Download or read book Analysis of Laser Ranging and VLBI Observations for Geodetic Purposes written by I. I. Shapiro and published by . This book was released on 1979 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: From three (Very Long Baseline Interferometry) VLBI experiments carried out in 1977 and 1978, the distances between the antenna at Onsala (Sweden) and radio telescopes at Haystack (Massachusetts), Green Bank (West Virginia) and Owens Valley (California) have been determined with formal standard errors as small as a few centimeters and repeatability generally within the 99% confidence interval of the root-sum-squares of these standard errors. Overall it appears that subdecimeter precision has been achieved in these estimates of baseline lengths. Using these data, we have also determined changes in UT1 and in the x and y components of polar motion. (Author).
Download or read book Analysis of Laser Ranging and VLBI Very Long Baseline Interferometry Observations for Geodetic Purposes written by United States. National Technical Information Service and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Lunar Laser Ranging Data and Performance and Analysis of VLBI Observations for Geodetic Purposes written by C. C Counselman (III.) and published by . This book was released on 1980 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lunar laser ranging (LLR) observations made by the McDonald Observatory from 1970 through 1980 have been analyzed to estimate the variation of latitude and Universal Time (UT). We have compared these estimates with determinations of earth rotation from other techniques. For observations obtained in two one-week periods in September and October 1980, during the International 'MERIT' (Measurement of Earth Rotation and Intercomparison of Techniques) Short Campaign, the root-mean-square difference between LLR and very long baseline interferometry determinations of UT was 0.3 milliseconds. We have also used LLR determinations of UT to derive changes in length-of-day (lod) and compared these with changes in lod inferred from changes in the polar component of the earth's atmospheric angular momentum. A common, persistent approx. 50-day fluctuation was identified in these lod values.
Download or read book Analysis of Lunar Laser and ALSEP VLBI Data for Geodetic Purposes written by Irwin I. Shapiro and published by . This book was released on 1974 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The M.I.T. Planetary Ephemeris Program has been used to perform simulated least squares estimates of geodetic and other parameters relevant to the analysis of lunar laser ranging observations. These observations can produce improved estimates of (a) observing station locations, (b) variations in the diurnal rotation rate, (c) polar motion, and (d) the earth's gravitational constant. Since the laser data are highly sensitive to the lunar physical libration, differential very-long-baseline interferometry observations of the ALSEP transmitters have been processed to aid in the analysis of the laser data. (Author).
Download or read book Laser Ranging and Very Long Baseline Interferometry for Geodetic Applications written by Irwin I. Shapiro and published by . This book was released on 1978 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three distinct tasks were undertaken to advance the application of space techniques to the measurement of geodetic parameters: error analyses were performed to estimate the accuracy with which the locations of satellite tracking stations and the motion of the earth's pole may be determined from laser-ranging observations of the LAGEOS satellite; a numerical model of the moon's rotation was developed to support the analysis of lunar laser ranging observations; and a very-long-baseline interferometry (VLBI) system was constructed and installed at the Onsala Space Observatory in Sweden for use in a program to monitor the earth's rotation through observations of extragalactic radio sources. The details of this work have been described in three previously published reports. (Author).
Download or read book Precise Geodetic Infrastructure written by National Research Council and published by National Academies Press. This book was released on 2010-10-25 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geodesy is the science of accurately measuring and understanding three fundamental properties of Earth: its geometric shape, its orientation in space, and its gravity field, as well as the changes of these properties with time. Over the past half century, the United States, in cooperation with international partners, has led the development of geodetic techniques and instrumentation. Geodetic observing systems provide a significant benefit to society in a wide array of military, research, civil, and commercial areas, including sea level change monitoring, autonomous navigation, tighter low flying routes for strategic aircraft, precision agriculture, civil surveying, earthquake monitoring, forest structural mapping and biomass estimation, and improved floodplain mapping. Recognizing the growing reliance of a wide range of scientific and societal endeavors on infrastructure for precise geodesy, and recognizing geodetic infrastructure as a shared national resource, this book provides an independent assessment of the benefits provided by geodetic observations and networks, as well as a plan for the future development and support of the infrastructure needed to meet the demand for increasingly greater precision. Precise Geodetic Infrastructure makes a series of focused recommendations for upgrading and improving specific elements of the infrastructure, for enhancing the role of the United States in international geodetic services, for evaluating the requirements for a geodetic workforce for the coming decades, and for providing national coordination and advocacy for the various agencies and organizations that contribute to the geodetic infrastructure.
Download or read book Applications of Laser Ranging and VLBI Observations for Selenodetic Control written by Francis A. Fajemirokun and published by . This book was released on 1971 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of Precise Satellite Orbits and Geodetic Parameters using Satellite Laser Ranging written by Krzysztof Sośnica and published by Astronomical Institute, University of Bern, Switzerland. This book was released on 2014-04-07 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contribution of Satellite Laser Ranging (SLR) to the definition of the origin of the reference frame (geocenter coordinates), the global scale, and low degree coefficients of the Earth's gravity field is essential due to the remarkable orbit stability of geodetic satellites and the accuracy of laser observations at a level of a few millimeters. Considering these aspects, SLR has an exceptional potential in establishing global networks and deriving geodetic parameters of the supreme quality. SLR faces today the highest requirements of the Global Geodetic Observing System (GGOS) yielding 1 mm of long-term station coordinate and 0.1 mm/y of station velocity stability. The goal of this work is to assess the contribution of the latest models and corrections to the SLR-derived parameters, to enhance the quality and reliability of the SLR-derived products, and to propose a new approach of orbit parameterization for low orbiting geodetic satellites. The impact of orbit perturbations is studied in detail, including perturbing forces of gravitational origin (Earth's gravity field, ocean and atmosphere tides) and perturbing forces of non-gravitational origin (atmospheric drag, the Yarkovsky effect, albedo and Earth's infrared radiation pressure). A multi-satellite combined solution is obtained using SLR observations to LAGEOS-1, LAGEOS-2, Starlette, Stella, and AJISAI. The quality of the SLR-derived parameters from the combined solution is compared with external solutions. The Earth rotation parameters are compared to the IERS-08-C04 series and the GNSS-derived series, whereas the time variable Earth's gravity field coefficients are compared to the CHAMP and GRACE-derived results.
Download or read book Applications of Laser Ranging and VLBI Observations for Selendetic Control written by Francis A. Fajemirokun and published by . This book was released on 1971 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Satellite Laser Ranging in the 1990s written by John James Degnan and published by . This book was released on 1994 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Satellite Laser Ranging in the 1990s Report of the 1994 Belmont Workshop written by and published by . This book was released on 1994 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Geodetic Observing System written by Hans-Peter Plag and published by Springer Science & Business Media. This book was released on 2009-07-25 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Global Geodetic Observing System (GGOS) has been established by the Int- national Association of Geodesy (IAG) in order to integrate the three fundamental areas of geodesy, so as to monitor geodetic parameters and their temporal varia- ?9 tions, in a global reference frame with a target relative accuracy of 10 or b- ter. These areas, often called ‘pillars’, deal with the determination and evolution of (a) the Earth’s geometry (topography, bathymetry, ice surface, sea level), (b) the Earth’s rotation and orientation (polar motion, rotation rate, nutation, etc. ), and (c) the Earth’s gravity eld (gravity, geoid). Therefore, Earth Observation on a global scale is at the heart of GGOS’s activities, which contributes to Global Change - search through the monitoring, as well as the modeling, of dynamic Earth processes such as, for example, mass and angular momentum exchanges, mass transport and ocean circulation, and changes in sea, land and ice surfaces. To achieve such an - bitious goal, GGOS relies on an integrated network of current and future terrestrial, airborne and satellite systems and technologies. These include: various positioning, navigation, remote sensing and dedicated gravity and altimetry satellite missions; global ground networks of VLBI, SLR, DORIS, GNSS and absolute and relative gravity stations; and airborne gravity, mapping and remote sensing systems.
Download or read book Scientific Applications of Lunar Laser Ranging written by J.D. Mulholland and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress of science during the past centuries has been in some measure energized by the development of new technologies. People are no more intelligent now than they were five centuries ago, or indeed five millenia ago. The differences are in the pool of past experience and the availability of means for manipulating the physical and mental environment. Until fairly recently, the development of new technologies in astronomy and geodesy has served primarily either to broaden the scope of phenomena that could be studied or to improve the precision with which one could examine already-studied phenomena. There seemed to be no likelihood that a situation could arise similar to that in particle physics, where the uncertainty principle indicates that the observation of the state of an object alters that state, affecting the observation. Indeed, we have not yet reached that point, but certain of the new techniques have introduced a degree of complication and inter dependence perhaps not previously encountered in the macro sciences. When observational capability is so fine that the data can be corrupted by the tidal motions of the instruments, for example, then there are a myriad of physical effects that must be considered in analyzing the data; the happy aspect of this is that the data can be used to study exactly these same effects. The complication does not, however, extend only to predictive computations against which the data are compared.
Download or read book Analysis of Laser Data for Geodetic Purposes written by Irwin I. Shapiro and published by . This book was released on 1973 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: MIT's Planetary Ephemeris Program has been modified to permit a weighted least squares estimate for variations in the earth's rotation and polar motion using earth satellite and lunar laser ranging data. A test solution was performed with data obtained during the first two years of the lunar laser ranging experiment. (Author).
Download or read book Time From Earth Rotation to Atomic Physics written by Dennis D. McCarthy and published by Cambridge University Press. This book was released on 2018-10-18 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This accessible reference presents the evolution of concepts of time and methods of time keeping, for historians, scientists, engineers, and educators. The second edition has been updated throughout to describe twentieth- and twenty-first-century advances, progress in devices, time and cosmology, the redefinition of SI units, and the future of UTC.
Download or read book Satellite Geodesy written by Günter Seeber and published by Walter de Gruyter. This book was released on 2008-08-22 with total page 613 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the entire field of satellite geodesy and is intended to serve as a textbook for advanced undergraduate and graduate students, as well as a reference for professionals and scientists in the fields of engineering and geosciences such as geodesy, surveying engineering, geomatics, geography, navigation, geophysics and oceanography. The text provides a systematic overview of fundamentals including reference systems, time, signal propagation and satellite orbits, together with observation methods such as satellite laser ranging, satellite altimetry, gravity field missions, very long baseline interferometry, Doppler techniques, and Global Navigation Satellite Systems (GNSS). Particular emphasis is given to positioning techniques, such as the NAVSTAR Global Positioning System (GPS), and to applications. Numerous examples are included which refer to recent results in the fields of global and regional control networks; gravity field modeling; Earth rotation and global reference frames; crustal motion monitoring; cadastral and engineering surveying; geoinformation systems; land, air, and marine navigation; marine and glacial geodesy; and photogrammetry and remote sensing. This book will be an indispensable source of information for all concerned with satellite geodesy and its applications, in particular for spatial referencing, geoinformation, navigation, geodynamics, and operational positioning.
