360310

AFRGDB V2.3: The Updated Gravity Database for Africa using RTM Technique

Article

Last updated: 04 Jan 2025

Subjects

-

Tags

Civil Engineering.

Abstract

In the framework of the activities of the IAG sub-commission on gravity and geoid in Africa, it is needed to have a uniform gridded gravity data set to determine the earth's mathematical surface (the geoid) in Africa using Stokes' integral in either the frequency or space domain. The available gravity data set for Africa consists of land point gravity data as well as shipborne and altimetry-derived gravity anomaly data. The available gravity data set has significantly large gaps, while in some particular areas the distribution is fairly dense. Also the shipborne and altimetry data have a line structure (along tracks). This leads to a problem in determining a reasonable empirical covariance function, and consequently limits the capability of the used least-squares prediction technique. Filtering the available gravity data and degrading the ocean gravity data took place to overcome this problem. The establishment of the updated gravity database for Africa has been carried-out using the well-known RTM reduction technique, employing a weighted least-squares prediction technique. The land gravity data get the highest precision, while the shipborne and altimetry gravity data get a moderate precision. The data gaps are filled with gravity anomalies derived from the GOCE_DIR_R5 global reference model, getting the lowest precision within the prediction technique. The weighted least-squares prediction technique is thus carried-out to estimate gridded gravity anomalies. The updated gravity database AFRGDB_V2.3 has been established after performing the proper RTM restore step. The precision of the developed gravity database is tested on internal and external levels.

DOI

10.21608/jaet.2022.149901.1219

Keywords

Africa, RTM reduction technique, gravity database, geoid determination, weighted least-squares prediction

Authors

First Name

Hussein

Last Name

Abd-Elmotaal

MiddleName

A.

Affiliation

Civil Engineering Department, Faculty of Engineering, Minia University

Email

hussein.abdelmotaal@gmail.com

City

Minia

Orcid

0000-0002-1232-6564

First Name

Kurt

Last Name

Seitz

MiddleName

-

Affiliation

Karlsruhe Institute of Technology, Germany

Email

kurt.seitz@kit.edu

City

Kralsruhe

Orcid

-

First Name

Norbert

Last Name

Kühtreiber

MiddleName

-

Affiliation

Graz University of Technology, Austria

Email

norbert.kuehtreiber@tugraz.at

City

Graz

Orcid

-

First Name

Bernhard

Last Name

Heck

MiddleName

-

Affiliation

Karlsruhe Institute of Technology, Germany

Email

bernhard.heck@kit.edu

City

Karlsruhe

Orcid

-

First Name

Hansjörg

Last Name

Kutterer

MiddleName

-

Affiliation

Karlsruhe Institute of Technology, Germany

Email

hansjoerg.kutterer@kit.edu

City

Karlsruhe

Orcid

-

Volume

43

Article Issue

2

Related Issue

48479

Issue Date

2024-06-01

Receive Date

2022-08-13

Publish Date

2024-06-01

Page Start

43

Page End

51

Print ISSN

2682-2091

Online ISSN

2812-5487

Link

https://jaet.journals.ekb.eg/article_360310.html

Detail API

https://jaet.journals.ekb.eg/service?article_code=360310

Order

360,310

Type

Original Article

Type Code

1,142

Publication Type

Journal

Publication Title

Journal of Advanced Engineering Trends

Publication Link

https://jaet.journals.ekb.eg/

MainTitle

AFRGDB V2.3: The Updated Gravity Database for Africa using RTM Technique

Details

Type

Article

Created At

25 Dec 2024