Znaleziono wyników: 3
Liczba wyników na stronie
Wyniki wyszukiwania
nabierają dużego znaczenia w świetle budowy kinematycznego układu wysokościowego. W opracowaniu podjęto tematykę pozyskania danych geodezyjnych (niwelacyjnych), które umożliwiłyby rozpoczęcie prac nad kinematycznym wyznaczeniem ruchów pionowych skorupy ziemskiej na obszarze Polski. Badany materiał niwelacyjny to dane z czterech ostatnich kampanii niwelacyjnych przeprowadzonych w latach: 1926-1937, 1953-1955, 1974-1982, 1997-2003. Sprawdzono także możliwość pozyskania informacji o ruchach pionowych z mapy ruchów pionowych z roku 1985.
design. In the paper, the author presents the possibilities of compiling the geodetic (levelling) data, what would enable commence works on defining the kinematic vertical movements of the Earth'scrust all over Poland. Data used in the research are taken last four comppppings, performed in 1926-1937, 19531955, 1974-1982, 1997-2003. Furthermore data from the verticalcrustal movements map from 1985 was taken into account.
course than the one offered by the national model PL-geoid2011. Only four measurement points in the area of Kraków were used to build a national quasigeoid model. It can be assumed that due to the small number of points and their uneven distribution over the city area, the quasigeoid can be determined less accurately. It became the reason for developing a local quasigeoid model based on a larger number of evenly distributed points. The quasigeoid model was based on 66 evenly distributed points (from 2.5 km to 5.0 km apart) in the study area. The process of modelling the quasigeoid used height anomalies determined at these points on the basis of normal heights derived through levelling and ellipsoidal heights derived through GNSS surveys. Height anomalies coming from the global geopotential model EGM2008 served as a long-wavelength trend in those derived from surveys. Analyses showed that the developed height anomaly model fits the empirical data at the level of single millimetres – mean absolute difference 0.005 m. The developed local model QuasigeoidKR2019, similar to the national model PL-geoid2011, are models closely related to the reference and height systems in Poland. Such models are used to integrate GNSS and levelling observations. A comparison of the local QuasigeoidKR2019 and national PL-geoid2011 model was made for the reference frame PL-ETRF2000 and height datum PL-KRON86-NH. The comparison of the two models with respect to GNSS/levelling height anomalies shows a triple reduction in the values of individual quartiles and a mean absolute difference for the developed local model. These summary statistics clearly indicate that the accuracy of the local model for the city of Krakow is significantly higher than that of the national one.
Ograniczanie wyników