Geodetic Operations Research Articles

Современные технологии геодезического обеспечения высотного строительства

High-rise characteristics of skyscrapers in different countries, including Russia, are given. There are promising projects of constructing new skyscrapers. These high-rise structures have their own design features, they are objects of a high responsibility level, and require arranging reliable geodetic support to be constructed and operated. The specifi cs of high-rise construction geodetic support are noted. The role of high-quality support increases with the amount of fl oors. The errors of the formwork removal to the installation horizons are considered. The accuracy requirements for geodetic operations and precision of creating a planned reference network are formed. The methods of transmitting plane coordinates to high horizons and the disadvantages of the currently used technologies are shown. Recommendations for the use of new geodetic technologies in high-rise construction are formulated. The ways of high-rise structure fl uctuations geodetic monitoring based on using video displacement sensors, GPS receiver, video hydrostatic sensors and inclinometers are presented. Measurements are performed with special computer programs. The proposed geodetic technology has been tested in Russia in a number of construction sites. Recommendations on the use of modern geodetic technologies in high-rise construction, depending on the height, are presented.

A comparison of existing transformation models to improve coordinate conversion between geodetic reference frames in Nigeria

Efficient transformation parameters are key to effective geodetic operations between any systems. With the advancement in technology, an improved interaction between geodetic reference frames has been noticed irrespective of their inherent heterogeneous deformations and the intermittently present oversight that exist as a result of the conversion methodology. The spatial data captured using the Global Navigation Satellite System (GNSS) have a reference datum based on the World Geodetic System 1984 (WGS84) ellipsoid. These data usually require a transformation to a local projection with its ellipsoid and datum and vice versa. These geodetic operations are unavoidably vulnerable to data loss due to distortion, especially if the applied model is unsuitable for the transformation between reference frames. Therefore, the main aim of this study is to authenticate the existing set of parameters for the local and geocentric systems in Nigeria by assessing the efficacy of the Bursa Wolf (BW) and the Molodensky Badekas (MB) models. To this end, both models (BW and MB) are compared in this study and used in the development of the Helmerts seven transformation parameters between Minna datum (Clarke 1880) and WGS84 reference ellipsoids for a large region in Southern Nigeria. Results show that the sets of datum shift transformation parameters for both models (a scale factor with three sets of translational and rotational parameters), derived from the exercise of the BW and the MB models revealed a high degree of correlation between the expected and derived set of coordinates during the validation/testing phase using each set of models. The validation exercise was carried out on a total of seven points, which were not part of the original computations. These points were distributed across the region to provide a better framework and a higher confidence level. Overall, an improvement of 68% is observed in terms of the correlation between expected and derived coordinates in the validation points and from the obtained root mean square values. Ultimately, the MB model is preferred to the BW model evidently because the transformation involves a global–local reference frame.

A Variance Model in NRTK-Based Geodetic Positioning as a Function of Baseline Length

This study examines the effect of baseline length on accuracy and precision in Network Real-Time Kinematic (NRTK) positioning and develops an experimental mathematical model to express this effect. The study also measures the performances of the Flaechen Korrektur Parameter (FKP) and Virtual Reference Stations (VRS) methods at different baseline lengths. The study makes use of the stations that form two Continuously Operating Reference Station (CORS) networks, one of which is local and the other national. Calculations were made to perform various geodetic operations, such as datum transformations between the two networks, identifications of positional velocities, and epoch shifting. BERNESE (v5.2) software was used to identify coordinate values assumed to be true based on International GNSS Service (IGS) products. No significant changes were observed in the RMSE values in baseline lengths of up to 40 km. In contrast, an average linear correlation of 69.2% was determined between precision and baseline length. Measurements were evaluated and tested using the variance model created as a function of the baseline length, in line with the aims of the study, and the results were found to be consistent. Moreover, in an examination of the Root Mean Square Error (RMSE) and precision values of the FKP and VRS measurements, no significant differences were observed. The mean differences were at the millimetre level.

GipsyX/RTGx, a new tool set for space geodetic operations and research

GipsyX/RTGx is the Jet Propulsion Laboratory’s (JPL) next generation software package for positioning, navigation, timing, and Earth science using measurements from three geodetic techniques: Global Navigation Satellite Systems (GNSS), Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS); with Very Long Baseline Interferometry (VLBI) under development. The software facilitates combined estimation of geodetic and geophysical parameters using a Kalman filter approach on real or simulated data in both post-processing and in real-time. The estimated parameters include station coordinates and velocities, satellite orbits and clocks, Earth orientation, ionospheric and tropospheric delays. The software is also capable of full realization of a dynamic terrestrial reference through analysis and combination of time series of ground station coordinates.Applying lessons learned from its predecessors, GIPSY-OASIS and Real Time GIPSY (RTG), GipsyX/RTGx was re-designed from the ground up to offer improved precision, accuracy, usability, and operational flexibility. We present some key aspects of its new architecture, and describe some of its major applications, including Real-time orbit determination and ephemeris predictions in the U.S. Air Force Next Generation GPS Operational Control Segment (OCX), as well as in JPL’s Global Differential GPS (GDGPS) System, supporting User Range Error (URE) of <5 cm RMS; precision post-processing GNSS orbit determination, including JPL’s contributions to the International GNSS Service (IGS) with URE in the 2 cm RMS range; Precise point positioning (PPP) with ambiguity resolution, both statically and kinematically, for geodetic applications with 2 mm horizontal, and 6.5 mm vertical repeatability for static positioning; Operational orbit and clock determination for Low Earth Orbiting (LEO) satellites, such as NASA’s Gravity Recovery and Climate Experiment (GRACE) mission with GRACE relative clock alignment at the 20 ps level; calibration of radio occultation data from LEO satellites for weather forecasting and climate studies; Satellite Laser Ranging (SLR) to GNSS and LEO satellites, DORIS-based and multi-technique orbit determination for LEO; production of terrestrial reference frames and Earth rotation parameters in support of JPL’s contribution to the International Terrestrial Reference Frame (ITRF).

Accuracy estimate of the paved surface of an automobile road after its reconstruction

The article outlines the importance of engineering and geodetic survey during the reconstruction of automobile roads. The main phases of engineering and geodetic survey, such as the creation of a horizontal and vertical control, topographic plotting, technologies for the detailed staking of circular curves, and softwares for the execution of data processing, are taken into consideration. Possible tolerance limits in building and geodetic operations are reported. Research on the evenness of the upper surface of the asphaltic coating of an automobile road after its reconstruction is carried out.

Mapping the Nation: Landscapes of Survey and the Material Cultures of the Early Ordnance Survey in Britain and Ireland

ABSTRACTStarting its work in 1791, the Ordnance Survey (OS) was a supranational organisation responsible for creating high quality and accurate topographic maps of the nations of Great Britain and Ireland. The detailed and rigorous field observations and geodetic operations of OS field-surveyors have left many traces in the landscape, but despite much careful and critical historical study of OS maps, and their wide use as sources in local studies and fieldwork, the material impacts and influences the OS had on British and Irish landscapes has been generally overlooked. This paper redresses this by exploring the ‘landscapes of survey’ created through the OS's trigonometrical and levelling operations for the first half of the nineteenth century. The paper first sets out how ‘excavating’ large-scale historic OS maps in digital mapping platforms provides a basis for identifying survey sites in the landscape, and how the positioning of these sites by the OS, both on the map and in the landscape, can uncover past survey practices and ‘ethnographies of cartography’ in the field. The second part of the paper focuses on the monuments used and created by surveyors to ensure a sound geodetic basis, examining OS survey sites as ‘material cultures’. Together, both parts of the paper make a case for greater recognition of the landscape legacies of the OS, a ‘survey heritage’ which has international significance in reflecting the OS's lasting contributions to scientific survey and geodesy, as well as for its role in shaping Britain and Ireland through mapping the nation.

Geodetic Service of Bosnia and Herzegovina 1880-2012

Three key periods of development of geodetic service in Bosnia and Herzegovina are described. The first land registers in B&amp;H come from the period of administration of the Ottoman Empire, from the fifteenth to the nineteenth century. During the occupation and annexation of B&amp;H by the Austro-Hungarian monarchy, land surveying was conducted, land cadastre and land registration were established, road infrastructure was built, mine fields were determined, etc. During the administration of the old and the new Yugoslavia, geodetic networks were established by applying more modern methods, new survey was conducted and new evidentions were established, high quality maps were produced...At the different geodetic operations in B&amp;H Geodetic Administration worked 982 professionals, during last 132 years.

The 2-edge geodetic number and graph operations

For a connected graph G = (V, E) of order n ≥ 2, a set \({S\subseteq V}\) is a 2-edge geodetic set of G if each edge \({e\in E - E(S)}\) lies on a u-v geodesic with d(u, v) = 2 for some vertices u and v in S. The minimum cardinality of a 2-edge geodetic set in G is the 2-edge geodetic number of G, denoted by eg2(G). It is proved that for any connected graph G, β1(G) ≤ eg2(G), where β1(G) is the matching number of G. It is shown that every pair a, b of integers with 2 ≤ a ≤ b is realizable as the matching number and 2-edge geodetic number, respectively, of some connected graph. We determine bounds for the 2-edge geodetic number of Cartesian product of graphs. Also we determine the 2-edge geodetic number of certain classes of Cartesian product graphs. The 2-edge geodetic number of join of two graphs is obtained in terms of the 2-edge geodetic number of the factor graphs. Open image in new window

Integration of space geodesy: A US National Geodetic Observatory

Abstract In the interest of improving the performance and efficiency of space geodesy a diverse group in the US, in collaboration with IGGOS, has begun to establish a unified National Geodetic Observatory (NGO). To launch this effort an international team will conduct a multi-year program of research into the technical issues of integrating SLR, VLBI, and GPS geodesy to produce a unified set of global geodetic products. The goal is to improve measurement accuracy by up to an order of magnitude while lowering the cost to current sponsors. A secondary goal is to expand and diversify international sponsorship of space geodesy. Principal benefits will be to open new vistas of research in geodynamics and surface change while freeing scarce NASA funds for scientific studies. NGO will proceed in partnership with, and under the auspices of, the International Association of Geodesy (IAG) as an element of the Integrated Global Geodetic Observation System project. The collaboration will be conducted within, and will make full use of, the IAG's existing international services: the IGS, IVS, ILRS, and IERS. Seed funding for organizational activities and technical analysis will come from NASA's Solid Earth and Natural Hazards Program. Additional funds to develop an integrated geodetic data system known as Inter-service Data Integration for Geodetic Operations (INDIGO), will come from a separate NASA program in Earth science information technology. INDIGO will offer ready access to the full variety of NASA's space geodetic data and will extend the GPS Seamless Archive (GSAC) philosophy to all space geodetic data types.

Special Order Geodetic Operations for a Canadian Pacific Railway Tunnel in the Canadian Rockies

A brief historical account is presented of the Canadian Pacific Railway involvement in the Rogers Pass that led to the decision to build 34 km of new track in the area, including a 14.5-km tunnel through the Pass. The specifications to be met for each of the two phases of the survey are described. The first phase consisted of the establishment of a surface control network and was carried out by Nortech in the summer of 1983. The second phase is the underground alignment survey to be carried out during the period 1984–1988. The unique survey problems of Phase A encountered in such a mountainous area are described together with the methods used for their solution. The observations selected, which consisted of distances, directions, Laplace azimuths and spirit leveled heights, led to results that exceeded, in terms of accuracy, the objectives initially set. A discussion on the importance of each data type used is presented.

Inertial survey systems in the geodetic arsenal

After reviewing the overall goals of geodesy, the paper focuses on the unique properties of inertial survey systems in the geodetic arsenal: three-dimensionality; ability to determine relative positions and changes in the anomalous components of the earth’s gravity field; and independence of line-of-sight observations and the effects of refraction, both traditional antagonists in geodetic operations. Inertial survey systems, including field and office computational procedures, are briefly reviewed. Their short-comings are pointed out and certain remedies offered. Future possible improvements in hardware and software, as well as the development of hybrid systems (e.g., with gravity gradiometers), are discussed.

The William Bowie medal: Citation and acceptance

The award of the Bowie Medal to Charles Whitten is long overdue. Knowing the high, even reverential, regard in which he is held by the geophysical community, I am confident that disagreement with this assertion would come only from Whitten himself. Especially to geodesists was it inevitable that a medal named after William Bowie should go to Charles Whitten—a traditional inheritance, so to speak. He is the natural, and worthy, successor to Bowie and Walter Lambert, the 1949 Bowie Medalist. The reputation of the U.S. Coast and Geodetic Survey (since 1971, the National Ocean Survey) as the leader in geodetic research and operations in the United States has been based to a large extent on the work and influence, in turn, of these three men.

A World Survey Control System and its Implications for National Control Networks

The establishment of a modern geodetic control network is shown to be affected by two developments, the coming of age of the method of satellite geodesy and the technical progress made in the general field of precise metrology. A general description is given of the method and potential of dynamic satellite geodesy and geometric satellite triangulation for the creation of a geodetic world-wide reference system as well as for the establishment of densification control on continental land masses. The three-dimensional densification nets are shown to provide a very precise framework to which the results of the conventional geodetic surface operations can be tied. This leads to a homogeneous and unambiguously defined presentation of both the geometric and the physical parameters determined by geodetic operations. The conceptual approach is paralleled with descriptions of programs now in progress, including statements about the contemplated schedule and the expected accuracies.

Geodetic operations

This report is on the geodetic activities of various agencies in the United States covering the period from January 1, 1967, through December 31, 1970. The material is arranged in five parts corresponding to the five Sections of the International Association of Geodesy: (1) Geometrical Determination of Positions; (2) Leveling and Ground Movements; (3) Geodetic Astronomy and Artificial Satellites; (4) Measurement of Gravity; and (5) Physical Geodesy.

Canadian tellurometer investigations 1957–1959

While the tellurometer is undoubtedly a very valuable and useful instrument, we are convinced that it must be used, for geodetic purposes at least, with a proper understanding of its limitations. Our investigations indicate that it is not a suitable instrument for the measurement of short lines. When used with proper precautions to measure lines longer than 10 or 15 kilometres, on the other hand, it appears to give results to an accuracy of about one part in 200, 000. “Proper precautions” include measurement across the whole carrier frequency range or cavity range of the instrument; repeated measurements spread over several hours and preferably on different days; attention to ambiguities and ground swing, and measurement from offset stations in cases wher this seems desirable; attention to weather conditions, and an attempt to make measurements when conditions at the two stations are representative of conditions along the line of sight; and attention to crystal frequency with checks on frequency when feasible. As with all geodetic operations, redundant quantities should be measured to provide checks, and if possible such checks should be applied as the work proceeds.

Geodetic operations in Mexico from June, 1952, to May, 1953

With some interruptions due to bad atmospheric conditions angular observations continued on the projected arc of triangulation in the State of Chiapas, which will shortly complete the triangulation tie with the triangulation of Guatemala.The observations on the chain along the 23rd parallel have been temporarily suspended in order to assign all the available elements to the Chiapas arc.

A Function Calculator as applied to Geodesy

The range of computation in normal calculators can be extended to functions by providing an usual machine both with a storage unit containing approximate values of functions for arguments in rough steps and factors of interpolation and a device for transferring the values from the storage unit into the calculator proper. Then values of function for any argument may be computed by direct or inverse interpolation from the values stored. Accuracy depends on the number and distribution of the stored values. If usual trigonometric functions are concerned, five-place sometimes even six-place accuracy may be obtained by storing no more than 100 values of function and 100 factors of interpolation. Such a degree of accuracy is sufficient for almost any computation in geodetic operations of lower order, including third-order triangulation. At the Geodetic Institute of the Stuttgart Technische Hochschule a try-out model was developed, with wich the functions sinx, cosx, lanx, cotanx and their inverse functions as well as sec tanx (secant of tangent) and $$\sqrt {x^2 } $$ can be computed. As basic machine a hand calculator with Odhner wheels was used. Experiments with the hand try-out calculator showed that the amount of computing erros is only half of that committed in the usual computations by the customary calculators and printed tables of functions. In addition, gain of time was reached in most computations, which amounts to 50 percent in certain problems. Tests also made it clear that the operation of the function calculator even in the actual state of the try-out machine is very simple and can easily be learnt so that also untrained people may operate it. It may be noted that the majority of the persons used in the testing the try-out machine were willing to repeat the computations if so required, by means of the function calculator, but not so with the function tables. Therefore the function calculator appears well suited not only to simplify geodetic computation considerably but also to make it more efficient.

Geodetic surveying in Latin America

In the United States there is so much activity in surveying, both public and private, that we are liable to ignore or at least to be indifferent to surveys being conducted in other sections of the world. This short discussion on geodetic surveys in Latin America is intended to present an account of extensive geodetic operations now being executed in our fellow Americas.At Washington in 1943, at Rio de Janeiro in 1944, at Caracas in 1946, and most recently at Buenos Aires in October, 1948, meetings have been held, resolutions have been passed, and standards for geodetic surveys have been adopted. The organization responsible for these meetings is the Pan American Consultation on Cartography under the sponsorship of the Pan American Institute of Geography and History. The member nations of the Pan American Union have banded together to formulate comprehensive plans and to coordinate systematic geodetic surveys of Central and South America, with the ultimate aims of establishing precise geodetic control throughout all of the Americas, of developing a continental datum for South America based on the International Ellipsoid, and of producing accurate maps of these regions. In the province of geodesy, it was resolved that the standards should not be below those recommended by the International Union of Geodesy and Geophysics.

William Bowie as an isostasist and as a man

I had the honor to be in intimate correspondence with William Bowie from 1923 until his death in 1940. Because Bowie's letters to me—40 in all—dealing with scientific and other questions of mutual interest will throw clear and pleasant light on Bowie's personality as a scientist and as a man, I shall include some quotations taken from these letters.It was fortunate for the geodetic science of the United States of America and of the whole world that there were as chiefs of the Division of Geodesy of the United States Coast and Geodetic Survey such far‐seeing scientists as J. F. Hayford and later William Bowie. Their scientific interest and high authority resulted in the fact that this large and well‐established institution was not content with the practical results of the geodetic operations, such as the computing of the coordinates of the fixed points and the heights of the points of the precise leveling, but it tried also to draw conclusions of a purely scientific character and also to use the time of the staff for such purposes. As a result of this endeavor we have now, for instance, the “International Earth Ellipsoid” of Hayford, the “Bowie reduction” of the gravity anomalies, and the Hayford‐Bowie isostatic system.

Annual report of progress of the Geodetic Work of the Coast and Geodetic Survey

Geodetic operations in the United States are accomplished in the main part by the Coast and Geodetic Survey which is the principal agency for the extension of control‐surveys consisting of triangulation and leveling, base‐measurements, astronomical observations, gravity‐determinations, and other operations incidental thereto. It has been reported at previous annual meetings that much control‐work was accomplished by the Bureau during 1933, 1934, and 1935 through the use of emergency funds. Those funds were exhausted in July 1935 and, as our regular appropriations had also been curtailed meanwhile, geodetic operations were necessarily very drastically reduced at that time. Operations since then have been through funds made available through reduced regular appropriations, by transfer of funds from cooperative agencies, and by cooperation with the Works Progress Administration in several States.