Determination of local geoid profile using GPS observations and leveling measurements in Afyonkarahisar

ABSTRACT Geoid determination is modelling of data such that geoid height can be obtained either as digitally or analogus at a point whose horizontal coordinates known. Geoid models can be developed as local, regional or global. Geoid determination methods can be classified according to used data and models. This study was made to observe the difference between geoid and elipsoid surrounding The Campus of Afyon Kocatepe University. Another meaning, the variation of geoid heights and geoid undulations 18 points were established approximate on the North-south direction during the road of Afyonkarahisar- Eskişehir. These points represents the areas specialities. GPS levelling were measured to calculate the difference of the elipsoidal heights. Orthometric heights were measured by geometric levelling that approximate the difference of orthometric heights computed. According to the results for this area the geoid height approximately was found 38.126 m regularity of the variations of the geoid undulations have observed. The regularities depends on the areas topography. Key Word : Geoid, Geoid Undulation, Ellipsoid, Elipsoidal Height, Orthometric Height, GPS/Levelling u