## 4 Evaluation and Conclusions  
The results presented in Figures 6 and 7 show that the dominant influence is the length correction from the projection, which takes the values of \(-\)10 cm/km on the tangential cartographic parallel running through the center of the Czech Republic and +14 cm/km on the edges of the Czech Republic [11]. The average value of the length correction from the deformations of the reference system is 0.36 cm/km; in the extreme case, the value is +2.5 cm/km; see Table 1. The above value is a negligible value for most common surveying work. An exception involves work in the field of railway surveying [13], where (particularly for high-speed lines) there is a requirement for an accuracy level of 1 cm/km. Therefore, it is necessary to combine the length corrections from the (original) Krovak projection and S-JTSK deformations (along with the introduction of the height correction for lengths, a factor that was not considered in the present study).  
Based on the results presented in Figure 9, the standard deviation of the determination of the length correction, which characterizes not only the accuracy of the determination but also the dependence of the length correction on the azimuth, i.e., the non-conformity, takes values in 5% of the area up to 1.0 cm/km. The results presented in Table 4 show that 99% of the values of the standard deviation of the length corrections from the deformations of the coordinate system lie in the interval up to \(\pm\)1.4 cm/km. The average standard deviation is 0.47 cm/km, with an extreme value of 3.6 cm/km; see Table 3. The scatter is characterized by the variability of the length correction with the azimuth, i.e., the non-conformity of the projection caused by the deformations in the coordinate system. For linear constructions that demand high precision, it is necessary to take this fact into account in geodetic works in locations with a standard deviation greater than 1 cm/km, which can be identified in Figure 10. In such a case, it should be considered whether it would be more beneficial for developers of a given project to define a local coordinate system with planar coordinates using a low-distortion map projection.  
Figure 11: The class frequencies of the standard deviations from the length correction averages at the nodes in cm/km.  
**Author Contributions:** Conceptualization, J.K. and P.C.; methodology, J.K.; software, J.K.; validation, P.C. and H.S.; formal analysis, H.S.; investigation, J.K.; resources, P.C.; data curation, J.K.; writing--original draft preparation, J.K.; writing--review and editing, P.C. and H.S.; visualization, J.K.; supervision, H.S. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research received no external funding.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The input data, i.e., the length corrections from the deformations and standard deviations for every node, are available upon request.  
**Acknowledgments:** The authors would like to thank [PERSON] and [PERSON], whose thesis was the starting point for this article.  
**Conflicts of Interest:** The authors declare no conflicts of interest.