About the stability of the altitude base benchmarks

The purpose of the study is to assess the stability of the height base benchmarks by comparing the approximate and strict methods of processing the results of repeated leveling cycles. The study involves the analysis of methods based on selecting the most stable benchmark, utilizing the principles of "relative" and "absolute" evaluation. The goal is also to identify the most efficient approach to the mathematical processing of leveling results within free geodetic networks, which pose a high risk of false identification of stable points. This issue mainly concerns the initial selection of the reference surface, which is essential for calculating the benchmark marks, their vertical displacements, and assessing the stability of the benchmarks themselves. Methods and results. The article considers various methods for assessing the stability of benchmarks, which can be classified into "relative" and "absolute", depending on the accuracy measurement criteria. Mathematical calculations are presented for the measurement results of the elevations between benchmarks in several leveling cycles of the leveling network at the industrial site. The maximum errors for each benchmark are determined. Through this analysis, benchmarks that meet the stability requirements were identified, and criteria were established for assessing the relative stability and instability of benchmarks. A comparison of the approximate and strict methods for evaluating benchmark stability, based on the measurement results, showed that the approximate method developed by A. Kostekhel is one of the most efficient approaches for determining the benchmark stability. The strict method allows for the accurate and reliable determination of the benchmark displacement; however, it may require more computational resources. The studies showed that the two methods considered in the article agree on the results of determining the benchmark stability. Scientific novelty. The article contains valuable information for ensuring the accuracy of monitoring deformations and the stability of building structures. By utilizing the proposed universal algorithm and open-source software to analyze measurement results from repeated leveling cycles, we accurately assessed the stability of benchmark heights. This assessment is vital when performing repeated geodetic measurements on large construction sites, as it ensures the precise determination of building and structure settlement.