# The Influence of the Quality of Digital Elevation Data on the Modelling of Terrain Vehicle Movement
## 4 Discussion  
The results of analyses of the digital terrain models DTM 5, DTM 4, DTM 3 and DTED 2 showed different qualities based on the resolution of the network of points. Each  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & **DTM 5** & **DTM 4** & **DTM 3** & **DTED 2** \\  & & **Area (\%)** & **Area (\%)** & **Area (\%)** & **Area (\%)** \\ \hline \multirow{3}{*}{No slope corrections} & GO & 80.03 & 81.62 & 84.56 & 86.24 \\  & SLOW GO & 16.12 & 15.29 & 14.38 & 12.89 \\  & NO GO & 3.85 & **3.09** & **1.06** & **0.87** \\ \hline \multirow{3}{*}{With slope corrections} & GO & 80.03 & 79.10 & 76.28 & 75.92 \\  & SLOW GO & 16.12 & 15.50 & 18.70 & 17.81 \\ \cline{1-1}  & NO GO & 3.85 & **5.40** & **5.02** & **6.27** \\ \hline \hline \end{tabular}
\end{table}
Table 8: The comparison of the extent of passable, hardly passable, and impassable areas with different elevation models without slope corrections and with slope corrections. Location: Dolni Morava, 3 km \(\times\) 3 km, arid conditions, GO max slope = 20\({}^{\circ}\), SLOW GO max slope = 30\({}^{\circ}\). The main improvements in the results are displayed as bold values.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & **DTM 5** & **DTM 4** & **DTM 3** & **DTED 2** \\  & & **Area (\%)** & **Area (\%)** & **Area (\%)** & **Area (\%)** \\ \hline \multirow{3}{*}{No slope corrections} & GO & 77.34 & 78.55 & 79.28 & 80.54 \\  & SLOW GO & 16.64 & 16.35 & 16.72 & 16.27 \\  & NO GO & 6.02 & **5.09** & **4.00** & **3.19** \\ \hline \multirow{3}{*}{With slope corrections} & GO & 77.34 & 78.24 & 77.91 & 76.82 \\  & SLOW GO & 16.64 & 15.86 & 15.61 & 15.55 \\ \cline{1-1}  & NO GO & 6.02 & **5.90** & **6.48** & **7.63** \\ \hline \hline \end{tabular}
\end{table}
Table 9: The comparison of the extent of passable, hardly passable, and impassable areas with different elevation models without slope corrections and with slope corrections. Combined 5 areas, 3 km \(\times\) 3 km, moist conditions, GO max slope = 10\({}^{\circ}\), SLOW GO max slope = 20\({}^{\circ}\). The main improvements in the results are displayed as bold values.  
elevation model had its possible usage in practise: from the most detailed 1 m \(\times\) 1 m model, namely, DTM 5, with a universal usage to the low detail model 30 m \(\times\) 30 m with limited use cases, mostly for small-scale overview maps. Currently, the lower detail elevation models are not used efficiently. Efficient use can be achieved by adjusting the accuracy to high-detail elevation models. These adjustments would increase the usability of all elevation models. Before implementing any modifications to digital terrain models, other types of data need to be considered as well.  
Individual parts of the landscape, i.e., terrain relief and soil cover, are represented by a different quality of data. Terrain relief is covered with detailed and accurate elevation models in the territory of European states. They are suitable for planning military operations down to the tactical level. Soil and surface conditions data is less reliable for detailed CCM analyses. This data has little detail or inaccurate determination of soil type boundaries. It is necessary to consider the shortcomings of the data used to properly interpret the results of passability analyses.