scholarly journals An Analysis of Choosing Gravity Anomalies for Solving Problems in Geodesy, Geophysics and Environmental Engineering

2020 ◽  
Author(s):  
Vytautas Puškorius ◽  
Eimuntas Paršeliūnas ◽  
Petras Petroškevičius ◽  
Romuald Obuchovski
Keyword(s):  
Gravity Field ◽  
Gravity Anomalies ◽  
Environmental Engineering ◽  
Correct Selection ◽  
Earth’S Gravity Field ◽  
The Earth ◽  
Pure Gravity ◽  
Geodynamic Processes ◽  
Selection Of

Gravity anomalies provide valuable information about the Earth‘s gravity field. They are used for solving various geophysical and geodetic tasks, mineral and oil exploration, geoid and quasi-geoid determination, geodynamic processes of Earth, determination of the orbits of various objects, moving in space around the Earth etc. The increasing accuracy of solving the above mentioned problems poses new requirements for the accuracy of the gravity anomalies. Increasing the accuracy of gravity anomalies can be achieved by gaining the accuracy of the gravimetric and geodetic measurements, and by improving the methodology of the anomalies detection. The modern gravimetric devices allow to measure the gravity with an accuracy of several microgals. Space geodetic systems allow to define the geodetic coordinates and ellipsoidal heights of gravimetric points within a centimeter accuracy. This opens up the new opportunities to calculate in practice both hybrid and pure gravity anomalies and to improve their accuracy. In this context, it is important to analyse the possibilities of detecting various gravity anomalies and to improve the methodology for detecting gravity anomalies. Also it is important the correct selection of the gravity anomalies for different geodetic, geophysical and environmental engineering tasks. The modern gravity field data of the territory of Lithuania are used for the research.

Assessment of efficiency of distribution centre at different variants of freight traffic consolidation

2021 ◽  
pp. 22-27
Author(s):  
Elena Dmitrievna Pserovskaya ◽  
◽  
Anna Pavlovna Grefenshteyn ◽  
Keyword(s):  
Potential Benefit ◽  
High Efficiency ◽  
Positive Influence ◽  
Correct Selection ◽  
Freight Traffic ◽  
Distribution Centre ◽  
Selection Of

For the determination of a potential benefit from creation of a distribution centre the paper proposes a method and presents results of calculation of a decrease of total number of rides and total run of automobiles at various variants of goods consolidation. The authors have established a positive influence of the centre on intracity transportation. At the same time, high efficiency of the considered technology can be reached by involvement of a bigger number of consignees and by consolidation of a relatively small number of goods batches in one automobile at efficient routing and correct selection of location of a distribution centre.

5. Gravity and the figure of the Earth

2018 ◽  
pp. 69-91
Author(s):  
William Lowrie
Keyword(s):  
Accurate Determination ◽  
Measurement Techniques ◽  
Gravity Anomalies ◽  
Dynamic Processes ◽  
The Core ◽  
The Earth ◽  
Free Air ◽  
Figure Of The Earth ◽  
Free Air Gravity

‘Gravity and the figure of the Earth’ discusses the measurement of gravity and its variation at the Earth’s surface and with depth. Gravity is about 0.5 per cent stronger at the poles than at the equator and it first increases with depth until the core–mantle boundary and then sinks to zero at the Earth’s centre. Using satellites to carry out geodetic and gravimetric observations has revolutionized geodesy, creating a powerful geophysical tool for observing and measuring dynamic processes on the Earth. The various measurement techniques employed fall in two categories: precise location of a position on the Earth (such as GPS) and accurate determination of the geoid and gravitational field. Bouguer and free-air gravity anomalies and isostasy are explained.

scholarly journals Evaluation of Gravity Data Derived from Global Gravity Field Models Using Terrestrial Gravity Data in Enugu State, Nigeria

2018 ◽  
Vol 8 (1) ◽  
pp. 145-153 ◽  
Author(s):  
O.I. Apeh ◽  
E.C. Moka ◽  
V.N. Uzodinma
Keyword(s):  
Gravity Field ◽  
Gravity Data ◽  
Gravity Anomalies ◽  
Mean Square ◽  
Bouguer Gravity ◽  
Bouguer Anomalies ◽  
The Earth ◽  
Global Gravity ◽  
Enugu State ◽  
Gravity Field Models

Abstract Spherical harmonic expansion is a commonly applied mathematical representation of the earth’s gravity field. This representation is implied by the potential coeffcients determined by using elements/parameters of the field observed on the surface of the earth and/or in space outside the earth in the spherical harmonic expansion of the field. International Centre for Gravity Earth Models (ICGEM) publishes, from time to time, Global Gravity Field Models (GGMs) that have been developed. These GGMs need evaluation with terrestrial data of different locations to ascertain their accuracy for application in those locations. In this study, Bouguer gravity anomalies derived from a total of eleven (11) recent GGMs, using sixty sample points, were evaluated by means of Root-Mean-Square difference and correlation coeficient. The Root-Mean-Square differences of the computed Bouguer anomalies from ICGEMwebsite compared to their positionally corresponding terrestrial Bouguer anomalies range from 9.530mgal to 37.113mgal. Additionally, the correlation coe_cients of the structure of the signal of the terrestrial and GGM-derived Bouguer anomalies range from 0.480 to 0.879. It was observed that GECO derived Bouguer gravity anomalies have the best signal structure relationship with the terrestrial data than the other ten GGMs. We also discovered that EIGEN-6C4 and GECO derived Bouguer anomalies have enormous potential to be used as supplements to the terrestrial Bouguer anomalies for Enugu State, Nigeria.

Determination of Polar Motion and Earth Rotation from Laser Tracking of Satellites

1979 ◽  
Vol 82 ◽  
pp. 231-238 ◽  
Author(s):  
David E. Smith ◽  
Ronald Kolenkiewicz ◽  
Peter J. Dunn ◽  
Mark Torrence
Keyword(s):  
Gravity Field ◽  
Radiation Pressure ◽  
Orbit Determination ◽  
Earth Rotation ◽  
Polar Motion ◽  
Ocean Tides ◽  
Earth’S Gravity Field ◽  
Laser Tracking ◽  
Order Of Magnitude

Laser tracking of the Lageos spacecraft has been used to derive the position of the Earth's pole of rotation at 5-day intervals during October, November and December 1976. The estimated precision of the results is 0.01 to 0.02 arcseconds in both x and y components, although the formal uncertainty is an order of magnitude better, and there is general agreement with the Bureau International de l'Heure smoothed pole path to about 0.02 arcseconds. Present orbit determination capability of Lageos is limited to about 25 cm rms fit to data over periods of 5 days and about 50 cm over 50 days. The present major sources of error in the perturbations of Lageos are Earth and ocean tides followed by the Earth's gravity field, and solar and Earth reflected radiation pressure. Ultimate accuracy for polar motion and Earth rotation from Lageos after improved modeling of the perturbing forces appears to be of order ± 5 cm for polar motion over a period of about 1 day and about ± 0.2 to ± 0.3 milliseconds in U.T. for periods up to 2 or 3 months.

Using the Digital Models of Gravity Anomalies for Zoning of the Earth’s Gravity Field

2018 ◽  
Vol 54 (6) ◽  
pp. 964-970
Author(s):  
V. N. Koneshov ◽  
S. A. Krylov ◽  
D. S. Loginov ◽  
V. B. Nepoklonov
Keyword(s):  
Gravity Field ◽  
Gravity Anomalies ◽  
Digital Models ◽  
Earth’S Gravity Field ◽  
Models Of Gravity

scholarly journals GRAVITY ANOMALY ASSESSMENT USING GGMS AND AIRBORNE GRAVITY DATA TOWARDS BATHYMETRY ESTIMATION

2016 ◽  
Vol XLII-4/W1 ◽  
pp. 287-297
Author(s):  
A. Tugi ◽  
A. H. M. Din ◽  
K. M. Omar ◽  
A. S. Mardi ◽  
Z. A. M. Som ◽  
...  
Keyword(s):  
Gravity Anomaly ◽  
Gravity Field ◽  
Ocean Circulation ◽  
Gravity Data ◽  
Gravity Anomalies ◽  
Airborne Gravity ◽  
Satellite Gravity ◽  
Earth’S Gravity Field ◽  
Explorer Mission ◽  
Satellite Gravity Missions

The Earth’s potential information is important for exploration of the Earth’s gravity field. The techniques of measuring the Earth’s gravity using the terrestrial and ship borne technique are time consuming and have limitation on the vast area. With the space-based measuring technique, these limitations can be overcome. The satellite gravity missions such as Challenging Mini-satellite Payload (CHAMP), Gravity Recovery and Climate Experiment (GRACE), and Gravity-Field and Steady-State Ocean Circulation Explorer Mission (GOCE) has introduced a better way in providing the information on the Earth’s gravity field. From these satellite gravity missions, the Global Geopotential Models (GGMs) has been produced from the spherical harmonics coefficient data type. The information of the gravity anomaly can be used to predict the bathymetry because the gravity anomaly and bathymetry have relationships between each other. There are many GGMs that have been published and each of the models gives a different value of the Earth’s gravity field information. Therefore, this study is conducted to assess the most reliable GGM for the Malaysian Seas. This study covered the area of the marine area on the South China Sea at Sabah extent. Seven GGMs have been selected from the three satellite gravity missions. The gravity anomalies derived from the GGMs are compared with the airborne gravity anomaly, in order to figure out the correlation (R<sup>2</sup>) and the root mean square error (RMSE) of the data. From these assessments, the most suitable GGMs for the study area is GOCE model, GO_CONS_GCF_2_TIMR4 with the R<sup>2</sup> and RMSE value of 0.7899 and 9.886 mGal, respectively. This selected model will be used in the estimating the bathymetry for Malaysian Seas in future.

scholarly journals Regional Recovery of Gravity Anomaly from the Inversion of Diagonal Components of GOCE Gravitational Tensor: A Case Study in Ethiopia

2018 ◽  
Vol 53 (2) ◽  
pp. 55-74 ◽  
Author(s):  
Mehdi Eshagh ◽  
Andenet A. Gedamu ◽  
Tulu B. Bedada
Keyword(s):  
Gravity Anomaly ◽  
Gravity Field ◽  
Ocean Circulation ◽  
Opposite Sign ◽  
Joint Inversion ◽  
Gravity Anomalies ◽  
The Earth ◽  
Tikhonov Regularisation ◽  
The Difference

Abstract The tensor of gravitation is traceless as the gravitational field of the Earth is harmonic outside the Earth’s surface. Therefore, summation of the 2nd-order horizontal derivatives on its diagonal components should be equal to the radial one but with the opposite sign. The gravity field can be recovered locally from either of them, or even their combination. Here, we use the in-orbit diagonal components of the gravitational tensor measured by the gravity field and steady state ocean circulation explorer (GOCE) mission for recovering gravity anomaly with a resolution of 1°×1° at sea level in Ethiopia. In order to solve the system of equations, derived after discretisation of integral equations, the Tikhonov regularisation is applied and the bias of this regularisation is estimated and removed from the estimated gravity anomalies. The errors of the anomalies are estimated and their significance of recovery from these diagonal components is investigated. Statistically, the difference between the recovered anomalies from each scenario is not significant comparing to their errors. However, their joint inversion of the diagonal components improved the solution by about 1 mGal. Furthermore, the inversion processes are better stabilised when using errors of the input data compared with its exclusion, but at the penalty of degradation in accuracy of the estimates.

scholarly journals Gravity Surveying in Early Geophysics. I. From Time-Keeping to Figure of the Earth

2007 ◽  
Vol 26 (2) ◽  
pp. 201-228 ◽  
Author(s):  
Richard Howarth
Keyword(s):  
Twentieth Century ◽  
Earth Science ◽  
Dominant Role ◽  
Late Nineteenth Century ◽  
Earth’S Gravity Field ◽  
The Earth ◽  
Figure Of The Earth ◽  
Geological Factors ◽  
Exploration Tool

This two-part review of the development of the measurement of the Earth's gravity field, and its application to geology, up to the early 1960s, is intended primarily for an earth-science readership. The focus here is on the pendulum, which played the dominant role in measurement of the intensity of gravity (g), both in absolute (at national observatories) and relative terms (at field stations), until the early twentieth century. Following discovery of the properties of the pendulum and its incorporation in time-keepers, early post-Newtonian investigations used the length of a pendulum beating seconds as a proxy for g. The goal was to obtain ever-improved knowledge of the "Figure of the Earth," initially encapsulated in determination of the degree of flattening of the oblate ellipsoid used as a model for the geometry of the globe. Developments in theory went hand-in-hand with both improvements in pendulum design and the establishment of a constantly expanding network of astrogeodetic stations as a basis for national cartographic surveys. By the late nineteenth century, results from astrogeodetic determinations of the length of a degree of arc and those derived from gravity determinations (by means of Clairaut's theorem) had converged to an inverse flattening of 298, and emphasis switched to determination of the geoid. However, by the 1840s, discrepancies between observed and model-fitted values were providing increasingly strong evidence that geological factors also affected the local value of g . This would give rise to the use of gravity determination as a geological exploration tool in the twentieth century.

Sign in / Sign up

Export Citation Format

Share Document