Acta Geodynamica et Geomaterialia

Title: GEOID HEIGHT COMPUTATION IN STRIP-AREA PROJECT BY USING LEAST-SQUARES COLLOCATION
Author: Doganalp Serkan
DOI: 10.13168/AGG.2015.0054
Journal: Acta Geodynamica et Geomaterialia, Vol. 13, No. 2 (182), Prague 2016
Full Text: PDF file (1.5 MB)
Keywords: GPS/leveling, Strip area, Least-squares collocation, Geoid, Interpolation
Abstract: GPS/leveling technique is the most effective engineering method for the determination of heights and height differences. This method is based on the principal of conversion of ellipsoid heights to orthometric heights. For transformation, polynomial surface models are generally used for study region or area. The accuracy of results depends on the location and distribution of selected reference stations with known ellipsoidal and orthometric heights. Especially, in the strip area projects (highway, railway, channel etc.) polynomial curve model is used instead of polynomial surface model due to reference stations disturbing along a route. In this research, Least Squares Collocation (LSC) methods used in determining the geoid heights of a strip area were examined. For this purpose, GPS/leveling data of Bozkurt-Dinar (Afyonkarahisar) train project which is approximately 75 km was used in order to examine LSC methods. The ground control stations of the project were classified as reference and test for the purpose of this research. The geoid heights of test stations were calculated by curve polynomial with different degrees. Additionally geoid heights at the same points were calculated using polynomial curve fitting based on LSC which is suggested by this research. The geoid heights by computed using LSC approach when compared to polynomial curve method were observed to yield better results.