Line lengths comparison results on the spatial reference basis SGUGiT

The results of line lengths comparison on the spatial reference basis (SRB) of SGUGiT, carried out according to the program in all combinations measurements in the forward direction from point BI01 to point BI10 in spring and summer of 2021 and 2023 using total station Leica TM30, as well as, in the same seasons of 2023 done by laser tracker Leica AT403 are given. Based on the analysis of multiple measurements of each section of the basis (at least 30 ones), the standard deviation and uncertainty were calculated. Meanwhile, at the extreme points of the base section, meteorological parameters (temperature, pressure and relative humidity) were recorded by two independent instruments, which were then entered immediately when metering with a Leica TM 30 electronic total station. In the case of the Leica AT403 laser tracker, they were automatically taken into account in specialized software management and processing of Spatial Analyzer measurement data. Due to the research results, it was found out that the expanded uncertainty in measuring the lengths of the basic lines in the range from 12 to 192 m on the WPT using a Leica AT403 laser tracker and a Leica TM30 electronic total station, taking into account the accepted errors that affect the final result, is no more than 1,4 mm, and the maximum contribution to the mistake in determining line lengths is made by the standard uncertainty estimated by type B. In addition, seasonal fluctuations in the position of individual basis points are observed