Determinations of the preliminary coordinates for the new gnss permanent stations in serbia

The new network of permanent GNSS (Global Navigation Satellite System) stations should be established by the end of this year. At the moment, 18 permanent stations are already established. All stations coordinates must be determined following the conditions dictated by the Republic Geodetic Authority of Serbia, i.e., the Rule Book for establishing the GNSS permanent stations network. The coordinates of stations, the final solution, must be calculated from three consecutive uninterrupted daily sessions as a combined solution of all three days. The essential condition that must be fulfilled is the daily repeatability of the coordinates of the points for the three daily solutions on the level of 10 mm in the horizontal direction and 15 mm in the vertical direction. In other words, GNSS coordinates of the permanent station can be treated as calculated and adopted as final if the differences between coordinates of the daily solution and final solution do not exceed 10 mm in the horizontal direction and 15 mm in the vertical direction. In this research, preliminary calculations of coordinates repeatability are checked using Bernese GNSS Software Version 5.2 and two online RINEX processing tools, Australian AUSPOS - Online GPS Processing Service and Canadian CSRS-PPP (Canadian Spatial Reference System Precise Point Positioning).