An Attempt Towards an Optimum Combination of Gravity Field Wavelengths in Geoid Computation

Abd-Elmotaal, Hussein A.; Kühtreiber, N.

doi:10.1007/978-3-540-85426-5_24

Cited by 2 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For a better combination of the different wavelengths of the earth's gravity field (e.g., Featherstone et al 1998;Abd-Elmotaal and Kühtreiber 2008), the contribution of the reduced gridded gravity anomalies g G wi n-red to the geoid N g win-red is determined on a 5 0 5 0 grid covering the African window using Stokes' integral employing Meissl (1971)…”

Section: Geoid Determinationmentioning

confidence: 99%

See 1 more Smart Citation

A Precise Geoid Model for Africa: AFRgeo2019

Abd-Elmotaal

Kühtreiber

Seitz

et al. 2020

International Association of Geodesy Symposia

View full text Add to dashboard Cite

In the framework of the IAG African Geoid Project, an attempt towards a precise geoid model for Africa is presented in this investigation. The available gravity data set suffers from significantly large data gaps. These data gaps are filled using the EIGEN-6C4 model on a 15′× 15′ grid prior to the gravity reduction scheme. The window remove-restore technique (Abd-Elmotaal and Kühtreiber, Phys Chem Earth Pt A 24(1):53–59, 1999; J Geod 77(1–2):77–85, 2003) has been used to generate reduced anomalies having a minimum variance to minimize the interpolation errors, especially at the large data gaps. The EIGEN-6C4 global model, complete to degree and order 2190, has served as the reference model. The reduced anomalies are gridded on a 5′× 5′ grid employing an un-equal weight least-squares prediction technique. The reduced gravity anomalies are then used to compute their contribution to the geoid undulation employing Stokes’ integral with Meissl (Preparation for the numerical evaluation of second order Molodensky-type formulas. Ohio State University, Department of Geodetic Science and Surveying, Rep 163, 1971) modified kernel for better combination of the different wavelengths of the earth’s gravity field. Finally the restore step within the window remove-restore technique took place generating the full gravimetric geoid. In the last step, the computed geoid is fitted to the DIR_R5 GOCE satellite-only model by applying an offset and two tilt parameters. The DIR_R5 model is used because it turned out that it represents the best available global geopotential model approximating the African gravity field. A comparison between the geoid computed within the current investigation and the existing former geoid model AGP2003 (Merry et al., A window on the future of geodesy. International Association of Geodesy Symposia, vol 128, pp 374–379, 2005) for Africa has been carried out.

show abstract

Section: Geoid Determinationmentioning

confidence: 99%

“…The choice of the Meissl modified kernel has been made because it proved to give good results (cf. Featherstone et al 1998;Abd-Elmotaal and Kühtreiber 2008). The full geoid restore expression for the window technique reads Kühtreiber 1999, 2003)…”

Section: Geoid Determinationmentioning

confidence: 99%

A Precise Geoid Model for Africa: AFRgeo2019

Abd-Elmotaal

Kühtreiber

Seitz

et al. 2020

International Association of Geodesy Symposia

View full text Add to dashboard Cite

show abstract

“…The optimal cap radius depends on the applied GGM and the method of modifying the Stokes integral kernel. Based on empirical tests using the EGM96 geopotential model (Lemoine et al 1998) as well as Meissl's modified Stokes' kernel, the optimal cap radius at the level of 1.78 was determined (Abd-Elmotaal & Kühtreiber 2009). In turn, using the EGM2008 geopotential model (Pavlis et al 2012) and Wong and Gore modified kernel, the 18 cap radius was found to be the most appropriate (Featherstone et al 2011).…”

Section: Introductionmentioning

confidence: 99%

Estimation of optimal quantitative parameters of selected input data used in local quasigeoid modelling by the GGI method

Trojanowicz

2014

Journal of Spatial Science

View full text Add to dashboard Cite

The analyses performed in this study relate to the method of quasigeoid modelling which uses the geophysical gravity data inversion technique (GGI method). The purpose of the analyses was to estimate the optimal values of quantitative parameters of selected input data used in the calculations. In particular, the following parameters were investigated: extents of a digital elevation model and the Moho depth model, the extent of the area covered by gravity data and density of gravity data. In order to perform the analyses, a series of local quasigeoid models was determined with different values of the above-mentioned parameters. The optimal values of the parameters were subsequently estimated based on the analyses of changes of quasigeoid models.

show abstract

An Attempt Towards an Optimum Combination of Gravity Field Wavelengths in Geoid Computation

Cited by 2 publications

References 10 publications

A Precise Geoid Model for Africa: AFRgeo2019

A Precise Geoid Model for Africa: AFRgeo2019

Estimation of optimal quantitative parameters of selected input data used in local quasigeoid modelling by the GGI method

Contact Info

Product

Resources

About