Determination of reference directions at a certified range using GNSS measurements

This work examines the results of experimental GNSS measurements in 2022 performed at the points of the scientific geodetic range (NSG). The purpose of the research is to perform simultaneous GNSS measurements at four points of the reference linear base (ELB) section and to process experimental GNSS observations at points of the metrological calibrated geodetic network to determine reference azimuths and directional angles. Method. Experimental measurements were carried out using two frequency GNSS receivers with every second registration of signals and binding to the nearest permanent stations that are part of the International GNSS service: GEOTERRACE. The paper considers the application of the method of calculating azimuths using geodetic coordinates of points and parameters of reference ellipsoids. The results. Data processing of synchronous observations of points (ELB) and permanent stations was performed in the Leica Geo Office software complex. The value of the marginal error of determining the coordinates of the investigated points does not exceed 5 mm. The results of the calculations of the investigated azimuths for different coordinate systems and the accuracy of their determination are given. The parameters of the Krasovsky, WGS-84 and ITRF 2000 ellipsoid references were used for the calculations. The calculated values of the direction angles in the USK 2000 coordinate system for the six-degree zone. Scientific novelty. The possibility of using GNSS measurements for creating reference directions, determining their azimuths and directional angles is shown. An accuracy assessment was carried out based on the results of the measurements. The calculated accuracy of determining the azimuths of the directions depends on the accuracy of determining their coordinates and the distance between observation points. The obtained formula for calculating the accuracy of direction determination in angular units. Practical significance. The stability of the points calibrated by the metrological service of the ELB NHP section over time has been confirmed, which gives grounds for using the investigated directions as standards for calibration of navigation equipment. Calculated azimuths and direction angles of the selected directions for different coordinate reference systems. The calculated value of the convergence of the meridians for the six-degree zone of USK 2000 point P-1. The obtained values of true azimuths can be used to study the inclination of the magnetic needle.