## 5 Conclusions  
The aim of this study was to develop software to enable the planning of GNSS measurements for a geodetic inventory of railway lines, roads, and other linear objects included in the terrain model. The resulting software was tested under simulated conditions. The experiments proved the high reliability of the model and confirmed the appropriateness of the measurement campaign planning.  
Due to improvements in navigation systems, geodetic receivers, and reference station networks, access to precise position data is increasingly widespread. The rapid development of various economic sectors, e.g., high-speed rails, has paved the way for GNSS measurements to be used in new applications. Not only do modern land surveying products require the highest possible precision, but also the stability of surveys and their high availability. The use of satellite systems solves many traditional geodetic problems while introducing new complications. Carrying out measurements during an unfavourable constellation status can end in failure despite using state-of-the-art technologies. For this reason, it is important to plan a GNSS measurement campaign. The planning process must faithfully model the satellite constellation movements and field obstacles.  
This publication raises an important and timely issue. Rapid technological development has raised the requirements imposed on geodetic products, which is noticeable in the field of the inspection of linear objects, including railway lines. The rising requirements for the precision and spatial resolution of data while reducing time windows for carrying out the measurements necessitates continuous improvements in the data acquisition process. The purpose of the issues addressed is to improve the quality of GNSS measurements by enabling the optimal use of the possibilities of satellite systems. In the future, planning may become a necessary step in every measurement campaign, and solutions such as the software presented will be indispensable tools in implementing this process.  
In the next stage of the research, it is planned to test the software for the planning of a linear object GNSS measurement campaign under real conditions. The empirical tests will be carried out in the same way as in the simulation tests, i.e., GNSS receivers will be installed on two inspection vehicles, which will receive satellite signals in two variants: GPS and GPS/GLONASS. These vehicles will cover the planned route at a constant speed without any breaks. Subsequently, for the pre-defined time frames, both vehicles will cover the planned route in a manner optimal in terms of the minimisation of the DOP value.  
Conceptualisation, C.S. and M.M.; data curation, S.F., A.S. and M.S.; formal analysis, S.F., A.S. and M.S.; investigation, S.F., A.S. and M.S.; methodology, C.S. and M.M.; software, S.F.; supervision, C.S. and M.M.; validation, C.S. and M.M.; visualisation, S.F., A.S. and M.S.; writing--original draft, S.F. and M.S.; writing--review and editing, C.S., M.M. and A.S. All authors have read and agreed to the published version of the manuscript.  
This research was funded from the statutory activities of Gdynia Maritime University, grant number WN/2021/PZ/05.  
Not applicable.  
The authors declare no conflict of interest.