Incorporation of the vertical gravity gradient observations to the determination of separation between geoid and quasigeoid on Poland territory

An application of observed gravity vertical gradient to the determination of the separation between geoid and Molodeski`s gusigeoid is discussed in the paper. The author gives results of studies obtained from gradientometric measurements in a vicinity of Warsaw (Central Poland) and in sub-mountainous area near Grybów (Cracow district-Carpathians). The values of (sigma)-N are not negligibly for GPS levelling, too. Component depending on the gravity gradient achieves the value up to 2 mm, while the Bouguer anomalies contribute about 25 mm to (sigma)-N.