Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Determination of a gravimetric geoid model of Sudan using the KTH method
KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Satellite Positioning.
2009 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The main objective of this study is to compute a new gravimetric geoid model of Sudan

using the KTH method based on modification of Stokes’ formula for geoid determination.

The modified Stokes’ formula combines regional terrestrial gravity with long-wavelength

gravity information provided by the global gravitational model (GGM). The collected

datasets for this study contained the terrestrial gravity measurements, digital elevation

model (DEM), GPS/levelling data and four global gravitational Models (GGMs), (EGM96,

EIGEN-GRACE02S, EIGEN-GL04C and GGM03S).

The gravity data underwent cross validation technique for outliers detection, three gridding

algorithms (Kriging, Inverse Distance Weighting and Nearest Neighbor) have been tested,

thereafter the best interpolation approach has been chosen for gridding the refined gravity

data. The GGMs contributions were evaluated with GPS/levelling data to choose the best

one to be used in the combined formula.

In this study three stochastic modification methods of Stokes’ formula (Optimum, Unbiased

and Biased) were performed, hence an approximate geoid height was computed. Thereafter,

some additive corrections (Topographic, Downward Continuation, Atmospheric and Ellipsoidal)

were added to the approximated geoid height to get corrected geoid height.

The new gravimetric geoid model (KTH-SDG08) has been determined over the whole

country of Sudan at 5′ x 5′ grid for area ( 4 ). The optimum method

provides the best agreement with GPS/levelling estimated to 29 cm while the agreement for

the relative geoid heights to 0.493 ppm. A comparison has also been made between the new

geoid model and a previous model, determined in 1991 and shows better accuracy.

􀁄 ≤φ ≤ 23􀁄 , 22􀁄 ≤ λ ≤ 38􀁄

Keywords: geoid model, KTH method, stochastic modification methods, modified Stokes’ formula,

additive corrections.

Place, publisher, year, edition, pages
2009.
Series
TRITA-GIT EX ; 09-001
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-199670OAI: oai:DiVA.org:kth-199670DiVA, id: diva2:1064844
Subject / course
Geodesy
Supervisors
Available from: 2017-01-19 Created: 2017-01-13 Last updated: 2017-01-19Bibliographically approved

Open Access in DiVA

fulltext(3209 kB)223 downloads
File information
File name FULLTEXT01.pdfFile size 3209 kBChecksum SHA-512
222a19665360c8f1a7df1edc4cf6b4e97bec86bf95bf02e1a4508730d750f79299945b9b008db16400f740c6afe87990eb9e66ccbaf7b9a4fa29949424716e18
Type fulltextMimetype application/pdf

By organisation
Geodesy and Satellite Positioning
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 223 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 410 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf