## 2 Materials and Methods
### Main Channel and Surrounding Topography Data  
The broken terrain of the assessed area and geometry of objects required the application of multiple processing procedures and methods in the process of data quality assessment. Determination of the degree of detail of the assessed area was specified with an adequate number of measured detail survey points. The density of their arrangement was adapted to the nature and morphometric characteristics of the terrain. For visible terrain changes, a procedure with denser arrangement of the measured detail survey points was chosen. A Leica GPS900 CS rover was configured in the field following the Slovak real-time positioning service (SRTPS) service provider's recommendations (max Position Dilution of Precision (PDOP) = 3, elevation mask 15\({}^{\circ}\), horizontal accuracy \(<\) 0.02 m, height accuracy \(<\) 0.4 m, one fixed position). The assessed area located within a residential area of the city of Presov extended between river km points 57 and 61 (Figure 2). The quality of processing of the geodetic survey and passportization depends on the accuracy of the spatial information obtained, and the choice of surveying procedures and methods. Surveying data is in the national coordinate system: Datum of Uniform Trigonometric Cadastral Network (D-UTCN) and in the national elevation system: Baltic Vertical Datum--After Adjustment. Subsequently, the resulting set of spatial information was \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Water Gauge Station Presov** \\ \hline Watercourse & Torysa & Annual average flow (period 2010–2014) \\ River Basin Area [km\({}^{2}\)]: & 673.89 & Runoff (\% WA) (period 2010–2014) = 8.33\% \\ Hydrological number: & 4-32-04-078-01 & The maximum value of the average monthly flow (m\({}^{3}\)s\({}^{-1}\)) for the period 2010–2014 is 29.382 m\({}^{3}\)s\({}^{-1}\) \\ River kilometer: & 58.30 & The minimum value of the average monthly flow (m\({}^{3}\)s\({}^{-1}\)) for the period 2010–2014 is 0.848 m\({}^{3}\)s\({}^{-1}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: General information about the state of the monitoring station of the observed area (Data from [56]). used for the preparation of comprehensive documentation relating to the processing of cross-sections and longitudinal profiles. In the monitored area, 516 terrain points were observed. Of consideration the large-scale of the study area at least (3500 m \(\times\) 50 m), the overview of real-time kinematic (RTK) points on the case study show following Figure 3.  
By using the selected category of software tools, it was possible to present the obtained results through a selected graphical interface (Computer-aided design CAD system). In terms of quality assessment of the spatial information, it is necessary to consider the method used for determining the position of each point in space and the character of the point's category. This regards points with important common integrity for the needs of using this file in the process of hydrodynamic modeling. The whole survey was carried out using the GNSS technology with the support of the SRTPS guaranteed by the state, using the kinematic method of measurement in real time (RTK). For RTK measurements in SRTPS (a network of permanent stations in the Slovak Republic), the operator of this service guarantees point accuracy of 2-4 cm. For the needs of further assessment, an illustrative list of coordinates of measured points is given in Table 2.  
According to the standard of quality assessment of the accuracy achieved in the file of information obtained, it was necessary also to consider the spatial error of point determination in 3D, which results directly from GNSS measurements (with respect to the use of that method). Based on the following (1), the expected and the real spatial error of determination of a point's position in space was compared.