Determination of the geoid profile between the Mediterranean and the Black Sea by GPS/levelling

Abstract. The geoid profile, which extends nearly in north-south direction between Antalya and Samsun tide gauges, is determined by GPS/levelling along the first order levelling line of Turkish National Vertical Control Network (TNVCN). 47 levelling benchmarks at 20-25 km intervals were selected as GPS/levelling points with known Helmert orthometric heights. Two GPS campaigns were conducted to determine the ellipsoidal heights at these benchmarks and some Turkish National Fundamental GPS Network (TNFGN) sites. Ankara (ANKR) and some other IGS stations were added to the processing and data were processed using Bernese GPS software V4.2. The repeatability of the height component (RMS) was found to be ±17 mm for GPS/levelling stations. The geoid heights computed from TNVCN orthometric heights, and GPS ellipsoidal heights were compared with geoi