A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination

Simple item page
dc.contributor.advisorGovind, Rameshen_ZA
dc.contributor.authorMphuthi, Siphiwe M Matthewsen_ZA
dc.date.accessioned2017-01-20T10:34:23Z
dc.date.available2017-01-20T10:34:23Z
dc.date.issued2016en_ZA
dc.description.abstractThe objective of the research was to study the performance of the least squares collocation (LSC) and the fast Fourier transform (FFT) techniques for gravimetric geoid computation. The Land Levelling Datum (LLD) is the South African vertical datum based on more than 100 years old tide gauge measurements of mean sea level (MSL). The LLD is poorly defined so an alternative is required. The SAGEOID10 (Merry, 2009) hybrid geoid model was computed for the purpose of replacing the existing vertical datum. Two gravimetric geoid models were computed using different techniques for evaluation of the Stokes' integral, such as, LSC and one dimensional fast Fourier transform (1D-FFT) technique. The long wavelength component of the geoid models were computed using the EGM2008 geopotential model truncated at degree 720. The use of fast spectral techniques is required due to an increase of both quality and type of data available for geoid determination. The FFT method is most reliable than the LSC method, since it requires less computational time on large data set than the LSC. A system of linear equations of order equal to the number of data points is generated on the LSC method. The geoid model was computed over the province of Gauteng. It was then compared to the SAGEOID10 hybrid geoid model. The computed geoid models, SiPLSC and SiPFFT geoid model compared to the SAGEOID10 model with standard deviation of 5.6cm. The long wavelength component of the computed geoid model compared to the EGM2008 geopotential geoid model with a standard deviation of 4.2cm.en_ZA
dc.identifier.apacitationMphuthi, S. M. M. (2016). <i>A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,School of Architecture, Planning and Geomatics. Retrieved from http://hdl.handle.net/11427/22854en_ZA
dc.identifier.chicagocitationMphuthi, Siphiwe M Matthews. <i>"A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,School of Architecture, Planning and Geomatics, 2016. http://hdl.handle.net/11427/22854en_ZA
dc.identifier.citationMphuthi, S. 2016. A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Mphuthi, Siphiwe M Matthews AB - The objective of the research was to study the performance of the least squares collocation (LSC) and the fast Fourier transform (FFT) techniques for gravimetric geoid computation. The Land Levelling Datum (LLD) is the South African vertical datum based on more than 100 years old tide gauge measurements of mean sea level (MSL). The LLD is poorly defined so an alternative is required. The SAGEOID10 (Merry, 2009) hybrid geoid model was computed for the purpose of replacing the existing vertical datum. Two gravimetric geoid models were computed using different techniques for evaluation of the Stokes' integral, such as, LSC and one dimensional fast Fourier transform (1D-FFT) technique. The long wavelength component of the geoid models were computed using the EGM2008 geopotential model truncated at degree 720. The use of fast spectral techniques is required due to an increase of both quality and type of data available for geoid determination. The FFT method is most reliable than the LSC method, since it requires less computational time on large data set than the LSC. A system of linear equations of order equal to the number of data points is generated on the LSC method. The geoid model was computed over the province of Gauteng. It was then compared to the SAGEOID10 hybrid geoid model. The computed geoid models, SiPLSC and SiPFFT geoid model compared to the SAGEOID10 model with standard deviation of 5.6cm. The long wavelength component of the computed geoid model compared to the EGM2008 geopotential geoid model with a standard deviation of 4.2cm. DA - 2016 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination TI - A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination UR - http://hdl.handle.net/11427/22854 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22854
dc.identifier.vancouvercitationMphuthi SMM. A comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determination. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,School of Architecture, Planning and Geomatics, 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22854en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentSchool of Architecture, Planning and Geomaticsen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherGeomaticsen_ZA
dc.titleA comparison of the least squares collocation and the fast Fourier transform methods for gravimetric geoid determinationen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
thesis_ebe_2016_mphuthi_siphiwe_m_matthews.pdf
Size:
1.33 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Masters