sistem-GGOS, glavna komponenta Internacionalne asocijacije za geodeziju, kao projekat za buduće generacije geodeta, opisan je na kraju. : During the six millennia of the existence of the civilization on the Earth, surveying techniques have been experienced difficult foreseeable changes. The definition and role of geodesy have been changing accordingly. Geodesy has evolved from its original classic definition that "studying the movements of celestial bodies, the shape and dimensions of the Earth" in the "science which, beside it noted above, studies its changes and complex dynamic processes that ongoing inside the Earth, on the surface, above its surfaces, and evironment. The paper is overview of the geodetic techniques and the surveying instruments, cadastre and cartography in the ancien civilizations: Mesopotamia, ancient Egypt, antic Greece, ancient Rome, to the Europeans, from the 17th century to modern times. A detailed description devoted to surveying and geodetic

  16. 3TU.Datacentrum serves data-curation needs of geodesy, hydrology, and climate science in the Netherlands

    Science.gov (United States)

    Princic, A.; Rombouts, J. P.; de Smaele, M. M. P.

    2012-04-01

    datasets. They are also used to generate ORE Resource Maps. Common solution to both collections is also the file format NetCDF. This is an open standard, primarily used for sets of multidimensional arrays with metadata included, enabling interoperability and easy use. The NetCDF format can be used by common tools and programming libraries. Differences in solutions to both collections are in the functionality offered to the user. For simple datasets a Fedora repository is used where datasets of any format are allowed: alongside the NetCDF an xml version (ncml) is stored that can be converted to other formats like Excel. For complex datasets of IDRA an OPeNDAP framework is used, which allows querying within and across datasets. The complex IDRA dataset contains raw data files, one or several processed data files, a quick-look file, and a user-friendly diagram displayed alongside the other metadata. Research data of different collections, be it simple or complex, and from different science disciplines such as hydrology, geodesy and climate research can be safely stored in 3TU.Datacentrum and become available for future use by the scientific community.

  17. The orbital decay of the semi-major axis of LARES and the LARASE contribution to SLR measurements for applications in the fields of space geodesy and geophysics

    Science.gov (United States)

    Pardini, Carmen; Anselmo, Luciano; Masimo Lucchesi, David; Bassan, Massimo; Magnafico, Carmelo; Nobili, Anna Maria; Peron, Roberto; Pucacco, Giuseppe; Stanga, Ruggero; Visco, Massimo

    2016-04-01

    The new laser-ranged satellite LARES (LAser RElativity Satellite) is expected to provide new refined measurements of relativistic physics as well as significant contributions to space geodesy and geophysics. The very low area-to-mass ratio of this passive and dense satellite was chosen to reduce as much as possible the disturbing effects due to the non-gravitational perturbations in order to compensate for its much lower altitude with respect to the two older LAGEOS (LAser GEOdynamic Satellite) satellites, currently the best tracked satellites of the International Laser Ranging Service network. Indeed, because of its height, about 1450 km with respect to the 5900 km of the two LAGEOS, LARES is subject to a much stronger perturbation provoked by the neutral drag than that on the two LAGEOS. From a Precise Orbit Determination (POD) of LARES over a time span of about 3.7 years we have been able to measure an orbital decay in the residuals of its semi-major axis of about 1 m/yr, that corresponds to a transversal mean acceleration of about -1.457×10-11 m/s2. This POD has been obtained analyzing LARES normal points with the GEODYN II (NASA/GSFC) software. Neither the neutral drag nor the thermal effects have been included in the dynamical models of GEODYN II. By means of a modified version of the SATellite Reentry Analysis Program (SATRAP) of ISTI/CNR, the neutral drag perturbation has been computed over the same time span accounting for the measured decay and considering the real evolution of the solar and geomagnetic activities for several atmospheric models. In particular, assuming as reference for the unmodeled transversal acceleration due to the neutral atmosphere the above value, the drag coefficient estimated by SATRAP is comparable to the average value estimated by GEODYN II in a least square fit of the tracking data. This means that the current best models developed for the atmosphere behavior are able to account for the observed decay, within their errors and

  18. Applications of the Fictitious Compress Recovery Approach in Physical Geodesy%虚拟压缩恢复法在物理大地测量学中的应用

    Institute of Scientific and Technical Information of China (English)

    申文斌; 李建成; 李进; 宁津生; 晁定波

    2008-01-01

    The fictitious compress recovery approach is introduced, which could be applied to the establishment of the Runge-Krarup theorem, the determination of the Bjerhammar's fictitious gravity anomaly, the solution of the "downward continuation" problem of the gravity field, the confirmation of the convergence of the spherical harmonic expansion series of the Earth's potential field, and the gravity field determination in three cases: gravitational potential case, gravitation case, and gravitational gradient case. Several tests using simulation experiments show that the fictitious compress recovery approach shows promise in physical geodesy applications.

  19. The GGOS Bureau of Networks and Observations: an update on the Space Geodesy Network and the New Implementation Plan for 2017 -18

    Science.gov (United States)

    Pearlman, Michael R.; Ma, Chopo; Neilan, Ruth; Noll, Carey; Pavlis, Erricos; Saunier, Jérôme; Schoene, Tilo; Barzaghi, Riccardo; Thaller, Daniela; Bergstrand, Sten; Mueller, Juergen

    2017-04-01

    Working with the IAG geometric services (VLBI, SLR, GNSS, and DORIS) the Bureau continues to advocate for the expansion and upgrade of the space geodesy networks for the maintenance and improvement of the reference frame and other application, and for the extension and integration with other techniques. New sites are being established following the GGOS concept of "core" and co-location sites; new technologies are being implemented to enhance performance in data yield as well as accuracy. In particular, several groups are undertaking initiatives and seeking partnerships to update existing sites and expand the networks in geographic areas void of coverage. The Bureau continues to meet with organizations to discuss possibilities of new and expanded participation and to promote the concept of partnerships. The Bureau provides the opportunity for representatives from the services to meet and share progress and plans, and to discuss issues of common interest. The Bureau monitors the status and projects the evolution of the network based on information from the current and expected future participants. Of particular interest at the moment is the integration of gravity and tide gauge networks. The Committees and Joint Working Groups play an essential role in the Bureau activity. The Standing Committee on Performance Simulations and Architectural Trade-off (PLATO) uses simulation and analysis techniques to project future network capability and to examine trade-off options. The Committee on Data and Information is working on a strategy for a GGOS metadata system on a near term plan for data products and a more comprehensive longer-term plan for an all-inclusive system. The Committee on Satellite Missions is working to enhance communication with the space missions, to advocate for missions that support GGOS goals and to enhance ground systems support. The IERS Working Group on Site Survey and Co-location (also participating in the Bureau) is working to enhance

  20. Theory of satellite geodesy applications of satellites to geodesy

    CERN Document Server

    Kaula, William M

    2000-01-01

    The main purpose of this classic text is to demonstrate how Newtonian gravitational theory and Euclidean geometry can be used and developed in the earth's environment. The second is to collect and explain some of the mathematical techniques developed for measuring the earth by satellite.Book chapters include discussions of the earth's gravitational field, with special emphasis on spherical harmonies and the potential of the ellipsoid; matrices and orbital geometry; elliptic motion, linear perturbations, resonance, and other aspects of satellite orbit dynamics; the geometry of satellite obser

  1. Geodesy and Mapping (Selected Articles),

    Science.gov (United States)

    1979-08-16

    Turku lies in the region of large vertical movements of seashore of the Baltic Sea , hence in an unstable area where local displacements of mass in the...Key: (1) Region; (2) Skopie, Yugoslavia; (3) Yugoslavia; (4) Greece; (5) Ae~eian Sea ; (6) Crete; (7) Albany; (8) Ionian Sea . Ib - 29- Table 4a...On the reference coordinate systems for Earth dynamics, Toruh~ 1974. 115] Molodensky M. S., The theory of natation and diurnal Earth’s tides, Commn

  2. Chameleon gravity and satellite geodesy

    CERN Document Server

    Morris, J R

    2014-01-01

    We consider the possibility of the detection of a chameleon effect by an earth orbiting satellite such as LAGEOS, and possible constraints that might be placed on chameleon model parameters. Approximate constraints presented here result from using a simple monopole approximation for the gravitational field of the earth, along with results from the Khoury-Weltman chameleon model, solar system constraints obtained from the Cassini mission, and parameter bounds obtained from the LAGEOS satellite. It is furthermore suggested that a comparison of ground-based and space-based multipole moments of the geopotential could reveal a possible chameleon effect.

  3. Mapping, Charting and Geodesy Handbook

    Science.gov (United States)

    1994-07-15

    whole degrees, whole minutes, and seconds to two decimal places. Trigonometry tells us that .01 arc seconds of latitude is equal to about 31 centimeters...drainage, transportation, and obstacle data. DTED * Level 1 coverage in included with the data base. Originally in Standard Linear Format, existing ITD is

  4. At the dawn of geodesy

    Science.gov (United States)

    Fischer, Irene K.

    1981-06-01

    The first land surveyors were rope stretchers and rope knotters, remembered in ancient documents and tomb paintings and also in some terminology. The L-shaped carpenter’s square, one of the earliest and most versatile basic tools, represents the observed direction of the plumb line versus the water level and appears as the shadow-casting gnomon and also as the geometrical gnomon in magically-restricted enlargements of altars. The related “Pythagorean” theorem was known in antiquity centuries before Pythagoras, with algebraic proofs in Babylonia and China. The spherical shape of the earth, deduced from the observation of circumpolar stars, was part of a complete equatorial astronomical system in ancient China. But although shadow measurements were generally used to establish north-south distances, only the Greeks derived from them the size of the earth. The striking difference between the abstract, geometric approach of Greece and the concrete, algebraic approach of Babylonia and China represents not a difference in talents but a difference in culture-bound interests.

  5. Marussi Hypothesis in Differential Geodesy

    Science.gov (United States)

    1994-06-13

    writings. IHow- vver , since the b~road cotit ext of t heir I heor ’% is wel l-4𔃾ined, i.e. it is t he physical differential geoinet r.. of thle gravi...and knowing that his audience would not be familiar with his motivation and viewpoint, they were unusually detailed and included material assumed...understand his procedure, one must carefully delete the unnecessary material , or to borrow a famous comment of Dirac ’eliminate the dead- wood’ from the

  6. Geodesy at Mercury with MESSENGER

    Science.gov (United States)

    Smith, David E.; Zuber, Maria t.; Peale, Stanley J.; Phillips, Roger J.; Solomon, Sean C.

    2006-01-01

    In 2011 the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft will enter Mercury orbit and begin the mapping phase of the mission. As part of its science objectives the MESSENGER mission will determine the shape and gravity field of Mercury. These observations will enable the topography and the crustal thickness to be derived for the planet and will determine the small libration of the planet about its axis, the latter critical to constraining the state of the core. These measurements require very precise positioning of the MESSENGER spacecraft in its eccentric orbit, which has a periapsis altitude as low as 200 km, an apoapsis altitude near 15,000 km, and a closest approach to the surface varying from latitude 60 to about 70 N. The X-band tracking of MESSENGER and the laser altimetry are the primary data that will be used to measure the planetary shape and gravity field. The laser altimeter, which has an expected range of 1000 to 1200 km, is expected to provide significant data only over the northern hemisphere because of MESSENGER's eccentric orbit. For the southern hemisphere, radio occultation measurements obtained as the spacecraft passes behind the planet as seen from Earth and images obtained with the imaging system will be used to provide the long-wavelength shape of the planet. Gravity, derived from the tracking data, will also have greater resolution in the northern hemisphere, but full global models for both topography and gravity will be obtained at low harmonic order and degree. The limiting factor for both gravity and topography is expected to be knowledge of the spacecraft location. Present estimations are that in a combined tracking, altimetry, and occultation solution the spacecraft position uncertainty is likely to be of order 10 m. This accuracy should be adequate for establishing an initial geodetic coordinate system for Mercury that will enable positioning of imaged features on the surface, determination of the planet's obliquity, and detection of the librational motion of the planet about its axis.

  7. Indications from space geodesy, gravimetry and seismology for slow Earth expansion at present - comment on "The Earth expansion theory and its transition from scientific hypothesis to pseudoscientific belief" by Sudiro (2014)

    Science.gov (United States)

    Edwards, Matthew R.

    2016-12-01

    In a recent article in this journal, Paolo Sudiro (2014) considered the long history of the expanding Earth theory and its recent descent into what he termed "pseudoscientific belief". The expanding Earth theory contends that the radius of the Earth was once one-half to two-thirds of its current value, with the Earth's continents forming a continuous sialic cover over the Earth. The theory has had two main variants: slow expansion at about 0.5 mm yr-1 radial increase since the time of Earth's formation and fast expansion at about 5 mm yr-1 since the Triassic. Focusing on Maxlow's model, Sudiro thoroughly addresses the possibly insurmountable difficulties of the fast version, such as an improbably high density and surface gravity prior to 200 Ma. He omits, however, any discussion of the slow expansion model, which has a longer history and far fewer theoretical difficulties. Moreover, recent evidence from space geodesy, gravimetry and seismology indicates that the Earth at present may be slowly expanding at 0.1-0.4 mm yr-1. It is concluded that Sudiro's obituary of the expanding Earth theory as a whole must be considered premature at this time.

  8. Primjena bespilotnih letjelica u geodeziji na primjeru aerofotogrametrijskog sistema SenseFly eBee : Application of unmanned aerial vehicles in geodesy on the example of aerial photogrammetric system SenseFly eBee

    Directory of Open Access Journals (Sweden)

    Amel Žilić

    2015-12-01

    Full Text Available U posljednjih nekoliko godina razvija se potpuno nova metoda snimanja Zemljine površine u svrhu premjera zemljišta i objekata. Koristeći bespilotne letjelice, omogućeno je snimanje većih površina u vrlo kratkom vremenskom roku s visokom tačnošću. Iako još uvijek postoje mnogobrojne nejasnoće, neminovno je da ova metoda predstavlja budućnost u geodeziji i njenim oblastima. U ovom radu opisana je metoda snimanja bespilotnom letjelicom SenseFly eBee i način dobivanja oblaka tačaka, digitalnog modela reljefa i digitalnog ortofoto plana. Implementiranjem standarda NSSDA za ocjenu prostornih podataka zaključeno je da tačnost rezultata zavisi od rezolucije snimanja, konfiguracije terena i vremenskih uslova. : During the last few years a completely new method for land and object surveying was devloped. Using unmanned aerial vehicle, it is possible to survey a large areas in very short period of time with high accuraccy. Although there are still many uncertainties, it is inevitable that this method represents the future in geodesy and its areas. This paper defines a method for land surveying using SenseFly eBee drone and proccess of creating point cloud, digital model of relief and digital ortofoto map. Using NSSDA standard for spatial data accuraccy on drone products, it was concluded that accuraccy of given results depends on the ground resolution, terrain relief and weather conditions.

  9. Andean tectonics: Implications for Satellite Geodesy

    Science.gov (United States)

    Allenby, R. J.

    1984-01-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  10. Planar electrostatic gradiometer for airborne geodesy

    Science.gov (United States)

    Foulon, B.; Christophe, B.; Lebat, V.; Boulanger, D.

    2011-12-01

    The knowledge of the gravity field of the Earth has been considerably improved for the last decades, thanks to satellites, in particular, both for gravity measurements and positioning. Gravity, and especially gravity gradiometry data are then of great interest to the study of the structure of the continental margins. Space gravity measurements, in particular with the GOCE satellite in orbit since 2009, provide an absolute gravity reference and should contribute to estimate the systematic effects that would affect the surface datasets. But the spatial resolution of those data essentially addresses the large and medium wavelengths of the field (down to a resolution of 90km) and it is therefore essential to complete them at the shorter wavelengths in particular in the littoral area. To this aim, gravity gradiometry systems may be particularly suitable by covering the land/sea transition zone with a uniform precision, and a spatial resolution higher than from gravimetry. The GREMLIT instrument is taking advantage of technologies, formerly developed by ONERA for the GRACE and GOCE space missions, by adapting them to an airborne environment, using a planar configuration for the gradiometer and designing and building a dedicated stabilized platform controlled by the common mode outputs of the instrument itself similarly to the drag free control of the GOCE satellite. The mains interests of the planar configuration are: - its definition, optimized for levitation in the Earth's gravity field ; - its intrinsic linearity, which minimizes the aliasing due to high frequency vibrations or motions generated outside the measurement bandwidth ; - its compactness, ensuring an excellent dimensional stability, a better thermal homogeneity and making the realization of the decoupling platform easier. The performance objective is 0.1 Eötvös. This lowered performance level with respect to a one hundred times better GOCE-type instrument, takes into account the difficulty of measurements onboard an aircraft as compared to the particularly conducive satellite measurement context.

  11. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael P.; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Ben

    2017-08-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic-tectonic interactions, and loss of volatiles plus densification of magma. The Cascade Range thus offers an outstanding opportunity for investigating a wide range of volcanic processes. Indeed, there may be areas of geodetic change that have yet to be discovered, and there is good potential for addressing a number of important questions about how arc volcanoes work before, during, and after eruptions by continuing geodetic research in the Cascade Range.

  12. Andean tectonics: Implications for Satellite Geodesy

    Science.gov (United States)

    Allenby, R. J.

    1984-09-01

    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  13. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic-tectonic interactions, and loss of volatiles plus densification of magma. The Cascade Range thus offers an outstanding opportunity for investigating a wide range of volcanic processes. Indeed, there may be areas of geodetic change that have yet to be discovered, and there is good potential for addressing a number of important questions about how arc volcanoes work before, during, and after eruptions by continuing geodetic research in the Cascade Range.

  14. Military Geodesy and Geospace Science. Unit Three

    Science.gov (United States)

    1981-02-01

    Description 3-56 Image Statistics 3-58 3.2.4 Non-Silver Imaging Materials 3-58 Non-Silver Inorganic Systems 3-60 Thermographic Systems 3-63 Photochromic ...Emulsions coated on thin sheets of glass are called photo- graphic plates. Specially whitened, high-quality paper or thin cardboard, sometimes treated...with a water-resistant sur- face coating to make it impervious to processing chemicals, is the base for photographic papers. Emulsions can also be

  15. Military Geodesy and Geospace Science. Unit Two,

    Science.gov (United States)

    1981-02-01

    be familiar with differential equations, analytic geometry, and linear algebra . Some acquaintance with vector calculus is useful but not essential...familiar with differential equations, analytic geometry, and linear algebra . Some acquaintance with vector calculus is useful but not essential. The...inertial sensors) using moderna - data processing techniques to produce an estimate of the state (position, velocity, attitude, etc.) of the vehicle

  16. Geometrical geodesy techniques in Goddard earth models

    Science.gov (United States)

    Lerch, F. J.

    1974-01-01

    The method for combining geometrical data with satellite dynamical and gravimetry data for the solution of geopotential and station location parameters is discussed. Geometrical tracking data (simultaneous events) from the global network of BC-4 stations are currently being processed in a solution that will greatly enhance of geodetic world system of stations. Previously the stations in Goddard earth models have been derived only from dynamical tracking data. A linear regression model is formulated from combining the data, based upon the statistical technique of weighted least squares. Reduced normal equations, independent of satellite and instrumental parameters, are derived for the solution of the geodetic parameters. Exterior standards for the evaluation of the solution and for the scale of the earth's figure are discussed.

  17. A Seafloor Benchmark for 3-dimensional Geodesy

    Science.gov (United States)

    Chadwell, C. D.; Webb, S. C.; Nooner, S. L.

    2014-12-01

    We have developed an inexpensive, permanent seafloor benchmark to increase the longevity of seafloor geodetic measurements. The benchmark provides a physical tie to the sea floor lasting for decades (perhaps longer) on which geodetic sensors can be repeatedly placed and removed with millimeter resolution. Global coordinates estimated with seafloor geodetic techniques will remain attached to the benchmark allowing for the interchange of sensors as they fail or become obsolete, or for the sensors to be removed and used elsewhere, all the while maintaining a coherent series of positions referenced to the benchmark. The benchmark has been designed to free fall from the sea surface with transponders attached. The transponder can be recalled via an acoustic command sent from the surface to release from the benchmark and freely float to the sea surface for recovery. The duration of the sensor attachment to the benchmark will last from a few days to a few years depending on the specific needs of the experiment. The recovered sensors are then available to be reused at other locations, or again at the same site in the future. Three pins on the sensor frame mate precisely and unambiguously with three grooves on the benchmark. To reoccupy a benchmark a Remotely Operated Vehicle (ROV) uses its manipulator arm to place the sensor pins into the benchmark grooves. In June 2014 we deployed four benchmarks offshore central Oregon. We used the ROV Jason to successfully demonstrate the removal and replacement of packages onto the benchmark. We will show the benchmark design and its operational capabilities. Presently models of megathrust slip within the Cascadia Subduction Zone (CSZ) are mostly constrained by the sub-aerial GPS vectors from the Plate Boundary Observatory, a part of Earthscope. More long-lived seafloor geodetic measures are needed to better understand the earthquake and tsunami risk associated with a large rupture of the thrust fault within the Cascadia subduction zone. Using a ROV to place and remove sensors on the benchmarks will significantly reduce the number of sensors required by the community to monitor offshore strain in subduction zones.

  18. Scientific value of Seasat for geodesy

    Science.gov (United States)

    Chovitz, B. H.

    1974-01-01

    SEASAT altimetry data which relate directly to geoid heights provide the means to obtain information on the geoid on a global scale which is not attenuated by height or by high frequency averaging. The most important geodetic application of these data is to provide a standard reference surface for oceans.

  19. RELATIVE MOTION AND DEFORMATION OF PACIFIC PLATE FROM SPACE GEODESY

    Institute of Scientific and Technical Information of China (English)

    JinShuanggen; ZhuWenyao

    2003-01-01

    The circum-Pacific tectonic system that contains of convergent, divergent and transform boundaries, is the most active region of volcanoes and earthquakes in the world, and involves many important theoretical questions in geosciences. The relative motion and deformation of Pacific plate is still an active subject of research. In this note, we analyze the deformation of Pacific plate and obtain reliable results of the relative motion rates at the circum-Pacific boundaries based on space geodetic data, which reveals the present-day motion characteristics of Pacific plate.

  20. Compression of the North Hemisphere derived from space geodesy

    Institute of Scientific and Technical Information of China (English)

    金双根; 朱文耀

    2003-01-01

    The convergent and divergent velocities of active plate boundaries in the North Hemisphere are obtained with space geodetic data. The relative motions of adjacent plates in north-south direction are almost convergent; the spreading rates of the north mid-Atlantic ridge are smaller than the south mid-Atlantic ridge; the closed differences of the baseline length rates between stations on different plates along the latitudinal circle of 7.7(, 23.3o, 34.8o, 42.0o and 51.0o are all negative. All these show that the North Hemisphere is a compressive hemisphere.

  1. Optimizing the African VLBI Network for Astronomy and Geodesy

    Science.gov (United States)

    de Witt, A.; Mayer, D.; MacLeod, G.; Combrinck, L.; Petrov, L.; Nickola, M.

    2016-12-01

    The African VLBI Network will be a pan-African network of radio telescopes comprised of converted redundant satellite Earth-station antennas and new purpose-built radio telescopes. The first of these antennas, in Ghana, is currently being converted to a radio telescope and current funding is estimated to permit the conversion of two more antennas in Africa. These antennas will initially be equipped with a 5-GHz and 6.7-GHz receiver and the next receiver likely to be fitted is a 1.4-1.7-GHz receiver. While it would be advantageous for the AVN antennas to be able to participate also in geodetic and astrometric VLBI observations, there is no funding currently for this. In this paper we re-visit the scientific justifications for the AVN in an attempt to optimize the AVN for each science case, both astronomical and geodetic.

  2. Earthquakes in India and the Himalaya: tectonics, geodesy and history

    Directory of Open Access Journals (Sweden)

    R. Bilham

    2004-06-01

    Full Text Available The record of earthquakes in India is patchy prior to 1800 and its improvement is much impeded by its dispersal in a dozen local languages, and several colonial archives. Although geological studies will necessarily complement the historical record, only two earthquakes of the dozens of known historical events have resulted in surface ruptures, and it is likely that geological data in the form of liquefaction features will be needed to extend the historical record beyond the most recent few centuries. Damage from large Himalayan earthquakes recorded in Tibet and in Northern India suggests that earthquakes may attain M = 8.2. Seismic gaps along two-thirds of the Himalaya that have developed in the past five centuries, when combined with geodetic convergence rates of approximately 1.8 m/cy, suggests that one or more M = 8 earthquakes may be overdue. The mechanisms of recent earthquakes in Peninsular India are consistent with stresses induced in the Indian plate flexed by its collision with Tibet. A region of abnormally high seismicity in western India appears to be caused by local convergence across the Rann of Kachchh and possibly other rift zones of India. Since the plate itself deforms little, this deformation may be related to incipient plate fragmentation in Sindh or over a larger region of NW India.

  3. Geodynamics of southeastern Tibet from seismic anisotropy and geodesy

    NARCIS (Netherlands)

    Sol, S; Meltzer, A.; Burgmann, R.; Hilst, R.D. van der; King, R.; Chen, Z.; Koons, P.; Lev, E.; Liu, Y.P.; Zeitler, P.K.; Zhang, X.; Zhang, J.; Zurek, B.

    2007-01-01

    Ongoing plate convergence between India and Eurasia provides a natural laboratory for studying the dynamics of continental collision, a first-order process in the evolution of continents, regional climate, and natural hazards. In southeastern Tibet, the fast directions of seismic anisotropy determin

  4. Central and South America GPS geodesy - CASA Uno

    Science.gov (United States)

    Kellogg, James N.; Dixon, Timothy H.

    1990-01-01

    In January 1988, scientists from over 25 organizations in 13 countries and territories cooperated in the largest GPS campaign in the world to date. A total of 43 GPS receivers collected approximately 590 station-days of data in American Samoa, Australia, Canada, Colombia, Costa Rica, Ecuador, New Zealand, Norway, Panama, Sweden, United States, West Germany, and Venezuela. The experiment was entitled CASA Uno. Scientific goals of the project include measurements of strain in the northern Andes, subduction rates for the Cocos and Nazca plates beneath Central and South America, and relative motion between the Caribbean plate and South America. A second set of measurements are planned in 1991 and should provide preliminary estimates of crustal deformation and plate motion rates in the region.

  5. Meter Accuracy Seafloor Geodesy using Repeated Multibeam Surveys

    Science.gov (United States)

    DeSanto, J. B.; Sandwell, D. T.

    2014-12-01

    Ship-board multibeam surveys are a useful tool in measuring tectonic deformation of the seafloor, having been used to measure the ~50 m of surface slip along the Japan trench during the 2011 Tohoku-Oki earthquake with an uncertainty of 20 m (Fujiwara et al, 2011, Science). In this study, we investigate the improvement in positioning accuracy obtainable when comparing multibeam and sidescan surveys repeated along the same track to within 1/10 of the critical baseline and taken at a slow ship speed of 1 knot. We compare two surveys of the Juan de Fuca Ridge axis fitting these criteria with two coincident surveys of the Cocos Ridge, taken at 11 knots. Both pairs of surveys were collected using a Simrad EM120 sonar system aboard the RV Roger Revelle. We find the multibeam surveys of the Juan de Fuca ridge axis sufficient to measure displacements accurate to better than 2 m, a marked improvement over the 50 m accuracy of the Cocos ridge surveys. Likewise, we can measure displacement accurate to 2 m using the sidescan data from the Juan de Fuca surveys. This accuracy is sufficient to observe meter-level horizontal movements on the deep ocean associated with large earthquakes and landslides.

  6. Beyond plate tectonics - Looking at plate deformation with space geodesy

    Science.gov (United States)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  7. Precise geodesy with the Very Long Baseline Array

    CERN Document Server

    Petrov, Leonid; Gipson, John; MacMillan, Dan; Ma, Chopo; Fomalont, Ed; Walker, R Craig; Carabajal, Claudia

    2008-01-01

    We report on a program of regular measurements between 1994 and 2007 which used the Very Long Baseline Array and up to 10 additional stations. One of the goals of these sessions was to monitor positions of the array at 1 millimeter level of accuracy and to tie the VLBA into the International Terrestrial Reference Frame. The large number of stations and the many competing goals made scheduling these sessions manually difficult, and lead to advances in scheduling software. We describe the analysis of these data, which is non-standard, and involves translating the data into a form useful for geodetic VLBI. We also describe several interesting geophysical results including measured station displacement due to crustal motion, earthquakes, and antenna tilt. In terms of both formal errors and observed scatter, these sessions are among the very best geodetic VLBI sessions.

  8. Integer-ambiguity resolution in astronomy and geodesy

    CERN Document Server

    Lannes, André

    2013-01-01

    Recent theoretical developments in astronomical aperture synthesis have revealed the existence of integer-ambiguity problems. Those problems, which appear in the self-calibration procedures of radio imaging, have been shown to be similar to the nearest-lattice point (NLP) problems encountered in high-precision geodetic positioning, and in global navigation satellite systems. In this paper, we analyse the theoretical aspects of the matter and propose new methods for solving those NLP problems. The related optimization aspects concern both the preconditioning stage, and the discrete-search stage in which the integer ambiguities are finally fixed. Our algorithms, which are described in an explicit manner, can easily be implemented. They lead to substantial gains in the processing time of both stages. Their efficiency was shown via intensive numerical tests.

  9. A clock network for geodesy and fundamental science

    CERN Document Server

    Lisdat, C; Quintin, N; Shi, C; Raupach, S M F; Grebing, C; Nicolodi, D; Stefani, F; Al-Masoudi, A; Dörscher, S; Häfner, S; Robyr, J -L; Chiodo, N; Bilicki, S; Bookjans, E; Koczwara, A; Koke, S; Kuhl, A; Wiotte, F; Meynadier, F; Camisard, E; Abgrall, M; Lours, M; Legero, T; Schnatz, H; Sterr, U; Denker, H; Chardonnet, C; Coq, Y Le; Santarelli, G; Amy-Klein, A; Targat, R Le; Lodewyck, J; Lopez, O; Pottie, P -E

    2015-01-01

    Leveraging the unrivaled performance of optical clocks in applications in fundamental physics beyond the standard model, in geo-sciences, and in astronomy requires comparing the frequency of distant optical clocks truthfully. Meeting this requirement, we report on the first comparison and agreement of fully independent optical clocks separated by 700 km being only limited by the uncertainties of the clocks themselves. This is achieved by a phase-coherent optical frequency transfer via a 1415 km long telecom fiber link that enables substantially better precision than classical means of frequency transfer. The fractional precision in comparing the optical clocks of three parts in $10^{17}$ was reached after only 1000 s averaging time, which is already 10 times better and more than four orders of magnitude faster than with any other existing frequency transfer method. The capability of performing high resolution international clock comparisons paves the way for a redefinition of the unit of time and an all-optic...

  10. Crustal kinematics of the Colorado Plateau from GPS geodesy

    Science.gov (United States)

    Holland, A. A.; Broermann, J.; Bennett, R. A.; Kreemer, C.; Blewitt, G.

    2013-12-01

    We present results from new continuous and campaign GPS networks spanning the state of Arizona and the southern portion of Utah. The 33 station continuous GPS network, funded by the NSF EarthScope Program, supplements a sparse distribution of continuous GPS stations that comprise the NSF EarthScope Plate Boundary Observatory network. The campaign network originally established by the National Geodetic survey in the mid-1990's, has been reoccupied two or more times over the past five years with support from the Arizona Geological Survey. The data from the continuous GPS stations are analyzed independently with the GIPSY and GAMIT software. The new horizontal velocity data set provides an improved image of deformation in the transition zone between the Colorado Plateau and the Northern and Southern Basin and Ranges Provinces. Preliminary modeling of the crustal kinematics reveals that only a very limited part of the region can be modeled as a rigid-body rotation. Most of the area is part of a broad zone of diffuse east-west directed extension from the Rio Grande Rift in the East to the Mojave Desert in the west. Only near the transition from the northern Colorado Plateau to the northern Basin and Range Province is the extension more localized. Besides a discussion of the regional kinematics, we will also discuss the affect the 2010 El Mayor-Cucapah earthquake had on the geodetic data in the southern Basin and Range.

  11. Conformal Geometry, Hotine’s Conjecture, and Differential Geodesy.

    Science.gov (United States)

    1987-07-27

    satisfied. We now check that the equations of Gauss and Mainardi -Codazzi rv~. hold in V3 i.e., ~4 3 10 .1 .1 - J * (2.15) Rt 3 b bm -b bA + Rhijkx xf3...8217xX6 ,1 0’ % (2.16) b -b -h 1 i j k 0 (T[3; (r YfW Rhijk 0 1 X Equation (2.15) is the Gauss equation and (2.16) are the equations of j Mainardi -Codazzi

  12. Status of the planar electrostatic gradiometer GREMLIT for airborne geodesy

    Science.gov (United States)

    Lebat, Vincent; Liorzou, Françoise; Huynh, Phuong-Anh; Boulanger, Damien; Foulon, Bernard; Christophe, Bruno

    2017-04-01

    Taking advantage of technologies, developed by ONERA for the GRACE and GOCE space missions, the GREMLIT airborne gravity gradiometer is based of a planar electrostatic gradiometer configuration. The feasibility of the instrument and of its performance was proved by realistic simulations, based on actual data and recorded environmental aircraft perturbations, with performance of about one Eötvös along the two horizontal components of the gravity gradient. In order to assess the operation of the electrostatic gradiometer on its associated stabilized platform, a one axis prototype has also been built. The next step is the realization of the stabilization platform, controlled by the common mode outputs of the instrument itself, in order to reject the perturbations induced by the airborne environment in the horizontal directions. The poster will emphasize the status of realization of the instrument and of its stabilized platform.

  13. Detecting surface geostrophic currents using wavelet filter from satellite geodesy

    Institute of Scientific and Technical Information of China (English)

    HSU; HouTse

    2007-01-01

    According to the features of spatial spectrum of the dynamic ocean topography (DOT),wavelet filter is proposed to reduce short-wavelength and noise signals in DOT. The surface geostrophic currents calculated from the DOT models filtered by wavelet filter in global and Kuroshio regions show more detailed information than those from the DOT models filtered by Gaussian filter. Based on a satellite gravity field model (CG01C) and a gravity field model (EGM96),combining an altimetry-derived mean sea surface height model (KMSS04),two mean DOT models are estimated. The short-wavelength and noise signals of these two DOT models are removed by using wavelet filter,and the DOT models asso-ciated global mean surface geostrophic current fields are calculated separately. Comparison of the surface geostrophic currents from CG01C and EGM96 model in global,Kuroshio and equatorial Pacific regions with that from oceanography,and comparison of influences of the two gravity models errors on the precision of the surface geostrophic currents velocity show that the accuracy of CG01C model has been greatly improved over pre-existing models at long wavelengths. At large and middle scale,the surface geostrophic current from satellite gravity and satellite altimetry agrees well with that from oceanography,which indicates that ocean currents detected by satellite measurement have reached relatively high precision.

  14. Detecting surface geostrophic currents using wavelet filter from satellite geodesy

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZiZhan; LU Yang; HSU HouTse

    2007-01-01

    According to the features of spatial spectrum of the dynamic ocean topography (DOT), wavelet filter is proposed to reduce short-wavelength and noise signals in DOT. The surface geostrophic currents calculated from the DOT models filtered by wavelet filter in global and Kuroshio regions show more detailed information than those from the DOT models filtered by Gaussian filter. Based on a satellite gravity field model (CG01C) and a gravity field model (EGM96), combining an altimetry-derived mean sea surface height model (KMSS04), two mean DOT models are estimated. The short-wavelength and noise signals of these two DOT models are removed by using wavelet filter, and the DOT models associated global mean surface geostrophic current fields are calculated separately. Comparison of the surface geostrophic currents from CG01C and EGM96 model in global, Kuroshio and equatorial Pacific regions with that from oceanography, and comparison of influences of the two gravity models errors on the precision of the surface geostrophic currents velocity show that the accuracy of CG01C model has been greatly improved over pre-existing models at long wavelengths. At large and middle scale, the surface geostrophic current from satellite gravity and satellite altimetry agrees well with that from oceanography, which indicates that ocean currents detected by satellite measurement have reached relatively high precision.

  15. International VLBI Service for Geodesy and Astrometry 2004 Annual Report

    Science.gov (United States)

    Behrend, Dirk (Editor); Baver, Karen D. (Editor)

    2005-01-01

    Contents include the following: Combination Studies using the Cont02 Campaign. Coordinating Center report. Analysis coordinator report. Network coordinator report. IVS Technology coordinator report. Algonquin Radio observatory. Fortaleza Station report for 2004. Gilmore Creek Geophysical Observatory. Goddard Geophysical and Astronomical observatory. Hartebeesthoek Radio Astronomy Observatory (HartRAO). Hbart, Mt Pleasant, station report for 2004. Kashima 34m Radio Telescope. Kashima and Koganei 11-m VLBI Stations. Kokee Park Geophysical Observatory. Matera GGS VLBI Station. The Medicina Station status report. Report of the Mizusawa 10m Telescope. Noto Station Activity. NYAL Ny-Alesund 20 metre Antenna. German Antarctic receiving Station (GARS) O'higgins. The IVS network station Onsala space Observatory. Sheshan VLBI Station report for 2004. 10 Years of Geodetic Experiments at the Simeiz VLBI Station. Svetloe RAdio Astronomical Observatory. JARE Syowa Station 11-m Antenna, Antarctica. Geodetic Observatory TIGO in Concepcion. Tsukuba 32-m VLBI Station. Nanshan VLBI Station Report. Westford Antenna. Fundamental-station Wettzell 20m Radiotelescope. Observatorio Astroonomico Nacional Yebes. Yellowknife Observatory. The Bonn Geodetic VLBI Operation Center. CORE Operation Center Report. U.S. Naval Observatory Operation Center. The Bonn Astro/Geo Mark IV Correlator.

  16. Image-Based Approach to Mapping, Charting, and Geodesy.

    Science.gov (United States)

    1982-02-01

    a.ve-ttor- bas-ed tipo I pi calIlIv t i l t ill-( I C I S) I (,r PiPC t; al p I( I i lt i ll (S fai-p i(%’ c t alI . , 1978’) , tr I F :TI, rt it I.,r...it.’vctf’l oitoro stuchit s di ffiring pompp * r p aT 0,’if comp lot i (11t1’r is illi’a ill terctitt s, (10(1 simple errors , c-all (t It It I IIK

  17. A clock network for geodesy and fundamental science

    Science.gov (United States)

    Lisdat, C.; Grosche, G.; Quintin, N.; Shi, C.; Raupach, S. M. F.; Grebing, C.; Nicolodi, D.; Stefani, F.; Al-Masoudi, A.; Dörscher, S.; Häfner, S.; Robyr, J.-L.; Chiodo, N.; Bilicki, S.; Bookjans, E.; Koczwara, A.; Koke, S.; Kuhl, A.; Wiotte, F.; Meynadier, F.; Camisard, E.; Abgrall, M.; Lours, M.; Legero, T.; Schnatz, H.; Sterr, U.; Denker, H.; Chardonnet, C.; Le Coq, Y.; Santarelli, G.; Amy-Klein, A.; Le Targat, R.; Lodewyck, J.; Lopez, O.; Pottie, P.-E.

    2016-08-01

    Leveraging the unrivalled performance of optical clocks as key tools for geo-science, for astronomy and for fundamental physics beyond the standard model requires comparing the frequency of distant optical clocks faithfully. Here, we report on the comparison and agreement of two strontium optical clocks at an uncertainty of 5 × 10-17 via a newly established phase-coherent frequency link connecting Paris and Braunschweig using 1,415 km of telecom fibre. The remote comparison is limited only by the instability and uncertainty of the strontium lattice clocks themselves, with negligible contributions from the optical frequency transfer. A fractional precision of 3 × 10-17 is reached after only 1,000 s averaging time, which is already 10 times better and more than four orders of magnitude faster than any previous long-distance clock comparison. The capability of performing high resolution international clock comparisons paves the way for a redefinition of the unit of time and an all-optical dissemination of the SI-second.

  18. Using a Numerical Weather Model to Improve Geodesy

    CERN Document Server

    Niell, A

    2004-01-01

    The use of a Numerical Weather Model (NWM) to provide in situ atmosphere information for mapping functions of atmosphere delay has been evaluated using Very Long Baseline Interferometry (VLBI) data spanning eleven years. Parameters required by the IMF mapping functions (Niell 2000, 2001) have been calculated from the NWM of the National Centers for Environmental Prediction (NCEP) and incorporated in the CALC/SOLVE VLBI data analysis program. Compared with the use of the NMF mapping functions (Niell 1996) the application of IMF for global solutions demonstrates that the hydrostatic mapping function, IMFh, provides both significant improvement in baseline length repeatability and noticeable reduction in the amplitude of the residual harmonic site position variations at semidiurnal to long-period bands. For baseline length repeatability the reduction in the observed mean square deviations achieves 80 of the maximum that is expected for the change from NMF to IMF. On the other hand, the use of the wet mapping fun...

  19. The role of laser determined orbits in geodesy and geophysics

    Science.gov (United States)

    Kolenkiewicz, R.; Smith, D. E.; Dunn, P. J.; Torrence, M. H.; Robbins, J. W.

    1991-01-01

    Some of the results of orbit analysis from the NASA SLR analysis group are presented. The earth's orientation was determined for 5-day intervals to 1.9 mas for the pole and 0.09 msec for length of day. The 3d center of mass station positions was determined to 33 mm over a period of 3 months, and geodesic rates of SLR tracking sites were determined to 5 mm/yr.

  20. Connection of Geodesy and Archaeology in Modern Geovisualisation

    Directory of Open Access Journals (Sweden)

    Vesna Poslončec-Petrić

    2007-05-01

    Full Text Available One type of thematic maps is also the map of archeological sites. In order to obtain high-quality cartographic presentation on thematic maps of archaeological sites, a cartographer must know the basic terms and classification of archaeology. The paper presents a few existing archaeological maps (static and interactive and there is also the interactive map of archaeological sites on the island Pag presented. The map has been made within the frame of the diploma thesis by a student Martina Triplat, and the data presented are the result of research made at the archaeological sites of the island Pag and of the geodetic works made at the excavation sites in Uvala Vlaška, the locality Blato and at the economic objects in the vicinity of the locality Blato.

  1. Interior of Mars from InSight geodesy

    Science.gov (United States)

    Dehant, V.; Folkner, W.; Asmar, S.; Rivoldini, A.; Van Hoolst, T.; Banerdt, B.

    2012-04-01

    Within the INSIGHT mission, the radioscience experiment aims at obtaining the rotation and interior structure of Mars. It is called for that reason RISE (Rotation and Interior Structure Experiment). It does not uses an instrument stricto sensus but uses the spacecraft X-band communication system. The parameters that will be determined from the rotation and orientation observation (i.e. from length-of-day variations, precession (long-term changes in the rotational orientation), and nutations (periodic changes in the rotational orientation)) are the angular momentum of the atmosphere, the moments of inertia of the whole planet and of the core. This will allow to constrain the interior models of Mars. The Doppler effect on the radio signal is related to the variations of the rotation and orientation of the planet Mars. When measured for a time longer than the seasonal timescale, the observation can provide values for the moments of inertia. The mean moment of inertia is a strong constraint on the core size and density, core temperature and mantle mineralogy. The size of the core has major consequences for internal structure and planetary evolution. For example, a large core makes a perovskite-bearing lower mantle impossible, due to insufficient pressure at the base of the mantle. The endothermic phase transition spinel-perovskite has a strong effect on mantle convection. The size and composition of the core are also important in the history of the magnetic dynamo, which in turn has important consequences for the retention of the atmosphere and the possible habitability of the surface early in Mars' history.

  2. Beyond plate tectonics - Looking at plate deformation with space geodesy

    Science.gov (United States)

    Jordan, Thomas H.; Minster, J. Bernard

    1988-01-01

    The requirements that must be met by space-geodetic systems in order to constrain the horizontal secular motions associated with the geological deformation of the earth's surface are explored. It is suggested that in order to improve existing plate-motion models, the tangential components of relative velocities on interplate baselines must be resolved to an accuracy of less than 3 mm/yr. Results indicate that measuring the velocities between crustal blocks to + or - 5 mm/yr on 100-km to 1000-km scales can produce geologically significant constraints on the integrated deformation rates across continental plate-boundary zones such as the western United States.

  3. Central and South America GPS geodesy - CASA Uno

    Science.gov (United States)

    Kellogg, James N.; Dixon, Timothy H.

    1990-01-01

    In January 1988, scientists from over 25 organizations in 13 countries and territories cooperated in the largest GPS campaign in the world to date. A total of 43 GPS receivers collected approximately 590 station-days of data in American Samoa, Australia, Canada, Colombia, Costa Rica, Ecuador, New Zealand, Norway, Panama, Sweden, United States, West Germany, and Venezuela. The experiment was entitled CASA Uno. Scientific goals of the project include measurements of strain in the northern Andes, subduction rates for the Cocos and Nazca plates beneath Central and South America, and relative motion between the Caribbean plate and South America. A second set of measurements are planned in 1991 and should provide preliminary estimates of crustal deformation and plate motion rates in the region.

  4. A General Surface Representation Module Designed for Geodesy

    Science.gov (United States)

    1980-06-01

    quantities at the points P and Q can be shown to equal T a C -Cp C CQ the variance is obtained for Q P ( Heiskanen and Moritz, 1967; p 269 ff.) I’ -14...Report No. 650Z-1, Stanford Electronics Laboratories, Stanford, California. Heiskanen , W. A. and H. Moritz (1967): Physical Geodcsy. W. H. Freeman and

  5. Deformation of Northwestern South America from GPS Geodesy

    Science.gov (United States)

    Mora-Paez, H.; La Femina, P. C.; Mothes, P. A.; Ruiz, A. G.; Fernandes, R. M.

    2013-12-01

    The North Andes block (NAB) is a hypothesized tectonic block that migrates (escapes) north-northeast relative to a stable South American reference frame. The motion of this block is thought-to-be derived by the collision of the Carnegie Ridge in southern Ecuador and/or by oblique convergence and high degrees of interplate coupling north of the ridge (i.e., strain partitioning). At the latitude of Ecuador, the NAB is defined by transpressional deformation accommodating east-northeastward motion along its boundary with South America. In southern to central Colombia, the NAB is dissected by several mapped and prominent regional shear zones. At these latitudes the NAB may be bound to the west by the Choco block and the transpressional Atrato-Uraba fault system and to the east by the Guayaquil-Algeciras fault system. And in northern Colombia the Caribbean - South America plate boundary is defined by the NAB and proposed Maracaibo and Guajira blocks. We investigate the deformation of northwestern South America, including the kinematics of NAB utilizing a new velocity field based on continuous GPS and existing episodic GPS data in Ecuador, Colombia, Venezuela and Panama. We reference these new velocities to a newly estimated Euler vector for the South America plate based on inversion of cGPS data from stations east of the Andes. The new velocity field and published earthquake slip vectors are inverted to solve for the Euler vectors of the NAB, Choco, Panama, Maracaibo and Guajira blocks and interseismic elastic strain accumulation (interseismic coupling) on block-bounding faults using a block modeling approach. We test a suite of block models to investigate the tectonic nature of the NAB along strike and the style of faulting in the upper plate accommodating block motion. Through the estimation of elastic strain accumulation on all block-bounding faults, we improve the understanding of interseismic coupling along a convergent margin capable of producing M>8 earthquakes and faults in the upper plate capable of generating M>6 earthquakes.

  6. The use of the Long Baseline Array in Australia for precise geodesy and absolute astrometry

    CERN Document Server

    Petrov, Leonid; Bertarini, Alessandra; Deller, Adam; Pogrebenko, Sergei; Mujunen, Ari

    2008-01-01

    We report the results of a successful 12 hour 22 GHz VLBI experiment using a heterogeneous network that includes radio telescopes of the Long Baseline Array (LBA) in Australia and several VLBI stations that regularly observe in geodetic VLBI campaigns. We have determined positions of three VLBI stations, ATCA-104, Ceduna and Mopra, with an accuracy of 3-30 mm using a novel technique of data analysis. These stations have never before participated in geodetic experiments. We observed 105 radio sources, and amongst them 5 objects which have not previously been observed with VLBI. We have determined positions of these new sources with the accuracy of 2-6 mas. We make conclusion that the LBA network is capable of conducting absolute astrometry VLBI surveys with accuracy better than 5 mas.

  7. High-Speed Data Recorder for Space, Geodesy, and Other High-Speed Recording Applications

    Science.gov (United States)

    Taveniku, Mikael

    2013-01-01

    A high-speed data recorder and replay equipment has been developed for reliable high-data-rate recording to disk media. It solves problems with slow or faulty disks, multiple disk insertions, high-altitude operation, reliable performance using COTS hardware, and long-term maintenance and upgrade path challenges. The current generation data recor - ders used within the VLBI community are aging, special-purpose machines that are both slow (do not meet today's requirements) and are very expensive to maintain and operate. Furthermore, they are not easily upgraded to take advantage of commercial technology development, and are not scalable to multiple 10s of Gbit/s data rates required by new applications. The innovation provides a softwaredefined, high-speed data recorder that is scalable with technology advances in the commercial space. It maximally utilizes current technologies without being locked to a particular hardware platform. The innovation also provides a cost-effective way of streaming large amounts of data from sensors to disk, enabling many applications to store raw sensor data and perform post and signal processing offline. This recording system will be applicable to many applications needing realworld, high-speed data collection, including electronic warfare, softwaredefined radar, signal history storage of multispectral sensors, development of autonomous vehicles, and more.

  8. Methods of Celestial Mechanics Volume II: Application to Planetary System, Geodynamics and Satellite Geodesy

    CERN Document Server

    Beutler, Gerhard

    2005-01-01

    G. Beutler's Methods of Celestial Mechanics is a coherent textbook for students as well as an excellent reference for practitioners. Volume II is devoted to the applications and to the presentation of the program system CelestialMechanics. Three major areas of applications are covered: (1) Orbital and rotational motion of extended celestial bodies. The properties of the Earth-Moon system are developed from the simplest case (rigid bodies) to more general cases, including the rotation of an elastic Earth, the rotation of an Earth partly covered by oceans and surrounded by an atmosphere, and the rotation of an Earth composed of a liquid core and a rigid shell (Poincaré model). (2) Artificial Earth Satellites. The oblateness perturbation acting on a satellite and the exploitation of its properties in practice is discussed using simulation methods (CelestialMechanics) and (simplified) first order perturbation methods. The perturbations due to the higher-order terms of the Earth's gravitational potential and reso...

  9. Quantifying crustal response to deep active intrusions with geodesy-based finite element modeling

    Science.gov (United States)

    Henderson, S. T.; Pritchard, M. E.; Elliott, J.

    2013-12-01

    The Altiplano-Puna Volcanic Complex (APVC, 21-24 S, 66-69 W) is a first order feature of the Central Andes Volcanic Arc. The APVC consists of over 10,000 km^3 of dacitic ignimbrites deposited in the late Miocene, making it one of the largest concentrations of silicic volcanism in the world. The persistent and intense magmatic flux in this region has likely contributed to the thickened crust (50-70 km), elevated geotherm (>50 C/km) and extensive partial melt (mass balance between source and sink reservoirs, and require physically realistic rheological parameters of the crust. Modeling is performed with Pylith finite element software on a cylindrical three dimensional domain with a radius of 300 km and depth of 200 km. Our models assume pressurization in a viscoelastic crust, and therefore describe crustal response rather than dynamic processes of fluid creation and motion. Surface deformation timescales are highly dependent on geothermal gradient and source pressurization history. While still inconclusive, the potential for an abrupt end to surface deformation has important implications for the characterization of creep versus relaxation processes occurring in response to deep intrusions. Ultimately, crustal scale numerical models provide a means to check petrologically-derived depths of fluid accumulation, in addition to theoretical estimates of softening that occurs with distributed partial melt. The specific models presented are tuned to the subsurface conditions of the APVC, but may be relevant to arc intrusions below the brittle-ductile transition elsewhere.

  10. The Tropospheric Products of the International VLBI Service for Geodesy and Astrometry

    Science.gov (United States)

    Heinkelmann, Robert; Schwatke, Christian

    2010-01-01

    The IVS runs two tropospheric products: The IVS tropospheric parameter rapid combination monitors the zenith wet delay (ZWD) and zenith total delay (ZTD) of the rapid turnaround sessions R1 and R4. Goal of the combination is the identification and the exclusion of outliers by comparison and the assessment of the precision of current VLBI solutions in terms of tropospheric parameters. The rapid combination is done on a weekly basis four weeks after the observation files are released on IVS Data Centers. Since tropospheric and geodetic parameters, such as vertical station components, can significantly correlate, the consistency of the ZTD can be a measure of the consistency of the corresponding TRF as well. The ZWD mainly rely on accurate atmospheric pressure data. Thus, besides estimation techniques, modeling and analyst s noise, ZWD reflects differences in the atmospheric pressure data applied to the VLBI analysis. The second product, called tropospheric parameter long-term combination, aims for an accurate determination of climatological signals, such as trends of the atmospheric water vapor observed by VLBI. Therefore, the long-term homogeneity of atmospheric pressure data plays a crucial role for this product. The paper reviews the methods applied and results achieved so far and describes the new maintenance through DGFI.

  11. Kinematics of the Himalayan arc from GPS geodesy and structural geology

    Science.gov (United States)

    Styron, R.; Taylor, M. H.

    2009-12-01

    The distribution, orientation, and kinematics of active faults in the Himalayan arc suggests arc-parallel extension. Here we use ~130 Himalayan and south Tibetan GPS geodetic vectors from published sources in ITRF2000 relative to stable Eurasia, decomposed into arc-normal and arc-parallel components, to quantify arc-parallel extension and arc-normal shortening. Arc-parallel velocities increase from zero in eastern Nepal, where India’s convergence with the Himalaya is normal to the arc, to ~20 mm /yr towards the syntaxes, where convergence is highly oblique. Arc-parallel extension of >30 mm /yr from Ladakh through Sikkim is observed, as is dextral shear of 6-7 mm /yr across the arc in the northwest Himalaya, which decreases to insignificant values in eastern Nepal. We also present results of field mapping of the active, subvertical, right-slip, Tibrikot fault, which cuts the MCT zone of western Nepal. The location and kinematics of this fault suggests it represents the southeastward propagation of the Karakoram-Humla fault system, which kinematically link rifts such as the Thakkhola graben and the Gurla Mandhata and Leo Pargil core complexes. These fault systems accommodate extension and progressive translation of the Himalaya relative to south Tibet commensurate with the progressive increase in convergence obliquity between India and the Himalaya.

  12. A study of risk in the metropolitan area of Guadalajara through dense GPS geodesy

    Science.gov (United States)

    Marquez-Azua, B.; Saldana-Hernandez, F.; Medina de La Pena, H.

    2007-05-01

    Geodesic measurements from the Global Positioning System (GPS) are used extensively for basic earth science research into natural hazards and seismic risk. In the private sector, GPS technology is additionally used for cadastral and photogrammetric mapping surveys, definition of political-administrative limits, space analysis with thematic cartography, GIS, and land-use planning, with a wide variety of applied social, economic, and political purposes, including conservation of the environment. The city of Guadalajara and its surrounding urban area has expanded greatly in the last three decades as a result of industrial, commercial and housing activity that have substantially changed in their urban morphology. This period of unprecedented growth has occurred primarily in an unplanned and sometimes disarticulated and unbalanced manner, incongruous with the development of the most important city in western Mexico. The Department of Geography of the University of Guadalajara and the Institute of Territorial Information of the State of Jalisco (IITJ) have initiated a study of 89 geodetic sites that are located in the metropolitan zone of Guadalajara to assist in future planning and regulation of urban development, including urban and rural cadastral surveys and the establishment of diverse public services. Our work includes careful examination and evaluation of the quality and distribution of these geodetic sites with regard to anticipated growth of the metropolitan municipalities, and the vulnerability of urban zones to ground subsidence or landslides. Guadalajara is also located in a seismic zone, making precise continuous GPS measurements useful for identifying rates of strain accumulation and aseismic strain events that cannot be measured by seismographs.

  13. Research in Geodesy Based Upon Radio Interferometric Observations of GPS (Global Positioning System) Satellites.

    Science.gov (United States)

    1986-12-31

    1983. Robertson, D. S., Carter, W. E., Eanes, R. J., Schutz , B. E., Tapley, B. D., King, R. W., Langley, R. B., Morgan, P. J., and Shapiro, I. I... Alfred Leick (on leave from the Univ. of Maine) Staff Scientists: Drs. Richard I. Abbot, Yehuda Bock, and Sergei A. Gourevitch Principal Research

  14. Active orogeny of the south-central Andes studied with GPS geodesy

    Directory of Open Access Journals (Sweden)

    E. Kendrick

    2006-12-01

    Full Text Available We present GPS measurements of the crustal velocity field in the southern Central Andes between the Santa Cruz corner and the Malargüe fold and thrust belt, and model this interseismic velocity field as the combination of an ephemeral, elastic signal associated with locking of the main plate boundary, and a steady and non-reversing component of displacement associated with localized backarc convergence and growth of the mountain belt. We find that this second component, i.e. the ongoing and permanent displacement of the forearc and the high Andes relative to the craton, can be modeled very well as a steady clockwise rotation of an Andean microplate about a pole located in southern Argentina. Near the Malargüe Basin, this microplate (or block is moving nearly parallel to the strike of the orogen, transporting material towards the bend in the central Andes. Farther north, in the southern limb of the Central Andes, the motion of this same crustal block is directed nearly perpendicular to the strike of the mountain belt. Our results suggest that permanent deformation rates in the backarc range from a maximum of ~ 6-7 mm/yr in the Bolivian Subandes to less than ~ 3 mm/yr in the Argentine Precordillera and Malargue fold and thrust belt. It is likely that most active backarc deformation is accruing in a narrow zone (~ 50 km wide associated with the backarc boundary (usually defined as the thrust front though at this stage it is impossible to distinguish whether specific backarc structures are actively accruing strain.

  15. VLBI in the service of geodesy 1968-2000: An Onsala perspective

    Science.gov (United States)

    Elgered, G.; Haas, R.

    Very-Long-Baseline Interferometry (VLBI) has been used at the Onsala Space Observatory since 1968. In this paper we summarize the geodetic application of VLBI in terms of the observations so far obtained and the main geodetic results. Estimated time series of intercontinental as well as European baseline lengths are presented. The present facilities include the 20 m radome enclosed radio telescope, several continuously operating GPS receivers, a 21/31 GHz microwave radiometer for studies of the atmospheric excess propagation path due to water vapour, and a gravimetry foundation anchored in the solid granite rock in a laboratory environment. Geodetic VLBI continues to play an important role for the maintenance of the International Terrestrial Reference Frame (ITRF). The international CORE programme has the goal to continuously measure the earth rotation parameters. Over long time scales nutation and UT1 are not possible to estimate reliably from techniques using satellites in orbits around the earth.

  16. Development status of the planar electrostatic gradiometer GREMLIT for airborne geodesy

    Science.gov (United States)

    Foulon, B.; Christophe, B.; Douch, K.; Panet, I.

    2012-12-01

    The GREMLIT airborne gravity gradiometer is taking advantage of technologies, formerly developed by ONERA for the GRACE and GOCE space missions. Built using a planar configuration with four proof-masses at the corners of a square, the gradiometer is mounted on a dedicated stabilized platform which is controlled by the common mode outputs of the instrument itself to achieve a sufficient rejection ratio of the perturbations/vibrations induced by the airborne environment in the horizontal directions. The levitation of the proof-masses along the normal gravity and the vibration isolation of the platform are designed to allow the instrument to support between +2.5 g and 0 g along the vertical axis. With the help of additional fiber gyro data, the gradiometer differential measurements provide the necessary information to extract the 3 Tyy, Tzz and Tyz independent components of the gravity gradient tensor at the location of the instrument. In addition to be especially well suited to sustain the proof-mass levitation in the Earth's gravity field, such a planar configuration also presents an intrinsic linearity of the horizontal control loops which minimizes the aliasing due to high frequency vibrations or motions generated outside the measurement bandwidth. The compactness of the gradiometer design, with all the electrodes of the 4 accelerometers engrave on the same ULE plate, ensures excellent dimensional stability, good thermal homogeneity and makes the conception of the stabilized platform easier. The detailed error budget of the gradiometer instrument associated with the estimated performance of the platform and the assumed characteristics of the additional attitude, rate and position sensors lead to expect a performance objective between 0.1 and 1 Eötvös taking into account the difficulty of measurements onboard an aircraft by comparison to the particularly conducive satellite measurement environment. The GREMLIT gravity gradiometer systems is more particularly developed to cover the land/sea transition zone with a uniform precision, and a spatial resolution expected higher than from classical airborne gravimetry.

  17. Up-dated configuration of the planar electrostatic gradiometer GREMLIT for airborne geodesy

    Science.gov (United States)

    Foulon, Bernard; Douch, Karim; Christophe, Bruno; Panet, Isabelle; Boulanger, Damien; Lebat, Vincent

    2013-04-01

    The knowledge of the gravity field of the Earth has been considerably improved thanks to global positioning satellites constellations and to space gravity measurements from recent GRACE and GOCE missions. But the spatial resolution of those gravity data essentially addresses the large and medium wavelengths of the field (down to a resolution of 90km) and it is therefore essential to complete them at the shorter wavelengths in particular in the areas where spatial distribution and quality of ground data remain quite uneven like in high mountain or coastal areas. Taking advantage of technologies, formerly developed by ONERA for the GRACE and GOCE space missions, the GREMLIT airborne gravity gradiometer is more particularly developed to cover the land/sea transition zone with a uniform precision, and a spatial resolution expected higher than from classical airborne gravimetry. Built using a configuration with eight planar proof-masses at the corners of a cube, the gradiometer is mounted on a dedicated stabilized platform which is controlled by the common mode outputs of the instrument itself to achieve a sufficient rejection ratio of the perturbations/vibrations induced by the airborne environment in the horizontal directions. The levitation of the proof-masses along the normal gravity and the vibration isolation of the platform are designed to allow the instrument to support between +2.5 g and 0 g along the vertical axis. The gradiometer differential measurements along the two horizontal axes provide the necessary information to extract the six components of the gravity gradient tensor at the location of the instrument. Well suited to sustain the proof-mass levitation in the Earth's gravity field, the planar configuration of each accelerometer also presents an intrinsic linearity of the horizontal control loops which minimizes the aliasing due to high frequency vibrations or motions generated outside the measurement bandwidth. The compactness of the gradiometer design ensures excellent dimensional stability, good thermal homogeneity and makes the conception of the stabilized platform easier. The detailed error budget of the gradiometer instrument associated with the estimated performance of the platform and the assumed characteristics of the additional attitude, rate and position sensors lead to expect a performance objective between 0.1 and 1 Eötvös taking into account the difficulty of measurements onboard an aircraft by comparison to the particularly conducive satellite measurement environment.

  18. Neotectonics of Puerto Rico and the Virgin Islands, northeastern Caribbean, from GPS geodesy

    Science.gov (United States)

    Jansma, Pamela E.; Mattioli, Glen S.; Lopez, Alberto; Demets, Charles; Dixon, Timothy H.; Mann, Paul; Calais, Eric

    2000-12-01

    The boundary between the North American and Caribbean plates is characterized primarily by left-lateral motion along predominantly east-west striking faults. Seismicity and marine geophysical survey data are consistent with at least two, and possibly three, microplates in the diffuse boundary zone in the northeastern Caribbean: (1) the Gonave, (2) the Hispaniola, and (3) the Puerto Rico-northern Virgin Islands (PRVI). We discuss results from GPS geodetic measurements acquired since 1994 to test the microplate hypothesis, define PRVI translation and rotation within the boundary zone, and constrain PRVI neotectonics. GPS-derived velocities are analyzed with respect to both North American and Caribbean plate reference frames. Integrated displacements across PRVI are limited to a few millimeters per year, consistent with a rigid PRVI and permitting calculation of an average velocity for PRVI. The motions of PRVI relative to North America and the Caribbean are 16.9±1.1 mm/yr toward N68°E±3° (1σ) and 2.4±1.4 mm/yr toward S79°W±26° (1σ), respectively. In contrast with some recent models, ongoing rotation of PRVI about a nearby (effects along the north Hispaniola deformed belt and the Septentrional fault zone are considered. The opening rate implies an age of the Mona rift of 2-3 million years, agreeing with marine geophysical data that support a young age for the structure.

  19. From Geodesy to Tectonics: Observing Earthquake Processes from Space (Augustus Love Medal Lecture)

    Science.gov (United States)

    Parsons, Barry

    2017-04-01

    A suite of powerful satellite-based techniques has been developed over the past two decades allowing us to measure and interpret variations in the deformation around active continental faults occurring in earthquakes, before the earthquakes as strain accumulates, and immediately following them. The techniques include radar interferometry and the measurement of vertical and horizontal surface displacements using very high-resolution (VHR) satellite imagery. They provide near-field measurements of earthquake deformation facilitating the association with the corresponding active faults and their topographic expression. The techniques also enable pre- and post-seismic deformation to be determined and hence allow the response of the fault and surrounding medium to changes in stress to be investigated. The talk illustrates both the techniques and the applications with examples from recent earthquakes. These include the 2013 Balochistan earthquake, a predominantly strike-slip event, that occurred on the arcuate Hoshab fault in the eastern Makran linking an area of mainly left-lateral shear in the east to one of shortening in the west. The difficulty of reconciling predominantly strike-slip motion with this shortening has led to a wide range of unconventional kinematic and dynamic models. Using pre-and post-seismic VHR satellite imagery, we are able to determine a 3-dimensional deformation field for the earthquake; Sentinel-1 interferometry shows an increase in the rate of creep on a creeping section bounding the northern end of the rupture in response to the earthquake. In addition, we will look at the 1978 Tabas earthquake for which no measurements of deformation were possible at the time. By combining pre-seismic 'spy' satellite images with modern imagery, and pre-seismic aerial stereo images with post-seismic satellite stereo images, we can determine vertical and horizontal displacements from the earthquake and subsequent post-seismic deformation. These observations suggest post-seismic slip concentrated on a thrust ramp at the end of the likely earthquake fault and, together with new radar measurements, can be modeled with slip rates declining approximately inversely with time from the earthquake. Measurements such as these examples provide the basis for investigating the dynamic response to the earthquakes to changes in stress occurring in them.

  20. Aseismic slip and seismogenic coupling in the Marmara Sea: What can we learn from onland geodesy?

    Science.gov (United States)

    Klein, E.; Duputel, Z.; Masson, F.; Yavasoglu, H.; Agram, P.

    2017-04-01

    Ever since the Mw7.4 Izmit earthquake in 1999, evaluation of seismic hazard associated with the last unbroken segments of the North Anatolian fault is capital. A strong controversy remains over whether Marmara fault segments are locked or are releasing strain aseismically. Using a Bayesian approach, we propose a preliminary probabilistic interseismic model constrained by published GPS data sets. The posterior mean model show that Ganos and Cinarcik segments are locked while creep is detected in the central portion of Marmara fault. Our analysis, however, reveals that creeping segments are associated with large model uncertainties, which mainly results from the sparsity of current geodetic observations. We then discuss how the GPS network can be improved to attain more reliable assessment of interseismic slip rates. With this purpose, we implement a network optimization procedure to identify the most favorable distribution of stations measuring strain accumulation in the Marmara Sea.

  1. Geodesy for Evaluating the Impact of Sea Level Rise on NASA Centers and Facilities

    Science.gov (United States)

    Bell, L. J.; Nerem, R.; Masters, D. S.; Meertens, C. M.

    2012-12-01

    Sea level is rising in response to climate change. Currently the global mean rate is a little over 3 mm/year, but it is expected to accelerate significantly over this century. This will have a profound impact on coastal populations and infrastructure, including NASA centers and facilities. A detailed study proposed by the University of Colorado's Center for Astrodynamics Research on the impact of sea level rise on a few of NASA's most vulnerable facilities was recently funded by NASA. Individual surveys at several high-risk NASA centers will be conducted and used as case studies for a broader investigation that needs to be done for coastal infrastructure around the country. The first year of the study will include implementing and conducting a terrestrial laser scanning (TLS) and GPS survey at Kennedy Space Center, Cape Canaveral, Florida, and potentially at Wallops Flight Facility, Wallops Island, Virginia, and Langley Research Center, Hampton, Virginia. We will use a broad array of geodetic tools to perform this study - much of which has been developed over the last few decades by NASA and its investigators. We will use airborne lidar data and terrestrial laser scanning (TLS) data to construct detailed digital elevation models (DEMs) of the facilities that we assess. We will use GPS data to assess the rate of vertical land movement at the facilities and to tie the DEM to tide gauges and other reference points. We will use satellite altimeter data from TOPEX, Jason-1, and Jason-2 to assess the sea level changes observed near these NASA facilities over the last 20 years to see if it offers clues for the future. We will also use GRACE satellite gravity observations to predict the regional changes in sea level caused by the melting of ice complexes around the world. We will use these datasets along with sea level projections from global climate models (GCMs) and semi-empirical projections to make detailed maps of sea level inundation for the years 2050 and 2100 for varying amounts of sea level rise. We will also work with other selected investigators to assess the effects of tidal variations and storm surge when coupled with changes in mean sea level, as storm surge is likely when initial damage due to sea level rise will occur.

  2. GEODESY AND DIGITAL CARTOGRAPHIC SURVEY IN FILDES PENINSULA,REY JORGE ISLAND,ANTARCTICA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The present paper summarizes a joint effort undertaken by the Instituto Geográfico Militar de Chile (IGM) and the Instituto Antártico Chileno (INACH) in order to obtain digital cartography of the Fildes Peninsula,Rey Jorge Island,Antarctica.This peninsula constitutes the prototype project area for the main IGM_INACH project N° 153 “Cartographic Survey and Geographic Information System of the South Shetlands Islands" The Digital Cartography was implemented at the 1∶5 000 scale,using geodetic GPS control points referenced to ITRF 92 and WGS 84 Data.The UTM Projection was used.All products were produced in compliance with the cartographic standards of the IGM. This cartography was designed in order to satisfy the requirements of a Geographic Information System developed by INACH.This geo_referenced database incorporates a variety of thematic information,enabling it to support scientific investigations,environmental and multi_disciplinary studies,and other applications. As a result of this project the Instituto Geográfico Militar de Chile produced a map at 1∶5 000 scale in digital format,and also a 1∶10 000 topographic map,in paper format,with two editions: first edition of two charts and a second edition with one chart covering the whole project area. Chile and other countries have a number of important permanent activities in this area. These maps are designed to support several and diverse geo_spatial studies related to these activities.

  3. NASA Space Geodesy Program: GSFC data analysis, 1992. Crustal Dynamics Project VLBI geodetic results, 1979 - 1991

    Science.gov (United States)

    Ryan, J. W.; Ma, C.; Caprette, D. S.

    1993-01-01

    The Goddard VLBI group reports the results of analyzing 1648 Mark 3 data sets acquired from fixed and mobile observing sites through the end of 1991, and available to the Crustal Dynamics Project. Two large solutions were used to obtain Earth rotation parameters, nutation offsets, radio source positions, site positions, site velocities, and baseline evolution. Site positions are tabulated on a yearly basis for 1979 to 1995, inclusive. Site velocities are presented in both geocentric Cartesian and topocentric coordinates. Baseline evolution is plotted for 200 baselines, and individual length determinations are presented for an additional 356 baselines. This report includes 155 quasar radio sources, 96 fixed stations and mobile sites, and 556 baselines.

  4. The Earth's gravity field from satellite geodesy - a 30 year adventure.

    Science.gov (United States)

    Rapp, R. H.

    1991-12-01

    The first information on the Earth's gravitational field from artificial satellite observations was published in 1958. The next years have seen a dramatic improvement in the resolution and accuracy of the series representation of the Earth's gravity field. The improvements have taken place slowly taking advantage of improved measurement accuracy and the increasing number of satellites. The proposed ARISTOTELES mission would provide the opportunity to take a significant leap in improving our knowledge of the Earth's gravity field.

  5. Time biases in laser ranging observations: A concerning issue of Space Geodesy

    Science.gov (United States)

    Exertier, Pierre; Belli, A.; Lemoine, J. M.

    2017-09-01

    Time transfer by Laser Ranging (LR) recently demonstrated a remarkable stability (a few ps over ∼1000 s) and accuracy (service. The approach we investigate is to compute time synchronization between clocks used at LR stations using accurate data of the Time Transfer by Laser Link (T2L2) experiment onboard the satellite Jason-2 (Samain et al., 2014). Systematic time biases are estimated against the UTC time scale for a set of 22 observing stations in 2013, in the range of zero to a few μ s. Our results suggest that the ILRS network suffers from accuracy issues, due to time biases in the laser ranging observations. We discuss how these systematic effects impact the precise orbit determination of LAGEOS geodetic satellites over a 1-year analysis, and additionally give a measure of the local effect into station coordinates, regarding in particular the effect in the east-west component that is of 2-6 mm for a typical systematic time bias of one μ s.

  6. Space Geodesy and Geochemistry Applied to the Monitoring, Verification of Carbon Capture and Storage

    Energy Technology Data Exchange (ETDEWEB)

    Swart, Peter

    2013-11-30

    This award was a training grant awarded by the U.S. Department of Energy (DOE). The purpose of this award was solely to provide training for two PhD graduate students for three years in the general area of carbon capture and storage (CCS). The training consisted of course work and conducting research in the area of CCS. Attendance at conferences was also encouraged as an activity and positive experience for students to learn the process of sharing research findings with the scientific community, and the peer review process. At the time of this report, both students have approximately two years remaining of their studies, so have not fully completed their scientific research projects.

  7. GPS Medium-Range Kinematic Positioning for the Seafloor Geodesy of Eastern Taiwan

    Directory of Open Access Journals (Sweden)

    Toshiaki Tsujii

    2011-01-01

    Full Text Available To realize the plate motion of the Philippine Sea Plate (PSP and the characteristics of crustal deformation in the plate boundary zone between the PSP and Eurasia Plate, three seafloor geodetic arrays using a combination of GPS kinematic positioning and acoustic ranging techniques have been established off eastern Taiwan since 2008. Each array is composed of three transponders deployed on the ocean bottom in a triangular shape and has been observed at least two times since 2009. The GPS kinematic positioning in the relative distance ranging from 80 to 120 km off the eastern coast of Taiwan plays a main role in the whole seafloor geodetic deformation system. Seven stations from Taiwan Continuous GPS Array are taken as reference sites and three or four rover GPS units are set up on the vessel or buoy. Both on-land reference and onboard rover receivers record data in sampling rates of 1 and 5 Hz to determine the instantaneous positions of transducer onboard which transmits and receives the acoustic signal to and from seafloor transponders and the attitude of vessel or buoy in kinematic mode. We compare the results of medium-range kinematic positioning between the on-land reference stations and rovers onboard by the GrafNav and Bernese V5.0 software, respectively. In addition, we determine the attitude at all times by way of computing the inter-distance of rover receivers onboard. Hence there are two positioning results can be estimated which are direct (by short relative distances from onboard and indirect (by medium-range kinematic mode for each GPS unit from on-land continuous stations methods, and the difference reveals in decimeter level.

  8. GPS MEDIUM-RANGE KINEMATIC POSITIONING FOR THE SEAFLOOR GEODESY OFF EASTERN TAIWAN

    Directory of Open Access Journals (Sweden)

    Masataka Ando

    2011-01-01

    Full Text Available To realize the plate motion of the Philippine Sea Plate (PSP and the characteristics of crustal deformation in the plate boundary zone between the PSP and Eurasia Plate, three seafloor geodetic arrays using a combination of GPS kinematic positioning and acoustic ranging techniques have been established off eastern Taiwan since 2008. Each array is composed of three transponders deployed on the ocean bottom in a triangular shape and has been observed at least two times since 2009. The GPS kinematic positioning in the relative distance ranging from 80 to 120 km off the eastern coast of Taiwan plays a main role in the whole seafloor geodetic deformation system. Seven stations from Taiwan Continuous GPS Array are taken as reference sites and three or four rover GPS units are set up on the vessel or buoy. Both on-land reference and onboard rover receivers record data in sampling rates of 1 and 5 Hz to determine the instantaneous positions of transducer onboard which transmits and receives the acoustic signal to and from seafloor transponders and the attitude of vessel or buoy in kinematic mode. We compare the results of medium-range kinematic positioning between the on-land reference stations and rovers onboard by the GrafNav and Bernese V5.0 software, respectively. In addition, we determine the attitude at all times by way of computing the inter-distance of rover receivers onboard. Hence there are two positioning results can be estimated which are direct (by short relative distances from onboard and indirect (by medium-range kinematic mode for each GPS unit from on-land continuous stations methods, and the difference reveals in decimeter level.

  9. Underground atom gradiometer array for mass distribution monitoring and advanced geodesy

    Science.gov (United States)

    Canuel, B.

    2015-12-01

    After more than 20 years of fundamental research, atom interferometers have reached sensitivity and accuracy levels competing with or beating inertial sensors based on different technologies. Atom interferometers offer interesting applications in geophysics (gravimetry, gradiometry, Earth rotation rate measurements), inertial sensing (submarine or aircraft autonomous positioning), metrology (new definition of the kilogram) and fundamental physics (tests of the standard model, tests of general relativity). Atom interferometers already contributed significantly to fundamental physics by, for example, providing stringent constraints on quantum-electrodynamics through measurements of the hyperfine structure constant, testing the Equivalence Principle with cold atoms, or providing new measurements for the Newtonian gravitational constant. Cold atom sensors have moreover been established as key instruments in metrology for the new definition of the kilogram or through international comparisons of gravimeters. The field of atom interferometry (AI) is now entering a new phase where very high sensitivity levels must be demonstrated, in order to enlarge the potential applications outside atomic physics laboratories. These applications range from gravitational wave (GW) detection in the [0.1-10 Hz] frequency band to next generation ground and space-based Earth gravity field studies to precision gyroscopes and accelerometers. The Matter-wave laser Interferometric Gravitation Antenna (MIGA) presented here is a large-scale matter-wave sensor which will open new applications in geoscience and fundamental physics. The MIGA consortium gathers 18 expert French laboratories and companies in atomic physics, metrology, optics, geosciences and gravitational physics, with the aim to build a large-scale underground atom-interferometer instrument by 2018 and operate it till at least 2023. In this paper, we present the main objectives of the project, the status of the construction of the instrument and the motivation for the applications of MIGA in geosciences

  10. BepiColombo's geodesy and relativity experiments from an extended mission

    Science.gov (United States)

    Imperi, Luigi; Junior Mariani, Mirco; Iess, Luciano

    2015-04-01

    The Mercury Orbiter Radio science Experiment (MORE) of the ESA-JAXA BepiColombo mission to Mercury consists of ground and onboard instrumentation enabling a highly stable, multi-frequency radio link at X and Ka band (8.4 and 32.5 GHz). Range rate measurements obtained from this advanced radio link will be unaffected by plasma noise and are expected to attain accuracies of 3 micron/s (at 1000 seconds integration time) at nearly all elongation angles. Thanks to a novel wideband ranging system, based on a 24 Mcps pseudo-noise modulation, the spacecraft range will be measured to an accuracy 20 cm (two-way). The MORE investigation will greatly benefit from a direct measurement of the vectorial non-gravitational accelerations by means of the Italian Spring Accelerometer (ISA). The high quality radio-metric observables will provide a precise reconstruction of the spacecraft orbit and an accurate estimation of the gravity field and rotational state of the planet. Thanks to the dedicated onboard instrumentation, MORE is expected to improve significantly the already outstanding MESSENGER results, limited by plasma noise and the difficulty of modeling non-gravitational accelerations. In addition, BepiColombo will carry out tests of general relativity by reconstructing the orbit of the planet and the propagation of photons in the solar gravitational field. Indeed, since the orbit of Mercury is affected more than any other planets by relativistic effects, the relativity experiment aims at improving the determination of several Post-Newtonian (PN) parameters. Further physical parameters such as the rate of change of the gravitational constant G and the oblateness factor J2 of the Sun will be estimated as well. Several numerical simulations of the MORE experiment have been carried out over the past years. In this work we present a new set of simulations under the latest mission scenario and instrument performances, as obtained from ground tests of the instrumentation. Our simulation setup solves simultaneously for gravity harmonic coefficients, rotational state elements and relativistic PN parameters. The paper reports on the results obtained under the nominal, one year, mission duration, and shows the improvements attained by an extended mission of one or two years. Indeed, the pericenter of BepiColombo's planetary orbiter will drift from 15 degree N to 13, 41, 70 degree S respectively in one, two and three years. In addition the pericenter altitude will decrease from 480 to 250 km in three years. This will allow a more comprehensive and homogeneous reconstruction of the gravity field and rotational state of Mercury. We show also that an extended mission would be greatly beneficial also to the relativity experiment.

  11. MIGA: Combining laser and matter wave interferometry for mass distribution monitoring and advanced geodesy

    CERN Document Server

    Canuel, B; Amand, L; Bertoldi, A; Cormier, E; Fang, B; Gaffet, S; Geiger, R; Harms, J; Holleville, D; Landragin, A; Lefèvre, G; Lhermite, J; Mielec, N; Prevedelli, M; Riou, I; Bouyer, P

    2016-01-01

    The Matter-Wave laser Interferometer Gravitation Antenna, MIGA, will be a hybrid instrument composed of a network of atom interferometers horizontally aligned and interrogated by the resonant field of an optical cavity. This detector will provide measurements of sub Hertz variations of the gravitational strain tensor. MIGA will bring new methods for geophysics for the characterization of spatial and temporal variations of the local gravity field and will also be a demonstrator for future low frequency Gravitational Wave (GW) detections. MIGA will enable a better understanding of the coupling at low frequency between these different signals. The detector will be installed underground in Rustrel (FR), at the "Laboratoire Souterrain Bas Bruit" (LSBB), a facility with exceptionally low environmental noise and located far away from major sources of anthropogenic disturbances. We give in this paper an overview of the operating mode and status of the instrument before detailing simulations of the gravitational backg...

  12. Interest of a combined electrostatic/cold atoms gradiometers configuration for airborne geodesy

    Science.gov (United States)

    Foulon, Bernard; Christophe, Bruno; Douch, Karim; Panet, Isabelle; Bresson, Alexandre

    2014-05-01

    During these two last decades, the knowledge of the gravity field of the Earth has been considerably improved thanks to global positioning satellites constellations and to recent space gravity missions. However these gravity data do not address spatial resolution shorter than 90 km. Taking advantage of technologies, developed by ONERA for the GRACE and GOCE space missions, the GREMLIT airborne gravity gradiometer is more particularly developed to complete them at the short wavelengths in particular in the areas where spatial distribution and quality of ground data remain quite uneven like for example land/sea transition. Built using a double planar electrostatic gradiometer with eight proof-masses in a cubic configuration, the GREMLIT instrument is mounted on a dedicated stabilized platform which is controlled by the common mode outputs of the instrument itself to achieve a sufficient rejection ratio of the perturbations/vibrations induced by the airborne environment in the horizontal directions. The levitation of the proof-masses along the normal gravity and the vibration isolation of the platform are designed to allow the instrument to support 1g ± 1g along the vertical axis. In addition to be well suited to sustain the proof-mass levitation in the Earth's gravity field, the planar configuration of each accelerometer also presents an intrinsic linearity of the horizontal control loops which minimizes the aliasing due to high frequency vibrations or motions generated outside the measurement bandwidth. Taking into account the estimated performance of the platform and associated with its additional attitude and angular rate sensors, the gradiometer differential measurements along the two horizontal axes provide the necessary information to extract 5 of the 6 components of the gravity gradient tensor at the location of the instrument with a performance objective better than 1 Eötvös along the two Txx and Tyy horizontal components. The last vertical Tzz component of the gravity gradient tensor is nominally deduced from the null trace property. But using cold atoms interferometry along this vertical axis and combining its data (gravity gradient and absolute gravity magnitude) with the ones provided by GREMLIT can induce a very fruitful improvement for both instruments. A combined configuration based the GREMLIT electrostatic gradiometer associated with the GIBON cold atoms interferometer, both under development in ONERA's Physics Department, will be proposed. In spite of an increased technological complexity, the theoretical interest of such a configuration is to associate the high resolution of the electrostatic instrument with the absolute stability of the cold atoms interferometer.

  13. Updated Status of the Planar Electrostatic Gradiometer GREMLIT for Airborne Geodesy

    Science.gov (United States)

    Foulon, B.; Christophe, B.; Douch, K.; Lebat, V.; Panet, I.

    2014-12-01

    In spite of the important improvement provided by the recent space missions GRACE and GOCE to the accuracy of Earth's gravity field models, many geodetic and geophysical issues require higher resolution models. To address spatial resolution in the range between 80 km and 10 km, the airborne gravity gradiometry is a convenient way to complete these global models at the short wavelengths in particular in land/sea transition areas where the gravity field is poorly covered by current measurements. Taking advantage of technologies, developed by ONERA for the accelerometers used in these space gravity missions, the new GREMLIT airborne gravity gradiometer is more particularly developed to determine the horizontal components of the gravity gradient tensor in the instrumental frame. GREMLIT is composed of a double deck of a compact planar assembly of 4 electrostatic accelerometers. The eight plane proof-masses are arranged in a cubic configuration and the whole instrument is mounted on a dedicated stabilized platform which is controlled by the common mode outputs of the instrument itself to achieve a sufficient rejection ratio of the perturbations induced by the airborne environment in the horizontal directions. In addition to be well suited to sustain the proof-mass levitation in the Earth's gravity field, the planar configuration presents an intrinsic linearity of the control loops which minimizes the aliasing effects. Concerning the present development, in addition to the one axis prototype manufactured in order to verify the hardware performance of the concept, detailed numerical simulations were conducted over some realistic coastal test areas. Taking into account the data sheet performance of the associated commercial angular and data rate sensors and assuming actual airplane acceleration measurements, they lead to exhibit accuracy below 1E along the Txx and Tyy horizontal components. The characteristic of the controlled platform being one of the key point of the development, a specific study was conducted to conceive, specify and verify its performance through a complete simulation. Finally, the interest of a combined integration of this horizontal high resolution electrostatic instrument with a very stable and absolute vertical cold atoms interferometer will also be mentioned.

  14. The planar electrostatic gradiometer GREMLIT for airborne geodesy and its dedicated controlled platform

    Science.gov (United States)

    Foulon, Bernard; Christophe, Bruno; Huynh, Phuong-Anh; Lebat, Vincent; Perrot, Eddy

    2015-04-01

    Thanks to global positioning satellites constellations and to recent space gravity missions, the knowledge of the gravity field of the Earth has been considerably improved this last decade. Nevertheless these gravity data do not address spatial resolution shorter than 90 km and airborne gravity data collection will be of the highest interest to complete them at the short wavelengths in particular in the areas where spatial distribution and quality of ground data remain quite uneven like for example land/sea transition. Taking advantage of technologies, developed by ONERA for the GRACE and GOCE space missions, the GREMLIT airborne gravity gradiometer is composed of a double planar electrostatic gradiometer with eight proof-masses in a cubic configuration, the GREMLIT instrument is mounted on a dedicated stabilized platform which is controlled by the common mode outputs of the instrument itself to achieve a sufficient rejection ratio of the perturbations/vibrations induced by the airborne environment in the horizontal directions. The levitation of the proof-masses along the normal gravity and the vibration isolation of the platform are designed to allow the instrument to support 1g ± 1g along the vertical axis. In addition to be well suited to sustain the proof-mass levitation in the Earth's gravity field, the planar configuration of each accelerometer also presents an intrinsic linearity of the horizontal control loops which minimizes the aliasing due to high frequency vibrations or motions generated outside the measurement bandwidth. Realistic simulations, based on actual data and recorded environmental aircraft perturbations, demonstrate that a performance better or equal to one Eötvös can be obtained at least along the two horizontal components of the gravity gradient. If the performance of the electrostatic gradiometer is well assessed through the experience of the space accelerometers, the overall performance has also to take into account the estimated performance of the platform associated with its additional attitude and angular rate sensors. The presentation will emphasize the principle of the platform control and how it permits to achieve such performance objective.

  15. Climate-driven vertical acceleration of Icelandic crust measured by continuous GPS geodesy

    KAUST Repository

    Compton, Kathleen

    2015-02-06

    © 2015 The Authors. Earth\\'s present-day response to enhanced glacial melting resulting from climate change can be measured using Global Positioning System (GPS) technology. We present data from 62 continuously operating GPS instruments in Iceland. Statistically significant upward velocity and accelerations are recorded at 27 GPS stations, predominantly located in the Central Highlands region of Iceland, where present-day thinning of the Iceland ice caps results in velocities of more than 30mm/yr and uplift accelerations of 1-2mm/yr2. We use our acceleration estimates to back calculate to a time of zero velocity, which coincides with the initiation of ice loss in Iceland from ice mass balance calculations and Arctic warming trends. We show, through a simple inversion, a direct relationship between ice mass balance measurements and vertical position and show that accelerated unloading is required to reproduce uplift observations for a simple elastic layer over viscoelastic half-space model.

  16. The Geodesy of the Main Saturnian Satellites from Range Rate Measurements of the Cassini Spacecraft

    Science.gov (United States)

    Ducci, M.; Iess, L.; Armstrong, J. W.; Asmar, S. W.; Jacobson, R. A.; Lunine, J. I.; Racioppa, P.; Rappaport, N. J.; Stevenson, D. J.; Tortora, P.

    2012-03-01

    During Cassini's eight-year tour in the saturnian system, the gravity field of the main satellites was inferred from range rate measurements of the spacecraft. Here we present our latest results and an overview of our analysis methods.

  17. MIGA: combining laser and matter wave interferometry for mass distribution monitoring and advanced geodesy

    Science.gov (United States)

    Canuel, B.; Pelisson, S.; Amand, L.; Bertoldi, A.; Cormier, E.; Fang, B.; Gaffet, S.; Geiger, R.; Harms, J.; Holleville, D.; Landragin, A.; Lefèvre, G.; Lhermite, J.; Mielec, N.; Prevedelli, M.; Riou, I.; Bouyer, P.

    2016-04-01

    The Matter-Wave laser Interferometer Gravitation Antenna, MIGA, will be a hybrid instrument composed of a network of atom interferometers horizontally aligned and interrogated by the resonant field of an optical cavity. This detector will provide measurements of sub Hertz variations of the gravitational strain tensor. MIGA will bring new methods for geophysics for the characterization of spatial and temporal variations of the local gravity field and will also be a demonstrator for future low frequency Gravitational Wave (GW) detections. MIGA will enable a better understanding of the coupling at low frequency between these different signals. The detector will be installed underground in Rustrel (FR), at the "Laboratoire Souterrain Bas Bruit" (LSBB), a facility with exceptionally low environmental noise and located far away from major sources of anthropogenic disturbances. We give in this paper an overview of the operating mode and status of the instrument before detailing simulations of the gravitational background noise at the MIGA installation site.

  18. Understanding geodesy and geoscience processes through interactive demonstrations for the general public

    Science.gov (United States)

    Olds, S. E.; Bartel, B. A.

    2016-12-01

    Hands-on demonstrations are an effective way for novice learners, whether they are students, public, or museum visitors, to experience geoscience processes. UNAVCO and community members have developed hands-on demonstrations of a variety of geophysical processes highlighting the geodetic techniques used to measure these processes. These demonstrations illustrate how observations of changes at the earth's surface can be quantified and inform us about forces within the earth that we can't see. They also emphasize the societal impact of research related to each earth process. In this presentation, we will provide descriptions of a suite of these demonstrations, major concepts covered, materials needed, instructions for assembly and how to lead the demonstration, sample questions to ask participants, weaknesses inherent in the model, and a list of supporting handouts that augment the demonstration. Some of the demonstrations to be highlighted include: volcanic deformation using flour or an augmented-reality sandbox; isostatic rebound from glacial melt using flubber; compression of the Pacific Northwest using springs; and tsunami early warning using a tub of water and foam buoys. We will also discuss the process of developing interactive demonstrations and provide initial feedback from classroom and science festival events. Write-ups of the demonstrations are freely available on the UNAVCO Education website (search terms: UNAVCO geodetic demonstrations).

  19. Deformation of the Western Caribbean and Northwestern South America From GPS Geodesy

    Science.gov (United States)

    LaFemina, Peter; Mora-Paez, Hector; Kobayashi, Daisuke; Fernandes, Rui; Mothes, Patricia

    2014-05-01

    We investigate the current kinematics of the western Caribbean and northwestern South America, two regions that are affected by ongoing collision of aseismic ridges and the motion of forearc slivers. We investigate these regions using a new PS derived surface velocity field spanning from Guatemala to Ecuador. The new velocity field and published earthquake slip vectors are inverted to solve for the Euler vectors of forearc blocks and interseismic elastic strain accumulation on block bounding faults using a block modeling approach. Along the western Caribbean margin, it has been demonstrated that the Cocos Ridge collision drives the Central American forearc block to the northwest. GPS network expansion in Panama and Colombia allows us to investigate the effect of ridge collision on the Panama region. In northwestern South America, the North Andes block (NAB) is a hypothesized tectonic block that migrates north-northeast relative to a stable South American reference frame. The motion of this block is thought to be derived by the collision of the Carnegie Ridge in southern Ecuador or by oblique convergence and high degrees of interplate coupling north of the ridge (i.e., strain partitioning). We test a suite of block models to investigate the tectonic nature of the Panama Region and North Andes block and the style of faulting in the upper plate accommodating block motion. Through the estimation of elastic strain accumulation on all block bounding faults, we improve the understanding of interseismic coupling along a convergent margin capable of producing M>8 earthquake and upper plate faults capable of M>6 earthquake.

  20. A Mathematical Appreciation of Antonio Marussi’s Contributions to Geodesy

    Science.gov (United States)

    1989-11-20

    founder (and for many years the director) of the Istituto di Geodesia e Geofisica at this university. 4 Marussi’s association with the I.G.M. gave him...appalled at what they regarded as a cannibalization of their work. A thirty year war was fought over which theory was superior , and it is one of the most... Geodesia intrinseca, Annali Universita di Trieste, Serie IV, 19 (1949), 1-15. [5] A. MARUSSI, Fondements de g6ome-trie differentielle absolu du champ

  1. U.S. national report to the International Union of Geodesy and Geophysics

    Science.gov (United States)

    Gorney, D. J.

    1987-01-01

    This paper highlights progress by U.S. authors during 1983-1986 in the broad area of auroral research. Atmospheric emissions and their use as a tool for remote-sensing the dynamics, energetics, and effects of auroral activity is a subject which is emphasized here because of the vast progress made in this area on both observational and theoretical fronts. The evolution of primary auroral electrons, the acceleration of auroral ions, small-scale electric fields, auroral kilometric radiation, auroral empirical models and activity indices are also reviewed. An extensive bibliography is supplied.

  2. Characterizing land subsidence mechanisms as a function of urban basin geohazards using space geodesy

    Science.gov (United States)

    Bawden, G. W.

    2016-12-01

    Land subsidence in urban basins will likely become a more significant geohazard in many of the global sedimentary basins as population growth, resource availability, and climate change compound natural and anthropogenic contributors that influence basin elevation. Coastal basins are at the greatest risk where land subsidence is additive to sea level rise, thereby increasing the rate of exposure to coastal populations. Land surface elevation change is a function of many different parameters, including: elastic and inelastic surface response to managed and natural groundwater levels; anthropogenic activities (hydrocarbon extraction, wastewater injection, fracking, geothermal production, and mass redistribution); local tectonic deformation and regional tectonic drivers (such as repeated uplift and subsidence cycles above subduction zones); climate change (influencing the timing, magnitude, nature and duration of seasonal/annual precipitation and permafrost extent); material properties of the basin sediments (influencing susceptibility to soil compaction, oxidization, and dissolution); post glacial rebound; isostatic flexure associated with sea-level and local mass changes; and large scale gravitational processes (such as growth faults and landslides). Geodetic measurements, such as InSAR and GPS, help track spatial and temporal changes in both relative and absolute basin elevation thereby helping to characterize the mechanism(s) driving the geohazards. In addition to a number of commercial radar satellites, European Space Agency's Sentinel-1a/b satellites are beginning to provide a wealth of data over many basin targets with C-band (5.5 cm wavelength). The NISAR (NASA-ISRO Synthetic Aperture Radar) L-band (24 cm wavelength) mission (anticipated 2021 launch) will image nearly every basin globally every 12 days and data from the mission will help characterize land subsidence and many other solid-Earth and hydrologic geohazards that impact urban basins.

  3. Regional tectonic deformation in Southern California, inferred from terrestrial geodesy and the global positioning system

    Science.gov (United States)

    Shen, Zhengkang

    Tectonic deformation in two regions in Southern California, the Southern Coast Ranges and the Los Angeles Basin, was studied. Results show that in the Southern Coast Ranges, regional deformation is predominantly controlled by deep strike slip motion along the San Andreas Fault, at a rate of 32 plus or minus 2 mm/yr. The deep slip along the San Gregorio-Hosgri Fault is about 1-3 mm/yr, assuming a locked fault depth of 20 km. Convergence normal to the San Andreas Fault in the Southern Coast ranges is not significantly different from zero. About 5 mm/yr convergence is detected from the Santa Maria Basin. In the Los Angeles Basin area, this study demonstrates about 10 mm/yr relative motion trending northwest from San Pedro Hill to the San Gabriel Mountains. The direction of motion closely parallels to the trend of the frontal fault system at the southern margin of the San Gabriel Mountains. The basin suffers from north-south convergence and east-west extension, at a rate of about 0.07 mu rad/yr for either components. The convergence rate normal to the San Andreas across the basin is 4 plus or minus 3 mm/yr, implying smaller compression than previous estimates (e.g., Cline et al. 1984).

  4. Atmospheric Pressure Corrections in Geodesy and Oceanography: a Strategy for Handling Air Tides

    Science.gov (United States)

    Ponte, Rui M.; Ray, Richard D.

    2003-01-01

    Global pressure data are often needed for processing or interpreting modern geodetic and oceanographic measurements. The most common source of these data is the analysis or reanalysis products of various meteorological centers. Tidal signals in these products can be problematic for several reasons, including potentially aliased sampling of the semidiurnal solar tide as well as the presence of various modeling or timing errors. Building on the work of Van den Dool and colleagues, we lay out a strategy for handling atmospheric tides in (re)analysis data. The procedure also offers a method to account for ocean loading corrections in satellite altimeter data that are consistent with standard ocean-tide corrections. The proposed strategy has immediate application to the on-going Jason-1 and GRACE satellite missions.

  5. ExoMars Lander Radioscience LaRa, a Space Geodesy Experiment to Mars.

    Science.gov (United States)

    Dehant, Veronique; Le Maistre, Sebastien; Yseboodt, Marie; Peters, Marie-Julie; Karatekin, Ozgur; Van Hove, Bart; Rivoldini, Attilio; Baland, Rose-Marie; Van Hoolst, Tim

    2017-04-01

    The LaRa (Lander Radioscience) experiment is designed to obtain coherent two-way Doppler measurements from the radio link between the ExoMars lander and Earth over at least one Martian year. The instrument life time is thus almost twice the one Earth year of nominal mission duration. The Doppler measurements will be used to observe the orientation and rotation of Mars in space (precession, nutations, and length-of-day variations), as well as polar motion. The ultimate objective is to obtain information / constraints on the Martian interior, and on the sublimation / condensation cycle of atmospheric CO2. Rotational variations will allow us to constrain the moment of inertia of the entire planet, including its mantle and core, the moment of inertia of the core, and seasonal mass transfer between the atmosphere and the ice caps. The LaRa experiment will be combined with other ExoMars experiments, in order to retrieve a maximum amount of information on the interior of Mars. Specifically, combining LaRa's Doppler measurements with similar data from the Viking landers, Mars Pathfinder, Mars Exploration Rovers landers, and the forthcoming InSight-RISE lander missions, will allow us to improve our knowledge on the interior of Mars with unprecedented accuracy, hereby providing crucial information on the formation and evolution of the red planet.

  6. Relativistic geodesy and gravimetry with quantum sensors - on Earth and in Space

    Science.gov (United States)

    Flury, Jakob

    2016-07-01

    Quantum metrology and precision optical metrology enable new measurement techniques on the fields of inertial sensors, extremely precise ranging, atomic frequency standards and optical frequency transfer. Their precision level is highly relevant both for fundamental physics and for geodetic applications, including the monitoring of global and regional change processes in the frame of the Global Geodetic Observing System (GGOS). The Hannover Collaborative Research Center geo-Q focuses on the development of such techniques. We investigate laser interferometry in space - originally developed for gravitational wave astronomy - that can be used for inter-satellite ranging and for optical gravity gradiometry using multiple macroscopic testmasses in order to increase the resolution in satellite gravimetry. Prototypes for these techniques are flown on the LISA pathfinder and GRACE Follow-On missions. Complementarily, sensors based on atom interferometry are promising for accelerometry and gradiometry in terms of sensitivity, versatility and low systematic errors. Optical atomic clocks and optical frequency transfer allow tying gravitational measurements to an atomic reference, which could improve fundamental geodetic reference frames.

  7. The State of GPS Vertical Positioning Precision : Separation of Earth Processes by Space Geodesy

    CERN Document Server

    2003-01-01

    Observed signals in GPS data are the sum of noise and real crustal motions. Interpretation of the data depends on our ability to extract a signal of interest from the total signal. This workshop will highlight the difficulties associated with extracting a signal such as post-glacial rebound, plate tectonics or loading, from vertical geodetic data.

  8. The Contribution of the University of Padova to Central European Geodesy

    Science.gov (United States)

    Caporali, A.

    2003-04-01

    The definition and maintenance of a geodetic reference system by modern techniques requires systematic temporal changes of the position of the defining stations to be taken into account. Most of these drifts are accommodated by present day plate tectonics. If the lithospheric plate to which a given station belongs were perfectly rigid, then a simple plate model based upon rigid rotations about Eulerian poles would suffice to predict the horizontal coordinates of each station at any epoch, once the coordinates of that station are known at a reference epoch. In Europe, there are stations well located inside old, stable areas which may be considered rigid, but other stations are at or near continental margins undergoing active deformation, or are within a relatively recent portion of a tectonic unit subject to intraplate stress or volcanism. Velocities of stations in the most recent ITRF solutions do, in fact, exhibit in some cases departures from the NUVEL1A NNR plate model in Europe and elsewhere, but the reasons for these discrepancies are not always well understood. For example, if a particular station of the network exhibits a velocity anomaly relative to a reference velocity model, then it is of interest to understand the reasons for the anomaly, and its spatial extent, that is if it is local to that station, or if nearby stations are also affected, and with which tapering as a function of distance. As part of the research activities in support of the CEI/CERGOP and EUREF, the time series of coordinates of European Permanent Network (EPN) stations in the Alpine Mediterranean Dinarides region are examined both in the time and space domains, and hypotheses are formulated on the reasons of systematic departures from linearity. The time domain analysis consists in the construction of the Power Spectral Density and autocorrelation function of the time series of each coordinate for each station, the assessment of the type(s) of noise and periodicities, and an estimate of the uncertainty in the velocity. The space domain approach consists in cross correlating time series of stations and investigating the cross correlation function as a function of the space separation between pairs of stations. The combined analysis in the space and time domains of the time series provides a description of small but non negligible changes of coordinates the permanent stations which should be taken into account if the realization of the reference system is to be as accurate as the coordinates of the defining stations.

  9. Analytical model of surface uplift above axisymmetric flat-lying magma intrusions: Implications for sill emplacement and geodesy

    OpenAIRE

    Galland, Olivier; Scheibert, Julien

    2013-01-01

    58 pages, 17 figures, 2 tables. Accepted in Journal of Volcanology and Geothermal Research; International audience; In this paper, we develop a new axisymmetric analytic model of surface uplift upon sills and laccoliths, based on the formulation of a thin bending plate lying on an elastic foundation. In contrast to most former models also based on thin bending plate formulation, our model accounts for (i) axi-symmetrical uplift, (ii) both upon and outside the intrusion. The model accounts for...

  10. Gravimetric geodesy and sea surface topography studies by means of satellite-to-satellite tracking and satellite altimetry

    Science.gov (United States)

    Siry, J. W.

    1972-01-01

    A satellite-to-satellite tracking experiment is planned between ATS-F and GEOS-C with a range accuracy of 2-meters and a range rate accuracy of 0.035 centimeters per second for a 10-second integration time. This experiment is planned for 1974. It is anticipated that it will improve the spatial resolution of the satellite geoid by half an order of magnitude to about 6 degrees. Longer integration times should also permit a modest increase in the acceleration resolution. Satellite altimeter data will also be obtained by means of GEOS-C. An overall accuracy of 5-meters in altitude is the goal. The altimeter, per se, is expected to have an instrumental precision of about 2 meters, and an additional capability to observe with a precision of about 0.2 meters for limited periods.

  11. Deformation derived from GPS geodesy associated with Bárðarbunga 2014 rifting event in Iceland

    KAUST Repository

    Ofeigsson, Benedikt Gunnar

    2015-04-01

    On August 16, 2014 an intense seismic swarm started below the eastern part of Bárðarbunga Caldera in the north-western corner of Vatnajökull ice-cap, Iceland, marking the onset of the first rifting event in Iceland since the Krafla fires (1975-1984). The migration of the seismicity was corroborated by ground deformation in areas outside the ice cap and on nunataks within the ice cap suggesting a lateral propagation of magma, from the Bárðabunga system. The sesimicity migrated out of the caldera forming a dyke with roughly three segments, changing direction each time until August 28 when the migration stopped around 10 km south of Askja Volcano, eventually leading to a short lived eruption in Holuhraun north of Dyngjujökull. A second fissure eruption started in Holuhraun on August 31 which is still ongoing at the time of this writing. In the months prior to the onset of the activity, subtle signs of inflation where observed on continuous GPS sites around the Bárðarbunga indicating a volume increase in the roots of the volcanic system. When the activity started on August 16, the deformation pattern indicated a simultaneous deflation centered within the caldera and a lateral growth of a dyke also reflected in the migration of seismicity along segments of variable strike. A maximum widening of 1.3 m occurred between stations on opposite sides of the dyke spaced 25 km apart. Significant movements where detected on GPS site more then 80 km away from the tip of dyke. Displacements indicated the fastest rate of widening at any time in the most distal segment of the dyke throughout its evolution. After the dyke stopped propagating, the inflation continued, decaying exponentialy with time. On September 4, five days into the second fissure eruption, the movements associated with the dyke where no longer significant. As the fissure eruption continues, a slowly decaying contraction is observed around the Bárðarbunga central volcano, both shown in the piston like subsidence of the caldera floor, observed on a GPS instrument located on the ice surface within the caldera, as well as in the region around the caldera outside and within the ice cap, with no detectable deformation associated with the formed dyke or the eruptive fissure. Prior to the onset of the activity, extensive GPS campaign measurements had been conducted in the area. These observations allowed us to constrain the deformation field directly associated with the rifting. This proved essential when adding new continuous sites during the active rifting hence tracking the dyke formation as it propagated. To better constrain the deformation field in real time, 8 hour coordinate solutions where processed in real time enabling sub-daily updates to track the rapid deformation associated with the rifting.

  12. Multi-technique combination of space geodesy observations: Impact of the Jason-2 satellite on the GPS satellite orbits estimation

    Science.gov (United States)

    Zoulida, Myriam; Pollet, Arnaud; Coulot, David; Perosanz, Félix; Loyer, Sylvain; Biancale, Richard; Rebischung, Paul

    2016-10-01

    In order to improve the Precise Orbit Determination (POD) of the GPS constellation and the Jason-2 Low Earth Orbiter (LEO), we carry out a simultaneous estimation of GPS satellite orbits along with Jason-2 orbits, using GINS software. Along with GPS station observations, we use Jason-2 GPS, SLR and DORIS observations, over a data span of 6 months (28/05/2011-03/12/2011). We use the Geophysical Data Records-D (GDR-D) orbit estimation standards for the Jason-2 satellite. A GPS-only solution is computed as well, where only the GPS station observations are used. It appears that adding the LEO GPS observations results in an increase of about 0.7% of ambiguities fixed, with respect to the GPS-only solution. The resulting GPS orbits from both solutions are of equivalent quality, agreeing with each other at about 7 mm on Root Mean Square (RMS). Comparisons of the resulting GPS orbits to the International GNSS Service (IGS) final orbits show the same level of agreement for both the GPS-only orbits, at 1.38 cm in RMS, and the GPS + Jason2 orbits at 1.33 cm in RMS. We also compare the resulting Jason-2 orbits with the 3-technique Segment Sol multi-missions d'ALTimétrie, d'orbitographie et de localisation précise (SSALTO) POD products. The orbits show good agreement, with 2.02 cm of orbit differences global RMS, and 0.98 cm of orbit differences RMS on the radial component.

  13. Combining Space Geodesy, Seismology, and Geochemistry for Monitoring Verification and Accounting of CO2 in Sequestration Sites

    Energy Technology Data Exchange (ETDEWEB)

    Swart, Peter K. [Univ. of Miami, Key Biscayne, FL (United States); Dixon, Tim [Univ. of South Florida, Tampa, FL (United States)

    2014-09-30

    A series of surface geophysical and geochemical techniques are tested in order to demonstrate and validate low cost approaches for Monitoring, Verification and Accounting (MVA) of the integrity of deep reservoirs for CO2 storage. These techniques are (i) surface deformation by GPS; ii) surface deformation by InSAR; iii) passive source seismology via broad band seismometers; and iv) soil gas monitoring with a cavity ring down spectrometer for measurement of CO2 concentration and carbon isotope ratio. The techniques were tested at an active EOR (Enhanced Oil Recovery) site in Texas. Each approach has demonstrated utility. Assuming Carbon Capture, Utilization and Storage (CCUS) activities become operational in the future, these techniques can be used to augment more expensive down-hole techniques.

  14. A method to calculate zero-signature satellite laser ranging normal points for millimeter geodesy - a case study with Ajisai

    Science.gov (United States)

    Kucharski, Daniel; Kirchner, Georg; Otsubo, Toshimichi; Koidl, Franz

    2015-03-01

    High repetition-rate satellite laser ranging (SLR) offers new possibilities for the post-processing of the range measurements. We analyze 11 years of kHz SLR passes of the geodetic satellite Ajisai delivered by Graz SLR station (Austria) in order to improve the accuracy and precision of the principal SLR data product - normal points. The normal points are calculated by three different methods: 1) the range residuals accepted by the standard 2.5 sigma filter, 2) the range residuals accepted by the leading edge filter and 3) the range residuals given by the single corner cube reflector (CCR) panels of Ajisai.

  15. Kinematics of rotating panels of E-W faults in the San Andreas system: what can we tell from geodesy?

    Science.gov (United States)

    Platt, J. P.; Becker, T. W.

    2013-09-01

    Sets of E- to NE-trending sinistral and/or reverse faults occur within the San Andreas system, and are associated with palaeomagnetic evidence for clockwise vertical-axis rotations. These structures cut across the trend of active dextral faults, posing questions as to how displacement is transferred across them. Geodetic data show that they lie within an overall dextral shear field, but the data are commonly interpreted to indicate little or no slip, nor any significant rate of rotation. We model these structures as rotating by bookshelf slip in a dextral shear field, and show that a combination of sinistral slip and rotation can produce the observed velocity field. This allows prediction of rates of slip, rotation, fault-parallel extension and fault-normal shortening within the panel. We use this method to calculate the kinematics of the central segment of the Garlock Fault, which cuts across the eastern California shear zone at a high angle. We obtain a sinistral slip rate of 6.1 ± 1.1 mm yr-1, comparable to geological evidence, but higher than most previous geodetic estimates, and a rotation rate of 4.0 ± 0.7° Myr-1 clockwise. The western Transverse Ranges transect a similar shear zone in coastal and offshore California, but at an angle of only 40°. As a result, the faults, which were sinistral when they were at a higher angle to the shear zone, have been reactivated in a dextral sense at a low rate, and the rate of rotation of the panel has decreased from its long-term rate of ˜5° to 1.6° ± 0.2° Myr-1 clockwise. These results help to resolve some of the apparent discrepancies between geological and geodetic slip-rate estimates, and provide an enhanced understanding of the mechanics of intracontinental transform systems.

  16. Investigating crustal deformation associated with the North America-Pacific plate boundary in southern California with GPS geodesy

    Science.gov (United States)

    Spinler, Joshua C.

    The three largest earthquakes in the last 25 years in southern California occurred on faults located adjacent to the southern San Andreas fault, with the M7.3 1992 Landers and M7.1 1999 Hector Mine earthquakes occurring in the eastern California shear zone (ECSZ) in the Mojave Desert, and the M7.2 2010 El Mayor-Cucapah earthquake occurring along the Laguna Salada fault in northern Baja California, Mexico. The locations of these events near to but not along the southern San Andreas fault (SSAF) is unusual in that the last major event on the SSAF occurred more than 300 years ago, with an estimated recurrence interval of 215 +/- 25 years. The focus of this dissertation is to address the present-day deformation field along the North America-Pacific plate boundary in southern California and northern Baja California, through the analysis of GPS data, and elastic block and viscoelastic earthquake models to determine fault slip rates and rheological properties of the lithosphere in the plate boundary zone. We accomplish this in three separate studies. The first study looks at how strain is partitioned northwards along-strike from the southern San Andreas fault near the Salton Sea. We find that estimates for slip-rates on the southern San Andreas decrease from ~23 mm/yr in the south to ~8 mm/yr as the fault passes through San Gorgonio Pass to the northwest, while ~13-18 mm/yr of slip is partitioned onto NW-SE trending faults of the ECSZ where the Landers and Hector Mine earthquakes occurred. This speaks directly to San Andreas earthquake hazards, as a reduction in the slip rate would require greater time between events to build up enough slip deficit in order to generate a large magnitude earthquake. The second study focuses on inferring the rheological structure beneath the Salton Trough region. This is accomplished through analysis of postseismic deformation observed using a set of the GPS data collected before and after the 2010 El Mayor-Cucapah earthquake. By determining the slip-rates on each of the major crustal faults prior to the earthquake, we are able to model the pre-earthquake velocity field for comparison with velocities measured using sites constructed post-earthquake. We then determine how individual site velocities have changed in the 3 years following the earthquake, with implications for the rate at which the lower crust and upper mantle viscously relax through time. We find that the viscosity of the lower crust is at least an order of magnitude higher than that of the uppermost mantle, and hypothesize that this is due to mafic material emplaced at the base of the crust as the spreading center developed beneath the Salton Trough since about 6 Ma. The final study investigates crustal deformation and fault slip rates for faults in the northern Mojave and southern Walker Lane regions of the ECSZ. Previous geodetic studies estimated slip-rates roughly double those inferred via geological dating methods in this region for NW striking strike-slip faults, but significantly smaller than geologic estimates for the Garlock fault. Through construction of a detailed elastic block model, which selects only active fault structures, and applying a new, dense GPS velocity field in this region, we are able to estimate slip-rates for the strike-slip faults in the ECSZ that are much closer to those reported from geology.

  17. Accuracy of Shipborne Kinematic GPS Surveying

    Science.gov (United States)

    1991-09-01

    found in many books on physical geodesy, such as" Physical Geodesy" by Heiskanen and Moritz [Ref 3]. Kepler’s laws follow from Newton’s law of...Carrier Phase Measurements. 3. Heiskanen W.A. and Moritz H., Physical Geodesy, Institute of Physical Geodesy, Technical University, Graz, Austria 198". 4

  18. Earth sciences within the project Ev-K2-CNR: Geodesy and geophysics; Le scienze della Terra nel progetto Ev-K2-CNR: Geodesia e geofisica

    Energy Technology Data Exchange (ETDEWEB)

    Poretti, Giorgio [Trieste, Univ. (Italy). Dipt. di Scienze Matematiche

    1997-05-01

    Earth Sciences started the Ev-K2-CNR project in 1987 with the comparison between the heights of Mt. Everest and K2. Several gravimetric campaigns followed in the most difficult areas of the Himalayas. In 1991 a GPS network was established in Nepal for the determination of the Earth crust movements in the area. In 1992 a precise measurement of mount Everest was performed with classical and satellite technologies. Mount K2 was remeasured in Summer 1996.

  19. Active orogeny of the south-central Andes studied with GPS geodesy Orogenia activa de los Andes centro-australes estudiada mediante geodesia de GPS

    Directory of Open Access Journals (Sweden)

    E. Kendrick

    2006-12-01

    Full Text Available We present GPS measurements of the crustal velocity field in the southern Central Andes between the Santa Cruz corner and the Malargüe fold and thrust belt, and model this interseismic velocity field as the combination of an ephemeral, elastic signal associated with locking of the main plate boundary, and a steady and non-reversing component of displacement associated with localized backarc convergence and growth of the mountain belt. We find that this second component, i.e. the ongoing and permanent displacement of the forearc and the high Andes relative to the craton, can be modeled very well as a steady clockwise rotation of an Andean microplate about a pole located in southern Argentina. Near the Malargüe Basin, this microplate (or block is moving nearly parallel to the strike of the orogen, transporting material towards the bend in the central Andes. Farther north, in the southern limb of the Central Andes, the motion of this same crustal block is directed nearly perpendicular to the strike of the mountain belt. Our results suggest that permanent deformation rates in the backarc range from a maximum of ~ 6-7 mm/yr in the Bolivian Subandes to less than ~ 3 mm/yr in the Argentine Precordillera and Malargue fold and thrust belt. It is likely that most active backarc deformation is accruing in a narrow zone (~ 50 km wide associated with the backarc boundary (usually defined as the thrust front though at this stage it is impossible to distinguish whether specific backarc structures are actively accruing strain.Se presentan mediciones GPS del campo de velocidad en los Andes centro-australes entre el extremo norte de Santa Cruz y la faja plegada de Malargüe. Se modela el campo de velocidad intersísmico como la combinación de una señal elástico/efímera asociada con el anclaje del límite principal de placas, y una componente constante, no reversible de desplazamiento asociada con una convergencia localizada en el retroarco y crecimiento del cinturón montañoso andino. Se encuentra que esta segunda componente, por ejemplo en el desplazamiento actual relativo al cratón del antearco y los altos Andes, puede ser modelada muy bien como una rotación horaria constante de la microplaca andina alrededor de un polo de Euler localizado en el sur de Argentina. Cerca de Malargüe, esta microplaca (o bloque se mueve subparalelamente al rumbo del orógeno, transportando material hacia la inflexión de los Andes Centrales. Más al norte, en el sector austral de los Andes Centrales, el movimiento de este bloque es casi perpendicular al rumbo de la cadena montañosa. Se sugiere que las tasas de deformación permanente en el retroarco varían entre un máximo de ~ 6-7 mm/año en el Subandino Boliviano y menos de ~ 3 mm/año en la Precordillera Argentina y en la faja plegada de Malargüe. Es probable que la deformación activa más importante esté ocurriendo en una delgada faja (~ 50 km de ancho asociada con el límite del retroarco (usualmente definido como el frente orogénico. En esta etapa, es imposible distinguir si estructuras específicas del retroarco está acumulando deformación.

  20. 25 Jahre - Institut fuer Geodaesie, Teil 2: Forschungsarbeiten und Veroeffentlichungen (25 Years - Institute of Geodesy, Part 2: Research Areas and Publications)

    Science.gov (United States)

    2000-01-01

    Festpunktfeld Ruanda - 1992 - SIRGAS ( Sistema de refer6ncia geocdntrico para Amdrica del Sur) - 1995 - Festpunktfeld Per6 - 1996 Die DOENAV-Kampagne...Forschungsschwerpunkte Mit dem Sistema di Referdncia Geoc6ntrico para a Amd~rica do Sul (SIRGAS) wurde 1995 in einer Gerneinschaftsaktion aller... digitaler Form gespei- chert werden. Aus demn dabei anfallenden redundanten Datensatz erhalt man im Wege einer Ausgleichung den H6henunterschied

  1. 25 Jahre - Institut fuer Geodaesie, Teil 1: Wissenschaftliche Beitraege und Berichte (25 Years - Institute of Geodesy, Part 1: Scientific Contributions and Reports)

    Science.gov (United States)

    2000-01-01

    des Dispersionswinkels zur Bestimmung der Refraktion. AVN 100, S. 51-62, 1993 HAMMING, R., W.: Digitale Filter. VCH-Verlag, Weinheim 1987 HAMPEL, F...KRONMOLLER, H.: Digitale Signalverarbeitung. Springer-Verlag, Berlin 1991 KUHLMANN, H.: Ein Beitrag zur Oberwachung von Briickenbauwerken mit...1987), das Europdische Referenzsystem - EUREF (SEEGER/ALTINER/ENGELHARDT/FRANKE/HABRICH/SCHLC- TER 1998) und das Sistema di Referencia del America del

  2. 25 Jahre - Institut fuer Geodaesie, Teil 3: Aus dem Leben des Instituts (25 Years - Institute of Geodesy, Part 3: The Life of the Institute)

    Science.gov (United States)

    2000-01-01

    vorhandenen Bfiro- und LehrgebU~ude renoviert und auch neue Gebdude errichtet werden. Gleichzeitig wurden Appart - ments, fUr die Studenten gebaut...Sea I see waters flowing gravitationally down to magnetic north Whereas my view is directed mapping down geographic south. But still, as you all...living through the earth rotation with its nutation and precession In life habit not distinguishing between gravity and gravitation Nor taking care above

  3. Source characteristics of the 2015 MW 7.8 Gorkha (Nepal) earthquake and its MW 7.2 aftershock from space geodesy

    Science.gov (United States)

    Feng, Wanpeng; Lindsey, Eric; Barbot, Sylvain; Samsonov, Sergey; Dai, Keren; Li, Peng; Li, Zhenhong; Almeida, Rafael; Chen, Jiajun; Xu, Xiaohua

    2017-08-01

    On April 25, 2015, a destructive MW 7.8 earthquake struck the capital of Nepal, Kathmandu, killing more than 8800 people and destroying numerous historical structures. We analyze six coseismic interferograms from several satellites (ALOS-2, Sentinel-1 A, and RADARSAT-2), as well as three-dimensional displacements at six GPS stations to investigate fault structure and slip distribution of the Gorkha earthquake. Using a layered crustal structure, the best-fit slip model shows that the preferred dip angle of the mainshock fault is 6 ± 3.5° and the major slip is concentrated within depths of 8-15 km. The maximum slip of 6.0 m occurs at a depth of 11 km, 70 km south east of the epicenter. The coseismic rupture extends 150 km eastward of the epicentre with a cumulative geodetic moment of 7.8 × 1020 Nm, equivalent to an earthquake of MW 7.84. We also investigate the MW 7.2 aftershock on 12 May 2015 using another three postseismic interferograms from ALOS2, RADARSAT-2, and Sentinel-1 A. The InSAR-based best-fit slip model of the largest aftershock implies that its major slip is next to the eastern lower end of the mainshock rupture with a similar maximum slip of 6 m at a depth of 13 km. This study generates various coseismic geodetic measurements to determine the source parameters of the MW 7.8 Gorkha earthquake and 12 May MW 7.2 afershock, providing an additional chance to understand the local fault structure and slip extent.

  4. A possible experiment with two counter-orbiting drag-free satellites to obtain a new test of Einstein's general theory of relativity and improved measurements in geodesy

    Science.gov (United States)

    Van Patten, R. A.; Everitt, C. W. F.

    1976-01-01

    In 1918, Lense and Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. We describe an experiment to measure this effect by means of two counter-orbiting drag-free satellites in polar orbit about the earth. For a 2-1/2 year experiment, the measurement should approach an accuracy of 1%. An independent measurement of the geodetic precession of the orbit plane due to the motion about the sun may also be possible to about 10% accuracy. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler data are taken at points of passing near the poles to yield an accurate measurement of the separation distance between the two satellites. New geophysical information on both earth harmonics and tidal effects is inherent in this polar ranging data.

  5. Slip pulse and resonance of Kathmandu basin during the 2015 Mw 7.8 Gorkha earthquake, Nepal imaged with space geodesy

    Science.gov (United States)

    Galetzka, John; Melgar, D.; Genrich, J.F.; Geng, J.; Owen, S.; Lindsey, E. O.; Xu, X.; Bock, Y.; Avouac, J.-P.; Adhikari, L. B.; Upreti, B. N.; Pratt-Sitaula, B.; Bhattarai, T. N.; Sitaula, B. P.; Moore, A.; Hudnut, Kenneth W.; Szeliga, W.; Normandeau, J.; Fend, M.; Flouzat, M; Bollinger, L.; Shrestha, P.; Koirala, B.; Gautam, U.; Bhatterai, M.; Gupta, R.; Kandel, T.; Timsina, C.; Sapkota, S. N.; Rajaure, S.; Maharjan, N.

    2015-01-01

    Detailed geodetic imaging of earthquake rupture enhances our understanding of earthquake physics and induced ground shaking. The April 25, 2015 Mw 7.8 Gorkha, Nepal earthquake is the first example of a large continental megathrust rupture beneath a high-rate (5 Hz) GPS network. We use GPS and InSAR data to model the earthquake rupture as a slip pulse of ~20 km width, ~6 s duration, and with peak sliding velocity of 1.1 m/s that propagated toward Kathmandu basin at ~3.3 km/s over ~140 km. The smooth slip onset, indicating a large ~5 m slip-weakening distance, caused moderate ground shaking at high >1Hz frequencies (~16% g) and limited damage to regular dwellings. Whole basin resonance at 4-5 s period caused collapse of tall structures, including cultural artifacts.

  6. Topography surveying and geodesy on the moon(4)%月球地形测绘和月球大地测量(4)

    Institute of Scientific and Technical Information of China (English)

    陈俊勇

    2004-01-01

    主要介绍了美国在20世纪70年代著名的"阿波罗(Apollo)"登月项目,和90年代的"克莱门汀号(Clementine)"、"月球探测(Lunar Prospector)",以及欧共体的"SMART-1"探月航天器.1969年至1972年间阿波罗项目前后进行了17次环绕登月的各种试验,其中有6次成功登月.它们分别是"阿波罗"11,12,14,15,16,17号."阿波罗"和以后的探月项目向科学家提供了大量的月球数据,其中有影像资料,月面和环月试验的成果,同时还进行了样本收集、月面及其周围环境的地学勘测和月球大地测量等各项工作.

  7. The 2014-2015 eruption at Fogo volcano: constraining the geometry of the intrusion and erupted volumes with space-geodesy

    Science.gov (United States)

    Bagnardi, M.; González, P. J.; Hooper, A. J.; Wright, T. J.

    2015-12-01

    After twenty years of quiescence, Fogo volcano, the most active in the Cape Verde archipelago, erupted for more than two months between November 2014 and February 2015. Voluminous and fast-moving lava flows were erupted from a linear fissure located at the base of Pico do Fogo cone and inundated the summit area of the volcano, destroying two villages. In our work we first use interferometric synthetic aperture radar (InSAR) data from the European Space Agency's Sentinel-1A satellite, which had been operative for only a few weeks at the time of the onset of the eruption, to constrain the geometry of the intrusion that fed the eruption. The InSAR data was acquired in the TOPS (Terrain Observation by Progressive Scans) mode and the eruption at Fogo represents the first volcanic eruption imaged by Sentinel-1 in its standard acquisition mode. To accurately model TOPS data, variations in both incidence and squint angle of the satellite line-of-sight (LoS) vector need to be taken into account when projecting 3D displacements into the LoS direction. Following this approach, we perform a Bayesian inversion of the InSAR data and infer that the measured deformation is best explained by the intrusion of a sub-vertical dike beneath the southwestern flank of Pico do Fogo cone. This intrusion seems to have first propagated upwards beneath the cone and subsequently laterally towards the southwestern flank of Pico do Fogo, where it reached the surface. Successively, we evaluate differences between pre- and post-eruptive digital elevation models (DEMs) of the volcano to estimate the volume of the most recent lava flows. The DEMs are formed using synthetic aperture radar imagery from the TanDEM-X (TerraSAR add-on for Digital Elevation Measurements) satellite mission and tri-stereo optical imagery from the Pléiades satellite constellation. Preliminary results show that during the 2014-2015 eruption almost 50 million cubic meters of lava were emplaced at the surface of the volcano over an area of ~5 square kilometers.

  8. Constraining models of postglacial rebound using space geodesy: a detailed assessment of model ICE-5G (VM2) and its relatives

    Science.gov (United States)

    Argus, Donald F.; Peltier, W. Richard

    2010-05-01

    Using global positioning system, very long baseline interferometry, satellite laser ranging and Doppler Orbitography and Radiopositioning Integrated by Satellite observations, including the Canadian Base Network and Fennoscandian BIFROST array, we constrain, in models of postglacial rebound, the thickness of the ice sheets as a function of position and time and the viscosity of the mantle as a function of depth. We test model ICE-5G VM2 T90 Rot, which well fits many hundred Holocene relative sea level histories in North America, Europe and worldwide. ICE-5G is the deglaciation history having more ice in western Canada than ICE-4G; VM2 is the mantle viscosity profile having a mean upper mantle viscosity of 0.5 × 1021Pas and a mean uppermost-lower mantle viscosity of 1.6 × 1021Pas T90 is an elastic lithosphere thickness of 90 km; and Rot designates that the model includes (rotational feedback) Earth's response to the wander of the North Pole of Earth's spin axis towards Canada at a speed of ~1° Myr-1. The vertical observations in North America show that, relative to ICE-5G, the Laurentide ice sheet at last glacial maximum (LGM) at ~26 ka was (1) much thinner in southern Manitoba, (2) thinner near Yellowknife (Northwest Territories), (3) thicker in eastern and southern Quebec and (4) thicker along the northern British Columbia-Alberta border, or that ice was unloaded from these areas later (thicker) or earlier (thinner) than in ICE-5G. The data indicate that the western Laurentide ice sheet was intermediate in mass between ICE-5G and ICE-4G. The vertical observations and GRACE gravity data together suggest that the western Laurentide ice sheet was nearly as massive as that in ICE-5G but distributed more broadly across northwestern Canada. VM2 poorly fits the horizontal observations in North America, predicting places along the margins of the Laurentide ice sheet to be moving laterally away from the ice centre at 2 mm yr-1 in ICE-4G and 3 mm yr-1 in ICE-5G, in disagreement with the observation that the interior of the North American Plate is deforming more slowly than 1 mm yr-1. Substituting VM5a T60 for VM2 T90, that is, introducing into the lithosphere at its base a layer with a high viscosity of 10 × 1021Pas, greatly improves the fit of the horizontal observations in North America. ICE-4G VM5a T60 Rot predicts most of the North American Plate to be moving horizontally more slowly than ~1 mm yr-1, in agreement with the data. ICE-5G VM5a T60 Rot well fits both the vertical and horizontal observations in Europe. The space geodetic data cannot distinguish between models with and without rotational feedback, in the vertical because the velocity of Earth' centre is uncertain, and in the horizontal because the areas of the plate interiors having geodetic sites is not large enough to detect the small differences in the predictions of rotational feedback going across the plate interiors.

  9. Global geodetic observing system meeting the requirements of a global society on a changing planet in 2020

    CERN Document Server

    Plag, Hans-Peter

    2009-01-01

    Geodesy plays a key role in geodynamics, geohazards, the global water cycle, global change, atmosphere and ocean dynamics. This book covers geodesy's contribution to science and society and identifies user needs regarding geodetic observations and products.

  10. Indications from space geodesy, gravimetry and seismology for slow Earth expansion at present – comment on “The Earth expansion theory and its transition from scientific hypothesis to pseudoscientific belief” by Sudiro (2014)

    OpenAIRE

    Edwards, M R

    2016-01-01

    In a recent article in this journal, Paolo Sudiro (2014) considered the long history of the expanding Earth theory and its recent descent into what he termed “pseudoscientific belief”. The expanding Earth theory contends that the radius of the Earth was once one-half to two-thirds of its current value, with the Earth's continents forming a continuous sialic cover over the Earth. The theory has had two main variants: slow expansion at about 0.5 mm yr−1 radial increase since ...

  11. The metod of SVD improving ridge estimate and its appliation in geodesy%奇异改进型岭估计及其在大地测量中的应用

    Institute of Scientific and Technical Information of China (English)

    李屹旭; 张俊

    2007-01-01

    在大地测量中,法方程病态问题大量存在.由于病态性的存在,致使按最小二乘法解算参数估值精度变差甚至发生扭曲,最终使所得结果不能使用.针对这种情况人们提出用有偏估计来解决问题,其中岭估计是最常用到的方法之一.本文提出一种新的有偏估计方法-奇异改进型岭估计,试验表明该方法能够有效克服病态性对平差系统带来的不良影响,是一种值得重视的有偏估计方法.

  12. European Geophysical Society (23rd) General Assembly, Annales Geophysicae, Part 1, Society Symposia, Solid Earth Geophysics & Geodesy, Supplement 1 to Volume 16 Held in Nice, France on 20-24 April 1998

    Science.gov (United States)

    1998-01-01

    7,1-20129 Milano, Italy) G. Bianco (Centro di Geodesia Spaziale, Agenzia Spaziale Italiana . Localita Terlecchia, C.P. Aperta, 75100 Matera, Italy...Telespazio SpA, Centro di Geodesia Spaziale "G. Colombo", Matera, Italy) F. Vespe (Agenzia Spaziale Italiana - Centro di Geodesia Spaziale "G. Colombo...Matematicas, Ciudad Universitaria, 28040, Madrid, Espana (3) USGS, Menlo Park, CA, USA. kristy@fractal.colorado.edu Ground deformation is a

  13. Present-day loading rate of faults in southern California and northern Baja California, Mexico, and post-seismic deformation following the M7.2 April 4, 2010, El Mayor-Cucapah earthquake from GPS Geodesy

    Science.gov (United States)

    Spinler, J. C.; Bennett, R. A.

    2012-12-01

    We use 142 GPS velocity estimates from the SCEC Crustal Motion Map 4 and 59 GPS velocity estimates from additional sites to model the crustal velocity field of southern California, USA, and northern Baja California, Mexico, prior to the 2010 April 4 Mw 7.2 El Mayor-Cucapah (EMC) earthquake. The EMC earthquake is the largest event to occur along the southern San Andreas fault system in nearly two decades. In the year following the EMC earthquake, the EarthScope Plate Boundary Observatory (PBO) constructed eight new continuous GPS sites in northern Baja California, Mexico. We used our velocity model, which represents the period before the EMC earthquake, to assess postseismic velocity changes at the new PBO sites. Time series from the new PBO sites, which were constructed 4-18 months following the earthquake do not exhibit obvious exponential or logarithmic decay, showing instead fairly secular trends through the period of our analysis (2010.8-2012.5). The weighted RMS misfit to secular rates, accounting for periodic site motions is typically around 1.7 mm/yr, indicating high positioning precision and fairly linear site motion. Results of our research include new fault slip rate estimates for the greater San Andreas fault system, including model faults representing the Cerro Prieto (39.0±0.1 mm/yr), Imperial (35.7±0.1 mm/yr), and southernmost San Andreas (24.7±0.1 mm/yr), generally consistent with previous geodetic studies within the region. Velocity changes at the new PBO sites associated with the EMC earthquake are in the range 1.7±0.3 to 9.2±2.6 mm/yr. The maximum rate difference is found in Mexicali Valley, close to the rupture. Rate changes decay systematically with distance from the EMC epicenter and velocity orientations exhibit a butterfly pattern as expected from a strike slip earthquake. Sites to the south and southwest of the Baja California shear zone are moving more rapidly to the northwest relative to their motions prior to the earthquake. Sites to the west of the Laguna Salada fault zone are moving more westerly. Sites to the east of the EMC rupture move more southerly than prior to the EMC earthquake. Continued monitoring of these velocity changes will allow us to differentiate between lower crustal and upper mantle relaxation processes.

  14. Time-Frequency Filtering and Carrier-Phase Ambiguity Resolution for GPS-Based TSPI Systems in Jamming Environment

    Science.gov (United States)

    2007-08-15

    34Efficiency of carrier-phase integer ambiguity resolution for precise GPS positioning in noisy environments," Journal of Geodesy 81, 149-156 (2007). * A...and S. Mahmood "Efficiency of carrier-phase integer ambiguity resolution for precise GPS positioning in noisy environments," Journal of Geodesy 81...was an active collaboration with Drs. S. Mohamod and J. Murchison at Eglin AFB. The activities resulted in one joint paper published in Journal of Geodesy . During

  15. Global Positioning System Bibliography

    Science.gov (United States)

    1992-03-01

    Morgan, P. (1987). "Models for GPS network design." Australian Journal of Geodesy , Photogrammetry and Surveying, December, Nos. 46 & 47, pp. pp. 41-55...Morgan, P., C. Xing, C. Rogers, and D. R. Larden (1986). "Validation procedures in GPS surveys." Australian Journal of Geodesy , Photogrammetry, and...Luck (1987). "The Australian GPS orbit determination pilot project." Australian Journal of Geodesy , Photogrammetry and Surveying, December, No. 46

  16. An Investigation Into the Feasibility of Using a Modern Gravity Gradient Instrument for Passive Aircraft Navigation and Terrain Avoidance

    Science.gov (United States)

    2009-03-01

    the gravity gradients in the local % 19 % north -oriented and orbital referencse frames. Journal of % % Geodesy , Vol 80, 117 -127% % % % % % % by...Integration% % of low orbiter ’s trajctory perturbed by the % 20 % Earth non -sphericity , Journal of Geodesy , % % vol 72:578 -585 % % % % Borre , Kai...pp. 43–57, 1990. 9. D. Nagy, G. Papp, and J. Benedek, “The gravitational potential and its derivatives for the prism,” Journal of Geodesy , vol. 74, pp

  17. New and Improved Solar Radiation Models for GPS Satellites Based on Flight Data

    Science.gov (United States)

    1997-04-12

    Bar-Sever, Y.E., A New Model for GPS Yaw Attitude, Journal of Geodesy , 70, pp 714-723, 1996. Bar-Sever, Y.E., Strategies for Near Real Time...1983. Watkins, M.M, Bar-Sever, Y.E., Yuan, D-N, Evaluation of GPS orbital Ephemerides with Satellite laser Ranging, Journal of geodesy , 1997

  18. Error Analysis of Padding Schemes for DFT’s of Convolutions and Derivatives

    Science.gov (United States)

    2012-01-31

    spectral techniques for geoid computations over large regions. Journal of Geodesy , 70(6), 357-373. Tziavos IN, Sideris MG, Forsberg R, Schwarz KP...362- 378. Zhang C (1995) A general formula and its inverse formula for gravimetric transformations by use of convolution and deconvolution techniques. Journal of Geodesy , 70(1-2), 51-64. 24

  19. DETERMINATION OF THE LOVE NUMBER k2 OF WAVES Mf AND Mm IN SOLID EARTH TIDE --THE RESULTS FROM SPACE GEODESY%Mf和Mm波固体潮Love数k2的确定--来自空间大地测量的结果

    Institute of Scientific and Technical Information of China (English)

    吴斌; 彭碧波; 郝兴华

    2000-01-01

    初步探讨用日长和卫星轨道摄动方法研究半月潮Mf和月潮Mm的Love数k2,结果表明,日长方法给出k2=0.3032+i0.0028(Mf),0.3026+i0.0012(Mm),卫星轨道摄动方法为k2=0.3083-i0.0100(Mf),0.3014-i0,0010(Mm),并与理论固体潮计算结果较为相符.另外,上述结果更接近滞弹地球模型计算的结果,因此精确地测定长期潮Love数将对固体潮理论和地幔滞弹性提供重要的结束.

  20. United States Air Force Summer Faculty Research Program (1984). Program Management Report.

    Science.gov (United States)

    1984-12-01

    6 Two-Color Refractometry for Dr. John D. R. Bahng Astronomical Geodesy 7 Long Wavelength infrared Emissions Dr. James C. Baird from a Recomnining...hardware, and conducting the experiment. 4 114 , -. ., -. . . . . . . . - ... . . .. . . . . . . . . . . . . . . . . . . TWO-ODLOR REFRACTOMETRY FOR

  1. Relevancy of mathematical support for geophysics determinations

    Science.gov (United States)

    Vîlceanu, Clara-Beatrice; Grecea, Carmen; Muşat, Cosmin

    2017-07-01

    The importance of gravity in geodesy is recognized even since the 16th century. Starting with the experiments and theories of Galileo Galilei, the gravity and its global variation has continued to play an important role for those preoccupied with measuring the Earth's surface. The benefits of Physical Geodesy (studying the Earth's gravitational field) are extended to other disciplines such as Seismology, Oceanography, Volcanology etc. The aim of the present paper consists in highlighting the connection between gravity and the geodesist's profession. This was possible only throughout an extended study of Physical Geodesy realized with the support given by the International Gravity Office, Military Topographic Direction, The National Centre of Cartography and different specialists from these domains. Gravity represents the main factor which influences the Earth's shape and dimensions and when it comes to geodetic measurements, the gravity and its influence upon the measurements realized by specialists in geodesy has to be considered.

  2. PATHFINDER. Volume 8, Number 5. September/October 2010

    Science.gov (United States)

    2010-10-01

    analysts began reviewing the first Dari-language Image City Map co-produced by the Afghanistan Geodesy and Cartography Head Office. The map, of...navigation, planning and urban area operations. NGA photo Arabic language map co-produced by Afghanistan Geodesy and Cartography Head Office. » Soccer...by the 1st Cavalry Division GIS Cell, MND-Baghdad, 07 July 2009 Security District outlines validated by 4th Infantry Division Geospatial Information

  3. The Possibilities Of Spatial Data Integration For Building Construction In GIS Software

    Science.gov (United States)

    Mitka, Bartosz; Pluta, Magda

    2015-12-01

    This paper shows possibilities of using GIS packages for creating complete information system about buildings. The building of Faculty of Environmental Engineering and Geodesy was used as an example possibilities of integration data from Department of Geodesy and Cartography with data from architectural stocktaking expanded about attributes and descriptive information. The aim of the work is analysis of possibilities of using this kind of system and available functions for end user.

  4. Danko Markovinović, PhD in Technical Sciences

    Directory of Open Access Journals (Sweden)

    Miljenko Lapaine

    2009-12-01

    Full Text Available Danko Markovinović defended his dissertation Gravimetric Reference System of the Republic of Croatia at the Faculty of Geodesy of the University of Zagreb on October 16, 2009. The dissertation was defended in front of the committee: Prof. Dr. Mario Brkić, Prof. Dr. Tomislav Bašić (mentor and Assist. Prof. Dr. Miran Kuhar from the Faculty of Civil Engineering and Geodesy of the University of Ljubljana.

  5. Geography From Another Dimension

    Science.gov (United States)

    2002-01-01

    The GEODESY software program is intended to promote geographical awareness among students with its remote sensing capabilities to observe the Earth's surface from distant vantage points. Students and teachers using GEODESY learn to interpret and analyze geographical data pertaining to the physical attributes of their community. For example, the program provides a digital environment of physical features, such as mountains and bodies of water, as well as man-made features, such as roads and parks, using aerial photography, satellite imagery, and geographic information systems data in accordance with National Geography Standards. The main goal is to have the students and teachers gain a better understanding of the unique forces that drive their coexistence. GEODESY was developed with technical assistance and financial support from Stennis Space Center's Commercial Remote Sensing Program Office, now known as the Earth Science Applications Directorate.

  6. Academician and geodetic general Stevan P. Bošković, the head of Military Geographic Institute in Belgrade

    Directory of Open Access Journals (Sweden)

    Stevan RADOJČIĆ

    2014-03-01

    Full Text Available Stevan P. Bošković (1868-1957 was a Serbian geodesist, geographer and cartographer. As a head of Military Geographic Institute, he was the organizer of the first modern geodetic works in Serbia and Yugoslavia. He was the first our geodetic general and the first academician in Serbia and Yugoslavia in the area of geodesy. He innovated and improved geodetic instruments, equipment and methods. He gave a remarkable contribution to activities of the International Union of Geodesy and Geophysics. Stevan P. Bošković is one of the most educated oficers of Serbian and Yugoslav Armed Forces, and our scientists of that time in general. This paper gives the basic fact about the work of Stevan P. Bošković work and life and his importance in history of geodesy in Serbia and Europe.

  7. DORIS applications for solid earth and atmospheric sciences

    Science.gov (United States)

    Willis, Pascal; Soudarin, Laurent; Jayles, Christian; Rolland, Lucie

    2007-12-01

    DORIS is a French precise orbit determination system. However, in the past four years, through the creation of the International DORIS Service, a larger international cooperation was involved. Furthermore, the precision of its scientific applications (geodesy, geophysics) gradually improved and expanded to new fields (atmospheric sciences), leading, for example, to the publication of a special issue of the Journal of Geodesy. The goal of this manuscript is to present and explain these changes and to put them in perspective with current results obtained with other space geodetic techniques, such as GPS or Satellite Laser Ranging.

  8. Milan Rezo, PhD in Technical Sciences

    Directory of Open Access Journals (Sweden)

    Tomislav Bašić

    2010-12-01

    Full Text Available On October, 7th 2010, Milan Rezo defended his dissertation The Meaning and the Application of Physical Parameters in Modern Approach in State Survey at the Faculty of Geodesy of the University of Zagreb, and in front of the Commission consisting of Assoc. Prof. Dr. Željko Bačić, Prof. Dr. Tomislav Bašić (mentor, both from the Faculty of Geodesy, University of Zagreb, and Assist. Prof. Božo Soldo from the Faculty of Geotechnical Engineering Varaždin of University of Zagreb.

  9. Coordinate systems and map projections

    CERN Document Server

    Maling, DH

    1992-01-01

    A revised and expanded new edition of the definitive English work on map projections. The revisions take into account the huge advances in geometrical geodesy which have occurred since the early years of satellite geodesy. The detailed configuration of the geoid resulting from the GEOS and SEASAT altimetry measurements are now taken into consideration. Additionally, the chapter on computation of map projections is updated bearing in mind the availability of pocket calculators and microcomputers. Analytical derivation of some map projections including examples of pseudocylindrical and polyconic

  10. Prospect on Present-Day Crustal Kinematics and Dynamics Research in Sichuan-Yunnan Area with Geodetic Data

    Institute of Scientific and Technical Information of China (English)

    XU Caijun; LI Zhicai; WANG Qi

    2005-01-01

    Combining the dense GPS and gravity observation data in Sichuan-Yunnan area, where there are the relatively complete active tectonic zones and seismic data, this paper applies the geodesy and geophysical inversion technique and the advanced numerical simulation to the synthesis study of geodesy inversion to find the dynamic process of tectonic movement and deformation in the area and finally to investigate the kinematics characteristic of the geological structure of different layer and different scale. This paper discusses the kinematics, dynamics model about the crustal movement of active blocks in Sichuan-Yunnan area and its adjacent areas.

  11. Dimensions of a Planet.

    Science.gov (United States)

    Hayward, O. T.; And Others

    This publication is one of a series of single-topic problem modules designed for use in undergraduate geology and earth science courses. The first section, "Ain't It Flat? A Series of Experiments in Geodesy," presents various experiments for determining the earth's circumference (historically) and describes the use of satellites in determining the…

  12. Measuring the Heavens to Rule the Territory: Filipe Folque and the Teaching of Astronomy at the Lisbon Polytechnic School and the Modernization of the State Apparatus in Nineteenth Century Portugal

    Science.gov (United States)

    Carolino, Luis Miguel

    2012-01-01

    This paper focuses on the astronomy teaching at the Lisbon Polytechnic School and its role in building a modern technoscientific state in Portugal during the nineteenth century. It examines particularly the case of Filipe Folque, who taught astronomy and geodesy at the Lisbon Polytechnic from 1837 to 1856, and played a pivotal role in the geodetic…

  13. Caspar Wessel (1745-1818). Surveyor and Mathematician

    DEFF Research Database (Denmark)

    Branner, Bodil; Johansen, Nils Voje

    1999-01-01

    This is a biography. It focus on Caspar Wessel's work as surveyor under the auspices of the Royal Danish Academy of Sciences and Letters, in particular on some of his theoretical investigations of geodesy that lead him to use complex numbers to represent directions in a plane at least as early...

  14. Solutions of Maxwell equations for hollow curved wave conductor

    CERN Document Server

    Bashkov, V I

    1995-01-01

    In the present paper the idea is proposed to solve Maxwell equations for a curved hollow wave conductor by means of effective Riemannian space, in which the lines of motion of fotons are isotropic geodesies for a 4-dimensional space-time. The algorithm of constructing such a metric and curvature tensor components are written down explicitly. The result is in accordance with experiment.

  15. Measuring the Heavens to Rule the Territory: Filipe Folque and the Teaching of Astronomy at the Lisbon Polytechnic School and the Modernization of the State Apparatus in Nineteenth Century Portugal

    Science.gov (United States)

    Carolino, Luis Miguel

    2012-01-01

    This paper focuses on the astronomy teaching at the Lisbon Polytechnic School and its role in building a modern technoscientific state in Portugal during the nineteenth century. It examines particularly the case of Filipe Folque, who taught astronomy and geodesy at the Lisbon Polytechnic from 1837 to 1856, and played a pivotal role in the geodetic…

  16. Recent Developments in at the CDDIS in Support of GGOS

    Science.gov (United States)

    Noll, C. E.; Michael, B. P.; Pollack, N.

    2015-12-01

    The Crustal Dynamics Data Information System (CDDIS) supports data archiving and distribution activities for the space geodesy and geodynamics community. The main objectives of the system are to store space geodesy and geodynamics related data and products in a central data bank, to maintain information about the archival of these data, to disseminate these data and information in a timely manner to a global scientific research community and provide user based tools for the exploration and use of the archive. The CDDIS data system and its archive is a key component in several of the operational services within the International Association of Geodesy (IAG) and its observing system the Global Geodetic Observing System (GGOS), including the IGS, the International DORIS Service (IDS), the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), and the International Earth Rotation and Reference Systems Service (IERS). In early 2015, CDDIS enhanced its operations with a new search tool enabling users to quickly search the archives in both spatial and temporal parameters. Also, in partnership with the IGS Real Rime Service, CDDIS established a new GNSS real-time streaming service with over 150 data streams and 30 products streams to the GNSS community providing additional capability and redundancy to the IGS Real Time Service (RTS). This poster will showcase these enhancements and others that CDDIS has made over the past year for the geodetic community and describe future plans for the system.

  17. BKG/DGFI Combination Center Annual Report 2012

    Science.gov (United States)

    Bachmann, Sabine; Loesler, Michael; Heinkelmann, Robert; Gerstl, Michael

    2013-01-01

    This report summarizes the activities of the Federal Agency for Cartography and Geodesy (Bundesamt fuer Kartographie und Geodaesie, BKG) and the German Geodetic Research Institute (Deutsches Geodaetisches Forschungsinstitut, DGFI)BKG/DGFI Combination Center in 2011 and outlines the planned activities for the year 2012. The main focus was to stabilize outlier detection and to update the Web presentation of the combined products.

  18. GNET detected an anomalous "spike" in ice loss in Greenland during the 2010 melting season

    DEFF Research Database (Denmark)

    Bevis, Michael G; Wahr, John M; Khan, Shfaqat Abbas

    The Greenland GPS Network (GNET) uses GPS geodesy to measure the displacement of bedrock exposed near the margins of the Greenland Ice Sheet. The amplitudes of the observed vertical velocities indicate that over most of coastal Greenland these displacements are dominated by the solid earth’s inst...

  19. Irwin I. Shapiro received the William Bowie Medal of the American Geophysical Union.

    Science.gov (United States)

    1994-04-01

    I. I. Shapiro has pushed the limits of geodesy to the very edges of the universe, using the signals from the extragalactic radio sources (quasars) to measure the motions of lithospheric plates, to monitor variations in the rotation of the Earth and to determine the flattening of the Earth's fluid core.

  20. 48 CFR 242.202 - Assignment of contract administration.

    Science.gov (United States)

    2010-10-01

    ... civil public works, including harbors, docks, port facilities, military housing, development of..., charting, and geodesy services; (F) Base, post, camp, and station purchases; (G) Operation or maintenance... services; (I) Installation, operation, and maintenance of space-track sensors and relays; (J) Dependents...

  1. A decade of ERS satellite orbits and altimetry

    NARCIS (Netherlands)

    Scharroo, R.

    2002-01-01

    The First European Remote Sensing Satellite, ERS-1, was launched in July 1991, fol- lowed by ERS-2 in April 1995. Both satellites carry a radar altimeter to serve oper- ational applications and scientific research in the fields of geodesy, oceanography, glaciology and meteorology. Together, the sate

  2. CDDIS Data Center Summary for the IVS 2012 Annual Report

    Science.gov (United States)

    Noll, Carey

    2013-01-01

    This report summarizes activities during 2012 and future plans of the Crustal Dynamics Data Information System (CDDIS) with respect to the International VLBI Service for Geodesy and Astrometry (IVS). Included in this report are background information about the CDDIS, the computer architecture, staff supporting the system, archive contents, and future plans for the CDDIS within the IVS.

  3. Algorithms for Global Positioning

    DEFF Research Database (Denmark)

    Borre, Kai; Strang, Gilbert

    and replaces the authors' previous work, Linear Algebra, Geodesy, and GPS (1997). An initial discussion of the basic concepts, characteristics and technical aspects of different satellite systems is followed by the necessary mathematical content which is presented in a detailed and self-contained fashion...

  4. Options and Functions of the Revised IVS Combination Web Site

    Science.gov (United States)

    Messerschmitt, Linda; Bachmann, Sabine; Thaller, Daniela

    2016-12-01

    The World Wide Web is one of the most important communication and information exchange platforms today. Because of the high amount of users and the global accessibility, every business is interested in the Internet. It opens up new possibilities of international cooperation. In geodesy, this aspect of international cooperation is of prime importance.

  5. Dependency of resolvable gravitational spatial resolution on space-borne observation techniques

    NARCIS (Netherlands)

    Visser, P.N.A.M.; Schrama, E.J.O.; Sneeuw, N.; Weigelt, M.

    2009-01-01

    The so-called Colombo-Nyquist (Colombo, The global mapping of gravity with two satellites, 1984) rule in satellite geodesy has been revisited. This rule predicts that for a gravimetric satellite flying in a (near-)polar circular repeat orbit, the maximum resolvable geopotential spherical harmonic de

  6. Prof. Cai Shuming Receives 2005 Wetland Conservation Award

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Prof. Cai Shuming, an expert in wetland studies from the CAS Institute of Geodesy & Geophysics, has been honored with a Ramsar Wetland Conservation Award in 2005. The announcement was made by the Standing Committee of the Ramsar Convention on June 10 in Gland,Switzerland.

  7. Geophysics: The Earth in Space. A Guide for High School Students.

    Science.gov (United States)

    American Geophysical Union, Washington, DC.

    Geophysics is the application of physics, chemistry, and mathematics to the problems and processes of the earth, from its innermost core to its outermost environs in space. Fields within geophysics include the atmospheric sciences; geodesy; geomagnetism and paleomagnetism; hydrology; oceanography; planetology; seismology; solar-planetary…

  8. Beyond the Classroom: Finding the First Cornerstone

    Science.gov (United States)

    Garran, Daniella K.

    2011-01-01

    What could two dozen middle school students, two teachers, land surveyors, journalists, divers, college professors, lawyers, archaeologists, an author, and an 85-year old retiree possibly have in common? The answer is their insatiable quest to redefine colonial American history. From geodesy to glaciology, from geology to hydrology, from…

  9. Point-Mass Modeling of the Gravity Field with Emphasis on the Oceanic Geoid.

    Science.gov (United States)

    1983-02-01

    approximately 980 gals). Equation (4.7) follows from the Bruns formula presented on page 85 of [ Heiskanen and Moritz, 1967]. If ds and ds’ are...Monogr. Ser., Vol. 2, Environ. Sci. Serv. Admin., Washington, D.C., 1969. Heiskanen , W.A. and H. Moritz, Physical Geodesy. W.H. Freeman and Co., San

  10. Local Covariance Functions and Density Distributions.

    Science.gov (United States)

    1984-06-01

    each to one of the variables in K(P, Q). In the spectral domain, the eigenvalue of operator (2.6) is well known to be ( Heiskanen and Moritz, 1967, p. 97...M.Y. Ryshik: Table of integrals, series, and products. Academic Press, New York, 1965. Heiskanen , W.A. and H. Moritz: Physical geodesy. Freeman, 1967

  11. The Influence of Reference System Disparity on Navigation and Positioning,

    Science.gov (United States)

    1983-03-23

    were derived using gravimetric methods and data ( Heiskanen and Vening Meinesz, 1958). Much more refined models can now be developed using a combination...4. Heiskanen , W.A. and Vening Meinesz, F.A., The Earth and Its Gravity Field, McGraw-Hill Book Co., New York, 1958. 5. Rapp, R.H., Geometric Geodesy

  12. Dependency of resolvable gravitational spatial resolution on space-borne observation techniques

    NARCIS (Netherlands)

    Visser, P.N.A.M.; Schrama, E.J.O.; Sneeuw, N.; Weigelt, M.

    2009-01-01

    The so-called Colombo-Nyquist (Colombo, The global mapping of gravity with two satellites, 1984) rule in satellite geodesy has been revisited. This rule predicts that for a gravimetric satellite flying in a (near-)polar circular repeat orbit, the maximum resolvable geopotential spherical harmonic

  13. Mitrofan Khandrikov: new facts of life (to 180 anniversary of his birth)

    Science.gov (United States)

    Kazantseva, L. V.

    2017-05-01

    Mitrofan Khandrykov (1837-1915) headed the department of astronomy and geodesy at Kiev University and was director of the University Observatory more than 30 years. He was the author of a long series of publications, many textbooks in mathematics, astronomy and geodesy for university students. He started some observational and theoretical directions for the observatory, he updated observational instruments, began publishing a periodical scientific publication in the observatory. He trained and prepared a worthy replacement, developed and launched specialized teaching of astronomy in other educational establishments. His biography is found in many national and international encyclopedias. But the facts of personal life of his are poorly understood. Joint research of materials, which collected by Astronomical Museum and which are in other archives, available digitized sources allow to restore some facts from the life of famous former employee Observatory.

  14. 5th International Conference on Engineering Surveying Brijuni, September 22-24, 2011

    Directory of Open Access Journals (Sweden)

    Rinaldo Paar

    2011-12-01

    Full Text Available 5th International Conference on Engineering Surveying was held on the Brijuni Islands from 22 to 24 September 2011. The conference organizers were the Department of Surveying Faculty of Civil Engineering at the Slovak University of Technology in Bratislava and the Institute for Applied Geodesy at the Faculty of Geodesy, University of Zagreb, with the FIG Commission 6. The conference was held under the patronage of the Ministry of Environmental Protection, Physical Planning and Construction of the Republic of Croatia. The conference took place in the Castrum Congress Hall of Hotel Neptun-Istra. The official language of the conference was English. The conference was attended by 70 representatives from Croatia, Slovenia, Serbia, Kosovo, Austria, Germany, Hungary, Greece, Czech Republic and Slovakia, and a total of 40 papers were presented.

  15. Earth's density flattening and hypothesis of latitudinal normal density

    Institute of Scientific and Technical Information of China (English)

    HAO; Xiaoguang

    2001-01-01

    [1]Moritz,H., The Figure of the Earth: Theoretical Geodesy and the Earth's Interior (in Chinese), translated by Chen Junyong and Zuo Chuanhui, Beijing: Surveying and Mapping Publishing House, 1992, 92-107.[2]Iona,M., Why is g larger at the poles? Am. J. Phys., 1978, 46: 790-791.[3]Maialle, M. Z., Hipolito, O., Acceleration of gravity for the earth model as an ellipsoidal mass with nonuniform density, Am. J. Phys., 1996, 64: 434-436.[4]Hao Xiaoguang, Modification of conception of latitude correction in gravity measurement, Crustal Deformation and Earthquake (in Chinese), 1996, 16(3): 8-13.[5]Guo Junyi, The Fundamental of Physical Geodesy (in Chinese), Wuhan: Wuhan Technology University of Surveying and Mapping Press, 1994, 135-136.

  16. Visual Analysis Based on the Data of Chinese Surveying and Mapping Journals

    Science.gov (United States)

    Li, Jing; Liu, Haiyan; Guo, Wenyue; Yu, Anzhu

    2016-06-01

    Taking four influential Chinese surveying and mapping journals as the data source, 5863 papers published during the period of 2003-2013 were obtained. Using the method of bibliometrics and visual analysis, summarizing the surveying and mapping papers in the past ten years (2003-2013), research themes, authors, and geographical distribution were analyzed. In the study, the papers of geodesy, cartography and GIS are 59.9%, more than half of all the papers. We also determine that the core author group has 131 authors, mainly of whom are from big cities. 90% of top ten cities on the number of publishing papers are capital cities or municipalities directly under the central government.In conclusion, we found that the research focus was different every year, and the research content was richness, the content of geodesy, cartography and GIS were widely researched, and the development of surveying and mapping is imbalanced in China.

  17. IAU Symposium No. 32

    CERN Document Server

    Guinot, B

    1968-01-01

    AGU American Geophysical Union BIH Bureau International de l'Heure FAGS Federation of Astronomical and Geophysical Services lAG International Association of Geodesy IAU International Astronomical Union ICSU International Council of Scientific Unions ILS International Latitude Service IPMS International Polar Motion Service International Union of Geodesy and Geophysics IUGG PZT Photographic Zenith Tube UNESCO United Nations Educational, Scientific and Cultural Organization INTRODUCTION The hypothesis of continental drift has become of increasing interest to geophysicists in recent years. The IUGG Upper Mantle Committee has stated that the hypothesis of continental drift envisages horizontal displacements of the continents over th- sands of kilometers, and that it is a principal objective of the Upper Mantle Project to prove whether or not continental drift has occurred. The origin of the hypothesis may be traced to the close similarity in outlines of the coasts on the two sides of the Atlantic Ocean. The theor...

  18. Algorithms for Global Positioning

    DEFF Research Database (Denmark)

    Borre, Kai; Strang, Gilbert

    The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology and repla......The emergence of satellite technology has changed the lives of millions of people. In particular, GPS has brought an unprecedented level of accuracy to the field of geodesy. This text is a guide to the algorithms and mathematical principles that account for the success of GPS technology....... At the heart of the matter are the positioning algorithms on which GPS technology relies, the discussion of which will affirm the mathematical contents of the previous chapters. Numerous ready-to-use MATLAB codes are included for the reader. This comprehensive guide will be invaluable for engineers...

  19. New trends for the realization of the international terrestrial reference system

    Science.gov (United States)

    Altamimi, Zuheir; Boucher, Claude; Sillard, Patrick

    2002-07-01

    With the advent of Space geodesy techniques in early eighties, global terrestrial reference frames became available whose precision is still improving parallel to measuring and modeling advances. As a global reference, the realization of the International Terrestrial Reference System (ITRS), known as the International Terrestrial Reference Frame (ITRF), maintained by the International Earth Rotation Service, has sustained substantial improvement and enhancement. One of the major new trends is the 2000 ITRS realization, to be considered as a standard solution for a wide user community (geodesy, geophysics, astronomy, etc.). The ITRF2000 comprises on one hand primary core stations observed by VLBI, LLR, GPS, SLR and DORIS techniques and, on the other hand, significant extension provided by regional GPS networks for densifications as well as other useful geodetic markers tied to space geodetic ones. The ITRF2000 combination and implementation strategy are described in this paper. Important results in terms of datum definition as well as quality assessment of the ITRF2000 are presented.

  20. Scientific Advances from Paul Silver's Inspirational Leadership of the EarthScope Plate Boundary Observatory

    Science.gov (United States)

    Miller, M. M.; Calais, E.; Jackson, M. E.; Owen, S. E.; Segall, P.

    2009-12-01

    While major scientific endeavors and advances rely on the work and dedication of many, they are often made possible thanks to the passion and clear vision articulated by one or two leading scientists. Paul Silver was that leading visionary for EarthScope’s Plate Boundary Observatory. Paul Silver understood early on that the synergy of seismic and geodetic observations contained fundamental information on the coupled lithosphere-mantle system, the key to cracking the dynamics that underlies plate tectonics and continental deformation. This became a central theme of the Earthscope initiative, and Paul, a seismologist by training, became a tireless advocate for geodesy at all stages of the project - and for instrumentation over the broadest possible temporal bandwidth, from GPS geodesy to strainmeters. The presentation, given on behalf of UNAVCO and the UNAVCO community, will review and honor Paul's contributions to UNAVCO and the Plate Boundary Observatory science.

  1. Geodetski vestnik and its path to better international recognition

    OpenAIRE

    Koler Povh, Teja; Lisec, Anka

    2015-01-01

    The editorial board of Geodetski vestnik, the leading Slovenian scientific and professional journal in the fields of geodesy, land surveying, geoinformatics and land management, has taken many actions to increase the quality of the journal over the past decade. Among others, the reviewing procedures were improved by introducing double- blind peer review of articles, internationalisation of editorial and review boards has been done, the journal has been included ...

  2. Digital Signal Processor For GPS Receivers

    Science.gov (United States)

    Thomas, J. B.; Meehan, T. K.; Srinivasan, J. M.

    1989-01-01

    Three innovative components combined to produce all-digital signal processor with superior characteristics: outstanding accuracy, high-dynamics tracking, versatile integration times, lower loss-of-lock signal strengths, and infrequent cycle slips. Three components are digital chip advancer, digital carrier downconverter and code correlator, and digital tracking processor. All-digital signal processor intended for use in receivers of Global Positioning System (GPS) for geodesy, geodynamics, high-dynamics tracking, and ionospheric calibration.

  3. Proceedings of the Annual NASA and Department of Defense Precise Time and Time Interval (PITI) Planning Meeting (5th), Held at Goddard Space Flight Center on December 4-6, 1973

    Science.gov (United States)

    1972-01-01

    Propulsion Laboratory (JPL) for earthquake hazards estimation. This system, called ARIES (Astronomical Radio Interferometric Earth Surveying), will be...occurrence of SPA’s is related to sunspot activity with about one per day being observed somewhere on earth when the sunspot num- ber is about 85...Requirements for Radio Interferometric Earth Physics, J. B. Thomas and H, F. Fliegel 15 Time, Geodesy, and Astrometry: Results from Radio

  4. Instituto Geografico Nacional of Spain

    Science.gov (United States)

    Colomer, Francisco; Garcia-Espada, Susana; Gomez-Gonzalez, Jesus; Lopez-Fernandez, Jose Antonio; Santamaria-Gomez, Alvaro; De Vicente, Pablo

    2013-01-01

    This report updates the description of the space geodesy facilities of the Spanish National Geographic Institute (IGN). The current 40-meter radio telescope at Yebes, a network station for IVS, has performed geodetic VLBI observations regularly since September 2008. In addition to this, the project to establish an Atlantic Network of Geodynamical and Space Stations (RAEGE) is progressing with the construction of the first antenna, which is being erected at Yebes.

  5. Towards an Improved Realization of the BIH Terrestrial Frame

    Science.gov (United States)

    Boucher, Claude; Altamimi, Zuheir

    In order to redefine the BIH terrestrial system from 1984 onwards (to be known as BTS), a global adjustment has been carried out using, in addition to the ERP series, sets of coordinates of sites where space geodesy stations are operated. The model used in the analysis is recalled and the calculation realized for the BIH Annual Report for 1984 is described. The future maintenance as well as improvements of the BTS are also outlined.

  6. Ground Testing and Flight Demonstration of Charge Management of Insulated Test Masses Using UV LED Electron Photoemission

    OpenAIRE

    Saraf, Shailendhar; Buchman, Sasha; Balakrishnan, Karthik; Lui, Chin Yang; Soulage, Michael; Faied, Dohy; Hanson, John; Ling, Kuok; Jaroux, Belgacem; AlRashed, Abdullah; Nassban, Badr Al; Suwaidan, Badr Al; Harbi, Mohammed Al; Salamah, Badr Bin; Othman, Mohammed Bin

    2016-01-01

    The UV LED mission demonstrates the precise control of the potential of electrically isolated test masses that is essential for the operation of space accelerometers and drag free sensors. Accelerometers and drag free sensors were and remain at the core of geodesy, aeronomy, and precision navigation missions as well as gravitational science experiments and gravitational wave observatories. Charge management using photoelectrons generated by the 254 nm UV line of Hg was first demonstrated on G...

  7. GEOPHYSICS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20080091 Cheng Luying(Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China);Xu Houze Rotation of the Gravity Potential on the Earth’s Gravity Field Recovery(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,49(1),2006,p.93-98,3 illus.,24 refs.,with English abstract)

  8. Characteristics of the Navy Laboratory Warfare Center Technical Workforce

    Science.gov (United States)

    2013-09-29

    ten years behind them in a position to assume responsibilities quickly, possibly without the necessary professional seasoning . 2.2 Distribution...public website7 or provided upon request8: • “Employment status of civilian noninstitutional population by age, sex, and race” (not seasonally ... Astronomy & Space Sci. 1330 Cartography 1370 Chemistry 1320 Gen. Physical Science 1301 Geodesy 1372 Geology 1350 Geophysics 1313 Health Physics 1306

  9. A NEW MODELLING METHOD FOR EVALUATING EXTERNAL DISTURBING POTENTIAL BASED ON THEORY OF UNIFIED REPRESENTATION OF GRAVITATIONAL FIELD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    For a special use a new modelling method of evaluating external disturbing potential is presented in this paper. Being different from classical methods in physical geodesy this method is grounded upon the theory of unified representation of gravitational field. The models created in this way are particularly satisfactory for a high-speed computation of gravitational field in low altitude because they take account of topographic effects and have their kernel functions with simple structure and weak singularity.

  10. Optical Clocks in Space

    CERN Document Server

    Schiller, S; Nevsky, A; Koelemeij, J C J; Wicht, A; Gill, P; Klein, H A; Margolis, H S; Mileti, G; Sterr, U; Riehle, F; Peik, E; Tamm, C; Ertmer, W; Rasel, E; Klein, V; Salomon, C; Tino, G M; Lemonde, P; Holzwarth, R; Hänsch, T W; Tamm, Chr.

    2007-01-01

    The performance of optical clocks has strongly progressed in recent years, and accuracies and instabilities of 1 part in 10^18 are expected in the near future. The operation of optical clocks in space provides new scientific and technological opportunities. In particular, an earth-orbiting satellite containing an ensemble of optical clocks would allow a precision measurement of the gravitational redshift, navigation with improved precision, mapping of the earth's gravitational potential by relativistic geodesy, and comparisons between ground clocks.

  11. Two-Dimensional Planar Geosystems Subjected to Three-Dimensional Dynamic Loads

    Science.gov (United States)

    1992-09-01

    A. 1967. "Propagacion de Ondas de Rayleigh en Cujas Elasticas," Pub. 47, Dept. Geophysics & Geodesy, Univ. Chile, Santiago. Love, A. E. H. 1944. A...34Stresses and Deflections in Foundations and Pavements," 4th ed., Dept. Civil Engr., Univ. Calif., Berkeley , CA. 109 Mal, A. K. and Knopoff, L. 1965...pp 239-263. Udaka, T. and Lysmer, J. 1973. "Supplement to Computer Program SHAKE," Univ. Calif., Berkeley , CA. Vardoulakis, I. and Vrettos, C. 1988

  12. NASA reschedules Mars mission for 2018

    Science.gov (United States)

    Gwynne, Peter

    2016-04-01

    NASA has announced that its next mission to Mars will be launched in May 2018 following the discovery of a leak in a key scientific instrument. The mission - Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) - was originally scheduled to launch last month and reach Mars later this year, but the new launch window means it will now not land on the red planet until November 2018.

  13. Geodynamics: Introduction and Background

    Science.gov (United States)

    1984-01-01

    An overview is given of the field of geodynamics and its major scientific questions. The NASA geodynamics program is described as well as its status and accomplishments projected by 1988. Federal coordination and international cooperation in monitoring tectonic plate motion, polar motion, and Earth rotation are mentioned. The development of a GPS receiver for civilian geodesy and results obtained using satellite laser ranging and very long baseline interferometry in measuring crustal dynamics, global dynamics, and the geopotential field are reported.

  14. Handbook for Transformation of Datums, Projections, Grids, and Common Coordinate Systems

    Science.gov (United States)

    2004-05-01

    Publica - tion No. 251 Conformal Projections in Geodesy and Cartography. (Thomas, 1979) Engineer Technical Letter No. 1110-1-147 Engineering and...the NOAA Manual NOS NGS 5 and the Coast and Geodetic Survey Special Publica - tion No. 251 are available from National Geodetic Information Branch, N...Liberia (CD) 0 1987 -90 15 40 15 88 15 LUZON LUZ Clarke 1866 Philippines (Excluding Mindanao Island) LUZ -A (CC) 0 1987 -133 8 -77

  15. Varaždin Borl Jeruzalem Tour On the occasion of the 250th anniversary of the Vienna meridian survey

    Directory of Open Access Journals (Sweden)

    Miljenko Lapaine

    2012-06-01

    Full Text Available On Saturday, June 9, 2012, the Croatian Cartographic Society organized a tour and a visit to the oldest trigonometric point in Croatia on the occasion of the 250th anniversary of the Vienna meridian arc survey. The tour was included in the Program of Professional Improvement of the Croatian Chamber of Chartered Engineers of Geodesy, and the Committee for Permanent Professional Improvement decided to award 5 (five points a person.

  16. Map Design for Computer Processing: Literature Review and DMA Product Critique.

    Science.gov (United States)

    1985-01-01

    NORDA’s Mapping. Chart- ing and Geodesy Division and Dr. Charles Walker. head of NORDA’% Pat- tern Analysis Branch. provided valuable advice and support... Baudelaire , Palo Alto Research Center, Xerox Corp.); a cient solutions have been found.* Yet there is promise system based on spiral curves (Peter...Automated Methodology -, Bigelow, Charles and Donald Day (1983). Digital for Linear Generalization in Thematic Cartography. Typography. Scientific American

  17. Why the Greenwich Meridian Moved

    Science.gov (United States)

    2015-08-01

    determination Natural coordinates [Φ, Λ, H ] are related to geodetic lati- tude, ϕ, longitude, λ, and ellipsoidal height h, by ( Heiskanen and Moritz 1967): ξ...an equipo- tential reference ellipsoid along the meridian and the prime vertical, respectively, ( Heiskanen and Moritz 1967, section 2–22): ξgrav...problems, proceedings of IAUcolloquium178.Astr. Soc. Pacific Conference Series 208, pp 175–184 Heiskanen WA, Moritz H (1967) Physical geodesy. W.H. Freeman

  18. Recovery of Gravity Anomalies from Gridded Geoid Height Data.

    Science.gov (United States)

    1976-07-01

    Heiskanen and • Mori tz [5] , - ~2(N) = ~~~ - - ~ Q2 C,~ (28)“ n=K+l n 5 5 where = f S(4’)P~(cos 4’)sin~ d4’, (29) S S C~ is the degree var i ance... Heiskanen , W.A. and H. Moritz; Physical Geodesy; W.H. Freeman and Co.; San Francisco, Cal ifornia; 1967. - - - 6. Moritz, H.; Advanced Least—Squares Methods

  19. Satellite co-locations as a link between SLR, GPS and Low Earth Orbiting (LEO) satellites

    Science.gov (United States)

    Melachroinos, S. A.; Lemoine, F. G.; Chinn, D. S.; Nicolas, J. B.; Zelensky, N. P.; Wimert, J.; Radway, Y.

    2013-12-01

    The procedure applied for the determination of the International Terrestrial Reference Frame (ITRF) requires the combination of all four major techniques of Space Geodesy. This combination is only possibly realized by the introduction of the local-ties between co-located techniques. A local-tie is the lever arm vector between the marker points on the sites where two or more space geodesy instruments operate. The local ties are used as additional observations with proper variances. They are usually derived from local surveys using either classical geodesy or the global navigation satellite systems (GNSS). The Global Positioning System (GPS) plays a major role in the ITRF combination by linking together all the other three techniques SLR, DORIS and VLBI (Altamimi and Collilieux 2009). However, discrepancies between local ties and space geodesy estimates are well known although the reasons for these discrepancies are often not clear. These discrepancies could be either due to errors in local ties and in coordinate estimates or in both. In this study, we use the tracking to G05-35 and G06-36 and one LEO by SLR sites and their combined orbits, earth rotation parameters (ERPs) and station positions in order to establish space-based co-location ties on the stations. The LEO satellite used in this experiment is Jason-2, which carries both GPS and SLR. Therefore from the data-processing point of view the LEO satellite is used as a fast moving station (Thaller et al. 2011). Jason-2 is also equipped with DORIS, but it will be included into another combined analysis. Subsequently, we compare the consistency of our space-based co-locations to the ones from ITRF08 and SLRF08 - IGb08 solutions.

  20. Analysis of GRACE Range-rate Residuals with Emphasis on Reprocessed Star-Camera Datasets

    Science.gov (United States)

    Goswami, S.; Flury, J.; Naeimi, M.; Bandikova, T.; Guerr, T. M.; Klinger, B.

    2015-12-01

    Since March 2002 the two GRACE satellites orbit the Earth at rela-tively low altitude. Determination of the gravity field of the Earth including itstemporal variations from the satellites' orbits and the inter-satellite measure-ments is the goal of the mission. Yet, the time-variable gravity signal has notbeen fully exploited. This can be seen better in the computed post-fit range-rateresiduals. The errors reflected in the range-rate residuals are due to the differ-ent sources as systematic errors, mismodelling errors and tone errors. Here, weanalyse the effect of three different star-camera data sets on the post-fit range-rate residuals. On the one hand, we consider the available attitude data andon other hand we take the two different data sets which has been reprocessedat Institute of Geodesy, Hannover and Institute of Theoretical Geodesy andSatellite Geodesy, TU Graz Austria respectively. Then the differences in therange-rate residuals computed from different attitude dataset are analyzed inthis study. Details will be given and results will be discussed.

  1. The Contribution of GGOS to Understanding Dynamic Earth Processes

    Science.gov (United States)

    Gross, Richard

    2017-04-01

    Geodesy is the science of the Earth's shape, size, gravity and rotation, including their evolution in time. Geodetic observations play a major role in the solid Earth sciences because they are fundamental for the understanding and modeling of Earth system processes. Changes in the Earth's shape, its gravitational field, and its rotation are caused by external forces acting on the Earth system and internal processes involving mass transfer and exchange of angular and linear momentum. Thus, variations in these geodetic quantities of the Earth reflect and constrain mechanical and thermo-dynamic processes in the Earth system. Mitigating the impact on human life and property of natural hazards such as earthquakes, volcanic eruptions, debris flows, landslides, land subsidence, sea level change, tsunamis, floods, storm surges, hurricanes and extreme weather is an important scientific task to which geodetic observations make fundamental contributions. Geodetic observations can be used to monitor the pre-eruptive deformation of volcanoes and the pre-seismic deformation of earthquake fault zones, aiding in the issuance of volcanic eruption and earthquake warnings. They can also be used to rapidly estimate earthquake fault motion, aiding in the modeling of tsunami genesis and the issuance of tsunami warnings. Geodetic observations are also used in other areas of the Earth sciences, not just the solid Earth sciences. For example, geodesy contributes to atmospheric science by supporting both observation and prediction of the weather by geo-referencing meteorological observing data and by globally tracking change in stratospheric mass and lower tropospheric water vapor fields. Geodetic measurements of refraction profiles derived from satellite occultation data are routinely assimilated into numerical weather prediction models. Geodesy contributes to hydrologic studies by providing a unique global reference system for measurements of: sub-seasonal, seasonal and secular movements

  2. Incorporating GPS geodetic data into the undergraduate classroom to improve data and information literacy

    Science.gov (United States)

    Jansma, P. E.; Mattioli, G. S.

    2002-12-01

    As part of an NSF-funded project, we are incorporating Global Positioning System (GPS) geodesy into the classroom to improve data and information literacy among undergraduate students. Our objectives are: to introduce statistical concepts essential for the interpretation of large datasets; to promote communication skills; to enhance critical thinking; and to build teamwork. GPS geodesy is ideal for illustrating data literacy concepts. Data precision and accuracy depend upon several factors, including type of equipment, environmental conditions, length of occupations, monument design, site location, configuration of the geodetic network, and processing strategies. All of these can be varied, allowing the students to learn the trade-offs among cost, time, and quality and to determine the most efficient methodology for specific problems. In addition, precision, accuracy, and errors govern the interpretations that can be made and the potential to distinguish among competing models. Our focus is a semester-long course that uses GPS geodesy in real-world applications and also requires integration of GPS data into oral presentations and written reports. Students work in teams on "cases" that pose hypotheses for testing. The cases are derived from our on-going research projects and take advantage of on-line continuous GPS (CGPS) data as well as our archived campaign data. The case studies are: 1) Microplate tectonics in the northeastern Caribbean; 2) Inflation/deflation cycles of the Soufriere Hills volcano, Montserrat; and 3) Contribution of monument instability to the overall error in geodetic data from the New Madrid Seismic Zone. All course materials will be on-line and available for the community.

  3. Some Equal-area, Conformal and Conventional Map Projections: A Tutorial Review

    Science.gov (United States)

    Ghaderpour, Ebrahim

    2016-09-01

    Map projections have been widely used in many areas such as geography, oceanography, meteorology, geology, geodesy, photogrammetry and global positioning systems. Understanding different types of map projections is very crucial in these areas. This paper presents a tutorial review of various types of current map projections such as equal-area, conformal and conventional. We present these map projections from a model of the Earth to a flat sheet of paper or map and derive the plotting equations for them in detail. The first fundamental form and the Gaussian fundamental quantities are defined and applied to obtain the plotting equations and distortions in length, shape and size for some of these map projections.

  4. GPS for large-scale aerotriangulation

    Science.gov (United States)

    Rogowksi, Jerzy B.

    The application of GPS (Global Positioning System) measurements to photogrammetry is presented. The technology of establishment of a GPS network for aerotriangulation as a base for mapping at scales from 1:1000 has been worked out at the Institute of Geodesy and Geodetical Astronomy of the Warsaw University of Technology. This method consists of the design, measurement, and adjustment of this special network. The results of several pilot projects confirm the possibility of improving the aerotriangulation accuracy. A few-centimeter accuracy has been achieved.

  5. Chinese Surveying and Control Network for Earth-Orbit Satellites and Deep Space Detection

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The relationship between the surveying and control network(CSN) for earth-orbit satellite and spatial geodesy, and the relationship between the CSN for deep space celestial bodies and detectors, and deep space detection are briefly summarized, and so are the basic technical needs of the deep space surveying and control network(DSN). Then, the techniques, the constituents and the distributing of Chinese satellite CSN (CSCSN) and other radio observing establishments in China are introduced. Lastly, with the primary CSCSN and other observing establishments, some projects for China to rebuild a more perfect CSCSN, and to establish a DSN are analyzed and stated.

  6. ESPACE - a geodetic Master's program for the education of Satellite Application Engineers

    Science.gov (United States)

    Hedman, K.; Kirschner, S.; Seitz, F.

    2012-04-01

    In the last decades there has been a rapid development of new geodetic and other Earth observation satellites. Applications of these satellites such as car navigation systems, weather predictions, and, digital maps (such as Google Earth or Google Maps) play a more and more important role in our daily life. For geosciences, satellite applications such as remote sensing and precise positioning/navigation have turned out to be extremely useful and are meanwhile indispensable. Today, researchers within geodesy, climatology, oceanography, meteorology as well as within Earth system science are all dependent on up-to-date satellite data. Design, development and handling of these missions require experts with knowledge not only in space engineering, but also in the specific applications. That gives rise to a new kind of engineers - satellite application engineers. The study program for these engineers combines parts of different classical disciplines such as geodesy, aerospace engineering or electronic engineering. The satellite application engineering program Earth Oriented Space Science and Technology (ESPACE) was founded in 2005 at the Technische Universität München, mainly from institutions involved in geodesy and aerospace engineering. It is an international, interdisciplinary Master's program, and is open to students with a BSc in both Science (e.g. Geodesy, Mathematics, Informatics, Geophysics) and Engineering (e.g. Aerospace, Electronical and Mechanical Engineering). The program is completely conducted in English. ESPACE benefits from and utilizes its location in Munich with its unique concentration of expertise related to space science and technology. Teaching staff from 3 universities (Technische Universität München, Ludwig-Maximilian University, University of the Federal Armed Forces), research institutions (such as the German Aerospace Center, DLR and the German Geodetic Research Institute, DGFI) and space industry (such as EADS or Kayser-Threde) are

  7. The 9th-Generation International Geomagnetic Reference Field

    Science.gov (United States)

    Macmillan, S.; Maus, S.; Bondar, T.; Chambodut, A.; Golovkov, V.; Holme, R.; Langlais, B.; Lesur, V.; Lowes, F.; Lühr, H.; Mai, W.; Mandea, M.; Olsen, N.; Rother, M.; Sabaka, T.; Thomson, A.; Wardinski, I.

    2003-12-01

    The International Association of Geomagnetism and Aeronomy has recently released the 9th-Generation International Geomagnetic Reference Field-the latest version of a standard mathematical description of the Earth's main magnetic field used widely in studies of the Earth's deep interior, its crust and its ionosphere and magnetosphere. The coefficients were recently finalized at the XXIII General Assembly of the International Union of Geophysics and Geodesy, held at Sapporo in Japan in 2003 July. The IGRF is the product of a huge collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and from observatories and surveys around the world.

  8. On The Accuracy Of Current Mean Sea Surface Models For The Use With Goce Data

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Rio, M. H.

    2011-01-01

    The mean sea surface (MSS) is a fundamental parameter in geodesy and physical oceanography and knowledge about the error on the MSS is fundamental for the interpretation of GOCE geoid model for the study of large scale ocean circulation. The MSS is the sum of the geoid height G and the temporal...... mean of the ocean mean dynamic topography (MDT) like MSS = G + MDT, where the MDT is the quantity bridging the geoid and the MSS and the quantity constraining large scale ocean circulation. In order to evaluate the accurate of satellite derived ocean currents from the difference between the MSS...

  9. Earthquake Science: a New Start

    Institute of Scientific and Technical Information of China (English)

    Chen Yun-tai

    2009-01-01

    @@ Understanding the mechanisms which cause earthquakes and thus earthquake prediction, is inher-ently difficult in comparison to other physical phenom-ena. This is due to the inaccessibility of the Earth's inte-rior, the infrequency of large earthquakes, and the com-plexities of the physical processes involved. Conse-quently, in its broadest sense, earthquake science--the science of studying earthquake phenomena, is a com-prehensive and inter-disciplinary field. The disciplines involved in earthquake science include: traditional seismology, earthquake geodesy, earthquake geology, rock mechanics, complex system theory, and informa-tion and communication technologies related to earth-quake studies.

  10. Hrvoje Tomić, PhD in Technical Sciences

    Directory of Open Access Journals (Sweden)

    Siniša Mastelić Ivić

    2010-12-01

    Full Text Available Hrvoje Tomić defended his PhD thesis Geospatial Data Analysis for the Purpose of Real Estate Valuation in Urban Areas at the Faculty of Geodesy, University of Zagreb, on November 15, 2010. His mentor was Prof. Dr. Siniša Mastelić Ivić, and the other two members of the Grading and Defence Committee were Assist. Prof. Dr. Vlado Cetl and Prof. Dr. Goran Poljanec from the Faculty of Civil Engineering, University of Zagreb.

  11. UNAVCO Data Center Initiatives in CyberInfrastructure for Discovery, Services, and Distribution of Data and Products

    Science.gov (United States)

    Boler, F.; Meertens, C.

    2012-04-01

    The UNAVCO Data Center in Boulder, Colorado, archives for preservation and distributes geodesy data and products in the GNSS, InSAR, and LiDAR domains to the scientific and education community. The GNSS data, which in addition to geodesy are useful for tectonic, volcanologic, ice mass, glacial isostatic adjustment, meteorological and other studies, come from 2,500 continuously operating stations and 8000 survey-mode observation points around the globe that are operated by over 100 U.S. and international members of the UNAVCO consortium. SAR data, which are in many ways complementary to the GNSS data collection have been acquired in concert with the WInSAR Consortium activities and with EarthScope, with a focus on the western United States. UNAVCO also holds a growing collection of terrestrial laser scanning data. Several partner US geodesy data centers, along with UNAVCO, have developed and are in the process of implementing the Geodesy Seamless Archive Centers, a web services based technology to facilitate the exchange of metadata and delivery of data and products to users. These services utilize a repository layer implemented at each data center, and a service layer to identify and present any data center-specific services and capabilities, allowing simplified vertical federation of metadata from independent data centers. UNAVCO also has built web services for SAR data discovery and delivery, and will partner with other SAR data centers and institutions to provide access for the InSAR scientist to SAR data and ancillary data sets, web services to produce interferograms, and mechanisms to archive and distribute resulting higher level products. Improved access to LiDAR data from space-based, airborne, and terrestrial platforms through utilization of web services is similarly currently under development. These efforts in cyberinfrastructure, while initially aimed at intra-domain data sharing and providing products for research and education, are envisioned as

  12. Structure and tectonics of western continental margin of India: Implication for geologic hazards

    Digital Repository Service at National Institute of Oceanography (India)

    Chaubey, A.K.; Ajay, K.K.

    for the Cretaceousffertiary (KIf) biological mass extinction, must have had a profound influence on the crustal evolution (Ajay and Cbaubey, 2008) including the present-day configuration of the continental margin concealing the pre-existing geology and crustal structure....K., Sudhakar, T. and Nair, R.R., 1994b. Swath bathymetric investigation of the seamounts located in the Laxmi Basin, eastern Arabian Sea. Mar. Geodesy, 17:169 182. Biswas, S.K., 1987. Regional tectonic framework, structure and evolution of the western marginal...

  13. LRPDS Interim Technical Report. Appendices,

    Science.gov (United States)

    1971-06-15

    correspond to the functions I, II, III, and Aß of the same manual . However, the functions Afi and B5 of the manual are truncated ver- sions of the terms...BIBLIOGRAPHY 1. DOA Tech Manual TM 5-241-8, July 1958, "Universal Transverse Mercator Grid". 2. Thomas, Paul D., "Conformal Projections in Geodesy and...16:1. Also, the PS control panel is not used. Therefore, the allocation to the PCC/PS is .16 times the PS, or: A1220 = .16 (A3100 + A320 (^ - .16 (820

  14. Thatcher Receives 2004 Charles A. Whitten Medal

    Science.gov (United States)

    Stein, Ross

    2005-02-01

    Wayne Thatcher received the Whitten Medal at the 2004 Fall Meeting Honors Ceremony on 15 December, in San Francisco, California. The medal is given for outstanding achievement in research on the form and dynamics of the Earth and planets. Citation. Armed with geodesy, Wayne Thatcher has probed the behavior of great earthquakes, concentrating on the two sites where large events are frequent and the geodetic record is lush: the western United States and Japan. From this, he has garnered deep insights into the earthquake cycle-the pattern of strain accumulation and release of which an earthquake is only the most visible part.

  15. Optical Clocks and Relativity

    Science.gov (United States)

    Chou, C. W.; Hume, D. B.; Rosenband, T.; Wineland, D. J.

    2010-09-01

    Observers in relative motion or at different gravitational potentials measure disparate clock rates. These predictions of relativity have previously been observed with atomic clocks at high velocities and with large changes in elevation. We observed time dilation from relative speeds of less than 10 meters per second by comparing two optical atomic clocks connected by a 75-meter length of optical fiber. We can now also detect time dilation due to a change in height near Earth’s surface of less than 1 meter. This technique may be extended to the field of geodesy, with applications in geophysics and hydrology as well as in space-based tests of fundamental physics.

  16. Regge calculus and observations. II. Further applications.

    Science.gov (United States)

    Williams, Ruth M.; Ellis, G. F. R.

    1984-11-01

    The method, developed in an earlier paper, for tracing geodesies of particles and light rays through Regge calculus space-times, is applied to a number of problems in the Schwarzschild geometry. It is possible to obtain accurate predictions of light bending by taking sufficiently small Regge blocks. Calculations of perihelion precession, Thomas precession, and the distortion of a ball of fluid moving on a geodesic can also show good agreement with the analytic solution. However difficulties arise in obtaining accurate predictions for general orbits in these space-times. Applications to other problems in general relativity are discussed briefly.

  17. Vienna Special Analysis Center Annual Report 2012

    Science.gov (United States)

    Boehm, Johannes; Boehm, Sigrid; Krasna, Hana; Madzak, Matthias; Nilsson, Tobias; Plank, Lucia; Raposo, Virginia; Schuh, Harald; Soja, Benedikt; Sun Jing; Teke, Kamil; Ros, Claudia Tierno

    2013-01-01

    The main activities of the VLBI group at the Department of Geodesy and Geoinformation of the Vienna University of Technology were related to the development of the Vienna VLBI Software VieVS (http://vievs.hg.tuwien.ac.at/) and its application for various studies. For example, we dealt with scheduling, satellite tracking, and the estimation of geodynamical and astronomical parameters from VLBI observations. One highlight was the release of VieVS 2.0 just before the third VieVS User Workshop in September 2012.

  18. Least Squares Adjustment: Linear and Nonlinear Weighted Regression Analysis

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg

    2007-01-01

    This note primarily describes the mathematics of least squares regression analysis as it is often used in geodesy including land surveying and satellite positioning applications. In these fields regression is often termed adjustment. The note also contains a couple of typical land surveying...... and satellite positioning application examples. In these application areas we are typically interested in the parameters in the model typically 2- or 3-D positions and not in predictive modelling which is often the main concern in other regression analysis applications. Adjustment is often used to obtain...

  19. Plant documentation by means of a geographical information system - GIS at Bayerngas GmbH; Anlagendokumentation mittels eines Geographischen Informationssystems - GIS bei der Bayerngas GmbH

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, D. [PHOTOGRAMMETRIE GMBH, Muenchen (Germany); Schroecker, D.; Grosshennig, P. [Bayerngas GmbH, Muenchen (Germany)

    1998-11-01

    The report presents the gradual introduction of a geographical orientated information system using SMALLWORLD GIS for the documentation of the complete technical installations of Bayerngas. There is also a supplement description of the SMALLWORLD GIS, in particular the consideration of specific data of Bavarian geodesy. (orig.) [Deutsch] Im Bericht wird die phasenweise Einfuehrung eines geographisch orientierten Informationssystems unter Nutzung des SMALLWORLD GIS dargestellt, in dem alle technischen Anlagen bei der Bayerngas dokumentiert werden sollen. Es werden darueber hinaus Ergaenzungen zum SMALLWORLD GIS beschrieben, u.a. die Beruecksichtigung der bayernspezifischen Daten im Vermessungswesen. (orig.)

  20. Historical Review of Astro-Geodetic Observations in Serbia

    Science.gov (United States)

    Ogrizovic, V.; Delcev, S.; Vasilic, V.; Gucevic, J.

    2008-10-01

    Astro-geodetic determinations of vertical deflections in Serbia began during the first years of 20th century. The first field works were led by S. Bo\\vsković. After the 2nd World War, Military Geographic Institute, Department of Geodesy from the Faculty of Civil Engineering, and Federal Geodetic Directorate continued the determinations, needed for reductions of terrestrial geodetic measurements and the astro-geodetic geoid determination. Last years improvements of the astro-geodetic methods are carried out in the area of implementing modern measurement equipment and technologies.

  1. Using strain rates to forecast seismic hazards

    Science.gov (United States)

    Evans, Eileen

    2017-01-01

    One essential component in forecasting seismic hazards is observing the gradual accumulation of tectonic strain accumulation along faults before this strain is suddenly released as earthquakes. Typically, seismic hazard models are based on geologic estimates of slip rates along faults and historical records of seismic activity, neither of which records actively accumulating strain. But this strain can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.

  2. The Hawking radiation of the charged particle via tunnelling from the axisymmetric Sen black hole

    Institute of Scientific and Technical Information of China (English)

    Jiang Qing-Quan; Yang Shu-Zheng; Chen De-You

    2006-01-01

    Extending Parikh's semi-classical quantum tunnelling model, this paper has studied the Hawking radiation of the charged particle via tunnelling from the horizon of the axisymmetric Sen black hole. Different from the uncharged massless particle, the geodesies of the charged massive particle tunnelling from the horizon is not light-like. The derived result supports Parikh's opinion and provides a correct modification to Hawking strictly thermal spectrum developed by the fixed background space-time and not considering the energy conservation and the self-gravitation interaction.

  3. The earth's shape and gravity

    CERN Document Server

    Garland, G D; Wilson, J T

    2013-01-01

    The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp

  4. International Laser Ranging Service (ILRS): Terms of Reference

    Science.gov (United States)

    Husson, Van; Noll, Carey

    2000-01-01

    The International Laser Ranging Service (ILRS) is an established Service within Section II , Advanced Space Technology, of the International Association of Geodesy (IAG). The primary objective of the ILRS is to provide a service to support, through Satellite and Lunar Laser Ranging data and related products, geodetic and geophysical research activities as well as International Earth Rotation Service (IERS) products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). The service also develops the necessary standards/specifications and encourages international adherence to its conventions.

  5. Satellite triangulation in Europe from WEST and ISAGEX data. [computer programs

    Science.gov (United States)

    Leick, A.; Arur, M.

    1975-01-01

    Observational data that was acquired during the West European Satellite Triangulation (WEST) program and the International Satellite Geodesy Experiment (ISAGEX) campaign was obtained for the purpose of performing a geometric solution to improve the present values of coordinates of the European stations in the OSU WN14 solutions, adding some new stations and assessing the quality of the WN14 solution with the help of the additional data available. The status of the data as received, the preprocessing required and the preliminary tests carried out for the initial screening of the data are described. The adjustment computations carried out and the results of the adjustments are discussed.

  6. Dynamics and structure of the Alpine Fold Belt

    Science.gov (United States)

    Kahle, H. G.

    1985-01-01

    The structure and present-day dynamics of the Alps interms of geodesy and gravimetry are discusssed. A strong correlation of precise leveling and isostatic gravity along the central Alpine chain, especially in Canton Graubunden, East Switzerland are shown. It is assumed that the uplift is partly controlled by isostatic rebound effects. Field observations indicate that these phenomena are still active in the Alps. The study of the uplift processes by applying a number of geodetic and gravimetric measuring techniques, such as the determination of nonperiodic secular variations of gravity, of the deflections of the vertical and tilt changes monitored by hydrostatic leveling is proposed.

  7. World gravity standards

    Science.gov (United States)

    Uotila, U. A.

    1978-01-01

    In order to use gravity anomalies in geodetic computations and geophysical interpretations, the observed gravity values from which anomalies are derived should be referred to one consistent world wide system. The International Gravity Standardization Net 1971 was adapted by the International Union of Geodesy and Geophysics at Moscow in 1971, the network was result of extensive cooperation by many organizations and individuals around the world. The network contains more than 1800 stations around the world. The data used in the adjustment included more than 25,000 gravimetry, pendulum and absolute measurements.

  8. CAS to Address Water Eutrophication

    Institute of Scientific and Technical Information of China (English)

    Guo Haiyan; Zhao Baohua

    2002-01-01

    @@ At a meeting on April 5, the CAS authorities gave the green light to a proposal to carry out studies on the development and control of eutrophication on the middle and lower reaches of the Yangtze River. The five-year project,to cost 20 million yuan (about USS 2.4 million), will involve scientists from various CAS institutes, including the Nanjing Institute of Geography & Limnology, Wuhan Institute of Hydrobiology, Research Center for Eco-Environmental Sciences, Wuhan Institute of Botany, Institute of Chemistry, Institute of Geodesy & Geophysics, and Institute of Microbiology.

  9. A Bridge Deflection Monitoring with GPS

    Science.gov (United States)

    Figurski, M.; Gałuszkiewicz, M.; Wrona, M.

    2007-01-01

    This paper introduces results of investigation carried on by The Applied Geomatics Section in Military University of Technology. Research includes possibilities of monitoring dynamic behavior of a bridge using high rate GPS data. Whole event was executed with collaboration of The Road and Bridge Management and The Warsaw Geodesy Company. Interdisciplinary approach with this project allows authors to get reliable information about investigating constructions and their respond for true traffic loading detected by GPS receivers. Way of compute data and used software (TRACK) are also shown in this paper.

  10. Least Squares Spectral Analysis and Its Application to Superconducting Gravimeter Data Analysis

    Institute of Scientific and Technical Information of China (English)

    YIN Hui; Spiros D. Pagiatakis

    2004-01-01

    Detection of a periodic signal hidden in noise is the goal of Superconducting Gravimeter (SG) data analysis. Due to spikes, gaps, datum shrifts (offsets) and other disturbances, the traditional FFT method shows inherent limitations. Instead, the least squares spectral analysis (LSSA) has showed itself more suitable than Fourier analysis of gappy, unequally spaced and unequally weighted data series in a variety of applications in geodesy and geophysics. This paper reviews the principle of LSSA and gives a possible strategy for the analysis of time series obtained from the Canadian Superconducting Gravimeter Installation (CGSI), with gaps, offsets, unequal sampling decimation of the data and unequally weighted data points.

  11. Studies in geophysics: Active tectonics

    Science.gov (United States)

    1986-01-01

    Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

  12. Earth resources: A continuing bibliography with indexes (issue 58)

    Science.gov (United States)

    1988-01-01

    This bibliography lists 500 reports, articles, and other documents introduced into the NASA scientific and technical information system between April 1 and June 30, 1988. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis.

  13. Requirements for airborne vector gravimetry

    Science.gov (United States)

    Schwarz, K. P.; Colombo, O.; Hein, G.; Knickmeyer, E. T.

    1992-01-01

    The objective of airborne vector gravimetry is the determination of the full gravity disturbance vector along the aircraft trajectory. The paper briefly outlines the concept of this method using a combination of inertial and GPS-satellite data. The accuracy requirements for users in geodesy and solid earth geophysics, oceanography and exploration geophysics are then specified. Using these requirements, accuracy specifications for the GPS subsystem and the INS subsystem are developed. The integration of the subsystems and the problems connected with it are briefly discussed and operational methods are indicated that might reduce some of the stringent accuracy requirements.

  14. Inverse Methods. Interdisciplinary Elements of Methodology, Computation, and Applications

    Science.gov (United States)

    Jacobsen, Bo Holm; Mosegaard, Klaus; Sibani, Paolo

    Over the last few decades inversion concepts have become an integral part of experimental data interpretation in several branches of science. In numerous cases similar inversion-like techniques were developed independently in separate disciplines, sometimes based on different lines of reasoning, but not always to the same level of sophistication. This book is based on the Interdisciplinary Inversion Conference held at the University of Aarhus, Denmark. For scientists and graduate students in geophysics, astronomy, oceanography, petroleum geology, and geodesy, the book offers a wide variety of examples and theoretical background in the field of inversion techniques.

  15. A technology path to distributed remote sensing

    Science.gov (United States)

    Fountain, Glen H.; Gold, Robert E.; Jenkins, Robert E.; Lew, Ark L.; Raney, R. Keith

    2000-03-01

    The Johns Hopkins University Applied Physics Laboratory (APL) has been engaged for over 40 years in Earth science missions spanning geodesy to atmospheric science. In parallel, APL's Advanced Technology Program is supporting research in autonomy, scalable architectures, miniaturization, and instrument innovation. These are key technologies for the development of affordable observation programs that could benefit from distributed remote sensing. This paper brings these applications and technology themes together in the form of an innovative, three-satellite remote sensing scenario. This pathfinding mission fills an important scientific niche, and relies on state-of-the-art small-satellite technology.

  16. Photogrammetry at the Warsaw University of Technology – Past and Present

    Directory of Open Access Journals (Sweden)

    Zawieska Dorota

    2016-06-01

    Full Text Available The Department of Photogrammetry, Remote Sensing and Geographic Information Systems at the Warsaw University of Technology is one of six organizational units of the Faculty of Geodesy and Cartography. The photogrammetry has been under interest of scientists in Faculty for over 90 years. The last decades has been characterized by the incredible development of photogrammetric technologies, mainly towards wide automation and popularization of derivative products for processing data acquired at satellite, aerial, and terrestrial levels. The paper presents achievements of scientists employed in Photogrammetric Research Group during last decades related to projects that were carried out in this department.

  17. Numerical Methods for Harmonic Analysis on the Sphere

    Science.gov (United States)

    1981-03-01

    correspond to a subclass (linear subspace) of 2-D Fourier series. -7- For example: ( Heiskanen and Moritz, Chapter 1, 1967) P11 (cosO) =A sine Pa (cose...collocation remains Heiskanen and Moritz, (Ch. 7, 1967). Reasoning as in Heiskanen and Moritz (ibid), one can show that 0covmup’, v(Q) Z -- .-P(Cos OPQ) 11=0...Dover, New York, 1964. Heiskanen , W.A., and H. Moritz, Physical Geodesy, W.H. Freeman, U.S.A., 1967. Hobson, E. W., The Theory of Spherical and

  18. STS-GPS (Space Transportation System - Global Positioning System) Tracking Experiment for Gravitation Estimation: Feasibility Study

    Science.gov (United States)

    1989-02-01

    potential covariance function K(P,Q). Furthermore, under the usual spherical approximation ( Heiskanen and Moritz, 1967, p.87], the signals are linear...The aravity disturbance vector 6 in spherical geocentric coordinates r, t, is defined as [ Heiskanen 3nd Moritz, 1967, p.23 3] 2-13 6r T/b r 6 = grad...1978; AFGL-TR-78-0260; ADA 063990. 2.6. Heiskanen , W. A., and H. Moritz, Physical Geodesy, W. H. Freeman, San Francisco, 1967. 2-27 2.7. Kahn, W. D., S

  19. Extended Applicability of the Spherical-Harmonic and Point-Mass Modeling of the Gravity Field,

    Science.gov (United States)

    1980-02-01

    inertia. The following expressions are given, in a similar fom, on page 61 of [ Heiskanen and Moritz, 1967]: A00 = f d(kM) = kM ; (2.2a) A10 = fzd(kM), A11...deflectionofthe vertical (c) in any azimuth is given (see e.g. [ Heiskanen and Moritz,1967], page 112) as = -dN/ds In the north-south direction we have = -dN...Lab- oratory, Hanscom AFB, Massachusetts, 1976. Heiskanen , W.A. and H. Moritz, Physical Geodesy. W. H. Freeman and Co., San Francisco, 1967. -123

  20. The DORIS Data Center at the CDDIS

    Science.gov (United States)

    Noll, Carey E.; Dube, Maurice

    2000-01-01

    The DORIS system (Doppler Orbitography and Radio positioning Integrated by Satellite) was designed and developed by CNES, the National Geographic Institute, IGN (Institut G6ographique National), and the Space Geodesy Research Group, GRGS (Groupe de Recherches de Geodesie Spatiale - CNES/CNRS/Universite Paul Sabatier) to meet new needs for the precise determination of satellite positions on their orbits and for precise positioning of terrestrial beacons. This system has been carried since 1990 on the French SPOT 2 satellite, since 1992 on the French/American satellite TOPEX/POSEIDON, and since 1998 on the French SPOT 4 satellite. It will be part of the JASON (CNES/NASA) and ENVISAT (ESA) altimetric missions and also the SPOT follow-on Earth observation missions. DORIS is a radio-electrical system which takes Doppler measurements between a satellite in low orbit and a permanent global network for the purpose, on the one hand, of determining the satellite's position in orbit, and on the other hand, of locating ground beacons with a high degree of precision.

  1. Α Deformation study in Central Greece using 20 years of GPS data

    Science.gov (United States)

    Marinou, Aggeliki; Papazissi, Kaliopi; Mitsakaki, Christiana; Paradissis, Demitris; Papanikolaou, Xanthos; Anastasiou, Demitris

    2015-04-01

    Central Greece is a region recognized for its intense tectonic activity with the main characterics being the extension in the North-South direction. This extension is revealed mainly in the form of large parallel grabens. Among these rifts is the Corinth Gulf, which is the most active tectonically, the basin between Parnassos and Kallidromo Mt, the Locris basin and the graben of North Evoikos Gulf, while in the south lays the Thebes basin and the South Evoikos Gulf. Since the late eighties the Laboratory of Higher Geodesy and the Dionysos Satellite Observatory of the National Technical University of Athens, in cooperation with several National and International Universities and Institutions have established, in various Greek areas, of high seismic activity, geodetic networks in order to monitor tectonic displacements. These geodetic networks were observed periodically using Satellite Geodesy techniques and in recent years almost entirely GPS. In this study all the available GPS data, referring to the broader area of Evia, Attiki and Viotia, for the years 1989 to 2008, are analyzed. The displacement field and its temporal changes for the area between the two major geological features, the Corinth Gulf and the Evoikos Gulf, are investigated. Αll the kinematic models that were used do not confirm that the area of study is deforming homogeneously, while an indication of a discontinuity has been detected.

  2. The teaching of geophysics in Latin America: An updated assessment

    Science.gov (United States)

    Valencio, Daniel A.; Schneider, Otto

    The situation of geophysics in developing countries has been the subject of discussions and analysis by diverse international organizations. It was also discussed in some articles in Eos [e.g., Lomnitz, 1982; Urrutia Fucugauchi, 1982; Bolt, 1982]. We have been requested to contribute a current evaluation of the problem, with particular reference to geophysical education in Latin America.In the following report on specialized training of geophysicists in Latin American countries, we consider the “exact earth sciences” in the broader sense, i.e., the mathematical and physical (and, to a certain extent, chemical) aspects of the planet earth as a whole, including its fluid portions, as opposed to the more restricted concept of just solid earth geophysics. In other words, our inquiry follows the scope of both AGU and the International Union of Geodesy and Geophysics (IUGG), so geodesy, although not explicitly covered, will still be mentioned occasionally. We will also consider the applied branches, especially exploration geophysics, since these areas furnish powerful motivation for fostering our sciences, both in the governmental circles of developing countries and among the young people looking for a promising professional future.

  3. Field lines of gravity, their curvature and torsion, the Lagrange and the Hamilton equations of the plumbline

    Directory of Open Access Journals (Sweden)

    E. W. Grafarend

    1997-06-01

    Full Text Available The length of the gravitational field lines/of the orthogonal trajectories of a family of gravity equipotential surfaces/of the plumbline between a terrestrial topographic point and a point on a reference equipotential surface like the geoid í also known as the orthometric height í plays a central role in Satellite Geodesy as well as in Physical Geodesy. As soon as we determine the geometry of the Earth pointwise by means of a satellite GPS (Global Positioning System: «global problem solver» we are left with the problem of converting ellipsoidal heights (geometric heights into orthometric heights (physical heights. For the computation of the plumbline we derive its three differential equations of first order as well as the three geodesic equations of second order. The three differential equations of second order take the form of a Newton differential equation when we introduce the parameter time via the Marussi gauge on a conformally flat three-dimensional Riemann manifold and the generalized force field, the gradient of the superpotential, namely the modulus of gravity squared and taken half. In particular, we compute curvature and torsion of the plumbline and prove their functional relationship to the second and third derivatives of the gravity potential. For a spherically symmetric gravity field, curvature and torsion of the plumbline are zero, the plumbline is straight. Finally we derive the three Lagrangean as well as the six Hamiltonian differential equations of the plumbline, in particular in their star form with respect to Marussi gauge.

  4. Definition and Proposed Realization of the International Height Reference System (IHRS)

    Science.gov (United States)

    Ihde, Johannes; Sánchez, Laura; Barzaghi, Riccardo; Drewes, Hermann; Foerste, Christoph; Gruber, Thomas; Liebsch, Gunter; Marti, Urs; Pail, Roland; Sideris, Michael

    2017-05-01

    Studying, understanding and modelling global change require geodetic reference frames with an order of accuracy higher than the magnitude of the effects to be actually studied and with high consistency and reliability worldwide. The International Association of Geodesy, taking care of providing a precise geodetic infrastructure for monitoring the Earth system, promotes the implementation of an integrated global geodetic reference frame that provides a reliable frame for consistent analysis and modelling of global phenomena and processes affecting the Earth's gravity field, the Earth's surface geometry and the Earth's rotation. The definition, realization, maintenance and wide utilization of the International Terrestrial Reference System guarantee a globally unified geometric reference frame with an accuracy at the millimetre level. An equivalent high-precision global physical reference frame that supports the reliable description of changes in the Earth's gravity field (such as sea level variations, mass displacements, processes associated with geophysical fluids) is missing. This paper addresses the theoretical foundations supporting the implementation of such a physical reference surface in terms of an International Height Reference System and provides guidance for the coming activities required for the practical and sustainable realization of this system. Based on conceptual approaches of physical geodesy, the requirements for a unified global height reference system are derived. In accordance with the practice, its realization as the International Height Reference Frame is designed. Further steps for the implementation are also proposed.

  5. GALILEO with high eccentricity and equipped by Accelerometers:a tool for GR experiments

    Science.gov (United States)

    Vespe, Francesco

    2015-08-01

    In the last years three ingredients have enlarged the spectrum of scientific applications based on space techniques: the big number of satellites devoted to Space Geodesy and Earth Observation, the tremendous improvement of the Earth gravity field models due to CHAMP, GRACE and GOCE missions and the application of the Gravity Field Free technique (GFF). The last ingredient was applied for the first time to measure the Lense Thirring gravitomagnetic field (L-T). Essentially a linear combination of "n" orbital parameters of LAGEOS I & II satellites [1] was performed in order to cancel the contribution of the first (n-1) even zonals of the gravity field. The chance to put aboard GALILEO accelerometers (AoG) and the "unhappy" injection of two satellites on wrong highly eccentric orbits can make the direct involvement of GNSS satellites in scientific investigations more and more essential. We will investigate how all these ingredients can improve the quality of General Relativistic tests by using Space Geodesy satellites.

  6. Projectivity, affine, similarity and euclidean coordinates transformation parameters from ITRF to EUREF in Turkey

    Science.gov (United States)

    Ansari, Kutubuddin; Corumluoglu, Ozsen; Yetkin, Mevlut

    2017-03-01

    Today, in geodesy most practical applications is to use a datum to get three dimensional position of a particular point. The geodetic techniques generally provide time dependent coordinates in global datum. The difference between the global datum like international terrestrial reference frame (ITRF) to local datum like Europe fixed reference frame (EUREF) can be up to several centimeters due to different velocity rate of tectonic plates. To get high-precision measurements, there is an increasing need of time dependent transformations from the global level to local level. The present paper treats, this theoretical problem of geodesy by using mathematical dependency between two spatial coordinate systems whose common points are given in both systems. The paper describes four different (projective, affine, similarity and euclidean) modified methodologies for the transformation between global (ITRF) to local (EUREF) by using the Turkish permanent GPS network (TPGN) as an example. The time series from TPGN stations are used to review these transformations from ITRF 2008 to EUREF 2008. The transformation parameters in all cases shows that mostly transform coordinates depends on its counterparts (X to x and Y to y) and others coordinates have very less effect. Finally to show the validity of our model a comparative analysis with standard Bursa-Wolf and Molodensky-Badekas models has been presented. The test shows that our model error is equivalent to standard models, in this view the presented models are acceptable and can improve our understanding in coordinate transformation.

  7. Increasing long-wavelength relief across the southeastern flank of the Sierra Nevada, California

    Science.gov (United States)

    Bennett, R. A.; Fay, N. P.; Hreinsdóttir, S.; Chase, C.; Zandt, G.

    2009-09-01

    A high degree of correlation between present-day relative rock uplift measured using continuous GPS geodesy and spatially averaged surface elevations suggests that long-wavelength topographic relief is presently increasing along the southeastern flank of the Sierra Nevada range and within an adjacent portion of the northern Basin and Range province. Current estimates for erosion rate are an order of magnitude smaller than the relative rates determined by geodesy. Thus, although the uplift serves to enhance long-wavelength relief, it cannot be explained entirely as an isostatic response to erosion. If uplift rates have been constant through time, the duration over which the uplift could have been active (Sierra are evolving with time. According to either hypothesis, vertical surface motions may have slowly accelerated since ~mid-Pliocene time. Several possible mechanisms for progressive reduction of EET may be attributable to thermo-mechanical disequilibrium that began with the removal of an ultramafic root from the Sierran batholith during late Miocene or early Pliocene time. Specific mechanisms for ongoing enhancement of loads are less obvious. Based on these results, we suggest that dense networks of long-running continuous GPS stations around the world currently represent an underutilized resource for studies of orogenesis and upper mantle processes.

  8. Tracking on non-active collaborative objects from San Fernando Laser station

    Science.gov (United States)

    Catalán, Manuel; Quijano, Manuel; Cortina, Luis M.; Pazos, Antonio A.; Martín-Davila, José

    2016-04-01

    The Royal Observatory of the Spanish Navy (ROA) works on satellite geodesy from the early days of the space age, when the first artificial satellite tracking telescope was installed in 1958: the Baker-Nunn camera. In 1975 a French satellite Laser ranging (SLR) station was installed and operated at ROA . Since 1980, ROA has been operating this instrument which was upgraded to a third generation and it is still keep into a continuous update to reach the highest level of operability. Since then ROA has participated in different space geodesy campaigns through the International Laser Service Stations (ILRS) or its European regional organization (EUROLAS), tracking a number of artificial satellites types : ERS, ENVISAT, LAGEOS, TOPEX- POSEIDON to name but a few. Recently we opened a new field of research: space debris tracking, which is receiving increasing importance and attention from international space agencies. The main problem is the relatively low accuracy of common used methods. It is clear that improving the predicted orbit accuracy is necessary to fulfill our aims (avoiding unnecessary anti-collision maneuvers,..). Following results obtained by other colleagues (Austria, China, USA,...) we proposed to share our time-schedule using our satellite ranging station to obtain data which will make orbital elements predictions far more accurate (sub-meter accuracy), while we still keep our tracking routines over active satellites. In this communication we report the actions fulfill until nowadays.

  9. Improvement of the Planetary Gravitational Potentiel Field Knwoledge with Accurate Electrostatic Accelerometer / Gradiometer

    Science.gov (United States)

    Christophe, B.; Lebat, V.; Foulon, B.; Liorzou, F.; Perrot, E.; Boulanger, D.; Hardy, E.

    2014-12-01

    ONERA has developed since several years the most accurate accelerometers for the geodesy mission. The accelerometers are still operational in the GRACE mission. Their successors for the GRACE-FO mission are under manufacturing and will fly in 2017. Finally, the GOCE mission has proved the interest of gradiometer for a direct measurement of the gravity field.Now, ONERA proposes a new design of accelerometer, MicroSTAR, for interplanetary mission. It inherits of the same technology but with reduced mass and consumption. It has been proposed in several missions towards outer planets in order to test the deviation to the relativity general over large distance to the sun (with the addition of a bias rejection system). But the same instrument could be interesting to improve our knowledge of the planetary gravitational potential field, allowing a better understanding of the planet interior composition. The success of using accelerometer for geodesy mission could be imported in the planetary science.The paper will present the accuracy achievable on the gravity potential field according to different accelerometer configurations (one accelerometer, one gradiometer arm or a complete 3-axis gradiometer). Then, the instrument will be described and the integration of the instrument inside an interplanetary probe will be evoked.

  10. Improved mapping of planetary gravitational field with an electrostatic accelerometer/gradiometer

    Science.gov (United States)

    Foulon, Bernard; Huynh, Phuong-Anh; Liorzou, Francoise; Christophe, Bruno; Hardy, Emilie; Boulanger, Damien; Lebat, Vincent; Perrot, Eddy

    2015-04-01

    ONERA has a proven record spanning several years in developing the most accurate accelerometers for geodesy missions. They are still operational in the GRACE mission and their successors for the GRACE-FO mission will fly in 2017. Finally, the GOCE mission has shown the benefit of using a gradiometer for the direct measurement of the gravity field. Now, ONERA proposes a new accelerometer design, MicroSTAR, for interplanetary missions. This design based on the same technology as for the GRACE and GOCE space missions, with the notable addition of a bias rejection system, has a reduced mass and consumption. The accelerometer is embarked on Uranus Pathfinder (mission proposal for Cosmic M4) as up-scope instrument to achieve two scientific objectives: 1) to determine the gravity fields of Uranus and the satellites, allowing for a better understanding of the planet interior composition, 2) to test gravity at the largest possible length scales to search for deviations from General Relativity. The success of using accelerometer for geodesy mission could be imported in the planetary science field. The poster details the accuracy which can be achieved on the gravity potential field according to different accelerometer configurations. It describes the instrument and its integration inside an interplanetary probe. Finally, it explains the benefit of using this electrostatic accelerometer complementary to radio science technology for improved planetary gravitational field measurements.

  11. Mobile quantum gravity sensor with unprecedented stability

    CERN Document Server

    Freier, Christian; Schkolnik, Vladimir; Leykauf, Bastian; Schilling, Manuel; Wziontek, Hartmut; Scherneck, Hans-Georg; Müller, Jürgen; Peters, Achim

    2015-01-01

    Changes of surface gravity on Earth are of great interest in geodesy, earth sciences and natural resource exploration. They are indicative of Earth system's mass redistributions and vertical surface motion, and are usually measured with falling corner-cube- and superconducting gravimeters (FCCG and SCG). Here we report on absolute gravity measurements with a mobile quantum gravimeter based on atom interferometry. The measurements were conducted in Germany and Sweden over periods of several days with simultaneous SCG and FCCG comparisons. They show the best-reported performance of mobile atomic gravimeters to date with an accuracy of $\\mathrm{39\\,nm/s^2}$ and long-term stability of $\\mathrm{0.5\\,nm/s^2}$ short-term noise of $96\\,\\mathrm{nm/s^2/\\sqrt{Hz}}$. These measurements highlight the unique properties of atomic sensors. The achieved level of performance in a transportable instrument enables new applications in geodesy and related fields, such as continuous absolute gravity monitoring with a single instrum...

  12. Modern technologies and methodologies concerning permanent monitoring of position changes and entity state in space and time

    Directory of Open Access Journals (Sweden)

    Zoran Sušić

    2014-06-01

    Full Text Available The topic of the paper is the description of the modern sensor solutions used in the permanent-monitoring projects for deformations of entities in space and time, as well as of many other parameters necessary to a detailed analysis of spatial processes at the sites of large civil-engineering objects. The possibility of applying the monitoring with an alarm system, with a special comment concerning the LeicaGeoMos software, is also mentioned. Using an example of integrated multisensor system (GPS, inclinometers, accelerometers, robotised TS concerning the general solution for observing deformations of the Žeželj bridge (test examination and permanent observation during exploitation in Novi Sad the possibilities of new technologies will be presented and the place, role and importance of a specialist in geodesy in such projects will be indicated. The topic of the paper is an automated system of integrated sensors for measuring meteorological parameters and those of dynamical motions of water at the location of the future marina in the Kotor Bay at Kumbor. On the basis of the presented results of sensor application to the registration of quantities and their spatial and temporal variations new possibilities of geodesy in extension and participation in new services in multidisciplinary projects of other sciences are indicated.

  13. Definition and Proposed Realization of the International Height Reference System (IHRS)

    Science.gov (United States)

    Ihde, Johannes; Sánchez, Laura; Barzaghi, Riccardo; Drewes, Hermann; Foerste, Christoph; Gruber, Thomas; Liebsch, Gunter; Marti, Urs; Pail, Roland; Sideris, Michael

    2017-03-01

    Studying, understanding and modelling global change require geodetic reference frames with an order of accuracy higher than the magnitude of the effects to be actually studied and with high consistency and reliability worldwide. The International Association of Geodesy, taking care of providing a precise geodetic infrastructure for monitoring the Earth system, promotes the implementation of an integrated global geodetic reference frame that provides a reliable frame for consistent analysis and modelling of global phenomena and processes affecting the Earth's gravity field, the Earth's surface geometry and the Earth's rotation. The definition, realization, maintenance and wide utilization of the International Terrestrial Reference System guarantee a globally unified geometric reference frame with an accuracy at the millimetre level. An equivalent high-precision global physical reference frame that supports the reliable description of changes in the Earth's gravity field (such as sea level variations, mass displacements, processes associated with geophysical fluids) is missing. This paper addresses the theoretical foundations supporting the implementation of such a physical reference surface in terms of an International Height Reference System and provides guidance for the coming activities required for the practical and sustainable realization of this system. Based on conceptual approaches of physical geodesy, the requirements for a unified global height reference system are derived. In accordance with the practice, its realization as the International Height Reference Frame is designed. Further steps for the implementation are also proposed.

  14. Irene K. Fischer (1907-2009)

    Science.gov (United States)

    Morrison, Foster; Chovitz, Bernard; Fischer, Michael M. J.

    2010-05-01

    Irene Kaminka Fischer, a prominent geodesist whose career spanned the years 1952-1977, died on 22 October 2009 at the age of 102 at an assisted living facility in Brighton, Mass. Born in Vienna, Austria, on 27 July 1907, Irene grew up there; graduating with a degree in mathematics from the Vienna Institute of Technology; and met and married her husband, Eric, a noted geographer. In 1939, the Fischers fled Nazi Austria, first to Palestine, and by 1941 had relocated to the United States. During the next 11 years, Irene worked at various jobs, as well as playing the role of mother to her son and daughter. But when her daughter was ready for college, she began to look for a position that would fully utilize her considerable talents in mathematics. She found a perfect fit at her husband's federal agency, the U.S. Army Map Service (AMS). Her entire career in geodesy was spent with that organization and its successors (currently the National Geospatial-Intelligence Agency (NGA)). Hired as a mathematician, she eventually was promoted to chief of the Geoid Branch in the Geodesy Division. She retained that position until her retirement in 1977.

  15. About the geometry of the Earth geodetic reference surfaces

    Science.gov (United States)

    Husár, Ladislav; Švaral, Peter; Janák, Juraj

    2017-10-01

    The paper focuses on the comparison of metrics of three most common reference surfaces of the Earth used in geodesy (excluding the plane which also belongs to reference surfaces used in geodesy when dealing with small areas): a sphere, an ellipsoid of revolution and a triaxial ellipsoid. The two latter surfaces are treated in a more detailed way. First, the mathematical form of the metric tensors using three types of coordinates is derived and the lengths of meridian and parallel arcs between the two types of ellipsoids are compared. Three kinds of parallels, according to the type of latitude, can be defined on a triaxial ellipsoid. We show that two types of parallels are spatial curves and one is represented by ellipses. The differences of curvature of both kinds of ellipsoid are analysed using the normal curvature radii. Priority of the chosen triaxial ellipsoid is documented by its better fit with respect to the high-degree geoid model EIGEN6c4 computed up to degree and order 2160.

  16. Establishment of high-precision navigation system in the Republic of Armenia

    Directory of Open Access Journals (Sweden)

    Manukyan Larisa Vladimirovna

    2015-04-01

    Full Text Available Medium-Earth orbit satellite systems make it possible to provide services on time coordination and navigation support for a wide range of consumers. At present, there are global navigation satellite systems GLONASS (Russia and GPS (USA. Users of these systems have an opportunity to determine their location accurately with the given characteristics of their navigation devices. In all developed countries the progress of geodesy and cartography is closely related to the implementation of advanced new technologies in both scientific and industrial areas. The introduction of new technologies and equipment in production is essential for the development of geodesy and cartography, bringing the existing geodetic networks and cartographic materials to modern condition. In the Republic of Armenia there are also plans on introduction of the systems for monitoring and management of vehicles for various purposes, as well as it is proposed to establish and implement an effective satellite navigation system to monitor and control traffic on the basis of advanced satellite technology. The article describes the basic steps to create the network of reference stations, GPS, aerial photography of much of the territory of Armenia, the creation of digital terrain model and the new maps by orthophotoplans. The analysis of the materials were carried out, on the basis of which in the Republic in 2015 a high-precision navigation system will be created. Due to the hard work of surveyors, cartographers and topographers the Republic was brought to European states level.

  17. STRUVE arc and EUPOS® stations

    Science.gov (United States)

    Lasmane, Ieva; Kaminskis, Janis; Balodis, Janis; Haritonova, Diana

    2013-04-01

    The Struve Geodetic Arc was developed in Years 1816 to 1855, 200 years ago. Historic information on the points of the Struve Geodetic Arc are included in the UNESCO World Heritage list in 2005. Nevertheless, the sites of many points are still not identified nor included in the data bases nowadays. Originally STRUVE arc consisted of 258 main triangles with 265 triangulation points. Currently 34 of the original station points are identified and included in the in the UNESCO World Heritage list. identified original measurement points of the Meridian Arc are located in Sweden (7 points), Norway (15), Finland (83), Russia (1), Estonia (22), Latvia (16), Lithuania (18), Belorussia (28), Ukraine (59) and Moldova (27). In Year 2002 was initiated another large coverage project - European Position Determination System "EUPOS®". Currently there are about 400 continuously operating GNSS (Global Navigation Satellite Systems) stations covering EU countries Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Bulgaria, Romania and East European countries Ukraine and Moldavia. EUPOS® network is a ground based GNSS augmentation system widely used for geodesy, land surveying, geophysics and navigation. It gives the opportunity for fast and accurate position determination never available before. It is an honorable task to use the EUPOS® system for research of the Struve triangulation former sites. Projects with Struve arc can popularize geodesy, geo-information and its meaning in nowadays GIS and GNSS systems. Struve Arc and its points is unique cooperation cross-border object which deserve special attention because of their natural beauty and historical value for mankind. GNSS in geodesy discovers a powerful tool for the verification and validation of the height values of geodetic leveling benchmarks established historically almost 200 years ago. The differential GNSS and RTK methods appear very useful to identify vertical displacement of landscape by means of

  18. The recent progress of Chinese VLBI Network

    Science.gov (United States)

    Zheng, Weimin

    2015-08-01

    At present, Chinese VLBI Network (CVN) consists of 5 antennas (Seshan 25m, Urumqi 25m, Kunming 30m, Miyun 50m and Tianma 65m) and one data processing center in Shanghai Observatory, Chinese academy of sciences. It is a synthetic aperture radio telescope with the equivalent diameter up to 3000 Km. Through e-VLBI (electronic VLBI) technology, CVN is connected by the commuication network. It is a multi-purpose scientific research platform radio for geodesy, astronomy, as well as deep space exploration. In Geodesy, CVN is the component of the Crustal Movement Observation Network of China. Since the year of 2006, more than 20 geodetic domestic observations have been carried out. A set of phase-referencing observations of pulsars with CVN has carried out and got preliminary results. CVN also joined the Chinese lunar exploration Project from 2007 and supported 4 Chang’E series lunar probe missions. In Chang’E-3 mission, using the in-beam VLBI observations, the relative position accuracy of Rover and Lander is up to 1 meter.In recent years, we have updated the facilities of CVN from antenna, receivers, VLBI terminals to correlator. Participation of Tianma 65m antennas increases its performance. In 2012, Shanghai correlator was accepted as the IVS correlator. After upgrade, Shanghai correlator will try to provide the data process service for IVS community from 2015. To drive the construction of the planned VGOS (VLBI2010 Global Observing System) station, at least two VOGS 13m antenna will join CVN in the near future. Construction of the first VOGS antenna in Shanghai hopes to begin this year.The new VLBI correlator and digital terminal are under development. From participation in VGOS, we plan to study the earth rotation especially of high frequency and corresponding geophysical signals, to link China’s regional reference frame to ITRF, and etc. CVN is willing to join the research corporation with IVS, EVN, VLBA and AOV (Asia- Oceania VLBI Group for Geodesy and

  19. Associated Legendre Polynomials and Spherical Harmonics Computation for Chemistry Applications

    CERN Document Server

    Limpanuparb, Taweetham

    2014-01-01

    Associated Legendre polynomials and spherical harmonics are central to calculations in many fields of science and mathematics - not only chemistry but computer graphics, magnetic, seismology and geodesy. There are a number of algorithms for these functions published since 1960 but none of them satisfy our requirements. In this paper, we present a comprehensive review of algorithms in the literature and, based on them, propose an efficient and accurate code for quantum chemistry. Our requirements are to efficiently calculate these functions for all non-negative integer degrees and orders up to a given number (<=1000) and the absolute or the relative error of each calculated value should not exceed 10E-10. We achieve this by normalizing the polynomials, employing efficient and stable recurrence relations, and precomputing coefficients. The algorithm presented here is straightforward and may be used in other areas of science.

  20. On the use of airborne gravimetry in gravity field modelling: Experiences from the AGMASCO project

    DEFF Research Database (Denmark)

    Bastos, L.; Cunha, S.; Forsberg, René

    2000-01-01

    of the vertical accelerations acting on the airborne platform from the natural gravity signal. With the advances in DGPS techniques new prospects arise for gravity field recovery which are of great importance for geodesy, geophysics oceanography and satellite navigation. Furthermore, airborne gravimetric...... parameters play a major role in airborne measurements. Within AGMASCO the airborne system was applied both in a close and an open ocean (Skagerrak, Fram Strait and Azores) areas. The system proved to be a powerful tool in a variety of conditions. The results obtained showed that an accuracy better than 2m......Gal over 5 to 6 kilometres can be achieved. This was proven by comparison of the airborne data with ground truth and satellite data. This accuracy makes the system interesting for use in various applications including geophysical exploitation. Different hardware installations were experienced...

  1. Green's function solution to spherical gradiometric boundary-value problems

    Science.gov (United States)

    Martinec, Z.

    2003-05-01

    Three independent gradiometric boundary-value problems (BVPs) with three types of gradiometric data, {orr}, {or/,or5} and {o//mo55,o/5}, prescribed on a sphere are solved to determine the gravitational potential on and outside the sphere. The existence and uniqueness conditions on the solutions are formulated showing that the zero- and the first-degree spherical harmonics are to be removed from {or/,or5} and {o//mo55,o/5}, respectively. The solutions to the gradiometric BVPs are presented in terms of Green's functions, which are expressed in both spectral and closed spatial forms. The logarithmic singularity of the Green's function at the point `=0 is investigated for the component orr. The other two Green's functions are finite at this point. Comparisons to the paper by van Gelderen and Rummel [Journal of Geodesy (2001) 75: 1-11] show that the presented solution refines the former solution.

  2. Quasi-conformal mapping with genetic algorithms applied to coordinate transformations

    Science.gov (United States)

    González-Matesanz, F. J.; Malpica, J. A.

    2006-11-01

    In this paper, piecewise conformal mapping for the transformation of geodetic coordinates is studied. An algorithm, which is an improved version of a previous algorithm published by Lippus [2004a. On some properties of piecewise conformal mappings. Eesti NSV Teaduste Akademmia Toimetised Füüsika-Matemaakika 53, 92-98; 2004b. Transformation of coordinates using piecewise conformal mapping. Journal of Geodesy 78 (1-2), 40] is presented; the improvement comes from using a genetic algorithm to partition the complex plane into convex polygons, whereas the original one did so manually. As a case study, the method is applied to the transformation of the Spanish datum ED50 and ETRS89, and both its advantages and disadvantages are discussed herein.

  3. Physical meaning and temporal variation of the zonal components of the geopotential

    Science.gov (United States)

    Varga, P.

    2003-04-01

    The generalized form of the MacCullagh representation is derived for zonal spherical harmonic coefficients J_n for degrees n >= 2 extending previous results for n=2 (Journal of Geodesy 74 (2000), 7-8, 519-530). It is shown that the even, zonal coefficients J_n can be represented with a difference of multiple moments C_n and A_n which are the volume integrals of the function of the density ρ, the distance from the centre of the Earth r^n and of the geographical coordinates (ϕ, λ) and because of their dependence of secular Love number k_s it enables us to compute the time derivatives partial^J/partial_t as the time derivative of J_n as well as the despinning rate of a deformable body like the Earth.

  4. Laser controlled atom source for optical clocks

    Science.gov (United States)

    Kock, Ole; He, Wei; Świerad, Dariusz; Smith, Lyndsie; Hughes, Joshua; Bongs, Kai; Singh, Yeshpal

    2016-11-01

    Precision timekeeping has been a driving force in innovation, from defining agricultural seasons to atomic clocks enabling satellite navigation, broadband communication and high-speed trading. We are on the verge of a revolution in atomic timekeeping, where optical clocks promise an over thousand-fold improvement in stability and accuracy. However, complex setups and sensitivity to thermal radiation pose limitations to progress. Here we report on an atom source for a strontium optical lattice clock which circumvents these limitations. We demonstrate fast (sub 100 ms), cold and controlled emission of strontium atomic vapours from bulk strontium oxide irradiated by a simple low power diode laser. Our results demonstrate that millions of strontium atoms from the vapour can be captured in a magneto-optical trap (MOT). Our method enables over an order of magnitude reduction in scale of the apparatus. Future applications range from satellite clocks testing general relativity to portable clocks for inertial navigation systems and relativistic geodesy.

  5. A strontium lattice clock with $3 \\times 10^{-17}$ inaccuracy and its frequency

    CERN Document Server

    Falke, Stephan; Grebing, Christian; Lipphardt, Burghard; Weyers, Stefan; Gerginov, Vladislav; Huntemann, Nils; Hagemann, Christian; Al-Masoudi, Ali; Häfner, Sebastian; Vogt, Stefan; Sterr, Uwe; Lisdat, Christian

    2013-01-01

    We have measured the absolute frequency of the optical lattice clock based on $^{87}$Sr at PTB with an uncertainty of $3.9\\times 10^{-16}$ using two caesium fountain clocks. This is close to the accuracy of today's best realizations of the SI second. The absolute frequency of the 5s$^2$ $^1$S$_0$-5s5p $^3$P$_0$ transition in $^{87}$Sr is 429,228,004,229,873.13(17) Hz. Our result is in excellent agreement with recent measurements performed in different laboratories worldwide. We improved the total systematic uncertainty of our Sr frequency standard by a factor of five and reach $3\\times 10^{-17}$, opening new prospects for frequency ratio measurements between optical clocks for fundamental research, geodesy, or optical clock evaluation.

  6. The crustal micro-deformation anomaly and the credible precursor*

    Institute of Scientific and Technical Information of China (English)

    张雁滨; 蒋骏; 钱家栋; 陈京; 和升棋; 张燕; 和平

    2002-01-01

    @@ What is a credible seismic precursor in observation of deformation A real seismic precursor ought to be resulted from the variations in the earth strain and stress. The deformation observation can provide the information during earthquake gestation and occurrence period for us. Usually the seismic precursors can be divided into field and epicentral region precursors. The precursor information is very useful for seismic prediction from epicentral region or near epicentral region. Micro-deformation observation mainly includes tilt, strain and gravity observation. Compared with GPS, geodesy and mobile deformation observation, micro-deformation (tilt, strain) shows the change of deformation which is continual in a limited volume with dominant observed range of 10(6~10(10 m. Because the variation of the crustal nature and cracking can be directly obtained by micro-deformation observation, it is an effective way to find middle-short term and short-term precursor.

  7. Temporal variations of the gravity field and Earth precession-nutation

    CERN Document Server

    Bourda, G

    2007-01-01

    Due to the accuracy now reached by space geodetic techniques, and also considering some modelisations, the temporal variations of some Earth Gravity Field coefficients can be determined. They are due to Earth oceanic and solid tides, as well as geophysical reservoirs masses displacements. They can be related to the variations in the Earth's orientation parameters (through the inertia tensor). Then, we can try to improve our knowledge of the Earth Rotation with those space measurements of the Gravity variations. We have undertaken such a study, using data obtained with the combination of space geodetic techniques. In particular, we use CHAMP data that are more sensitive to such variations and that complete the ones already accumulated (for example with Starlette and LAGEOS I). In this first approach, we focus on the Earth precession nutation, trying to refine it by taking into account the temporal variations of the Earth dynamical flattening. The goal is mainly to understand how Geodesy can influence this fiel...

  8. A Test of General Relativity Using the LARES and LAGEOS Satellites and a GRACE Earth's Gravity Model

    CERN Document Server

    Ciufolini, Ignazio; Pavlis, Erricos C; Koenig, Rolf; Ries, John; Gurzadyan, Vahe; Matzner, Richard; Penrose, Roger; Sindoni, Giampiero; Paris, Claudio; Khachatryan, Harutyun; Mirzoyan, Sergey

    2016-01-01

    We present a test of General Relativity, the measurement of the Earth's dragging of inertial frames. Our result is obtained using about 3.5 years of laser-ranged observations of the LARES, LAGEOS and LAGEOS 2 laser-ranged satellites together with the Earth's gravity field model GGM05S produced by the space geodesy mission GRACE. We measure $\\mu = (0.994 \\pm 0.002) \\pm 0.05$, where $\\mu$ is the Earth's dragging of inertial frames normalized to its General Relativity value, 0.002 is the 1-sigma formal error and 0.05 is the estimated systematic error mainly due to the uncertainties in the Earth's gravity model GGM05S. Our result is in agreement with the prediction of General Relativity.

  9. A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model. Measurement of Earth's dragging of inertial frames

    Energy Technology Data Exchange (ETDEWEB)

    Ciufolini, Ignazio [Universita del Salento, Dipartimento Ingegneria dell' Innovazione, Lecce (Italy); Sapienza Universita di Roma, Scuola di Ingegneria Aerospaziale, Rome (Italy); Paolozzi, Antonio; Paris, Claudio [Sapienza Universita di Roma, Scuola di Ingegneria Aerospaziale, Rome (Italy); Museo della Fisica e Centro Studi e Ricerche Enrico Fermi, Rome (Italy); Pavlis, Erricos C. [University of Maryland, Joint Center for Earth Systems Technology (JCET), Baltimore County (United States); Koenig, Rolf [GFZ German Research Centre for Geosciences, Helmholtz Centre Potsdam, Potsdam (Germany); Ries, John [University of Texas at Austin, Center for Space Research, Austin (United States); Gurzadyan, Vahe; Khachatryan, Harutyun; Mirzoyan, Sergey [Alikhanian National Laboratory and Yerevan State University, Center for Cosmology and Astrophysics, Yerevan (Armenia); Matzner, Richard [University of Texas at Austin, Theory Center, Austin (United States); Penrose, Roger [University of Oxford, Mathematical Institute, Oxford (United Kingdom); Sindoni, Giampiero [Sapienza Universita di Roma, DIAEE, Rome (Italy)

    2016-03-15

    We present a test of general relativity, the measurement of the Earth's dragging of inertial frames. Our result is obtained using about 3.5 years of laser-ranged observations of the LARES, LAGEOS, and LAGEOS 2 laser-ranged satellites together with the Earth gravity field model GGM05S produced by the space geodesy mission GRACE. We measure μ = (0.994 ± 0.002) ± 0.05, where μ is the Earth's dragging of inertial frames normalized to its general relativity value, 0.002 is the 1-sigma formal error and 0.05 is our preliminary estimate of systematic error mainly due to the uncertainties in the Earth gravity model GGM05S. Our result is in agreement with the prediction of general relativity. (orig.)

  10. Realization of the BIH terrestrial system

    Science.gov (United States)

    Boucher, C.; Feissel, M.

    From 1968 through 1983, the BIH has maintained the orientation of the axes of a conventional terrestrial system on the basis of the stability of time series of the earth rotation parameters (ERP) that are implicitly referred to it. The principles of the definition and maintenance of this system are recalled, and its precision and long term stability are evaluated. It is now possible to realize the terrestrial reference system of the BIH, including the origin and orientation of the axes and the scale unit, on the basis of the permanent stations used in the monitoring of the earth's rotation by space geodesy. The transition to the proposed new realization is described. The principles of the future maintenance and dissemination of the BIH terrestrial system are also outlined.

  11. Handbook of satellite orbits from Kepler to GPS

    CERN Document Server

    Capderou, Michel

    2014-01-01

    Fifty years after Sputnik, artificial satellites have become indispensable monitors in many areas, such as economics, meteorology, telecommunications, navigation and remote sensing. The specific orbits are important for the proper functioning of the satellites. This book discusses the great variety of satellite orbits, both in shape (circular to highly elliptical) and properties (geostationary, Sun-synchronous, etc.). This volume starts with an introduction into geodesy. This is followed by a presentation of the fundamental equations of mechanics to explain and demonstrate the properties for all types of orbits. Numerous examples are included, obtained through IXION software developed by the author. The book also includes an exposition of the historical background that is necessary to help the reader understand the main stages of scientific thought from Kepler to GPS. This book is intended for researchers, teachers and students working in the field of satellite technology. Engineers, geographers and all those...

  12. The Goal of the IAU/IAG Joint Working Group on the Theory of Earth Rotation

    Science.gov (United States)

    Ferrandiz, J. M.; Gross, R. S.

    2013-01-01

    In 2012 the International Association of Geodesy (IAG) and the International Astronomical Union (IAU) initiated a process to establish a Joint Working Group (JWG) on theory of Earth rotation with the purpose of promoting the development of improved theories of the Earth rotation which reach the accuracy required to meet the needs of the near future as recommended by, e.g. GGOS, the Global Geodetic Observing System of the IAG. The JWG was approved by both organizations in April 2013 with the chairs being the two authors of this paper. Its structure comprises three Sub Working Groups (SWGs) addressing Precession/Nutation, Polar Motion and UT1, the Numerical Solutions and Validation, respectively. The SWGs should work in parallel for the sake of efficiency, but should keep consistency as an overall goal. This paper offers a view of the objectives and scope of the JWG and reports about its initial activities and plans.

  13. Three decades of harnessing the GPS data explosion for geophysics (Vening Meinesz Medal Lecture)

    Science.gov (United States)

    Blewitt, Geoffrey

    2015-04-01

    In this presentation, I attempt to convey the immensity of the task that faced the geodesy community three decades ago, and continues to challenge us, to harness all potentially valuable GPS data available in the world for geophysical science. It would be fair to see that three decades ago, we were struggling with controlled tests just to get GPS geodesy working, and had little time to imagine the flood of data today. Yet the geodesy community has succeeded in meeting this challenge. Today, for example, the Nevada Geodetic Laboratory produces and makes publicly available coordinate time series for over 12,000 geodetic GPS station around the globe with various data intervals, latencies, and reference frames. About 8,000 stations have their daily time series updated every week, with 4,000 being updated the next day with coordinates at daily and 5 minute intervals. About 2,000 stations have their time series updated every hour with coordinates at 5 minute intervals. I will show examples of how these time series are being used by NGL and many other scientists to study a wide variety of geophysical topics, including plate tectonics, earthquake modeling, seismic and tsunami hazard, volcanic deformation, water resources, mountain growth, terrestrial reference frame realization, glacial isostatic adjustment, ice sheet melting, sea level rise and coastal subsidence, and even fundamental physics, using GPS atomic clocks to probe the nature of dark matter in the universe. The explosion in GPS data has challenged us to invent new data processing algorithms and develop robust automation in order to keep up with the flood. This explosion has been exponential, and therefore it can be said that it is not a recent phenomena, but rather that it began in the earliest years of GPS geodesy, and has always posed a challenge to us. Over the course of my post-doctoral career starting in late 1985, I have had the good fortune to witness the key developments that have taken place since the

  14. Joint editorial - Fostering innovation and improving impact assessment for journal publications in hydrology

    Science.gov (United States)

    Koutsoyiannis, Demetris; Blöschl, Günter; Bárdossy, András; Cudennec, Christophe; Hughes, Denis; Montanari, Alberto; Neuweiler, Insa; Savenije, Hubert

    2016-06-01

    Editors from several journals in the field of hydrology met during the Assembly of the International Association of Hydrological Sciences-IAHS (within the Assembly of the International Union of Geodesy and Geophysics-IUGG) in Prague in June 2015. This event was a follow-up of a similar meeting in July 2013 in Gothenburg (as reported by Blöschl et al. (2014)). In these meetings the group of editors reviewed the current status of the journals and the publication process, and shared thoughts on future strategies. Journals were represented in the meeting through their editors, as shown in the list of authors. The main points on fostering innovation and improving impact assessment in journal publications in hydrology are communicated in this joint editorial published in journals that participated in the meeting.

  15. Joint editorial: Fostering innovation and improving impact assessment for journal publications in hydrology

    Science.gov (United States)

    Koutsoyiannis, Demetris; Blöschl, Günter; Bárdossy, András.; Cudennec, Christophe; Hughes, Denis; Montanari, Alberto; Neuweiler, Insa; Savenije, Hubert

    2016-04-01

    Editors of several journals in the field of hydrology met during the Assembly of the International Association of Hydrological Sciences—IAHS (within the Assembly of the International Union of Geodesy and Geophysics—IUGG) in Prague in June 2015. This event was a follow-up of a similar meeting held in July 2013 in Gothenburg (as reported by Blöschl et al. [2014]). These meetings enable the group of editors to review the current status of the journals and the publication process, and share thoughts on future strategies. Journals were represented in the 2015 meeting through their editors, as shown in the list of authors. The main points on fostering innovation and improving impact assessment in journal publications in hydrology are communicated in this joint editorial published in the above journals.

  16. Constraining the Nordtvedt parameter with the BepiColombo Radioscience experiment

    CERN Document Server

    De Marchi, Fabrizio; Milani, Andrea; Schettino, Giulia

    2016-01-01

    BepiColombo is a joint ESA/JAXA mission to Mercury with challenging objectives regarding geophysics, geodesy and fundamental physics. The Mercury Orbiter Radioscience Experiment (MORE) is one of the on-board experiments, including three different but linked experiments: gravimetry, rotation and relativity. The aim of the relativity experiment is the measurement of the post-Newtonian parameters. Thanks to accurate tracking between Earth and spacecraft, the results are expected to be very precise. However, the outcomes of the experiment strictly depends on our "knowledge" about solar system: ephemerides, number of bodies (planets, satellites and asteroids) and their masses. In this paper we describe a semi-analytic model used to perform a covariance analysis to quantify the effects, on the relativity experiment, due to the uncertainties of solar system bodies parameters. In particular, our attention is focused on the Nordtvedt parameter $\\eta$ used to parametrize the strong equivalence principle violation. Afte...

  17. A new concept for creating the basic map

    Science.gov (United States)

    Parzyński, Zenon

    2014-12-01

    A lot of changes have been made to the legislative regulations associated with geodesy during the implementation of the INSPIRE Directive in Poland (amongst others, the structure of databases). There have also been great changes concerning the basic map and the method of its creation and updating. A new concept for creating the basic map is presented in this article Dokonaliśmy wielu zmian w prawnych regulacjach dotyczących geodezji w trakcie implementacji Dyrektywy INSPIRE w Polsce (m.in. struktury baz danych). Bardzo duże zmiany objęły mapę zasadniczą i procedury jej tworzenia i uaktualniania. W artykule jest zaprezentowana nowa koncepcja tworzenia mapy zasadniczej.

  18. Imaging the distribution of transient viscosity after the 2016 Mw 7.1 Kumamoto earthquake

    Science.gov (United States)

    Moore, James D. P.; Yu, Hang; Tang, Chi-Hsien; Wang, Teng; Barbot, Sylvain; Peng, Dongju; Masuti, Sagar; Dauwels, Justin; Hsu, Ya-Ju; Lambert, Valère; Nanjundiah, Priyamvada; Wei, Shengji; Lindsey, Eric; Feng, Lujia; Shibazaki, Bunichiro

    2017-04-01

    The deformation of mantle and crustal rocks in response to stress plays a crucial role in the distribution of seismic and volcanic hazards, controlling tectonic processes ranging from continental drift to earthquake triggering. However, the spatial variation of these dynamic properties is poorly understood as they are difficult to measure. We exploited the large stress perturbation incurred by the 2016 earthquake sequence in Kumamoto, Japan, to directly image localized and distributed deformation. The earthquakes illuminated distinct regions of low effective viscosity in the lower crust, notably beneath the Mount Aso and Mount Kuju volcanoes, surrounded by larger-scale variations of viscosity across the back-arc. This study demonstrates a new potential for geodesy to directly probe rock rheology in situ across many spatial and temporal scales.

  19. 第31届欧洲地震委员会大会在希腊克里特岛召开

    Institute of Scientific and Technical Information of China (English)

    欧阳杰

    2008-01-01

    @@ 2008年9月7~12日,第31届欧洲地震委员会大会(31st General Assembly of European Seismological Commis-sion,31th General Assembly of ESC)在希腊克里特岛(Hersonissos,Crete island,Greece)会议中心举行.ESC是隶属于IUGG(International Union of Geodesy and Geophysics,国际大地测量和地球物理学联盟)的国际性组织,其主要目的是促进欧洲地震的研究,研究区域集中在地中海沿岸及其相邻国家.

  20. Use of Low-Cost Acquisition Systems with an Embedded Linux Device for Volcanic Monitoring.

    Science.gov (United States)

    Moure, David; Torres, Pedro; Casas, Benito; Toma, Daniel; Blanco, María José; Del Río, Joaquín; Manuel, Antoni

    2015-08-19

    This paper describes the development of a low-cost multiparameter acquisition system for volcanic monitoring that is applicable to gravimetry and geodesy, as well as to the visual monitoring of volcanic activity. The acquisition system was developed using a System on a Chip (SoC) Broadcom BCM2835 Linux operating system (based on DebianTM) that allows for the construction of a complete monitoring system offering multiple possibilities for storage, data-processing, configuration, and the real-time monitoring of volcanic activity. This multiparametric acquisition system was developed with a software environment, as well as with different hardware modules designed for each parameter to be monitored. The device presented here has been used and validated under different scenarios for monitoring ocean tides, ground deformation, and gravity, as well as for monitoring with images the island of Tenerife and ground deformation on the island of El Hierro.

  1. Performance analysis of satellite constellations for the next generation of gravity missions

    Science.gov (United States)

    Raimondo, J.; Flechtner, F.; Löcher, A.; Kusche, J.

    2011-12-01

    The GOCE and GRACE gravity missions have dramatically improved the knowledge of the Earth's static and time-variable gravity field due to their highly precise on-board instrumentation. This resulted in new information about the mass distribution and transport within or around the Earth system to be used in solid Earth geophysics, oceanography and sea level studies, hydrology, ice mass budget investigations and geodesy. GFZ Potsdam and IGG Bonn, with partners from German industry and universities, have conducted several studies in order to develop a concept for a future gravity mission based on low-low satellite-to-satellite tracking, but realized with laser metrology. In our poster we summarize the performance of different mission scenarios through full-scale simulations and their capacity to reach the science objectives.

  2. Beyond the usual mapping functions in GPS, VLBI and Deep Space tracking.

    Science.gov (United States)

    Barriot, Jean-Pierre; Serafini, Jonathan; Sichoix, Lydie

    2014-05-01

    We describe here a new algorithm to model the water contents of the atmosphere (including ZWD) from GPS slant wet delays relative to a single receiver. We first make the assumption that the water vapor contents are mainly governed by a scale height (exponential law), and secondly that the departures from this decaying exponential can be mapped as a set of low degree 3D Zernike functions (w.r.t. space) and Tchebyshev polynomials (w.r.t. time.) We compare this new algorithm with previous algorithms known as mapping functions in GPS, VLBI and Deep Space tracking and give an example with data acquired over a one day time span at the Geodesy Observatory of Tahiti.

  3. Phasemeter core for intersatellite laser heterodyne interferometry: modelling, simulations and experiments

    CERN Document Server

    Gerberding, Oliver; Bykov, Iouri; Kullmann, Joachim; Delgado, Juan Jose Esteban; Danzmann, Karsten; Heinzel, Gerhard

    2013-01-01

    Inter satellite laser interferometry is a central component of future space-borne gravity instruments like LISA, eLISA, NGO and future geodesy missions. The inherently small laser wavelength allows to measure distance variations with extremely high precision by interfering a reference beam with a measurement beam. The readout of such interferometers is often based on tracking phasemeters, able to measure the phase of an incoming beatnote with high precision over a wide range of frequencies. The implementation of such phasemeters is based on all digital phase-locked loops, hosted in FPGAs. Here we present a precise model of an all digital phase locked loop that allows to design such a readout algorithm and we support our analysis by numerical performance measurements and experiments with analog signals.

  4. An intensity-based stochastic model for terrestrial laser scanners

    Science.gov (United States)

    Wujanz, D.; Burger, M.; Mettenleiter, M.; Neitzel, F.

    2017-03-01

    Up until now no appropriate models have been proposed that are capable to describe the stochastic characteristics of reflectorless rangefinders - the key component of terrestrial laser scanners. This state has to be rated as unsatisfactory especially from the perception of Geodesy where comprehensive knowledge about the precision of measurements is of vital importance, for instance to weigh individual observations or to reveal outliers. In order to tackle this problem, a novel intensity-based stochastic model for the reflectorless rangefinder of a Zoller + Fröhlich Imager 5006 h is experimentally derived. This model accommodates the influence of the interaction between the emitted signal and object surface as well as the acquisition configuration on distance measurements. Based on two different experiments the stochastic model has been successfully verified for three chosen sampling rates.

  5. Operational aspects of CASA UNO '88-The first large scale international GPS geodetic network

    Science.gov (United States)

    Neilan, Ruth E.; Dixon, T. H.; Meehan, Thomas K.; Melbourne, William G.; Scheid, John A.; Kellogg, J. N.; Stowell, J. L.

    1989-01-01

    For three weeks, from January 18 to February 5, 1988, scientists and engineers from 13 countries and 30 international agencies and institutions cooperated in the most extensive GPS (Global Positioning System) field campaign, and the largest geodynamics experiment, in the world to date. This collaborative eperiment concentrated GPS receivers in Central and South America. The predicted rates of motions are on the order of 5-10 cm/yr. Global coverage of GPS observations spanned 220 deg of longitude and 125 deg of latitude using a total of 43 GPS receivers. The experiment was the first civilian effort at implementing an extended international GPS satellite tracking network. Covariance analyses incorporating the extended tracking network predicted significant improvement in precise orbit determination, allowing accurate long-baseline geodesy in the science areas.

  6. Code and codeless ionospheric measurements with NASA's Rogue GPS Receiver

    Science.gov (United States)

    Srinivasan, Jeff M.; Meehan, Tom K.; Young, Lawrence E.

    1989-01-01

    The NASA/JPL Rogue Receiver is an 8-satellite, non-multiplexed, highly digital global positioning system (GPS) receiver that can obtain dual frequency data either with or without knowledge of the P-code. In addition to its applications for high accuracy geodesy and orbit determination, the Rogue uses GPS satellite signals to measure the total electron content (TEC) of the ionosphere along the lines of sight from the receiver to the satellites. These measurements are used by JPL's Deep Space Network (DSN) for calibrating radiometric data. This paper will discuss Rogue TEC measurements, emphasizing the advantages of a receiver that can use the P-code, when available, but can also obtain reliable dual frequency data when the code is encrypted.

  7. The Prisma Hyperspectra Mission

    Science.gov (United States)

    Loizzo, R.; Ananasso, C.; Guarini, R.; Lopinto, E.; Candela, L.; Pisani, A. R.

    2016-08-01

    PRISMA (PRecursore IperSpettrale della Missione Applicativa) is an Italian Space Agency (ASI) hyperspectral mission currently scheduled for the lunch in 2018. PRISMA is a single satellite placed on a sun- synchronous Low Earth Orbit (620 km altitude) with an expected operational lifetime of 5 years. The hyperspectral payload consists of a high spectral resolution (VNIR-SWIR) imaging spectrometer, optically integrated with a medium resolution Panchromatic camera. PRISMA will acquire data on areas of 30 km Swath width and with a Ground Sampling Distance (GSD) of 30 m (hyperspectral) and of 5 m Panchromatic (PAN). The PRISMA Ground Segment will be geographically distributed between Fucino station and ASI Matera Space Geodesy Centre and will include the Mission Control Centre, the Satellite Control Centre and the Instrument Data Handling System. The science community supports the overall lifecycle of the mission, being involved in algorithms definition, calibration and validation activities, research and applications development.

  8. Network science landers for Mars

    DEFF Research Database (Denmark)

    Harri, A.M.; Marsal, O.; Lognonne, P.

    1999-01-01

    The NetLander Mission will deploy four landers to the Martian surface. Each lander includes a network science payload with instrumentation for studying the interior of Mars, the atmosphere and the subsurface, as well as the ionospheric structure and geodesy. The NetLander Mission is the first...... FMI (the Finnish Meteorological Institute), DLR (the German Space Agency), and other research institutes. According to current plans, the NetLander Mission will be launched in 2005 by means of an Ariane V launch, together with the Mars Sample Return mission. The landers will be separated from...... the spacecraft and targeted to their locations on the Martian surface several days prior to the spacecraft's arrival at Mars. The landing system employs parachutes and airbags. During the baseline mission of one Martian year, the network payloads will conduct simultaneous seismological, atmospheric, magnetic...

  9. Photogrammetric computer vision statistics, geometry, orientation and reconstruction

    CERN Document Server

    Förstner, Wolfgang

    2016-01-01

    This textbook offers a statistical view on the geometry of multiple view analysis, required for camera calibration and orientation and for geometric scene reconstruction based on geometric image features. The authors have backgrounds in geodesy and also long experience with development and research in computer vision, and this is the first book to present a joint approach from the converging fields of photogrammetry and computer vision. Part I of the book provides an introduction to estimation theory, covering aspects such as Bayesian estimation, variance components, and sequential estimation, with a focus on the statistically sound diagnostics of estimation results essential in vision metrology. Part II provides tools for 2D and 3D geometric reasoning using projective geometry. This includes oriented projective geometry and tools for statistically optimal estimation and test of geometric entities and transformations and their rela­tions, tools that are useful also in the context of uncertain reasoning in po...

  10. The German joint research project "concepts for future gravity satellite missions"

    Science.gov (United States)

    Reubelt, Tilo; Sneeuw, Nico; Fichter, Walter; Müller, Jürgen

    2010-05-01

    Within the German joint research project "concepts for future gravity satellite missions", funded by the Geotechnologies programme of the German Federal Ministry of Education and Research, options and concepts for future satellite missions for precise (time-variable) gravity field recovery are investigated. The project team is composed of members from science and industry, bringing together experts in geodesy, satellite systems, metrology, sensor technology and control systems. The majority of team members already contributed to former gravity missions. The composition of the team guarantees that not only geodetic aspects and objectives are investigated, but also technological and financial constraints are considered. Conversely, satellite, sensor and system concepts are developed and improved in a direct exchange with geodetic and scientific claims. The project aims to develop concepts for both near and mid-term future satellite missions, taking into account e.g. advanced satellite formations and constellations, improved orbit design, innovative metrology and sensor systems and advances in satellite systems.

  11. Lithospheric stress patterns: A global view

    Science.gov (United States)

    Zoback, Mary Lou; Burke, Kevin

    The present-day lithospheric stress state is the result of a variety of forces that act on and within the tectonic plates forming the Iithosphere. Knowledge of this stress state provides important constraints on forces acting at a variety of scales and, hence, helps to solve scientific problems of interest to a wide spectrum of scientists and engineers.Six years of effort by scientists from all over the world (listed at end of article) brought together under the International Lithosphere Program (ILP) of the joint International Union of Geodesy and Geophysics/International Union of Geological Sciences (IUGG/IUGS) Interunion Commission on the Lithosphere culminated in the July 1992 publication of the World Stress Map and nineteen accompanying research papers in a special issue of the Journal of Geophysical Research-Solid Earth (volume 87, number B8). Figure 1 shows a reduced version of the published 1:40,000,000 color map.

  12. International Geomagnetic Reference Field: the seventh generation.

    Science.gov (United States)

    Barton, C. E.

    A seventh-generation revision of the International Geomagnetic Reference Field (IGRF) was adopted by the International Association of Geomagnetism and Aeronomy (IAGA) at the XXI General Assembly of the International Union of Geodesy and Geophysics in July 1995. The new spherical harmonic models adopted are based on weighted averages of candidate models submitted by NASA's Goddard Space Flight Center, the Russian Institute of Terrestrial Magnetism, Ionospheric, and Radio Wave Propagation - IZMIRAN, and jointly by the US Naval Oceanographic Office and the British Geological Survey. The revised IGRF specifies the Earth's main field from 1900 to 2000 and is declared to be definitive from 1945 to 1990. This paper lists the IGRF coefficients, describes the derivation of the new IGRF models, and examines aspects of the IGRF's accuracy, continuity, and behaviour during the 20th century.

  13. Design of Geodetic SVLBI Satellite Orbit and Its Tracking Network%SVLBI用于大地测量的卫星轨道及其跟踪网设计

    Institute of Scientific and Technical Information of China (English)

    魏二虎; 刘经南; KULKARNI M.N.; FREY Sándor

    2008-01-01

    SVLBI (space very long baseline interferometry) has some important potential applications in geodesy and geodynam- ics, for which one of the most difficult tasks is to precisely determine the orbit of an SVLBI satellite. This work studies several technologies that will possibly be able to determine the orbit of a space VLBI satellite. Then, according to the types and charac- teristics of the satellite and the requirements for geodetic study and the geometry of the GNSS (GPS, GALILEO) satellite to track the space VLBI satellite, the six Keplerian elements of the SVLBI satellite (TEST-SVLBI) are determined. A program is designed to analyze the coverage area of space of different altitudes by the stations of the network, with which the tracking network of TEST-SVLBI is designed. The efficiency of tracking TEST-SVLBI by the network is studied, and the results are presented.

  14. Russian State Leveling Network (present and future)

    Science.gov (United States)

    Mazurova, Elena; Kopeikin, Sergei; Karpik, Aleksander

    2017-04-01

    In August 2016 the sixth session of the United Nations Committee of Experts of Global Geospatial Information Management (UN-GGIM) endorsed the roadmap for the development of a Global Geodetic Reference Frame (GGRF) and urged countries to join efforts for its creation. In response to the UN appeal in this article describes the current state of the high-precision Leveling Network in Russia and prospects of its development. In this paper, we consider projects related to the construction of new high-precision leveling lines by the classical methods, as well as issues of creating high-precision leveling network, associated with the development and implementation of a fundamentally new method of determining heights in geodesy - chronometric leveling based on the application of quantum metrology of time and the fundamental laws of general relativity. Keywords: leveling network, chronometric leveling, quantum metrology of time, the general theory of relativity.

  15. GNSS Reflectometry and Remote Sensing: New Objectives and Results

    CERN Document Server

    Jin, Shuanggen; 10.1016/j.asr.2010.01.014.

    2010-01-01

    The Global Navigation Satellite System (GNSS) has been a very powerful and important contributor to all scientific questions related to precise positioning on Earth's surface, particularly as a mature technique in geodesy and geosciences. With the development of GNSS as a satellite microwave (L-band) technique, more and wider applications and new potentials are explored and utilized. The versatile and available GNSS signals can image the Earth's surface environments as a new, highly precise, continuous, all-weather and near-real-time remote sensing tool. The refracted signals from GNSS Radio Occultation satellites together with ground GNSS observations can provide the high-resolution tropospheric water vapor, temperature and pressure, tropopause parameters and ionospheric total electron content (TEC) and electron density profile as well. The GNSS reflected signals from the ocean and land surface could determine the ocean height, wind speed and wind direction of ocean surface, soil moisture, ice and snow thick...

  16. Observing tectonic plate motions and deformations from satellite laser ranging

    Science.gov (United States)

    Christodoulidis, D. C.; Smith, D. E.; Kolenkiewicz, R.; Klosko, S. M.; Torrence, M. H.

    1985-01-01

    The scope of geodesy has been greatly affected by the advent of artificial near-earth satellites. The present paper provides a description of the results obtained from the reduction of data collected with the aid of satellite laser ranging. It is pointed out that dynamic reduction of satellite laser ranging (SLR) data provides very precise positions in three dimensions for the laser tracking network. The vertical components of the stations, through the tracking geometry provided by the global network and the accurate knowledge of orbital dynamics, are uniquely related to the center of mass of the earth. Attention is given to the observations, the methodologies for reducing satellite observations to estimate station positions, Lageos-observed tectonic plate motions, an improved temporal resolution of SLR plate motions, and the SLR vertical datum.

  17. GPS测定垂线偏差及嵌入式数据采集%Determination Of Vertical Delfection With GPS And Data Acquisition With Embedded System

    Institute of Scientific and Technical Information of China (English)

    黄伟; 冯涛

    2015-01-01

    Vertical delfection is an important data in geodesy.but traditional measurement methods are greatly inlfuenced by weather conditions. This paper introduces a method that using GPS and precision level to determine the vertical delfection. The experimental results show that under certain conditions, the precision of this method meets the requirements.%垂线偏差在大地测量中是一项重要的数据,传统的测量方法受天气状况影响较大。该文介绍了一种利用GPS和精密水准仪来测定垂线偏差的计算方法,实验结果表明,在一定条件下,该方法的精度符合要求。

  18. General inverse of Stokes, Vening-Meinesz and Molodensky formulae

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The operator operations between the disturbing potential and the geoidal undulation, the gravity anomaly, the deflection of the vertical are defined based on the relations among the gravity potential, the normal gravity potential and the disturbing potential. With the sphere as the boundary surface, based on the solution of the external boundary value problem for the disturbing potential by the spherical harmonics in the physical geodesy, the general inverse Stokes' formula, the general inverse Vening-Meinesz formula and the general Molodensky's formula are derived from the operator operations defined. The general formulae can get rid of the restriction of the classical formulae only used on the geoid. If the boundary surface is defined as the geoid, the general formulas are degenerated into the classic ones.

  19. Frames and other bases in abstract and function spaces novel methods in harmonic analysis

    CERN Document Server

    Gia, Quoc; Mayeli, Azita; Mhaskar, Hrushikesh; Zhou, Ding-Xuan

    2017-01-01

    The first of a two volume set on novel methods in harmonic analysis, this book draws on a number of original research and survey papers from well-known specialists detailing the latest innovations and recently discovered links between various fields. Along with many deep theoretical results, these volumes contain numerous applications to problems in signal processing, medical imaging, geodesy, statistics, and data science. The chapters within cover an impressive range of ideas from both traditional and modern harmonic analysis, such as: the Fourier transform, Shannon sampling, frames, wavelets, functions on Euclidean spaces, analysis on function spaces of Riemannian and sub-Riemannian manifolds, Fourier analysis on manifolds and Lie groups, analysis on combinatorial graphs, sheaves, co-sheaves, and persistent homologies on topological spaces. Volume I is organized around the theme of frames and other bases in abstract and function spaces, covering topics such as: The advanced development of frames, including ...

  20. Recent applications of harmonic analysis to function spaces, differential equations, and data science novel methods in harmonic analysis

    CERN Document Server

    Gia, Quoc; Mayeli, Azita; Mhaskar, Hrushikesh; Zhou, Ding-Xuan

    2017-01-01

    The second of a two volume set on novel methods in harmonic analysis, this book draws on a number of original research and survey papers from well-known specialists detailing the latest innovations and recently discovered links between various fields. Along with many deep theoretical results, these volumes contain numerous applications to problems in signal processing, medical imaging, geodesy, statistics, and data science. The chapters within cover an impressive range of ideas from both traditional and modern harmonic analysis, such as: the Fourier transform, Shannon sampling, frames, wavelets, functions on Euclidean spaces, analysis on function spaces of Riemannian and sub-Riemannian manifolds, Fourier analysis on manifolds and Lie groups, analysis on combinatorial graphs, sheaves, co-sheaves, and persistent homologies on topological spaces. Volume II is organized around the theme of recent applications of harmonic analysis to function spaces, differential equations, and data science, covering topics such a...

  1. Miljenko Lapaine i Dušan Marjanović (Ed.: Elementa Geometriae Practicae, Zemlyomirje, Introduction to Practical Geometry / Surveying

    Directory of Open Access Journals (Sweden)

    Tomislav Malvić

    2010-12-01

    Full Text Available It has been my pleasant task to write a review of a very interesting book with its attractively archaic appearance of the cover and a layout which, it needs to be said, completely matches its contents. Furthermore, it is interestingly conceptualized; a working result of scientific teams from Croatia and Hungary within a framework of bilateral project Najstariji hrvatski udžbenik geodezije (The oldest Croatian textbook of Geodesy in a way that its preface and abstract have been written trilingually – in Croatian, Hungarian and English. The results of the project work have been conjoined, in a fitted final whole, by the book’s editors Miljenko Lapaine and Dušan Marjanović.

  2. Geographic information systems in public health and medicine.

    Science.gov (United States)

    Mullner, Ross M; Chung, Kyusuk; Croke, Kevin G; Mensah, Edward K

    2004-06-01

    Geographic information systems (GIS) are increasingly being used in public health and medicine. Advances in computer technology, the encouragement of its use by the federal government, and the wide availability of academic and commercial courses on GIS are responsible for its growth. Some view GIS as only a tool for spatial research and policy analysis, while others believe it is part of a larger emerging new science including geography, cartography, geodesy, and remote sensing. The specific advantages and problems of GIS are discussed. The greatest potential of GIS is its ability to clearly show the results of complex analyses through maps. Problems in using GIS include its costs, the need to adequately train staff, the use of appropriate spatial units, and the risk it poses to violating patient confidentiality. Lastly, the fourteen articles in this special issue devoted to GIS are introduced and briefly discussed.

  3. Laboratory for development of open source geospatial technologies – role in education and research

    Directory of Open Access Journals (Sweden)

    Milan Kilibarda

    2014-06-01

    Full Text Available International Cartographic CBOs (International Cartographic Association- ICA in partnership with the Open Source Geospatial Foundation-OSGeo has started the initiative ICA-OSGeo Labs to promote and use open source technologies in education and research. For many years, the use and development of open source software and technologies have been present in the field of research and education at the Faculty of Civil Engineering at the Department of Geodesy and Geoinformatics, University of Belgrade. Additionally, at the University of Belgrade, Faculty of Civil Engineering a laboratory called "Laboratory for development of open source geospatial technologies - OSGL" has recently been established. This paper presents the current experience of the lab members in using open source software in geoinformatics, research and education as well as the perspectives and future activities of the newly formed laboratory.

  4. Cartographic and geodetic methods to characterize the potential landing sites for the future Russian missions Luna-Glob and Luna-Resurs

    Science.gov (United States)

    Karachevtseva, I. P.; Kokhanov, A. A.; Konopikhin, A. A.; Nadezhdina, I. E.; Zubarev, A. E.; Patratiy, V. D.; Kozlova, N. A.; Uchaev, D. V.; Uchaev, Dm. V.; Malinnikov, V. A.; Oberst, J.

    2015-04-01

    Characterization of the potential landing sites for the planned Luna-Glob and Luna-Resurs Russian missions requires cartographic and geodetic support prepared with special methods and techniques that are briefly overviewed here. The data used in the analysis, including the digital terrain models (DTMs) and the orthoimages acquired in the survey carried out from the Lunar Reconnaissance Orbiter and Kaguya spacecraft, are described and evaluated. By way of illustration, different regions of the lunar surface, including the subpolar regions of the Moon, are characterized with the suggested methods and the GIS-technologies. The development of the information support for the future lunar missions started in 2011, and it is now carried on in MIIGAiK Extraterrestrial Laboratory (MExLab), which is a department of the Moscow State University of Geodesy and Cartography (MIIGAiK).

  5. The InSight Mars Lander and Its Effect on the Subsurface Thermal Environment

    Science.gov (United States)

    Siegler, Matthew A.; Smrekar, Suzanne E.; Grott, Matthias; Piqueux, Sylvain; Mueller, Nils; Williams, Jean-Pierre; Plesa, Ana-Catalina; Spohn, Tilman

    2017-02-01

    The 2018 InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) Mission has the mission goal of providing insitu data for the first measurement of the geothermal heat flow of Mars. The Heat Flow and Physical Properties Package (HP3) will take thermal conductivity and thermal gradient measurements to approximately 5 m depth. By necessity, this measurement will be made within a few meters of the lander. This means that thermal perturbations from the lander will modify local surface and subsurface temperature measurements. For HP3's sensitive thermal gradient measurements, this spacecraft influence will be important to model and parameterize. Here we present a basic 3D model of thermal effects of the lander on its surroundings. Though lander perturbations significantly alter subsurface temperatures, a successful thermal gradient measurement will be possible in all thermal conditions by proper ( >3 m depth) placement of the heat flow probe.

  6. The International Mass Loading Service

    CERN Document Server

    Petrov, Leonid

    2015-01-01

    The International Mass Loading Service computes four loadings: a) atmospheric pressure loading; b) land water storage loading; c) oceanic tidal loading; and d) non-tidal oceanic loading. The service provides to users the mass loading time series in three forms: 1) pre-computed time series for a list of 849 space geodesy stations; 2) pre-computed time series on the global 1deg x 1deg grid; and 3) on-demand Internet service for a list of stations and a time range specified by the user. The loading displacements are provided for the time period from 1979.01.01 through present, updated on an hourly basis, and have latencies 8-20 hours.

  7. Nonlinear dynamics of mini-satellite respinup by weak internal controllable torques

    Energy Technology Data Exchange (ETDEWEB)

    Somov, Yevgeny, E-mail: e-somov@mail.ru [Samara State Technical University, Department for Guidance, Navigation and Control, 244 Molodogvardeyskaya Str., Samara 443100 (Russian Federation)

    2014-12-10

    Contemporary space engineering advanced new problem before theoretical mechanics and motion control theory: a spacecraft directed respinup by the weak restricted control internal forces. The paper presents some results on this problem, which is very actual for energy supply of information mini-satellites (for communication, geodesy, radio- and opto-electronic observation of the Earth et al.) with electro-reaction plasma thrusters and gyro moment cluster based on the reaction wheels or the control moment gyros. The solution achieved is based on the methods for synthesis of nonlinear robust control and on rigorous analytical proof for the required spacecraft rotation stability by Lyapunov function method. These results were verified by a computer simulation of strongly nonlinear oscillatory processes at respinuping of a flexible spacecraft.

  8. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  9. Vienna SAC-SOS: Analysis of the European VLBI Sessions

    Science.gov (United States)

    Ros, C. T.; Pavetich, P.; Nilsson, T.; Böhm, J.; Schuh, H.

    2012-12-01

    The Institute of Geodesy and Geophysics (IGG) of the Vienna University of Technology as an IVS Special Analysis Center for Specific Observing Sessions (SAC-SOS) has analyzed the European VLBI sessions using the software VieVS. Between 1990 and 2011, 115 sessions have been carried out. The analyzed baselines have lengths ranging from approximately 445 to 4580 km, and they show good repeatabilities, apart from the ones containing station Simeiz. The station velocities have also been investigated. The stations situated in the stable part of Europe have not shown significant relative movements w.r.t. Wettzell, whereas the stations located in the northern areas have the largest vertical motions as a result of the post glacial isostatic rebound of the zone. The stations placed in Italy, around the Black Sea, in Siberia, and near the Arctic Circle show the largest relative horizontal motions because they belong to different geodynamical units.

  10. Measurement of the neutrino velocity with the OPERA detector in the CNGS beam using the 2012 dedicated data

    CERN Document Server

    Adam, T; Aleksandrov, A; Anokhina, A; Aoki, S; Ariga, A; Ariga, T; Autiero, D; Badertscher, A; Dhahbi, A.Ben; Beretta, M; Bertolin, A; Bozza, C; Brugiere, T; Brugnera, R; Brunet, F; Brunetti, G; Buettner, B; Buontempo, S; Carlus, B; Cavanna, F; Cazes, A; Chaussard, L; Chernyavsky, M; Chiarella, V; Chukanov, A; D'Ambrosio, N; De Lellis, G; De Serio, M; del Amo Sanchez, P; Di Crescenzo, A; Di Ferdinando, D; Di Marco, N; Dmitrievsky, S; Dracos, M; Duchesneau, D; Dusini, S; Dzhatdoev, T; Ebert, J; Ereditato, A; Esposito, L S; Favier, J; Felici, G; Ferber, T; Fini, R A; Fukuda, T; Garfagnini, A; Giacomelli, G; Girerd, C; Goellnitz, C; Goldberg, J; Golubkov, D; Gornushkin, Y; Grella, G; Grianti, F; Guerin, C; Guler, A M; Gustavino, C; Hagner, C; Hamada, K; Hara, T; Hierholzer, M; Hollnagel, A; Ishida, H; Ishiguro, K; Jakovcic, K; Jollet, C; Kamiscioglu, C; Kamiscioglu, M; Kawada, J; Kim, J H; Kim, S H; Kimura, M; Kitagawa, N; Klicek, B; Kodama, K; Komatsu, M; Kose, U; Kreslo, I; Lauria, A; Lazzaro, C; Lenkeit, J; Ljubicic, A; Longhin, A; Mancini-Terracciano, C; Malgin, A; Mandrioli, G; Marteau, J; Matsuo, T; Matveev, V; Mauri, N; Medinaceli, E; Meregaglia, A; Migliozzi, P; Mikado, S; Monacelli, P; Montesi, M C; Morishima, K; Moser, U; Muciaccia, M T; Nakamura, M; Nakano, T; Nakatsuka, Y; Naumov, D; Nikitina, V; Ogawa, S; Olchevsky, A; Ozaki, K; Palamara, O; Paoloni, A; Park, B D; Park, I G; Pastore, A; Patrizii, L; Pennacchio, E; Pessard, H; Pistillo, C; Podgrudkov, D; Polukhina, N; Pozzato, M; Pretzl, K; Pupilli, F; Rescigno, R; Roda, M; Roganova, T; Rokujo, H; Rosa, G; Rostovtseva, I; Rubbia, A; Russo, A; Ryazhskaya, O; Sato, O; Sato, Y; Schembri, A; Schmidt-Parzefall, W; Schuler, J; Shakiryanova, I; Sheshukov, A; Shibuya, H; Shoziyoev, G; Simone, S; Sioli, M; Sirignano, C; Sirri, G; Song, J S; Spinetti, M; Stanco, L; Starkov, N; Stellacci, S M; Stipcevic, M; Strauss, T; Takahashi, S; Tenti, M; Terranova, F; Tioukov, V; Tolun, P; Tufanli, S; Vilain, P; Vladimirov, M; Votano, L; Vuilleumier, J L; Wilquet, G; Wonsak, B; Wurtz, J; Yoon, C S; Yoshida, J; Zaitsev, Y; Zemskova, S; Zghiche, A; Zimmermann, R

    2013-01-01

    In spring 2012 CERN provided two weeks of a short bunch proton beam dedicated to the neutrino velocity measurement over a distance of 730 km. The OPERA neutrino experiment at the underground Gran Sasso Laboratory used an upgraded setup compared to the 2011 measurements, improving the measurement time accuracy. An independent timing system based on the Resistive Plate Chambers was exploited providing a time accuracy of $\\sim$1 ns. Neutrino and anti-neutrino contributions were separated using the information provided by the OPERA magnetic spectrometers. The new analysis profited from the precision geodesy measurements of the neutrino baseline and of the CNGS/LNGS clock synchronization. The neutrino arrival time with respect to the one computed assuming the speed of light in vacuum is found to be $\\delta t_\

  11. Bowie Lecture: Time Variable Gravity Measurements Come of Age

    Science.gov (United States)

    Watkins, M. M.

    2004-12-01

    The Earth and planetary science and geodesy communities have long recognized measurements of the static gravity field as primary for understanding bulk properties and formation histories. Use of the time varying field, however, to measure the cycling of volatiles has been only coarsely demonstrated over the past two decades. The GRACE mission has now realized the promise of those early studies and demonstrated that gravity field measurement is now a valid remote sensing concept for the Earth and eventually other planets in the solar system. We will discuss the latest GRACE results for the measurement of the Earth's water cycle on land, the oceans, and ice sheets, and outline prospects and capabilities of follow-on missions. We will conclude with an overview of the recent exciting results of both current and proposed planetary missions, especially at Mars, for time varying gravity measurements outside the Earth as well.

  12. Using Advanced Space-borne Radar Technology for Detection and Measurement of Land Subsidence and Interseismic Slip Rates, the Case Study: NW Iran

    Directory of Open Access Journals (Sweden)

    Sadra Karimzadeh

    2013-03-01

    Full Text Available We used synthetic aperture radar interferometry (InSAR to measure land subsidence in Tabriz Plain (TP and strain accumulation along North Tabriz Fault (NTF. Thermal power plant of Tabriz city locats in the area called Tabriz Plain which supplies electric energy for NW Iran. Its facilities need to be constantly cool, so there are more than twenty water pumping stations in some parts of TP. Moreover, the power plant, petrochemical, refinery and Vanyar dam are located near at a hazardous tectonic structure called North Tabriz Fault. InSAR is one of satellite radar observation methods which is used in space geodesy. In this paper, we have applied twenty ASAR SLC images of Envisat satellite from descending orbits during May 2003 to July 2010. InSAR analysis shows about 20mm/yr land subsidence and about 7mm/yr slip rate for NTF.

  13. Improvement in the geopotential derived from satellite and surface data (GEM 7 and 8)

    Science.gov (United States)

    Wagner, C. A.; Lerch, F. J.; Brownd, J. E.; Richardson, J. A.

    1976-01-01

    A refinement was obtained in the earth's gravitational field using satellite and surface data. In addition to a more complete treatment of data previously employed on 27 satellites, the new satellite solution (Goddard Earth Model 7) includes 64,000 laser measurements taken on 7 satellites during the international satellite geodesy experiment (ISAGEX) program. The GEM 7, containing 400 harmonic terms, is complete through degree and order 16. The companion solution GEM 8 combines the same satellite data as in GEM 7 with surface gravimetry over 39% of the earth. The GEM 8 is complete to degree and order 25. Extensive tests on data independent of the solution show that the undulation of the geoidal surface computed by GEM 7 has an accuracy of about 3m (rms). The overall accuracy of the geoid estimated by GEM 8 is estimated to be about 4-1/4m (rms), an improvement of almost 1m over previous solutions.

  14. GNET detected an anomalous "spike" in ice loss in Greenland during the 2010 melting season

    DEFF Research Database (Denmark)

    Bevis, Michael G; Wahr, John M; Khan, Shfaqat Abbas

    ’s instantaneous elastic response to contemporary losses in ice mass. Superimposed on longer term trends, an anomalous ‘pulse’ of uplift accumulated at many GNET stations during a ~5 month period in 2010, and we will show that this anomalous uplift is spatially correlated with the 2010 melting day anomaly (Tedesco......The Greenland GPS Network (GNET) uses GPS geodesy to measure the displacement of bedrock exposed near the margins of the Greenland Ice Sheet. The amplitudes of the observed vertical velocities indicate that over most of coastal Greenland these displacements are dominated by the solid earth...... et al., 2011). This result confirms the ability of GPS networks in Greenland, Antarctica and elsewhere to directly sense ice mass changes at sub-annual as well as longer timescales. GNET and similar GPS networks can therefore mitigate the loss of ice mass measurements following the anticipated...

  15. DORIS research activities at Geodetic Observatory Pecny

    Science.gov (United States)

    Štěpánek, Petr; Filler, Vratislav; Buday, Michal

    2017-04-01

    Geodesy Observatory Pecný (GOP) provides one of the International DORIS Service (IDS) analyses centers, participating on the combined IDS products including the solution for ITRF2014. As the unique approach, GOP employs a DORIS-developed version of the Bernese GPS Software. The recent research focuses on several topics. Our experiment, based on 9 year of data, shows a possibility to reach LOD estimation accuracy close to 0.1 msec per day (compared to reference IERS C04 model), when not adjusting the cross-track harmonics in the Satellite orbit model. We also compare different preprocessing strategies and data weighting and discuss the impact on the solution accuracy and on the scale bias. Moreover, we present the initial results of the station clock modelling from the DORIS/pseudorange measurements.

  16. A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model: Measurement of Earth's dragging of inertial frames.

    Science.gov (United States)

    Ciufolini, Ignazio; Paolozzi, Antonio; Pavlis, Erricos C; Koenig, Rolf; Ries, John; Gurzadyan, Vahe; Matzner, Richard; Penrose, Roger; Sindoni, Giampiero; Paris, Claudio; Khachatryan, Harutyun; Mirzoyan, Sergey

    2016-01-01

    We present a test of general relativity, the measurement of the Earth's dragging of inertial frames. Our result is obtained using about 3.5 years of laser-ranged observations of the LARES, LAGEOS, and LAGEOS 2 laser-ranged satellites together with the Earth gravity field model GGM05S produced by the space geodesy mission GRACE. We measure [Formula: see text], where [Formula: see text] is the Earth's dragging of inertial frames normalized to its general relativity value, 0.002 is the 1-sigma formal error and 0.05 is our preliminary estimate of systematic error mainly due to the uncertainties in the Earth gravity model GGM05S. Our result is in agreement with the prediction of general relativity.

  17. The International DORIS Service: Current Status and Future Plans

    Science.gov (United States)

    Soudarin, Laurent; Ferrage, Pascale; Saunier, Jérôme

    2017-04-01

    The International DORIS Service (IDS) was created in 2003 under the umbrella of the International Association of Geodesy (IAG) to foster scientific research related to the French DORIS tracking system and to deliver scientific products, mostly related to the International Earth rotation and Reference systems Service (IERS). Since its start, the organization has continuously evolved, leading to additional and improved operational products from an expanded set of DORIS Analysis Centers. IDS is now based on a reinforced structure with two Data Centers, six Analysis Centers, several associated groups and a Combination Center. Using the experience gained in the preparation of the ITRF2008 and ITRF2014, many improvements were made both in data analysis and on technical aspects. This presentation addresses the organizational aspects of the IDS and the recent achievements made by its components. We also discuss the future plans in terms of new products and activities.

  18. Large-Scale Hollow Retroreflectors for Lunar Laser Ranging at Goddard Space Flight Center

    Science.gov (United States)

    Preston, Alix

    2012-01-01

    Laser ranging to the retroreflector arrays placed on the lunar surface by the Apollo astronauts and the Soviet Luna missions have dramatically increased our understanding of gravitational physics along with Earth and Moon geophysics, geodesy, and dynamics. Although the precision of the range measurements has historically been limited by the ground station capabilities, advances in the APOLLO instrument at the Apache Point facility in New Mexico is beginning to be limited by errors associated with the lunar arrays. We report here on efforts at Goddard Space Flight Center to develop the next generation of lunar retroreflectors. We will describe a new facility that is being used to design, assemble, and test large-scale hollow retroreflectors. We will also describe results from investigations into various bonding techniques used to assemble the open comer cubes and mirror coatings that have dust mitigation properties.

  19. Airborne Gravity Data Denoising Based on Empirical Mode Decomposition: A Case Study for SGA-WZ Greenland Test Data

    DEFF Research Database (Denmark)

    Zhao, Lei; Wu, Meiping; Forsberg, René

    2015-01-01

    Surveying the Earth's gravity field refers to an important domain of Geodesy, involving deep connections with Earth Sciences and Geo-information. Airborne gravimetry is an effective tool for collecting gravity data with mGal accuracy and a spatial resolution of several kilometers. The main obstacle...... of airborne gravimetry is extracting gravity disturbance from the extremely low signal to noise ratio measuring data. In general, the power of noise concentrates on the higher frequency of measuring data, and a low pass filter can be used to eliminate it. However, the noise could distribute in a broad range...... of frequency while low pass filter cannot deal with it in pass band of the low pass filter. In order to improve the accuracy of the airborne gravimetry, Empirical Mode Decomposition (EMD) is employed to denoise the measuring data of two primary repeated flights of the strapdown airborne gravimetry system SGA...

  20. Schreiber Approach for GPS Carrier Phase Ambiguity Resolution

    Institute of Scientific and Technical Information of China (English)

    Zhu Jian-jun; Ding Xiao-li; Chen Yong-qi

    2003-01-01

    Differenced GPS carrier phase observations are usually used in GPS positioning to eliminate the various common GPS errors. A different approach is proposed in this paper where no differencing of the observations is required. In this method, the common GPS errors are modelled explicitly and eliminated by introducing the Schreiber method, which is used in traditional geodesy to eliminate the azimuth unknowns in observation equations. The paper first introduces the Schreiber method, and then discusses its application to the various GPS common-mode error models. It is shown that if only the real ambiguity solution is concerned, the estimate of the position parameters from the Schreiber approach is the same as that from the differencing approach. However, the variance of the ambiguity estimate from the Schreiber approach is smaller than that from the differencing approach. Numerical examples are given to show that the results are reliable.

  1. Summary of session C9: experimental gravitation

    Science.gov (United States)

    Lämmerzahl, Claus; Müller, Jürgen

    2014-05-01

    General relativity (GR) is based on the Universality of Free Fall, the Universality of the Gravitational Redshift, and Local Lorentz Invariance, alltogether called the Einstein Equivalence principle. This implies that gravity has to be described by a metrical theory. Such theories in general give rise to the standard effects like perihelion shift, light deflection, gravitational time delay, Lense-Thirring effect, and the Schiff effect. Only if the underlying theory is Einstein's GR we have certain values for these effects. GR in turn predicts the existence, certain properties, and a particular dynamics of gravitational waves, black holes, binary systems, etc. which are also subject to experimental/observational proof. This includes practical applications in clock synchronization, positioning, navigation and geodesy.

  2. Evaluation of the dynamics of change of shore cliff located in the vicinity of Pleśna village in the period 2006-2015

    Directory of Open Access Journals (Sweden)

    Czesław Suchocki

    2016-07-01

    Full Text Available Climate changes on our planet contribute to the rise in the average level of the seas, oceans, and a greater number of storms. It causes an increasing process of the sea abrasion on the cliffs. The paper presents the research, which determines the rate of retreat of the cliff shore fragment located in the vicinity of Pleśna village. The cliff displacements, which are the effect of erosive factors, were analysed on the basis of observations made in the years 2006-2015. Terrestrial laser scanning technology was applied to periodic measurements of the cliff. In the studies, the methodology of cliff shores monitoring was used, which was the result of five-year research performed by the staff of the Department of Geodesy Technical University of Koszalin. Keywords: abrasion, cliff, terrestrial laser scanner

  3. Electrostatic accelerometer with bias rejection for Gravitation and Solar System physics

    CERN Document Server

    Lenoir, Benjamin; Foulon, Bernard; Christophe, Bruno; Lamine, Brahim; Reynaud, Serge

    2010-01-01

    Radio tracking of interplanetary probes is an important tool for navigation purposes as well as for testing the laws of physics or exploring planetary environments. The addition of an accelerometer on board a spacecraft provides orbit determination specialists and physicists with an additional observable of great interest: it measures the value of the non-gravitational acceleration acting on the spacecraft, i.e. the departure of the probe from geodesic motion. This technology is now routinely used for geodesy missions in Earth orbits with electrostatic accelerometers. This article proposes a technological evolution which consists in adding a subsystem to remove the bias of an electrostatic accelerometer. It aims at enhancing the scientific return of interplanetary missions in the Solar System, from the point of view of fundamental physics as well as Solar System physics. The main part of the instrument is an electrostatic accelerometer called MicroSTAR, which inherits mature technologies based on ONERA's expe...

  4. FOSS4G Date Assessment on the Isprs Optical Stereo Satellite Data: a Benchmark for Dsm Generation

    Science.gov (United States)

    Di Rita, M.; Nascetti, A.; Crespi, M.

    2017-05-01

    The ISPRS Working Group 4 Commission I on "Geometric and Radiometric Modelling of Optical Spaceborne Sensors", provides a benchmark dataset with several stereo data sets from space borne stereo sensors. In this work, the Worldview-1 and Cartosat-1 datasets are used, in order to test the Free and Open Source Software for Geospatial (FOSS4G) Digital Automatic Terrain Extractor (DATE), developed at Geodesy and Geomatics Division, University of Rome "La Sapienza", able to generate Digital Surface Models starting from optical and SAR satellite images. The accuracy in terms of NMAD ranges from 1 to 3 m for Wordview-1, and from 4 to 6 m for Cartosat-1. The results obtained show a general better 3D reconstruction for Worldview-1 DSMs with respect to Cartosat-1, and a different completeness level for the three analysed tiles, characterized by different slopes and land cover.

  5. Stamping the Earth from space

    CERN Document Server

    Dicati, Renato

    2017-01-01

    This unique book presents a historical and philatelic survey of Earth exploration from space. It covers all areas of research in which artificial satellites have contributed in designing a new image of our planet and its environment: the atmosphere and ionosphere, the magnetic field, radiation belts and the magnetosphere, weather, remote sensing, mapping of the surface, observation of the oceans and marine environments, geodesy, and the study of life and ecological systems. Stamping the Earth from Space presents the results obtained with the thousands of satellites launched by the two former superpowers, the Soviet Union and the United States, and also those of the many missions carried out by the ESA, individual European countries, Japan, China, India, and the many emerging space nations. Beautifully illustrated, it contains almost 1100 color reproductions of philatelic items. In addition to topical stamps and thematic postal documents, the book provides an extensive review of astrophilatelic items. The most...

  6. A COMPARISON OF TWO METHODS FADING MEMORY FILTER AND ADAPTIVE KALMAN FILTER IN MONITORING CRUSTAL MOVEMENT

    Directory of Open Access Journals (Sweden)

    Cahit Tağı ÇELİK

    2004-01-01

    Full Text Available Monitoring the Crustal Movement in Geodesy is performed by the deformation survey and analysis. If monitoring the crustal movements involves more than two epochs of survey campaign then from the plate tectonic theory, stations do not move randomly from one epoch to the other, therefore Kalman Filter may be suitable to use. However, if sudden movements happened in the crust in particular earthquake happened, the crust moves very fast in a very short period of time. When Kalman Filter used for monitoring these movements, from associated epoch, for a number of epochs the results may be biased. In the paper, comparison of two methods for elimination of the above mentioned biases have been performed. These methods are Fading Memory Filter and Adaptive Kalman Filter for an unknown bias.

  7. Hollow Retroreflectors for Lunar Laser Ranging at Goddard Space Flight Center

    Science.gov (United States)

    Preston, Alix M.; Merkowitz, Stephen M.

    2012-01-01

    Laser ranging to the retroreflector arrays placed on the lunar surface by the Apollo astronauts and the Soviet Luna missions have dramatically increased our understanding of gravitational physics along with Earth and Moon geophysics, geodesy, and dynamics. Although the precision of the range measurements has historically been limited by the ground station capabilities, advances in the APOLLO instrument at the Apache Point facility in New Mexico is beginning to be limited by errors associated with the lunar arrays. At Goddard Space Flight Center, we have developed a facility where we can design, build, and test next-generation hollow retroreflectors for Lunar Laser Ranging. Here we will describe this facility as well as report on the bonding techniques used to assemble the retroreflectors. Results from investigations into different high reflectivity mirror coatings, as well as dust mitigation coatings will also be presented.

  8. Large-Scale Hollow Retroreflectors for Lunar Laser Ranging at Goddard Space Flight Center

    Science.gov (United States)

    Preston, Alix M.

    2012-05-01

    Laser ranging to the retroreflector arrays placed on the lunar surface by the Apollo astronauts and the Soviet Luna missions have dramatically increased our understanding of gravitational physics along with Earth and Moon geophysics, geodesy, and dynamics. Although the precision of the range measurements has historically been limited by the ground station capabilities, advances in the APOLLO instrument at the Apache Point facility in New Mexico is beginning to be limited by errors associated with the lunar arrays. We report here on efforts at Goddard Space Flight Center to develop the next generation of lunar retroreflectors. We will describe a new facility that is being used to design, assemble, and test large-scale hollow retroreflectors. We will also describe results from investigations into various bonding techniques used to assemble the open corner cubes and mirror coatings that have dust mitigation properties.

  9. Engineering surveying

    CERN Document Server

    Schofield, W

    2007-01-01

    Engineering surveying involves determining the position of natural and man-made features on or beneath the Earth's surface and utilizing these features in the planning, design and construction of works. It is a critical part of any engineering project. Without an accurate understanding of the size, shape and nature of the site the project risks expensive and time-consuming errors or even catastrophic failure.Engineering Surveying 6th edition covers all the basic principles and practice of this complex subject and the authors bring expertise and clarity. Previous editions of this classic text have given readers a clear understanding of fundamentals such as vertical control, distance, angles and position right through to the most modern technologies, and this fully updated edition continues that tradition.This sixth edition includes:* An introduction to geodesy to facilitate greater understanding of satellite systems* A fully updated chapter on GPS, GLONASS and GALILEO for satellite positioning in surveying* Al...

  10. Role of mantle flow in Nubia-Somalia plate divergence

    Science.gov (United States)

    Stamps, D. S.; Iaffaldano, G.; Calais, E.

    2015-01-01

    Present-day continental extension along the East African Rift System (EARS) has often been attributed to diverging sublithospheric mantle flow associated with the African Superplume. This implies a degree of viscous coupling between mantle and lithosphere that remains poorly constrained. Recent advances in estimating present-day opening rates along the EARS from geodesy offer an opportunity to address this issue with geodynamic modeling of the mantle-lithosphere system. Here we use numerical models of the global mantle-plates coupled system to test the role of present-day mantle flow in Nubia-Somalia plate divergence across the EARS. The scenario yielding the best fit to geodetic observations is one where torques associated with gradients of gravitational potential energy stored in the African highlands are resisted by weak continental faults and mantle basal drag. These results suggest that shear tractions from diverging mantle flow play a minor role in present-day Nubia-Somalia divergence.

  11. Conventionalism and integrable Weyl geometry

    Science.gov (United States)

    Pucheu, M. L.

    2015-03-01

    Since the appearance of Einstein's general relativity, gravitation has been associated to the space-time curvature. This theory introduced a geometrodynamic language which became a convenient tool to predict matter behaviour. However, the properties of space-time itself cannot be measurable by experiments. Taking Poincaré idea that the geometry of space-time is merely a convention, we show that the general theory of relativity can be completely reformulated in a more general setting, a generalization of Riemannian geometry, namely, the Weyl integrable geometry. The choice of this new mathematical language implies, among other things, that the path of particles and light rays should now correspond to Weylian geodesies. Such modification in the dynamic of bodies brings a new perception of physical phenomena that we will explore.

  12. Geodesics of Spherical Dilaton Spacetimes

    Institute of Scientific and Technical Information of China (English)

    ZENG Yi; L(U) Jun-Li; WANG Yong-Jiu

    2006-01-01

    The properties of spherical dilaton black hole spacetimes are investigated through a study of their geodesies. The closed and non-closed orbits of test particles are analysed using the effective potential and phase-plane method. The stability and types of orbits are determined in terms of the energy and angular momentum of the test particles. The conditions of the existence of circular orbits for a spherical dilaton spacetime with an arbitrary dilaton coupling constant a are obtained. The properties of the orbits and in particular the position of the innermost stable circular orbit are compared to those of the Reissner-Nordstrom spacetime. The circumferential radius of innermost stable circular orbit and the corresponding angular momentum of the test particles increase for a≠0.

  13. Subduction & orogeny: Introduction to the special volume

    Science.gov (United States)

    Rolland, Y.; Bosch, D.; Guillot, S.; de Sigoyer, J.; Martinod, J.; Agard, P.; Yamato, P.

    2016-05-01

    Subduction processes play a major role in plate tectonics and the subsequent geological evolution of Earth. This special issue focuses on ongoing research in subduction dynamics to a large extent (oceanic subduction, continental subduction, obduction…) for both past and active subduction zones and into mountain building processes and the early evolution of orogens. It puts together various approaches combining geophysics (imaging of subduction zones), petrology/geochemistry (metamorphic analysis of HP-UHP rocks, fluid geochemistry and magmatic signal, geochronology), seismology and geodesy (present-day evolution of subduction zones, active tectonics), structural geology (structure and evolution of mountain belts), and numerical modelling to provide a full spectrum of tools that can be used to constrain the nature and evolution of subduction processes and orogeny. Studies presented in this special issue range from the long-term (orogenic cycle) to short-term (seismic cycle).

  14. Structural safety evaluation of Karun III Dam and calibration of its finite element model using instrumentation and site observation

    Directory of Open Access Journals (Sweden)

    H. Mirzabozorg

    2014-06-01

    Full Text Available In the present paper, a comprehensive finite element model of Karun III double curvature arch dam is calibrated based on the micro geodesies measurements and instrumentation. Thermal properties of concrete are obtained by transient thermal analysis and the results are compared with those obtained from thermometers. Thermal analysis features include air temperature, water layers temperatures, and the solar radiation on the exposed faces. Structural calibration features include thermal distribution within the dam body, dam self-weight, hydrostatic pressure, and silt load applied on the model of dam–reservoir–foundation system. Finite element model calibration provides updated information related to the current dam status and can be used for further safety evaluations.

  15. A VLBI variance-covariance analysis interactive computer program. M.S. Thesis

    Science.gov (United States)

    Bock, Y.

    1980-01-01

    An interactive computer program (in FORTRAN) for the variance covariance analysis of VLBI experiments is presented for use in experiment planning, simulation studies and optimal design problems. The interactive mode is especially suited to these types of analyses providing ease of operation as well as savings in time and cost. The geodetic parameters include baseline vector parameters and variations in polar motion and Earth rotation. A discussion of the theroy on which the program is based provides an overview of the VLBI process emphasizing the areas of interest to geodesy. Special emphasis is placed on the problem of determining correlations between simultaneous observations from a network of stations. A model suitable for covariance analyses is presented. Suggestions towards developing optimal observation schedules are included.

  16. The Importance of Local Surveys for Tying Techniques Together

    Science.gov (United States)

    Long, James L.; Bosworth, John M.

    2000-01-01

    The synergistic benefits of combining observations from multiple space geodesy techniques located at a site are a main reason behind the proposal for the establishment of the International Space Geodetic and Gravimetric Network (ISGN). However, the full benefits of inter-comparison are only realized when the spatial relationships between the different space geodetic systems are accurately determined. These spatial relationships are best determined and documented by developing a local reference network of stable ground monuments and conducting periodic surveys to tie together the reference points (for example: the intersection of rotation axes of a VLBI antenna) of the space geodetic systems and the ground monument network. The data obtained from local surveys is vital to helping understand any systematic errors within an individual technique and to helping identify any local movement or deformation of the space geodetic systems over time.

  17. Use of Low-Cost Acquisition Systems with an Embedded Linux Device for Volcanic Monitoring

    Directory of Open Access Journals (Sweden)

    David Moure

    2015-08-01

    Full Text Available This paper describes the development of a low-cost multiparameter acquisition system for volcanic monitoring that is applicable to gravimetry and geodesy, as well as to the visual monitoring of volcanic activity. The acquisition system was developed using a System on a Chip (SoC Broadcom BCM2835 Linux operating system (based on DebianTM that allows for the construction of a complete monitoring system offering multiple possibilities for storage, data-processing, configuration, and the real-time monitoring of volcanic activity. This multiparametric acquisition system was developed with a software environment, as well as with different hardware modules designed for each parameter to be monitored. The device presented here has been used and validated under different scenarios for monitoring ocean tides, ground deformation, and gravity, as well as for monitoring with images the island of Tenerife and ground deformation on the island of El Hierro.

  18. The LARASE Spin Model of the two LAGEOS and LARES satellites

    Science.gov (United States)

    Visco, Massimo; Lucchesi, David; Anselmo, Luciano; Bassan, Massimo; Magnafico, Carmelo; Nobili, Anna Maria; Pardini, Carmen; Peron, Roberto; Pucacco, Giuseppe; Stanga, Ruggero

    2016-04-01

    Satellite Laser Ranging (SLR) represents a very important technique of the observational space geodesy. In fact, Lunar Laser Ranging, Very Long Baseline Interferometry, Global Navigation Satellite Systems, Doppler Orbitography and Radiopositioning Integrated by Satellite, together with SLR constitute the Global Geodetic Observing System (GGOS). In the context of the GGOS activities, improvements in technology and in modeling will produce advances in Geodesy and Geophysics as well as in General Relativity (GR) measurements. Therefore, these important research fields are not independent, but tightly related to each other. The LARASE (LAser RAnged Satellites Experiment) research program has its main objectives in tests and measurements of Einstein's theory of GR via Precise Orbit Determination (POD) of a set of geodetic satellites. In order to reach such goals by means of very precise measurements of a number of relativistic parameters (and, at the same time, to provide a robust and unassailable error budget of the main systematic effects), we are also reviewing previous models and we are developing new models for the main perturbations (both gravitational and non-gravitational) that act on the orbits of the two LAGEOS and on that of LARES satellites. Within this paper we focus on modeling the spin vector of these satellites. The spin knowledge, both in orientation and rate, is of fundamental importance in order to correctly model the thermal effects acting on the surface of these satellites. These are very important non-gravitational perturbations (NGP) that produce long-term effects on the orbit of the cited satellites, especially for the two LAGEOS, and improvements in their modeling will be very useful both in the field of GR measurements and in those of space geodesy and geophysical applications. Indeed, the current RMS value of the range residuals of the LAGEOS satellites, obtained by the Analysis Centers of the International Laser Ranging Service, is at the

  19. Crustal deformation study in the Canary Archipelago by the analysis of GPS observations

    Science.gov (United States)

    Martín, Adriana; Sevilla, Miguel; Zurutuza, Joaquín

    2014-06-01

    The Canary Archipelago is an active volcanic region located in the African plate, at 100 Km of the northwest coast of Africa. The Complutense University of Madrid, Institute of Astronomy and Geodesy (CSIC-UCM) and University of Jaén, established a GPS Network in this region and carried out six observations campaigns from 2002 to 2009. The focus of thiswork is processing and analyzing these observations to study the geodynamic behavior of the stations of this network. The data have been computed with the Bernese GPS Software Version 5.0 obtaining individual solutions of coordinates for each session and campaign, the coordinate velocities of the stations and the time series of baselines formed between them. Results show consistency of station velocities compared to behaviour of areas permanent stations and baselines stability. No deformations could be detected.

  20. Low Cost Intelligent Pervasive Location Tracking (iPLOT) in All Environments for the Management of Crime

    Science.gov (United States)

    Mautz, Rainer; Ochieng, Washington; Walsh, David; Brodin, Gary; Kemp, Andy; Cooper, John; Son Le, Thanh

    2006-05-01

    This paper details the current status of the development of an ‘automatic’ low-cost system based on wireless communications technology to provide continuous tracking of the location of devices in all environments. This task requires a multi-disciplinary approach combining communications systems design, digital signal processing to extract ranges and, importantly, approaches from the field of geodesy to develop novel network positioning techniques for ad-hoc networks. Such a network will support a number of services relevant to crime management where seamless tracking is required. The paper discusses the process for developing the system, christened intelligent pervasive location tracking (iPLOT), with a particular reference to user and system requirements, and how these have been used to explore a network positioning strategy.

  1. Die Physikalische Sammlung (Physical Collection)

    CERN Document Server

    Schrimpf, Andreas

    2015-01-01

    At the end of the 17th century, the collection was established through the acquisition of Leiden instrumentmaker Musschenbroek's collection. Its aim was to demonstrate physical phenomena. Until the end of the 18th century, the collection was used and extended by a number of professors from various university departments in teaching mechanics, hydrostatics, optics and electrostatics. The foundation of the Institute for Mathematics and Physics in 1817 and the appointment of Christian Ludwig Gerling to the position of Professor for Mathematics, Physics and Astronomy strengthened the subject considerably. Gerling extended the collection mainly with devices for geodesy and astronomy, with more instruments being added in the time up to the middle of the 20th century. Today, the collection allows an insight into the history of scientific instruments as witnesses of the past.

  2. On geodesic deviation in Schwarzschild spacetime

    CERN Document Server

    Philipp, Dennis; Laemmerzahl, Claus; Deshpande, Kaustubh

    2015-01-01

    For metrology, geodesy and gravimetry in space, satellite based instruments and measurement techniques are used and the orbits of the satellites as well as possible deviations between nearby ones are of central interest. The measurement of this deviation itself gives insight into the underlying structure of the spacetime geometry, which is curved and therefore described by the theory of general relativity (GR). In the context of GR, the deviation of nearby geodesics can be described by the Jacobi equation that is a result of linearizing the geodesic equation around a known reference geodesic with respect to the deviation vector and the relative velocity. We review the derivation of this Jacobi equation and restrict ourselves to the simple case of the spacetime outside a spherically symmetric mass distribution and circular reference geodesics to find solutions by projecting the Jacobi equation on a parallel propagated tetrad as done by Fuchs. Using his results, we construct solutions of the Jacobi equation for...

  3. The Dutch GOCE National User Group-Fact Sheet

    Science.gov (United States)

    Koop, R.; Visser, P.; Selig, A.; Ambrodius, B.

    2004-06-01

    Dutch groups and persons have been participating in GOCE activities from the early days of the project till now and are planning to stay involved until the goals of the mission will be realized. The activities, that actually go back all the way to the first ideas of the ARISTOTELES mission, have been evolving over many aspects of the mission, from instrument simulation via data processing to user applications. The groups now involved can rely on a long lasting expertise in the respective fields of interest: space geodesy, orbital mechanics, space research and technology, oceanography and geodynamics. In the context of GOCE, but also in related fields, the participating Dutch groups have established both national and international cooperation and reputation.

  4. GOCE Activities in the Netherlands

    Science.gov (United States)

    Koop, R.; Visser, P.; Selig, A.; Ambrosius, B.

    2004-06-01

    Dutch groups and persons have been participating in GOCE activities from the early days of the project till now and are planning to stay involved until the goals of the mission will be realised. The activities, that actually go back all the way to the first ideas of the ARISTOTELES mission, have been evolving over many aspects of the mission, from instrument simulation via data processing to user applications. The groups now involved can rely on a long lasting expertise in the respective fields of interest: space geodesy, orbital mechanics, space research and technology, oceanography and geodynamics. In the context of GOCE, but also in related fields, the participating Dutch groups have established both national and international cooperation and reputation. A Dutch GOCE User Community is being established and this paper will present the ongoing and planned GOCE activities within this community. In this overview we will deal with issues of organisation, science projects, cooperation and an outlook to the future after GOCE.

  5. Optical clock networks

    Science.gov (United States)

    Riehle, Fritz

    2017-01-01

    Within the last decade, optical atomic clocks have surpassed the best cesium clocks, which are used to realize the unit of time and frequency, in terms of accuracy and stability by about two orders of magnitude. When remote optical atomic clocks are connected by links without degradation in the clock signals, an optical clock network is formed, with distinct advantages for the dissemination of time, geodesy, astronomy and basic and applied research. Different approaches for time and frequency transfer in the microwave and optical regime, via satellites and free-space links, optical fibre links, or transportable optical atomic clocks, can be used to form a hybrid clock network that may allow a future redefinition of the unit of time based on an optical reference transition.

  6. The newest observational evidence on asymmetrical deformation of the Earth

    Institute of Scientific and Technical Information of China (English)

    黄立人; 马宗晋; 朱建新

    2002-01-01

    Based on the coordinates, velocities and their error estimations of 595 GPS, SLR and VLBI stations issued by IERS in March 2001, the current asymmetrical deformation of the Earth is studied. The results show that the northern hemisphere of the Earth is undergoing compressive deformation, and the southern hemisphere is undergoing extensional deformation with the equator as the boundary. If the longitude line of 90(E and 90(W is taken as the boundary, the Pacific hemisphere (with 180( as its central longitude) is undergoing compressive deformation, and the Atlantic hemisphere (with 0( as its central longitude) is undergoing extensional deformation. The deformation patterns indicate again that the Earth is undergoing some dual-asymmetrical deformation. Moreover, taking 6 366.740 km as the standard mean curvature radius of the Earth, the velocity of volume change calculated from the data of space geodesy is 6.65(1011 m3/a.

  7. 2500 years of space-time reference systems

    Science.gov (United States)

    Bizouard, C.; OMIM Group

    2014-12-01

    Time and space reference systems result from the historical developments of the observational techniques and concepts from Antiquity to nowadays. Moreover ancient observations, involving various techniques and epochs, are quite often reprocessed, because of the extension or modification of their compilations or for benefiting of the progress of the computer capabilities. These historical aspects constitute an other skill of SYRTE. For a better integration of our various researches and their achievements, and having an epistemological overview on them, we set up in 2013 an internal interdisciplinary group, assembling time and astro-geodesy competence centers with the historians. This is OMIM: "Observations, Mesures, Incertitude, Modèles" (i.e. Observations, Measurements, Uncertainties and Models). The present poster is aimed at illustrating the evolution in measuring/conceptualising space and time from the Greeks to our days.

  8. Observing tectonic plate motions and deformations from satellite laser ranging

    Science.gov (United States)

    Christodoulidis, D. C.; Smith, D. E.; Kolenkiewicz, R.; Klosko, S. M.; Torrence, M. H.

    1985-01-01

    The scope of geodesy has been greatly affected by the advent of artificial near-earth satellites. The present paper provides a description of the results obtained from the reduction of data collected with the aid of satellite laser ranging. It is pointed out that dynamic reduction of satellite laser ranging (SLR) data provides very precise positions in three dimensions for the laser tracking network. The vertical components of the stations, through the tracking geometry provided by the global network and the accurate knowledge of orbital dynamics, are uniquely related to the center of mass of the earth. Attention is given to the observations, the methodologies for reducing satellite observations to estimate station positions, Lageos-observed tectonic plate motions, an improved temporal resolution of SLR plate motions, and the SLR vertical datum.

  9. Radio sky and the right to observe it

    CERN Document Server

    Gulyaev, Sergei

    2012-01-01

    It was decided in May 2012 that the Square Kilometre Array (SKA) will be built in Africa and Australia, two Southern Hemisphere continents. Here we discuss the plan for SKA design and construction, and how New Zealand radio astronomers can participate in this project and contribute to astronomy and astrophysics research. Geodesy and the study of tectonic plate motion is another important area of research for New Zealand radio astronomy to contribute to. As New Zealand is located at the boundary between two colliding tectonic plates (Australian and Pacific) and most of geological activity in New Zealand originates from their motion, it is important to monitor the relative plate motion with high precision using both GPS and radio astronomical techniques. We discuss radio frequency interference (RFI) as a limiting factor for radio astronomy, and provide results of RFI measurements in different locations in New Zealand.

  10. The use of satellite laser observations in studying the crustal movements

    Directory of Open Access Journals (Sweden)

    Gamal F. Attia

    2012-12-01

    Full Text Available The mutual tectonic displacements of the lithospheric blocks take place within the deep fracture dividing them into hundreds and thousands kilometers long. It is possible to suggest that the reason of the accumulation of considerable local shift deformations is the change of the velocity of the tectonic motion in some or other parts of fractures as a result of different physical, chemical and mechanical processes. Nowadays, the range precision of Satellite Laser Ranging (SLR technique reaches a few millimeters level. Therefore, the space geodesy technique becomes a very important tool in detecting and monitoring recent crustal movements. Regular repeated measurements of the baselines between some stations on different plates give the possibility to construct precise and detail models of crustal movements. In this paper, the length of four baselines between Helwan-SLR station and other four SLR stations are calculated using satellite geodetical technique.

  11. The International Exchange of Students: Problems and Solutions at the Riga Technical University

    Directory of Open Access Journals (Sweden)

    Janis Strauhmanis

    2007-12-01

    Full Text Available The international exchange of students plays an important role in acquisition of new knowledge and skills. However, it was possible to start implementing such exchange programmes at the Riga Technical University only in 1991 after the reestablishment of the Department of Geodesy.  Currently, the Riga Technical University cooperates with several countries in implementing exchange programmes of students. The main problems encountered in this process are similar: inadequate foreign language skills, a lack of internationally recognized coursebooks and other study materials, insufficient cooperation between the universities that implement exchange programmes. These problems should be addressed by creating a working group and expanding cooperation, as well as enhancing requirements for students who participate in the exchange programmes.

  12. Best Student Papers for 1987 Spring Meeting

    Science.gov (United States)

    As they did at previous national meetings, several AGU sections selected Best Student Papers at the 1987 Spring Meeting in Baltimore, Md., during May 1987 as a means of encouraging student participation.Pal Wessel was selected by the Geodesy Section to receive their Best Student Paper Award for his paper entitled “Global Gravity Crossover Corrections: Implications and Applications,” which was coauthored by A. B. Watts (Lamont-Doherty Geological Observatory (LDGO), Palisades, N.Y.). Wessel received his B.Sc. (1982) and M.S. (1984) from the University of Oslo, Norway, in applied geophysics, while working on inversion of gravity anomalies over a continental rift (Oslo Graben). He is currently a Ph.D. candidate at LDGO. Wessel's research in gravity includes statistical analysis of shipboard gravity data, gridding algorithms, and computation of gravimetric geoids. He is also working on flexre of young oceanic lithosphere caused by thermal stresses.

  13. Operational aspects of CASA UNO '88-The first large scale international GPS geodetic network

    Science.gov (United States)

    Neilan, Ruth E.; Dixon, T. H.; Meehan, Thomas K.; Melbourne, William G.; Scheid, John A.; Kellogg, J. N.; Stowell, J. L.

    1989-01-01

    For three weeks, from January 18 to February 5, 1988, scientists and engineers from 13 countries and 30 international agencies and institutions cooperated in the most extensive GPS (Global Positioning System) field campaign, and the largest geodynamics experiment, in the world to date. This collaborative eperiment concentrated GPS receivers in Central and South America. The predicted rates of motions are on the order of 5-10 cm/yr. Global coverage of GPS observations spanned 220 deg of longitude and 125 deg of latitude using a total of 43 GPS receivers. The experiment was the first civilian effort at implementing an extended international GPS satellite tracking network. Covariance analyses incorporating the extended tracking network predicted significant improvement in precise orbit determination, allowing accurate long-baseline geodesy in the science areas.

  14. Calibration of Geodetic Instruments

    Directory of Open Access Journals (Sweden)

    Marek Bajtala

    2005-06-01

    Full Text Available The problem of metrology and security systems of unification, correctness and standard reproducibilities belong to the preferred requirements of theory and technical practice in geodesy. Requirements on the control and verification of measured instruments and equipments increase and the importance and up-to-date of calibration get into the foreground. Calibration possibilities of length-scales (of electronic rangefinders and angle-scales (of horizontal circles of geodetic instruments. Calibration of electronic rangefinders on the linear comparative baseline in terrain. Primary standard of planar angle – optical traverse and its exploitation for calibration of the horizontal circles of theodolites. The calibration equipment of the Institute of Slovak Metrology in Bratislava. The Calibration process and results from the calibration of horizontal circles of selected geodetic instruments.

  15. Ontological Engineering for the Cadastral Domain

    DEFF Research Database (Denmark)

    Stubkjær, Erik; Stuckenschmidt, Heiner

    2000-01-01

    conceptualization of the world is that much information remains implicit. Ontologies have set out to overcome the problem of implicit and hidden knowledge by making the conceptualization of a domain (e.g. mathematics) explicit. Ontological engineering is thus an approach to achieve a conceptual rigor......The term 'ontology' has been used in many ways and across different communities. In th following we will introduce ontologies as an explication of some shared vocabulary or conceptualization of a specific subject matter. The main problem with the use of a shared vocabulary according to a specific...... that characterizes established academic disciplines, like geodesy. Many university courses address more application oriented fields, like cadastral law, and spatial planning, and they may benefit from the ontological engineering approach. The paper provides an introduction to the field of ontological engineering...

  16. The surveyors' quest for perfect alignment

    CERN Multimedia

    2003-01-01

    Photogrammetry of a CMS endcap and part of the hadronic calorimeter.The structure was covered with targets photographed by digital cameras. Perfect alignment.... Although CERN's surveyors do not claim to achieve it, they are constantly striving for it and deploy all necessary means to come as close as they can. In their highly specialised field of large-scale metrology, the solution lies in geodesy and photogrammetry, both of which are based on increasingly sophisticated instruments and systems. In civil engineering, these techniques are used for non-destructive inspection of bridges, dams and other structures, while industrial applications include dimensional verification and deformation measurement in large mechanical assemblies. The same techniques also come into play for the metrology of research tools such as large telescopes and of course, particle accelerators. Particle physics laboratories are especially demanding customers, and CERN has often asked for the impossible. As a result, the alignment metro...

  17. The Goal of the IAU/IAG Joint Working Group on the Theory of Earth Rotation

    Science.gov (United States)

    Ferrandiz, J. M.; Gross, R. S.

    2013-01-01

    In 2012 the International Association of Geodesy (IAG) and the International Astronomical Union (IAU) initiated a process to establish a Joint Working Group (JWG) on theory of Earth rotation with the purpose of promoting the development of improved theories of the Earth rotation which reach the accuracy required to meet the needs of the near future as recommended by, e.g. GGOS, the Global Geodetic Observing System of the IAG. The JWG was approved by both organizations in April 2013 with the chairs being the two authors of this paper. Its structure comprises three Sub Working Groups (SWGs) addressing Precession/Nutation, Polar Motion and UT1, the Numerical Solutions and Validation, respectively. The SWGs should work in parallel for the sake of efficiency, but should keep consistency as an overall goal. This paper offers a view of the objectives and scope of the JWG and reports about its initial activities and plans.

  18. Exact relativistic theory of geoid's undulation

    CERN Document Server

    Kopeikin, Sergei; Karpik, Alexander

    2014-01-01

    Precise determination of geoid is one of the most important problem of physical geodesy. The present paper extends the Newtonian concept of the geoid to the realm of Einstein's general relativity and derives an exact relativistic equation for the unperturbed geoid and level surfaces under assumption of axisymmetric distribution of background matter in the core and mantle of the Earth. We consider Earth's crust as a small disturbance imposed on the background distribution of matter, and formulate the master equation for the anomalous gravity potential caused by this disturbance. We find out the gauge condition that drastically simplifies the master equation for the anomalous gravitational potential and reduces it to the form closely resembling the one in the Newtonian theory. The master equation gives access to the precise calculation of geoid's undulation with the full account for relativistic effects not limited to the post-Newtonian approximation. The geoid undulation theory, given in the present paper, uti...

  19. Towards an exact relativistic theory of Earth's geoid undulation

    Energy Technology Data Exchange (ETDEWEB)

    Kopeikin, Sergei M., E-mail: kopeikins@missouri.edu [Department of Physics & Astronomy, University of Missouri, Columbia, MO 65211 (United States); Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation); Mazurova, Elena M., E-mail: e_mazurova@mail.ru [Moscow State University of Geodesy and Cartography, 4 Gorokhovsky Alley, Moscow 105064 (Russian Federation); Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation); Karpik, Alexander P., E-mail: rector@ssga.ru [Siberian State Geodetic Academy, 10 Plakhotny St., Novosibirsk 630108 (Russian Federation)

    2015-08-14

    The present paper extends the Newtonian concept of the geoid in classic geodesy towards the realm of general relativity by utilizing the covariant geometric methods of the perturbation theory of curved manifolds. It yields a covariant definition of the anomalous (disturbing) gravity potential and formulates differential equation for it in the form of a covariant Laplace equation. The paper also derives the Bruns equation for calculation of geoid's height with full account for relativistic effects beyond the Newtonian approximation. A brief discussion of the relativistic Bruns formula is provided. - Highlights: • We apply general relativity to define the exact concept of relativistic geoid. • We derive relativistic equation of geoid and the reference level surface. • We employ the manifold perturbation theory to discuss geoid's undulation.

  20. Attosecond Precision Multi-km Laser-Microwave Network

    CERN Document Server

    Xin, M; Peng, M Y; Kalaydzhyan, A; Wang, W; Muecke, O D; Kaertner, F X

    2016-01-01

    Synchronous laser-microwave networks consisting of many optical and microwave sources distributed over km-distances are crucial for scientific efforts requiring highest spatio-temporal resolution. However, present synchronization techniques limit these networks to 10-fs relative timing jitter between their sub-sources. Here, we present a novel 4.7 km laser-microwave network with attosecond precision for over tens of hours of continuous operation. It is achieved through new metrological devices and careful balancing of fiber nonlinearities and fundamental noise contributions. This work may enable next-generation attosecond photon-science facilities to revolutionize many research fields from structural biology to material science and chemistry to fundamental physics. It will also accelerate the development in other research areas requiring high spatio-temporal resolution such as geodesy, very-long-baseline interferometry, high-precision navigation and multi-telescope arrays.

  1. Computer Programs for Prediction of Mining Area Deformation with Time Factor Taken into Consideration

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper discussed the current of works on computerisation of all problems related to mining subsidence, including the time factor,carried out in the Division of Mining Geodesy of Technical University of Silesia, Poland. First, the formulas implemented in the programs were presented. These formulas considerably increase the description accuracy of final deformations by taking into uncaved strip along extraction rib (extraction margin). They also improve the deformation description of areas located far from the extraction place. Then, the research results aiming to improving the description of deformation with time were introduced. Finally, the Windows-based version of the program for the creation of mining-geological opinions were presented in the form accepted by Mining Offices of Poland.

  2. On The Accuracy Of Current Mean Sea Surface Models For The Use With Goce Data

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Rio, M. H.

    2011-01-01

    The mean sea surface (MSS) is a fundamental parameter in geodesy and physical oceanography and knowledge about the error on the MSS is fundamental for the interpretation of GOCE geoid model for the study of large scale ocean circulation. The MSS is the sum of the geoid height G and the temporal...... mean of the ocean mean dynamic topography (MDT) like MSS = G + MDT, where the MDT is the quantity bridging the geoid and the MSS and the quantity constraining large scale ocean circulation. In order to evaluate the accurate of satellite derived ocean currents from the difference between the MSS...... and the new and future GOCE geoids it is of fundamental importance to know the error on the MSS. In this presentation, preliminary results investigating the various contributions to MSS model differences as well as quantifying the various contributions to the total MSS error are characterized and the error...

  3. First champ mission results for gravity, magnetic and atmospheric studies

    CERN Document Server

    Lühr, Hermann; Schwintzer, Peter

    2003-01-01

    In the summer of 2000 the German geo-research satellite CHAMP was launched into orbit. Its innovative payload arrangement and the low intial orbit allow CHAMP to simultaneously collect and almost continuously analyse precise data relating to gravity and magnetic fields at low altitude. In addition to this CHAMP also measures the neutral atmosphere and ionosphere using GPS techniques. Eighteen months after the launch, CHAMP research groups from all over the world met at the Geo-Forschungs-Zentrum in Potsdam for an initial exchange of experiences and results. The main outcome of this user meeting is summarized in this volume. Apart from technical information about the mission, the book offers a comprehensive insight into the present status of CHAMP data exploitation for Earth system research and practical applications in geodesy, geophysics and meteorology.

  4. International radiation commissions 1896 to 2008. Research into atmospheric radiation from IMO to IAMAS

    Energy Technology Data Exchange (ETDEWEB)

    Bolle, H.J. (comp.); Moeller, F.; London, J.

    2008-05-15

    The document covers a historical compilation on research into atmospheric radiation from 1896 to 2008. The first part is a brief history of the radiation commissions of IMO (International Meteorological Organization) and IUGG (International Union of Geodesy and Geophysics) for the period 1824 to 1948. Part 2 Covers the International Radiation Commission (IRC) of IAM (International Association of Meteorology)/IAMAS (International Association of Meteorology and Atmospheric Sciences)/IAMAP (International Association of Meteorology and Atmospheric Physics); the Re-constitution of the IUGG Radiation Commision, the Officers of the International Radiation Commission of IUUG 1948-2008, and the activities of the Radiation Commision of the IUGG 1948-2008. The appendices include the Radiation Commission Members, the summaries of presented papers from 1954 and 1957, the IRC publications, and acronyms.

  5. The RAEGE VLBI2010 radiotelescopes

    Science.gov (United States)

    Sust, Eberhard; López Fernández, José Antonio

    2012-09-01

    The goal of the RAEGE (Red Atlantica Estaciones Geodinamicas Espaciales) project is the establishment of a Spanish-Portuguese network of geodynamical and spatial geodesy stations by the installation and operation of four fundamental geodetic / astronomical stations provided with radio telescopes located at - Yebes, close to Madrid / Spain - Tenerife, Canary Islands / Spain - Santa Maria, Azores Islands / Portugal. VLBI 2010 radiotelescopes are belonging to a new generation of radiotelescopes suitable for high precision geodetical earth observation and measurements, that shall allow to built up a high precision global reference system. The design of the radiotelescopes has been finished by MT Mechatronics in summer 2011 and currently three radiotelescopes are being manufactured. The first one is scheduled for installation in summer 2012 at Yebes Observatory close to Madrid.

  6. Erdmessung mit Quanten und Relativit\\"at

    CERN Document Server

    Müller, Jürgen

    2016-01-01

    Recent developments in fundamental physics (in theory as well as in technology) provide novel capabilities for geodetic applications such as refined observations of the Earth`s gravity field. We will focus on two new concepts: one applies atomic interferometry for (satellite) gravimetry, the other uses clock measurements for observing potential values. In the first case, gravity anomalies are determined by observing free-falling atoms (quantum gravimetry), such technique can also be applied for future gradiometric measurements in space. In the second case according to Einstein`s theory of general relativity, frequency comparisons of highly precise optical clocks give access to differences of the gravity potential, even over long distances (relativistic geodesy). Also laser interferometry between test masses in space with nanometer accuracy belongs to these novel concepts. For the latter, technology developed for gravitational wave detection and successfully tested in the LISA/pathfinder mission is being prepa...

  7. François Arago a 19th century French humanist and pioneer in astrophysics

    CERN Document Server

    Lequeux, James

    2016-01-01

    François Arago, the first to show in 1810 that the surface of the Sun and stars is made of incandescent gas and not solid or liquid, was a prominent physicist of the 19th century. He used his considerable influence to help Fresnel, Ampere and others develop their ideas and make themselves known. This book covers his personal contributions to physics, astronomy, geodesy and oceanography, which are far from negligible, but insufficiently known. Arago was also an important and influential political man who, for example, abolished slavery in the French colonies. One of the last humanists, he had a very broad culture and range of interests. In parallel to his biography, this title also covers the spectacular progresses of science at the time of Arago, especially in France: the birth of physical optics, electromagnetism and thermodynamics. Francois Arago’s life is a fascinating epic tale that reads as a novel.

  8. Focus Upon Implementing the GGOS Decadal Vision for Geohazards Monitoring

    Science.gov (United States)

    LaBrecque, John; Stangl, Gunter

    2017-04-01

    The Global Geodetic Observing System of the IAG identified present and future roles for Geodesy in the development and well being of the global society. The GGOS is focused upon the development of infrastructure, information, analysis, and educational systems to advance the International Global Reference Frame, the International Celestial Reference System, the International Height Reference System, atmospheric dynamics, sea level change and geohazards monitoring. The geohazards initiative is guided by an eleven nation working group initially focused upon the development and integration of regional multi-GNSS networks and analysis systems for earthquake and tsunami early warning. The opportunities and challenges being addressed by the Geohazards working group include regional network design, algorithm development and implementation, communications, funding, and international agreements on data access. This presentation will discuss in further detail these opportunities and challenges for the GGOS focus upon earthquake and tsunami early warning.

  9. Static loading and vertical displacement at southern Siberia

    Directory of Open Access Journals (Sweden)

    Anton V. Timofeev

    2017-05-01

    Full Text Available Seismic method is usually used for elastic parametric estimation. This is why this method presents dynamic parameters of Earth. Frequency seismic range changes greatly from geodynamic modelling time. Now we have opportunity to use geodesy result for some years for elastic parameters estimation. Static solution from elastic theory may be used for the interpretation of long term results. It presents static elastic parameter. The inverse problem for different types of vertical surface loading on one year period is calculated. Two cases of loading with maximal and minimal area are presented. Results are determined by space geodesy and leveling methods. Current relation between atmospheric pressure and vertical displacements was estimated at the center of Siberian Anti Cyclone with size varied from 2000 km to 3000 km. Pressure-displacement coefficients (PDC can be achieved by three years observation (0.997 mm/mbar for NVSK GPS station. It is used for elastic module study of geology medium with maximum thickness up to 600 km. In the context of elastic model, the modulus of rigidity is estimated to be 113 GPa. Vast expanse of anti-cyclone may relate with rheology of crust and upper mantle. Smaller size of surface loading – local loading is seasonal variation of water reservoir. Annual vertical changes were obtained by leveling near the dam of the reservoir. PDC ratio was 1.15 mm/bar for these places. In elastic theory, the Young modulus E = 80 GPa (Poisson ratio = 0.25, the modulus of rigidity = 32 GPa was calculated by sixteen years of leveling measurements. This result can effectively be represented for upper crust. Our results were checked by solution for coseismic displacement of Chyia-Altai earthquake (Sep. 27, 2003, M = 7.3. Coseismic results calculated by static modules agree with experimental coseismic GPS data at 10% level.

  10. GOCE User Toolbox and Tutorial

    Science.gov (United States)

    Benveniste, Jérôme; Knudsen, Per

    2016-07-01

    The GOCE User Toolbox GUT is a compilation of tools for the utilisation and analysis of GOCE Level 2 products. GUT support applications in Geodesy, Oceanography and Solid Earth Physics. The GUT Tutorial provides information and guidance in how to use the toolbox for a variety of applications. GUT consists of a series of advanced computer routines that carry out the required computations. It may be used on Windows PCs, UNIX/Linux Workstations, and Mac. The toolbox is supported by The GUT Algorithm Description and User Guide and The GUT Install Guide. A set of a-priori data and models are made available as well. Without any doubt the development of the GOCE user toolbox have played a major role in paving the way to successful use of the GOCE data for oceanography. The GUT version 2.2 was released in April 2014 and beside some bug-fixes it adds the capability for the computation of Simple Bouguer Anomaly (Solid-Earth). During this fall a new GUT version 3 has been released. GUTv3 was further developed through a collaborative effort where the scientific communities participate aiming on an implementation of remaining functionalities facilitating a wider span of research in the fields of Geodesy, Oceanography and Solid earth studies. Accordingly, the GUT version 3 has: - An attractive and easy to use Graphic User Interface (GUI) for the toolbox, - Enhance the toolbox with some further software functionalities such as to facilitate the use of gradients, anisotropic diffusive filtering and computation of Bouguer and isostatic gravity anomalies. - An associated GUT VCM tool for analyzing the GOCE variance covariance matrices.

  11. Spatial and Spectral Representations of the Geoid-to-Quasigeoid Correction

    Science.gov (United States)

    Tenzer, Robert; Hirt, Christian; Claessens, Sten; Novák, Pavel

    2015-09-01

    In geodesy, the geoid and the quasigeoid are used as a reference surface for heights. Despite some similarities between these two concepts, the differences between the geoid and the quasigeoid (i.e. the geoid-to-quasigeoid correction) have to be taken into consideration in some specific applications which require a high accuracy. Over the world's oceans and marginal seas, the quasigeoid and the geoid are identical. Over the continents, however, the geoid-to-quasigeoid correction could reach up to several metres especially in the mountainous, polar and geologically complex regions. Various methods have been developed and applied to compute this correction regionally in the spatial domain using detailed gravity, terrain and crustal density data. These methods utilize the gravimetric forward modelling of the topographic density structure and the direct/inverse solutions to the boundary-value problems in physical geodesy. In this article, we provide a brief summary of existing theoretical and numerical studies on the geoid-to-quasigeoid correction. We then compare these methods with the newly developed procedure and discuss some numerical and practical aspects of computing this correction. In global applications, the geoid-to-quasigeoid correction can conveniently be computed in the spectral domain. For this purpose, we derive and present also the spectral expressions for computing this correction based on applying methods for a spherical harmonic analysis and synthesis of global gravity, terrain and crustal structure models. We argue that the newly developed procedure for the regional gravity-to-potential conversion, applied for computing the geoid-to-quasigeoid correction in the spatial domain, is numerically more stable than the existing inverse models which utilize the gravity downward continuation. Moreover, compared to existing spectral expressions, our definition in the spectral domain takes not only the terrain geometry but also the mass density heterogeneities

  12. Tearing the terroir: Details and implications of surface rupture and deformation from the 24 August 2014 M6.0 South Napa earthquake, California

    Science.gov (United States)

    DeLong, Stephen B.; Donnellan, Andrea; Ponti, Daniel J.; Rubin, Ron S.; Lienkaemper, James J.; Prentice, Carol S.; Dawson, Timothy E.; Seitz, Gordon G.; Schwartz, David P.; Hudnut, Kenneth W.; Rosa, Carla M.; Pickering, Alexandra J; Parker, Jay W.

    2016-01-01

    The Mw 6.0 South Napa earthquake of 24 August 2014 caused slip on several active fault strands within the West Napa Fault Zone (WNFZ). Field mapping identified 12.5 km of surface rupture. These field observations, near-field geodesy and space geodesy, together provide evidence for more than ~30 km of surface deformation with a relatively complex distribution across a number of subparallel lineaments. Along a ~7 km section north of the epicenter, the surface rupture is confined to a single trace that cuts alluvial deposits, reoccupying a low-slope scarp. The rupture continued northward onto at least four other traces through subparallel ridges and valleys. Postseismic slip exceeded coseismic slip along much of the southern part of the main rupture trace with total slip 1 year postevent approaching 0.5 m at locations where only a few centimeters were measured the day of the earthquake. Analysis of airborne interferometric synthetic aperture radar data provides slip distributions along fault traces, indicates connectivity and extent of secondary traces, and confirms that postseismic slip only occurred on the main trace of the fault, perhaps indicating secondary structures ruptured as coseismic triggered slip. Previous mapping identified the WNFZ as a zone of distributed faulting, and this was generally borne out by the complex 2014 rupture pattern. Implications for hazard analysis in similar settings include the need to consider the possibility of complex surface rupture in areas of complex topography, especially where multiple potentially Quaternary-active fault strands can be mapped.

  13. Pleistocene slip rates on the Boconó fault along the North Andean Block plate boundary, Venezuela

    Science.gov (United States)

    Pousse-Beltran, Lea; Vassallo, Riccardo; Audemard, Franck; Jouanne, François; Carcaillet, Julien; Pathier, Erwan; Volat, Matthieu

    2017-07-01

    The Boconó fault is a strike-slip fault lying between the North Andean Block and the South American plate which has triggered at least five Mw > 7 historical earthquakes in Venezuela. The North Andean Block is currently moving toward NNE with respect to a stable South American plate. This relative displacement at 12 mm yr-1 in Venezuela (within the Maracaibo Block) was measured by geodesy, but until now the distribution and rates of Quaternary deformation have remained partially unclear. We used two alluvial fans offset by the Boconó fault (Yaracuy Valley) to quantify slip rates, by combining 10Be cosmogenic dating with measurements of tectonic displacements on high-resolution satellite images (Pleiades). Based upon a fan dated at >79 ka and offset by 1350-1580 m and a second fan dated at 120-273 ka and offset by 1236-1500 m, we obtained two Pleistocene rates of 5.0-11.2 and <20.0 mm yr-1, consistent with the regional geodesy. This indicates that the Boconó fault in the Yaracuy Valley accommodates 40 to 100% of the deformation between the South American plate and the Maracaibo Block. As no aseismic deformation was shown by interferometric synthetic aperture radar analysis, we assume that the fault is locked since the 1812 event. This implies that there is a slip deficit in the Yaracuy Valley since the last earthquake ranging from 1 to 4 m, corresponding to a Mw 7-7.6 earthquake. This magnitude is comparable to the 1812 earthquake and to other historical events along the Boconó fault.

  14. COPERNICUS – PRACTICE OF DAILY LIFE IN A NATIONAL MAPPING AGENCY?

    Directory of Open Access Journals (Sweden)

    T. Wiatr

    2016-06-01

    Full Text Available Copernicus is an European system created for Earth observation and monitoring. It consists of a set of Earth observation satellites and in-situ sensors that provide geo-information that are used, through a set of Copernicus services, for applications related to the environment and global security. The main services of the Copernicus programme address six thematic areas: land, marine, atmosphere, climate change, emergency management and security. In Germany, there is a national service team of Copernicus service coordinators, who are responsible for the national development of the Copernicus services and for providing user-specific information about the Copernicus processes. These coordinators represent the contact points for all the programmes and services concerning their respective Copernicus theme. To publish information about Copernicus, national conferences and workshops are organised. Many people are involved in planning the continuous process of bringing the information to public authorities, research institutes and commercial companies. The Federal Agency for Cartography and Geodesy (Bundesamt für Kartographie und Geodäsie, BKG is one such organisation, and is mainly responsible for the national land monitoring service of Copernicus. To make use of the freely available data from the Copernicus programme, the Federal Agency for Cartography and Geodesy is currently developing new applications and projects in the field of remote sensing and land monitoring. These projects can be used by other public authorities as examples on how to use the Copernicus data and services for their individual demands and requirements. Copernicus data and services are currently not very commonly used in the daily routine of the national mapping agencies, but they will soon be.

  15. Expansion of geographic information components in the educational programs of cartographers at Taras Shevchenko National University of Kyiv

    Directory of Open Access Journals (Sweden)

    Людмила Даценко

    2017-09-01

    Full Text Available The article considers the necessity to make changes in the university curriculum in accordance with the requirements of today. Modern cartography is integrated with GIS and remote sensing and in this context we see the prospect of training experts at universities. GIS education has some specific features that distinguish it from other types of training such as the interdisciplinary nature, a wide range of highly informative software applications, a combination of geographical and engineering knowledge. GIS specialists must have system knowledge and skills in the design, operation and development in this field. Only intensive use of mapping, GIS, geodetic, and photogrammetric knowledge and methods in scientific research and their effective use in the practice of modern production allow the international community to achieve high results. The main directions of educational programs at the Department of Geodesy and Cartography are preservation and further development of the rich heritage of scientific and pedagogical achievements of higher cartographical education in Ukraine; the study and involvement in the educational process of the best achievements of foreign higher education; preparation and updating of scientific and methodological support of educational process; modernization of material and technical basis for the learning process and field training practices; involvement of new professional teaching staff; training of the faculty staff. The demand on mapping courses and related workshops at the Department of Geodesy and Cartography Geography Department is determined by certain factors: the growth of interdisciplinary research involving extensive mapping component; growing of demand for mapping and GIS products from scientific, practical, commercial, and educational institutions; the need to increase productivity in the field of cartography, geoinformatics and adjacent to their fields of study and practice; issues of general improvement of

  16. Current Situation of AFREF and First Results from GNSS Networks in Africa

    Science.gov (United States)

    Mahmoud, Salah; Farah, Hussein; Wonnacott, Richard

    2016-07-01

    The African Geodetic Reference Frame (AFREF) is conceived as a unified geodetic reference frame for Africa. It will be the fundamental basis for the national three-dimensional reference networks fully consistent and homogeneous with the International Terrestrial Reference Frame (ITRF). When fully implemented, its backbone will consist of a network of continuous, permanent GPS stations such that a user anywhere in Africa would have free access to, and would be at most 1000km from, such stations. Full implementation will include a unified vertical datum and support for efforts to establish a precise African geoid, in concert with the African Geoid project activities. The realization of AFREF has vast potentials for geodesy, mapping, surveying, geoinformation, natural hazards mitigation, earth sciences, etc. Its implementation will provide a major springboard for the transfer and enhancement of skills in surveying and geodesy and especially GPS technology and applications. AFREF is, therefore, an African initiative to unify the geodetic reference frames of Africa based on the ITRF through a network of GNSS base stations at a spacing such users will be at most within ~1000 km of a base station. First Reference Frame Solution of about 80 geodetic GPS stations in Africa has been started in February 2013 at some processing centers in Europe and Africa. Results of independent solutions being developed by various African scientific teams: Hart RAO, South Africa; Ardhi University, Tanzania and SEGAL, University of Beria Interior, Portugal, show an accuracy of aligned ITRF 2008 using 42 IGS stations in E and N components with 3.0 mm and in U component 7.5 mm.

  17. The GOCE User Toolbox (GUT) and Tutorial

    Science.gov (United States)

    Bingham, R. J.; Benveniste, J.; Knudsen, P.

    2015-12-01

    The GOCE User Toolbox (GUT) is an integrated suite of tools for the analysis and use of GOCE Level 2 gravity products. GUT supports applications in geodesy, oceanography and solid earth physics. The accompanying GUT tutorial provides information and guidance on how to use the toolbox for a variety of applications within each of these domains. An important motivation for the development of GUT has been the desire that users should be able to exploit the GOCE gravity products to calculate derived products relevant to their particular domains without necessarily needing to understand the technicalities of particular geodetic concepts and algorithms. As such, GUT is also suitable for use as an aid to the teaching of geophysics. A comprehensive and up-to-date set of a-priori data and models are supplied with the toolbox, together with a range of pre-defined workflows, allowing the user to immediately calculate useful geophysical quantities. The toolbox is supported by The GUT Algorithm Description and User Guide and The GUT Install Guide. GUT is cross-platform and may be used on Windows PCs, UNIX/Linux workstations and Macs. GUT version 2.2 was released in April 2014 and, besides some bug-fixes, the capability to calculate the simple Bouguer anomaly was added. Recently, GUT version 3 has been released. Through a collaborative effort between the relevant scientific communities, this version has built on earlier releases by further extending the functionality of the toolbox within the fields of geodesy, oceanography and solid earth physics. Additions include the ability to work directly with gravity gradients, anisotropic diffusive filtering, and the computation of Bouguer and isostatic gravity anomalies. The interface between the user and the toolbox has also been greatly improved and GUT version 3 now includes an attractive and intuitive Graphical User Interface. An associated GUT VCM tool for analysing the GOCE variance covariance matrices is also available.

  18. Societal challenges-oriented data-rich undergraduate teaching resources for geoscience classrooms and field courses

    Science.gov (United States)

    Pratt-Sitaula, B. A.; Walker, B.; Douglas, B. J.; Crosby, B. T.; Charlevoix, D. J.; Crosby, C. J.; Shervais, K.

    2016-12-01

    The NSF-funded GEodesy Tools for Societal Issues (GETSI) project is developing modules for use in introductory and majors-level courses that emphasize a broad range of geodetic data and quantitative skills applied to societally important issues of climate change, natural hazards, and water resources (serc.carleton.edu/getsi). The modules fill gaps in existing undergraduate curricula, which seldom include geodetic methods. Published modules are "Ice mass and sea level changes", "Imaging active tectonics with LiDAR and InSAR", "Measuring water resources with GPS, gravity, and traditional methods", "Surface process hazards", and "GPS, strain, and earthquakes". The GETSI Field Collection features geodetic field techniques. The field-oriented module "Analyzing high resolution topography with terrestrial laser scanning (TLS) and structure from motion (SfM)" is already published and "High precision positioning with static and kinematic GPS" will be published in 2017. Modules are 1-3 weeks long and include student exercises, data analysis, and extensive supporting materials. For field modules, prepared data sets are provided for courses that cannot collect field data directly. All modules were designed and developed by teams of faculty and content experts and underwent rigorous review and classroom testing. Collaborating institutions are UNAVCO (which runs NSF's Geodetic Facility), Indiana University, Mt San Antonio College, and Idaho State University. Science Education Resource Center (SERC) is providing assessment and evaluation expertise. If future funding is successful, the topic range will be expanded (e.g., volcanic hazards, more water resources, and ecological applications of geodesy). Funding to date has been provided by NSF's TUES (Transforming Undergraduate Education in STEM) and IUSE (Improving Undergraduate STEM Education).

  19. Orthogonality of Harmonic Potentials and Fields in Spheroidal Coordinates (Petrus Peregrinus Medal Lecture)

    Science.gov (United States)

    Lowes, F. J.

    2012-04-01

    Spherical harmonic scalar potentials are the independent solutions of the Laplace equation relevant in a spherical geometry; they are used widely in global geomagnetism and geodesy to represent the situation in the source-free region outside the Earth. It is well known that these harmonics are orthogonal over the sphere, as are the vector fields that are the gradients of the harmonics. If we have data (potential or field) over the sphere, this orthogonality enables us to use spherical harmonic analysis to determine separately the numerical coefficient relevant for each harmonic potential. But the Earth is better approximated by an oblate spheroid; and for sources near the surface it is more relevant to use a spheroidal coordinate system; in this case the appropriate solutions of the Laplace equation are now spheroidal harmonics. However these SPHEROIDAL harmonics are NOT orthogonal over the SPHEROID, and neither are the corresponding vector potential gradients. I show how this problem can be overcome by using an appropriate weighting factor that depends only on colatitude; the factor is different for potential and for field. By using the appropriate weighting factor it is then possible to do the spheroidal equivalent of spherical harmonic analysis, either for the scalar potential or the corresponding vector field. In the spherical case, because of the orthogonality it is possible to separate the total mean-square potential over the sphere into parts contributed by harmonics of different degrees, e.g. the 'degree variance' in geodesy. Similarly, in geomagnetism we have the 'power spectrum' that separates the total mean-square vector field into contributions from different degrees. But in the spheroidal case such a separation (of potential or field) is possible only if we use a WEIGHTED mean-square.

  20. MarsTwin: an M-mission to Mars with two geophysical laboratories

    Science.gov (United States)

    Dehant, V. M.; Breuer, D.; Grott, M.; Spohn, T.; Lognonne, P.; Read, P. L.; Vennerstroem, S.; Banerdt, B.

    2010-12-01

    Mars-Twin - a mission proposed for the running ESA cosmic vision M call - if selected it will be the first European mission to focus on interior processes and the early evolution of Mars, providing essential constraints for models of the thermal, geochemical, and geologic evolution of Mars and for a better understanding of SNC meteorites and future samples from Mars. Our fundamental understanding of the interior of the Earth comes from geophysics, geodesy, geochemistry, geomagnetism, and petrology. For geophysics, seismology, geodesy, magnetic field measurements, and surface heat flow have revealed the basic internal layering of the Earth, its thermal structure, its gross compositional stratification, as well as significant lateral variations in these quantities. The landers will also provide meteorological stations to monitor the Martian meteorology and climate and to obtain new measurements in the Martian boundary layer. The Mars-Twin mission will fill a longstanding gap in the scientific exploration of the solar system by performing an in-situ investigation of the interior of an Earth-like planet other than our own. Mars-Twin will provide unique and critical information about the fundamental processes of terrestrial planet formation and evolution. This investigation has been ranked as a high priority in virtually every set of European, US and international high-level planetary science recommendations for the past 30 years, and the objectives for the Mars-Twin mission are derived directly from these recommendations. In addition to geophysics, the mission will provide important constraints for the Astrobiology of Mars by helping to understand why Mars fails to have a magnetic field, by helping to understand the evolution of the climate, and by providing a limit to the chemoautrophic biosphere through a measurement of the heat flow. The paper will also address the synergy between the lander instruments and the possible orbiter instruments.

  1. Copernicus - Practice of Daily Life in a National Mapping Agency?

    Science.gov (United States)

    Wiatr, T.; Suresh, G.; Gehrke, R.; Hovenbitzer, M.

    2016-06-01

    Copernicus is an European system created for Earth observation and monitoring. It consists of a set of Earth observation satellites and in-situ sensors that provide geo-information that are used, through a set of Copernicus services, for applications related to the environment and global security. The main services of the Copernicus programme address six thematic areas: land, marine, atmosphere, climate change, emergency management and security. In Germany, there is a national service team of Copernicus service coordinators, who are responsible for the national development of the Copernicus services and for providing user-specific information about the Copernicus processes. These coordinators represent the contact points for all the programmes and services concerning their respective Copernicus theme. To publish information about Copernicus, national conferences and workshops are organised. Many people are involved in planning the continuous process of bringing the information to public authorities, research institutes and commercial companies. The Federal Agency for Cartography and Geodesy (Bundesamt für Kartographie und Geodäsie, BKG) is one such organisation, and is mainly responsible for the national land monitoring service of Copernicus. To make use of the freely available data from the Copernicus programme, the Federal Agency for Cartography and Geodesy is currently developing new applications and projects in the field of remote sensing and land monitoring. These projects can be used by other public authorities as examples on how to use the Copernicus data and services for their individual demands and requirements. Copernicus data and services are currently not very commonly used in the daily routine of the national mapping agencies, but they will soon be.

  2. Obituary: Soren W. Henriksen (1916-2011)

    Science.gov (United States)

    Chovitz, Bernard

    2011-12-01

    Soren Werner Henriksen, one of the first to apply space age data to the mapping sciences, died September 5, 2011, at the age of 95. He was a polymath in the fields of geodesy, surveying, photogrammetry, cartography, and astronomy, his culminating achievement being "Glossary of the Mapping Sciences" a 581 page compendium published in 1994. Soren was born in New York, New York, on August 5, 1916, and grew up in Chicago, Illinois. In 1938 he joined the Illinois National Guard, and transferred in 1941 to the U. S. Army. He served until August 1945, after being severely wounded in the Philippines that summer. He entered the Illinois Institute of Technology next year, earning a Bachelor's degree in 1949 in mathematics. A Master's degree from the University of Illinois in 1950, continuing in mathematics, followed. The U. S. Army Map Service (AMS), a component of the Army Corps of Engineers, was actively recruiting mathematicians at that time. The exigencies of the Cold War required improvements in knowledge of the figure of the Earth, intercontinental connections, and the Earth's gravity field. Soren joined AMS in 1951 and was assigned to the Occultation Section of the Research and Analysis Branch in the Geodetic Division. This was his fortuitous introduction to professional astronomy. He was lucky to have a first-rate mentor in John O'Keefe (BAAS, 2000. 32, 1683), the head of the Branch, whose expertise lay in the application of astronomical methods for position determination, in particular, lunar occultations and solar eclipses. Soren rapidly applied his mathematical skills to this area, and in 1955 was promoted to Chief of the Section. In addition to his operational duties of analyzing and reducing observational data, he authored the definitive manual on the subject: "The Application of Occultations to Geodesy," published as AMS Technical Report 46 in 1962. Well before the first artificial satellite launch in 1957 O'Keefe had realized the tremendous advantage of

  3. The EarthScope Plate Boundary Observatory (PBO) Facility: Innovations, Transformations, and Impact

    Science.gov (United States)

    Jackson, M. E.; Mencin, D.; Feaux, K.

    2013-12-01

    The word 'transformation' is not used lightly in science. However, the transformative nature of the EarthScope Plate Boundary Observatory facility on the science community is large and measurable. The impact of the creation, execution and delivery of the PBO resulted in radical changes in the way the geodesy community views permanent, continuously operating (and often) real-time GPS and strain networks, open data policies, and the ability for consortium based facilities, such as UNAVCO, to manage and deliver on large National Science Foundation investments. Our presentation will explore these innovations and transformations from the community, facility, and science perspectives. In the genesis of the EarthScope proposal there was a distinct shift away from the PBO being managed and constructed by prominent PI's within the community to a vesting of the responsibility and authority in UNAVCO to execute on behalf of the entire community. This tipping away from individual PI concerns towards a communal behavior allowed the construction of a facility based on broad input from, and equal access for, any member of the geodesy community. The open and transparent nature of EarthScope, including the open data policy for both facility and PI derived data was truly transformative. One of the key tenants of the PBO was strict adherence to not redesigning unless absolutely necessary. For example PBO monumentation and data processing practices were adopted wholesale from the SCIGN project, while the station selection, project management, permitting practices, data downloading, metadata, and, data communications were refactored for optimum use for the broader geodesy community and to scale with the large geography that confronted PBO. The PBO strainmeter network, one of the largest in the world, started by looking at the procedures of 30 years of heterogeneous installations around the word then crafted, created, and amalgamated new drilling, grouting, installation, and data

  4. On the potential of lunar observations in regular geodetic VLBI sessions

    Science.gov (United States)

    Klopotek, Grzegorz; Hobiger, Thomas; Haas, Rüdiger

    2017-04-01

    Artificial radio sources on the surface of the Moon enable us to observe lunar based transmitters with geodetic VLBI. Although during the last years a few dedicated VLBI experiments have already been carried out, the question still remains how and to what extend new information can be derived from observing such targets. Therefore, we perform Monte Carlo simulations using the c5++ software in order to evaluate how the inclusion of lunar observations into regular VLBI schedules would impact classical Earth-related target parameters of geodetic VLBI such as station coordinates and Earth Orientation Parameters, as well as how it would extend the possibilities to determine selenoidic parameters. Our study is based on modified IVS-R1 observing schedules, originally created by the International VLBI Service for Geodesy and Astrometry (IVS) to determine Earth Orientation Parameters, thus representing state-of-the-art VLBI observing programs. Based on our simulations, we demonstrate that an artificial radio source on the surface of the Moon can be located with both, accuracy and precision of better than 50 cm when observed along with quasars in the regular IVS-R1 session schedules. Moreover, we show that geodetic VLBI has the potential to improve our knowledge of lunar physical models and/or help to verify or update lunar ephemerides. We will discuss how the quality and quantity of lunar observations affect the uncertainty of the position of a non-moving artificial radio source located on the surface of the Moon and we highlight the factors limiting the determination of its position. Furthermore, we will reveal the impact of Moon VLBI observations on the determination of the Earth Orientation Parameters and VLBI station positions. We will also test the concept of VLBI lunar observations with simulations that reflect VGOS performance in terms of observation precision, number of scans and future network configurations. Thus, our simulations will provide valuable insights

  5. DORIS system and integrity survey

    Science.gov (United States)

    Jayles, C.; Chauveau, J. P.; Didelot, F.; Auriol, A.; Tourain, C.

    2016-12-01

    DORIS, as other techniques for space geodesy (SLR, VLBI, GPS) has regularly progressed to meet the ever increasing needs of the scientific community in oceanography, geodesy or geophysics. Over the past 10 years, a particular emphasis has been placed on integrity monitoring of the system, which has contributed to the enhancement of the overall availability and quality of DORIS data products. A high level of monitoring is now provided by a centralized control of the whole system, including the global network of beacons and the onboard instruments, which perform a constant end-to-end survey. At first signs of any unusual behavior, a dedicated team is activated with well-established tools to investigate, to anticipate and to contain the impact of any potential failures. The procedure has increased the availability of DORIS beacons to 90%. The core topic of this article is to demonstrate that DORIS has implemented a high-level integrity control of its data. Embedded in the DORIS receiver, DIODE (DORIS Immediate Orbit Determination) is a Real-Time On-Board Orbit Determination software. Its accuracy has also been dramatically improved when compared to Precise Orbit Ephemeris (P.O.E.), down to 2.7 cm RMS on Jason-2, 3.0 cm on Saral and 3.3 cm on CryoSat-2. Specific quality indices were derived from the DIODE-based Kalman filters and are used to monitor network and system performance. This paper covers the definition of these indices and how the reliability and the reactiveness to incidents or anomalies of the system are improved. From these indices, we have provided detailed diagnostic information about the DORIS system, which is available in real-time, on-board each DORIS satellite. Using these capabilities, we have developed real-time functions that give an immediate diagnosis of the status of key components in the DORIS system. The Near-Real Time navigation system was improved and can distinguish and handle both satellite events and beacon anomalies. The next missions

  6. Implementation of Active Teaching Methods and Emerging Topics in Photogrammetry and Remote Sensing Subjects

    Science.gov (United States)

    Kosmatin Fras, M.; Grigillo, D.

    2016-06-01

    Fast technological developments in photogrammetry and remote sensing areas demand quick and steady changes in the education programme and its realization. The university teachers and assistants are faced with ensuring the learning materials, data and software for practical lessons, as well as project proposals for student's team work and bachelor or master thesis. In this paper the emerging topics that already have a considerable impact in the practice are treated mostly from the educational aspect. These relatively new topics that are considered in this paper are unmanned aerial systems for spatial data collection, terrestrial and aerial laser scanning, mobile mapping systems, and novelties in satellite remote sensing. The focus is given to practical implementation of these topics into the teaching and learning programme of Geodesy and Geoinformation at the University of Ljubljana, Faculty of Civil and Geodetic Engineering, and experiences gained by the authors so far. Together with the technological advances, the teaching approaches must be modernized as well. Classical approaches of teaching, where a lecturer gives lecture ex cathedra and students are only listeners, are not effective enough. The didactics science of teaching has developed and proved in the practice many useful approaches that can better motivate students for more active learning. We can use different methods of team work like pro et contra debate, buzzing groups, press conference, moderated discussion etc. An experimental study on active teaching methods in the class of students of the Master programme of Geodesy and Geoinformation has been made and the results are presented. After using some new teaching methods in the class, the students were asked to answer two types of a questionnaire. First questionnaire was the standard form developed by Noel Entwistle, an educational psychologist who developed the Approaches to Studying Inventory (ASI) for identifying deep and surface approaches to

  7. A PRECISE, LOW-COST RTK GNSS SYSTEM FOR UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    W. Stempfhuber

    2012-09-01

    Full Text Available High accuracy with real-time positioning of moving objects has been considered a standard task of engineering geodesy for 10 to 15 years. An absolute positioning accuracy of 1–3 cm is generally possible worldwide and is further used in many areas of machine guidance (machine control and guidance, and farming (precision farming as well as for various special applications (e.g. railway trolley, mining, etc.. The cost of the measuring instruments required for the use of geodetic L1/L2 receivers with a local reference station amounts to approximately USD 30,000 to 50,000. Therefore, dual frequency RTK GNSS receivers are not used in the mass market. Affordable GPS/GNSS modules have already reached the mass market in various areas such as mobile phones, car navigation, the leisure industry, etc. Kinematic real-time positioning applications with centimetre or decimetre levels could also evolve into a mass product. In order for this to happen, the costs for such systems must lie between USD 1,000 to 2,000. What exactly low-cost means is determined by the precise specifications of the given individual application. Several university studies in geodesy focus on the approach of high-accuracy positioning by means of single frequency receivers for static applications [e.g. GLABSCH et. al. 2009, SCHWIEGER and GLÄSER 2005, ALKAN 2010, REALINI et. al. 2010, KORTH and HOFMANN 2011]. Although intelligent approaches have been developed that compute a trajectory in the post-processing mode [REALINI et. al., 2010], at present, there are only a very few GNSS Low-Cost Systems that enable real-time processing. This approach to precise position determination by means of the computation of static raw data with single frequency receivers is currently being explored in a research project at the Beuth Hochschule für Technik Berlin – and is being further developed for kinematic applications. The project is embedded in the European Social Fund. It is a follow-up project

  8. IMPLEMENTATION OF ACTIVE TEACHING METHODS AND EMERGING TOPICS IN PHOTOGRAMMETRY AND REMOTE SENSING SUBJECTS

    Directory of Open Access Journals (Sweden)

    M. Kosmatin Fras

    2016-06-01

    Full Text Available Fast technological developments in photogrammetry and remote sensing areas demand quick and steady changes in the education programme and its realization. The university teachers and assistants are faced with ensuring the learning materials, data and software for practical lessons, as well as project proposals for student’s team work and bachelor or master thesis. In this paper the emerging topics that already have a considerable impact in the practice are treated mostly from the educational aspect. These relatively new topics that are considered in this paper are unmanned aerial systems for spatial data collection, terrestrial and aerial laser scanning, mobile mapping systems, and novelties in satellite remote sensing. The focus is given to practical implementation of these topics into the teaching and learning programme of Geodesy and Geoinformation at the University of Ljubljana, Faculty of Civil and Geodetic Engineering, and experiences gained by the authors so far. Together with the technological advances, the teaching approaches must be modernized as well. Classical approaches of teaching, where a lecturer gives lecture ex cathedra and students are only listeners, are not effective enough. The didactics science of teaching has developed and proved in the practice many useful approaches that can better motivate students for more active learning. We can use different methods of team work like pro et contra debate, buzzing groups, press conference, moderated discussion etc. An experimental study on active teaching methods in the class of students of the Master programme of Geodesy and Geoinformation has been made and the results are presented. After using some new teaching methods in the class, the students were asked to answer two types of a questionnaire. First questionnaire was the standard form developed by Noel Entwistle, an educational psychologist who developed the Approaches to Studying Inventory (ASI for identifying deep and

  9. Geodetic Space Weather Monitoring by means of Ionosphere Modelling

    Science.gov (United States)

    Schmidt, Michael

    2017-04-01

    The term space weather indicates physical processes and phenomena in space caused by radiation of energy mainly from the Sun. Manifestations of space weather are (1) variations of the Earth's magnetic field, (2) the polar lights in the northern and southern hemisphere, (3) variations within the ionosphere as part of the upper atmosphere characterized by the existence of free electrons and ions, (4) the solar wind, i.e. the permanent emission of electrons and photons, (5) the interplanetary magnetic field, and (6) electric currents, e.g. the van Allen radiation belt. It can be stated that ionosphere disturbances are often caused by so-called solar storms. A solar storm comprises solar events such as solar flares and coronal mass ejections (CMEs) which have different effects on the Earth. Solar flares may cause disturbances in positioning, navigation and communication. CMEs can effect severe disturbances and in extreme cases damages or even destructions of modern infrastructure. Examples are interruptions to satellite services including the global navigation satellite systems (GNSS), communication systems, Earth observation and imaging systems or a potential failure of power networks. Currently the measurements of solar satellite missions such as STEREO and SOHO are used to forecast solar events. Besides these measurements the Earth's ionosphere plays another key role in monitoring the space weather, because it responses to solar storms with an increase of the electron density. Space-geodetic observation techniques, such as terrestrial GNSS, satellite altimetry, space-borne GPS (radio occultation), DORIS and VLBI provide valuable global information about the state of the ionosphere. Additionally geodesy has a long history and large experience in developing and using sophisticated analysis and combination techniques as well as empirical and physical modelling approaches. Consequently, geodesy is predestinated for strongly supporting space weather monitoring via

  10. Demystifying Scientific Data ­ Using Earth Science to Teach the Scientific Method

    Science.gov (United States)

    Nassiff, P. J.; Santos, E. A.; Erickson, P. J.; Niell, A. E.

    2006-12-01

    The collection of large quantities of data and their subsequent analyses are important components of any scientific process, particularly at research institutes such as MIT's Haystack Observatory, where the collection and analyses of data is crucial to research efforts. Likewise, a recent study on science education concluded that students should be introduced to analyzing evidence and hypotheses, to critical thinking - including appropriate skepticism, to quantitative reasoning and the ability to make reasonable estimates, and to the role of uncertainty and error in science. In order to achieve this goal with grades 9-12 students and their instructors, we developed lesson plans and activities based on atmospheric science and geodetic research at Haystack Observatory. From the complex steps of experimental design, measurement, and data analysis, students and teachers will gain insight into the scientific research processes as they exist today. The use of these space weather and geodesy activities in classrooms will be discussed. Space Weather: After decades of data collection with multiple variables, space weather is about as complex an area of investigation as possible. Far from the passive relationship between the Sun and Earth often taught in the early grades, or the beautiful auroras discussed in high school, there are complex and powerful interactions between the Sun and Earth. In spite of these complexities, high school students can learn about space weather and the repercussions on our communication and power technologies. Starting from lessons on the basic method of observing space weather with incoherent scatter radar, and progressing to the use of simplified data sets, students will discover how space weather affects Earth over solar cycles and how severe solar activity is measured and affects the Earth over shorter time spans. They will see that even from complex, seemingly ambiguous data with many variables and unknowns, scientists can gain valuable

  11. Contributions of the Onsala Space Observatory to the GGOS

    Science.gov (United States)

    Haas, Rüdiger; Elgered, Gunnar; Hobiger, Thomas; Scherneck, Hans-Georg

    2015-04-01

    The Onsala Space Observatory on the Swedish west coast is the fundamental geodetic station of Sweden and operates several geodetic and geophysical infrastructures that contribute to the GGOS. Onsala is the European observatory with the longest history in Very Long Baseline Interferometry (VLBI). Already 1968 Onsala was involved in geodetic/astrometric VLBI observations, at that time with the 25 m telescope. Since 1979 the 20 m telescope is used for geodetic/astrometric VLBI, and currently about 40-50 sessions per year are observed in the programs of the International VLBI Service for Geodesy and Astrometry (IVS). Onsala also participated in all continuous (CONT) campaigns of the IVS. In 2011 we received funding for twin telescopes at Onsala, to be part of the VLBI2010 Global Observing System (VGOS) network. The project has been delayed due to difficulties to get the necessary building permits, but finally a contract to purchase the new telescopes has been signed in late 2014. We expect that the Onsala Twin Telescopes will become operational in 2016/2017. In parallel to the VLBI activities, the observatory operates other instrumentation for geosciences, in particular receivers for Global Navigation Satellite Systems (GNSS), and ground-based microwave radiometers. There are several monuments used for GNSS measurements, and Onsala is actively contributing to the International GNSS Service (IGS). Recently a GNSS array consisting of six new GNSS monuments, in the area around the Onsala Twin Telescopes, has been installed. Also several microwave radiometers are operated for tropospheric measurements. A superconducting gravimeter is operated at the observatory since 2009 in a dedicated gravity laboratory which is also hosting visiting absolute gravimeters, and in 2011 a seismometer station has been installed that is part of the Swedish National Seismic Network (SNSN). Since 2010 we operate a so-called GNSS-R tide gauge, based on the principle of reflectometry. Additional

  12. NRT Atmospheric Water Vapour Retrieval on the Area of Poland at IGG WUELS AC

    Science.gov (United States)

    Kaplon, Jan; Bosy, Jaroslaw; Sierny, Jan; Hadas, Tomasz; Rohm, Witold; Wilgan, Karina; Ryczywolski, Marcin; Oruba, Artur; Kroszczynski, Krzysztof

    2013-04-01

    Global Navigation Satellite Systems (GNSS) are designed for positioning, navigation and amongst other possible applications it can also be used to derive information about the state of the atmosphere. Continuous observations from GNSS receivers provide an excellent tool for studying the neutral atmosphere, currently in near real-time. The Near Real-Time (NRT) neutral atmosphere and water vapour distribution models are currently obtained with high resolution from Ground Base Augmentation Systems (GBAS), where reference stations are equipped with GNSS and meteorological sensors. The Poland territory is covered by dense network of GNSS stations in the frame of GBAS system called ASG-EUPOS (www.asgeupos.pl). This system was established in year 2008 by the Head Office of Geodesy and Cartography in the frame of the EUPOS project (www.eupos.org) for providing positioning services. The GNSS data are available from 130 reference stations located in Poland and neighbour countries. The ground meteorological observations in the area of Poland and neighbour countries are available from ASG-EUPOS stations included in EUREF Permanent Network (EPN) stations, airports meteorological stations (METAR messages stations), and stations managed by national Institute of Meteorology and Water Management (SYNOP messages stations). Institute of Geodesy and Geoinformatics (IGG) of Wroclaw University of Environmental and Life Sciences had created permanent NRT service of ZTD (Zenith Total Delay) estimation for the area of Poland from GPS observations called IGGHZG. The first part of the paper presents the methodology of NRT GNSS data processing for ASG-EUPOS stations for ZTD estimation and its comparison to the results coming from EPN ACs and Military University of Technology in Warsaw AC (MUT AC). Second part covers the procedure of IWV (atmospheric Integrated Water Vapour content) estimation at IGG from IGGHZG product and ZHD (Zenith Hydrostatic Delay) derived from Saastamoinen formula (1972

  13. Micro-arcsecond Celestial Reference Frames: definition and realization - Impact of the recent IAU Resolutions

    Institute of Scientific and Technical Information of China (English)

    Nicole Capitaine

    2012-01-01

    The adoption of the International Celestial Reference System (ICRS),based on Very Long Baseline Interferometry (VLBI) observations of extragalactic radiosources by the International Astronomical Union (IAU) since 1998 January 1,opened a new era for astronomy.The ICRS and the corresponding frame,the International Celestial Reference Frame (ICRF),replaced the Fundamental Catalog (FK5) based on positions and proper motions of bright stars,with the Hipparcos catalog being adopted as the primary realization of the ICRS in optical wavelengths.According to its definition,the ICRS is such that the barycentric directions of distant extragalactic objects show no global rotation with respect to these objects; this provides a quasi-inertial reference for measuring the positions and angular motions of the celestial objects.Other resolutions on reference systems were passed by the IAU in 2000 and 2006 and endorsed by the International Union of Geodesy and Geophysics (IUGG) in 2003 and 2007,respectively.These especially concern the definition and realization of the astronomical reference systems in the framework of general relativity and transformations between them.First,the IAU 2000 resolutions refined the concepts and definition of the astronomical reference systems and parameters for Earth's rotation,and adopted the IAU 2000 precession-nutation.Then,the IAU 2006 resolutions adopted a new precession model that is consistent with dynamical theories; they also addressed definition,terminology or orientation issues relative to reference systems and time scales that needed to be specified after the adoption of the IAU 2000 resolutions.An additional IUGG 2007 resolution defined the International Terrestrial Reference System (ITRS) so that it strictly complies with the IAU recommendations.Finally,the IAU 2009 resolutions adopted a new system of astronomical constants and an improved realization of the ICRF.These fundamental changes have led to significant improvements in the fields

  14. Concept of information models in GGOS

    Science.gov (United States)

    Pachelski, Wojciech

    2010-05-01

    GGOS divides geodesy as a discipline into three parts, so called "pillars". First pillar consists of methods, techniques and theories that are used to determine Earth's shape (its surface: solid Earth, ice and oceans) as a global function of space and time (kinematics). Second pillar regards to Earth's gravitational field determination and monitoring, it also describes mass distributions and the shape of the geoid. Third pillar concerns planet rotation and forces related to interactions between Earth and other celestial bodies, especially the Moon and the Sun. These three pillars constitute province of modern geodesy. Different parts of the overall system are cross-linked through observations and inter-dependent. All these techniques are affected by and measure the "output" of the same unique Earth system, that is, the various geodetic fingerprints induced by mass redistribution and changes in the system's dynamics. Consistency of data processing, modeling, and conventions across the techniques and across the "three pillars" is mandatory for maximum exploitation of the full potential of the system. The main purpose of this paper is to make an introduction to full description of connections between all GGOS components and describe GGOS information structure - a great number of mutually related objects, phenomena, theories. Understanding of relations and dependences within GGOS is necessary to conscious usage of it products. The authors' intention is to show and explain examples of such relations related to the part of GGOS, which is described as "Geokinematics", "Gravity field", "Earth rotation", "Reference systems". The next step is to present those dependences using Unified Modeling Language (UML) - formal language, which is used to model and describe reality in object-oriented analysis and programming.There are packages "Geokinematics", "Gravity field", "Earth rotation", "Reference systems" and classes for each package defined. To show connections between some

  15. Processing of A New Digital Orthoimage Map of The Martian Western Hemisphere Using Data Obtained From The Mars Orbiter Camera At A Resolution of 256 Pixel/deg

    Science.gov (United States)

    Wählisch, M.; Niedermaier, G.; van Gasselt, S.; Scholten, F.; Wewel, F.; Roatsch, T.; Matz, K.-D.; Jaumann, R.

    We present a new digital orthoimage map of Mars using data obtained from the CCD line scanner Mars Orbiter Camera (MOC) of the Mars Global Surveyor Mis- sion (MGS) [1,2]. The map covers the Mars surface from 0 to 180 West and from 60 South to 60 North with the MDIM2 resolution of 256 pixel/degree and size. Image data processing has been performed using multiple programs, developed by DLR, Technical University of Berlin [3], JPL, and the USGS. 4,339 Context and 183 Geodesy images [2] were included. After radiometric corrections, the images were Mars referenced [4], geometrically corrected [5] and orthoprojected using a global Martian Digital Terrain Model (DTM) with a resolution of 64 pixel/degree, developed at DLR and based on MGS Mars Orbiter Laser Altimeter (MOLA) data [6]. To elim- inate major differences in brightness between the individual images of the mosaics, high- and low-pass filter processing techniques were applied for each image. After filtering, the images were mosaicked without registering or using block adjustment techniques in order to improve the geometric quality. It turns out that the accuracy of the navigation data has such a good quality that the orthoimages fit very well to each other. When merging the MOC mosaic with the MOLA data using IHS- trans- formation, we recognized very good correspondence between these two datasets. We create a topographic image map of the Coprates region (MC­18) adding contour lines derived from the global DTM to the mosaic. These maps are used for geological and morphological interpretations in order to review and improve our current Viking-based knowledge about the Martian surface. References: [1] www.mssss.com, [2] Caplinger, M. and M. Malin, "The Mars Or- biter Camera Geodesy Campaign, JGR, in press, [3] Scholten, F., Vol XXXI, Part B2, Wien 1996, p.351-356, [4] naïf.jpl.nasa.gov, [5] R.L.Kirk. et al. (2001), "Geometric Calibration of the Mars Orbiter Cameras and Coalignment with Mars Orbiter Laser Altimeter

  16. The Attraction of Gravity (Jean Dominique Cassini Medal Lecture)

    Science.gov (United States)

    Iess, Luciano

    2017-04-01

    The motion of planetary bodies, their interior structure, their shape, and ultimately their landscape, are all determined, more or less directly, by gravity. It is therefore not surprising that by measuring the orbital motion and the gravity field of planets and satellites we have been able to gather crucial information on the interior structure and evolution of those bodies, and at the same time to put the laws of gravity to the test. Planetary geodesy is now a fully developed discipline that uses methods and observable quantities adopted also in other fields, such as space navigation and telecommunications. Thanks to this winning synergy between science and engineering, we can now measure spacecraft velocities to 10-6 m/s and accelerations to 10-9 m/s2 over time scales as short as 1000 s, everywhere in the solar system. The past ten years have seen outstanding results in the scientific exploration of the deep space, with gravity investigations contributing to the success of many missions. Thanks to gravity measurements, MESSENGER was able to unveil the main features of Mercury's interior structure. GRAIL, the first planetary mission entirely devoted to gravity, recovered the structure of the lunar gravity anomalies to a spatial resolution and accuracy unmatched even for the Earth. The discovery and characterization of habitable environments in the Saturnian system, on Enceladus and Titan, were possible also by the radio science investigations of the mission Cassini. Thanks to a carefully designed orbit, with a pericenter just 3000 km above the cloud level, the spacecraft Juno is now carrying out precise gravity measurements at Jupiter to unveil the interior structure of the planet and the depth of its winds. With Cassini providing similar information at Saturn in the Grand Finale orbits, just before the final plunge into the planet, we will soon be able to reveal how similar or different the two gas giants are. But the interior structure of many planetary bodies

  17. The new gravimetric quasigeoid model KTH08 over Sweden

    Science.gov (United States)

    Ågren, Jonas; Sjöberg, Lars E.; Kiamehr, Ramin

    2009-08-01

    The least squares modification of Stokes formula has been developed in a series of papers published in Journal of Geodesy between 1984 and 2008. It consists of a least squares (stochastic) Stokes kernel modification with additive corrections for the topography, downward continuation, the atmosphere and the ellipsoidal shape of the Earth. The method, developed at the Royal Institute of Technology (KTH) will here be denoted by the abbreviated name the KTH method. This paper presents the computational results of a new gravimetric quasigeoid model over Sweden (the KTH08 model) by employing the KTH method. Traditionally the Nordic Geodetic Commission (NKG) has computed gravimetric quasigeoid models over Sweden and other Nordic countries; the latest model being NKG 2004. Another aim of this paper is therefore to compare KTH08 and NKG 2004 quasigeoid models and to evaluate their accuracies using GNSS/levelling height anomalies. The rms fit of KTH08 in 196 GNSS data points distributed over Sweden by using a 1(4)-parameter transformation is 22 (20) mm. It is concluded that KTH08 is a significant step forward compared to NKG 2004.

  18. High-rate precise point positioning (PPP) to measure seismic wave motions: An experimental comparison of GPS PPP with inertial measurement units

    Science.gov (United States)

    Xu, Peiliang; Shi, Chuang; Fang, Rongxin; Liu, Jingnan; Niu, Xiaoji; Zhang, Quan; Yanagidani, Takashi

    2013-04-01

    High-rate GPS has been widely used to construct displacement waveforms and to invert for source parameters of earthquakes. Almost all works on internal and external evaluation of high-rate GPS accuracy are based on GPS relative positioning. We build an experimental platform to externally evaluate the accuracy of 50 Hz PPP displacement waveforms. Since the shake table allows motion in any of six degrees of freedom, we install an inertial measurement unit (IMU) to measure the attitude of the platform and transform the IMU displacements into the GPS coordinate system. The experimental results have shown that high-rate PPP can produce absolute horizontal displacement waveforms at the accuracy of 2 to 4 millimeters and absolute vertical displacement waveforms at the sub-centimeter level of accuracy within a short period of time. The significance of the experiments indicates that high-rate PPP is capable of detecting absolute seismic displacement waveforms at the same high accuracy as GPS relative positioning techniques but requires no fixed datum station. We have also found a small scaling error of IMU and a small time offset of misalignment between high-rate PPP and IMU displacement waveforms by comparing the amplitudes of and cross-correlating both the displacement waveforms. For more details on this talk, one can now get access to the on-line-first version of our Journal of Geodesy paper: J Geod, DOI 10.1007/s00190-012-0606-z

  19. Orbitography for next generation space clocks

    CERN Document Server

    Duchayne, Loïc; Wolf, Peter

    2007-01-01

    Over the last decade of the 20th century and the first few years of the 21st, the uncertainty of atomic clocks has decreased by about two orders of magnitude, passing from the low 10^-14 to below 10^-16, in relative frequency . Space applications in fundamental physics, geodesy, time/frequency metrology, navigation etc... are among the most promising for this new generation of clocks. Onboard terrestrial or solar system satellites, their exceptional frequency stability and accuracy makes them a prime tool to test the fundamental laws of nature, and to study gravitational potentials and their evolution. In this paper, we study in more detail the requirements on orbitography compatible with operation of next generation space clocks at the required uncertainty based on a completely relativistic model. Using the ACES (Atomic Clock Ensemble in Space) mission as an example, we show that the required accuracy goal can be reached with relatively modest constraints on the orbitography of the space clock, much less str...

  20. GEOSAT: Combining VLBI, SLR, GPS, and DORIS at the observation level

    Science.gov (United States)

    Helge Andersen, Per; Dähnn, Michael; Fausk, Ingrid; Hjelle, Geir Arne; Kirkvik, Ann-Silje; Mysen, Eirik

    2015-04-01

    GEOSAT is a multi-technique geodetic software that has been under development for about 30 years [P. H. Andersen, "Multilevel arc combination with stochastic parameters". Journal of Geodesy 01/2000; 74(7): 531 - 551]. The last couple of years the development efforts have been headed by a team at the Norwegian Mapping Authority. The GEOSAT software can be used in the analysis of space geodetic data by combining data from VLBI, SLR, GPS and DORIS at the observation level epoch by epoch. As a result technique dependent systematic errors will be visible as anomalous a posteriori residuals, and can be compensated for by introducing technique dependent empirical models. GEOSAT is based on factorized Kalman filters which allow the estimation of stochastic parameters common for several techniques. GEOSAT contributed to the IVS solution used in the upcoming ITRF. In addition to VLBI analysis the software can process SLR and GPS data, while DORIS based analysis is under development. Experiments in combining data from different techniques according to the GEOSAT philosophy are currently being done. This presentation will be a description of how GEOSAT combines data from the different techniques, while at the same time reporting the current state of the project and our plans going forward.