## 1 Introduction
They have similar functions, and require the user to enter the following input data [38]:  
* Approximate ellipsoidal coordinates (B, L, h) of the measurement location;
* The indication of the difference between the local time and the Universal Time Coordinated (UTC), related to the selection of the appropriate time zone;
* The determination of the min. elevation cut-off. It was assumed in the surveying that this parameter value should be 10-15\({}^{\circ}\) depending on the type of field obstacles;
* The selection of the day and the time interval during which the measurements will be carried out;
* The determination, if required, of field obstacles that denote these parts of the celestial sphere that will be \"obscured\" by the surrounding objects. To this end, field obstacles are entered manually into the software for planning GNSS measurements. However, the current applications for the planning of a GNSS measurement campaign have many limitations that may result in the forecast measurement conditions being significantly different from the actual ones. Among other things, the available programs enable the determination of the effect of satellite constellation geometry on the positioning accuracy exclusively for a single measurement point. Therefore, they can only be used in surveying applications and should not be used for the planning of a linear object GNSS measurement campaign. Pursuant to [39], a linear object is a civil structure whose characteristic parameter is the length, in particular, a canal, a flood bank, a gas pipeline, a heat pipeline, a pipeline, a railway line, a road, a water supply, an overhead and underground (placed directly in the ground) cable line, cable ducting, as well as electric power line and traction. Another disadvantage of programs of this type is the approximate, and often inaccurate, determination of field obstacles found in the vicinity of the measurement location [40; 41]. This can be particularly noticeable in urban, built-up areas which are referred to in the literature as urban anyons [42; 43; 41], where the tracking of each additional satellite has a significant effect on the positioning accuracy by the user [44; 20]. It should also be noted that in urbanised areas, the multipath signal sent by the satellite to the user often occurs, which results in an increased position error [45; 46; 47]. Moreover, one must not forget the terrain model that is not taken into account in the applications for the planning of a GNSS measurement campaign. The authors believe that taking the Digital Surface Model (DSM) into account is an important factor when determining the satellite visibility, particularly those that are found at low topocentric elevations in relation to the observer. Therefore, it was reasonable to develop a system for the planning of a linear object GNSS measurement campaign to be implemented in motion, taking into account the terrain model and its coverage. According to the authors, it can be successfully used in navigation applications, e.g., when carrying out an inventory of railway routes [48]. Moreover, it allows DOP values to be determined in a more realistic and reliable manner than the widely available programs. The aim of this study is to test software for the planning of a linear object GNSS measurement campaign under simulated conditions. In order to achieve the main aim of the study, the following partial aims needed to be considered:  
1. The determination of the schedule for the optimum navigation of a linear object, generated by the software for the planning of a GNSS measurement campaign;
2. A comparison of the PDOP obtained during the performance of simulation tests;
3. The assessment of the effect of field obstacles found along the linear object on the accuracy of GNSS measurement campaign planning. This article is structured as follows: Section 2 describes the developed software for the planning of a linear object GNSS measurement campaign in terms of description, assumptions, requirements, user interface, input parameters, map, and results of the operation.