Nova formula za izračun koeficijenta korelacije u geodetskim mjerenjima za mali broj opažanja

When performing geodetic surveys, the number of measurements is usually small, which in the case of dependent series of measurements leads to an underestimation of the correlation coefficient calculated by the standard formula. A new formula for determining the correlation coefficient is proposed. The values of correlation coefficients calculated by the new formula and by the known ones were compared for the number of measurements . It was found that the correlation coefficient values calculated by the new formula will have higher values as compared to the values calculated by the known formulas, i.e. these values will be less biased with respect to the true values of the correlation coefficients. The correlation coefficients obtained by the new formula will be maximal at an appropriate level of significance and number of degrees of freedom. With a large number of measurements, the values of correlation coefficients obtained by the new formula and by the formulas that are widely used in geodesy and photogrammetry will not differ significantly.Prilikom izvođenja geodetskih izmjera, broj mjerenja je obično mali što u slučaju serije ovisnih mjerenja dovodi do niske procjene koeficijenta korelacije izračunatog pomoću standardne formule. Predlaže se nova formula za određivanje koeficijenta korelacije. Uspoređene su vrijednosti koeficijenta korelacije izračunate pomoću nove formule i pomoću poznatih formula za broj mjerenja . Utvrđeno je da će vrijednosti koeficijenta korelacije izračunate novom formulom biti veće u usporedbi s vrijednostima izračunatima pomoću poznatih formula, odnosno te vrijednosti će biti manje pristrane u odnosu na prave vrijednosti koeficijenata korelacije. Koeficijenti korelacije dobiveni pomoću nove formule bit će maksimalni na odgovarajućoj razini značaja i broja stupnjeva slobode. Za veliki broj mjerenja, vrijednosti koeficijenata korelacije dobivene novom formulom i formulama čija je upotreba raširena u geodeziji i fotogrametriji neće se značajno razlikovati

Nova formula za izračun koeficijenta korelacije u geodetskim mjerenjima za mali broj opažanja

When performing geodetic surveys, the number of measurements is usually small, which in the case of dependent series of measurements leads to an underestimation of the correlation coefficient calculated by the standard formula. A new formula for determining the correlation coefficient is proposed. The values of correlation coefficients calculated by the new formula and by the known ones were compared for the number of measurements . It was found that the correlation coefficient values calculated by the new formula will have higher values as compared to the values calculated by the known formulas, i.e. these values will be less biased with respect to the true values of the correlation coefficients. The correlation coefficients obtained by the new formula will be maximal at an appropriate level of significance and number of degrees of freedom. With a large number of measurements, the values of correlation coefficients obtained by the new formula and by the formulas that are widely used in geodesy and photogrammetry will not differ significantly.Prilikom izvođenja geodetskih izmjera, broj mjerenja je obično mali što u slučaju serije ovisnih mjerenja dovodi do niske procjene koeficijenta korelacije izračunatog pomoću standardne formule. Predlaže se nova formula za određivanje koeficijenta korelacije. Uspoređene su vrijednosti koeficijenta korelacije izračunate pomoću nove formule i pomoću poznatih formula za broj mjerenja . Utvrđeno je da će vrijednosti koeficijenta korelacije izračunate novom formulom biti veće u usporedbi s vrijednostima izračunatima pomoću poznatih formula, odnosno te vrijednosti će biti manje pristrane u odnosu na prave vrijednosti koeficijenata korelacije. Koeficijenti korelacije dobiveni pomoću nove formule bit će maksimalni na odgovarajućoj razini značaja i broja stupnjeva slobode. Za veliki broj mjerenja, vrijednosti koeficijenata korelacije dobivene novom formulom i formulama čija je upotreba raširena u geodeziji i fotogrametriji neće se značajno razlikovati

Comparative analysis for methods of building digital elevation models from topographic maps using geoinformation technologies

The article considers the question of estimating the accuracy of interpolation methods for building digital elevation models using Soviet topographic maps. The territory of the Kursk region of the Russian Federation was used as the study area, because it is located on the Central Russian Upland and characterized by the complex structure of the vertical and horizontal dissection of the relief. Contour lines automatically obtained using a Python algorithm were used as the initial elevation data to build a digital elevation model. Digital elevation models obtained by thirteen different interpolation methods in ArcGIS and Surfer software were built and analyzed. Special attention is paid to the ANUDEM method, which allows to obtain hydrologically correct digital elevation models. Recommendations for the use of one or another method of interpolation are given. The results can be useful for professionals who use topographic maps in their work and deals with the design using digital elevation models

Accuracy of coordinate determinations of the network of protected zone points according to the results of GNSS observations

The article examines errors of the planned position of the points of the educational and research site “Fortuna” of the Chernihiv Polytechnic National University (Ukraine), located in a forested area. Kinematic positioning has been performed using a GNSS receiver GeoMax Zenith 10/20 in real time mode. The network of permanent satellite GNSS stations System NET has been used as a coordinate basis. RTK Master Auxiliary Corrections (MAX) technology has been used to form the corrective amendments. The calculation of RTK corrections has been performed using the software package Leica GNSS Spider v4.3. The Transverse Mercator cartographic projection has been used to determine the flat rectangular coordinates in the USK-2000 system. The values of the coordinates determined in the RTK mode have been compared with the coordinates obtained by the method of electronic polygonometry, which are estimated to be 3 times more accurate. Coordinate differences have formed error vectors. As a result of analysis of the vector field, a stable tendency has been established: the deviation of the planned coordinates of the site points, determined by the method of GNSS-observations in real time mode and located in the forest park zone, in the direction of the base station