# The Influence of the Quality of Digital Elevation Data on the Modelling of Terrain Vehicle Movement
###### Abstract
The generic approach is to use artificial surfaces that can be described by mathematical models; therefore the 'true' output value can be pre-determined to avoid uncertainty caused by uncontrollable data errors. A prospective development and usage of a new surface model, namely, TanDEM-X High-Resolution Elevation Data Exchange Program (TREx), was introduced in [8]. Using this model to replace insufficient low detailed elevation models seems to be the only option to cover the information gap in some locations. One of the most important impacts of TREx is that it brings accurate results of the terrain analysis from a global perspective. The most useful analyses that can be gathered from it are visibility, propagation of radio signals, searching for areas suitable for air landing and route planning. Data can be procured in its raw form, but users may encounter issues with its extensive processing [9]. Global models can also be substituted for more detailed models in the case of the availability of local LIDAR data [10; 11]. The CCM model used in NATO is called New NATO Reference Mobility Model (NRMM); see [12] for a detailed description. The analyses of the model and its gaps are in [13; 14]. The NRMM was originally used to facilitate a comparison between vehicle design candidates by assessing the mobility of existing vehicles under specific terrain scenarios but has subsequently and most recently found expanded use in support of complex decision analyses associated with vehicle acquisition and operational planning support. A study [15] verified the usability of NRMM in new, so far untested conditions. It is based on a comparison of the empirically based NRMM with the physics-based Nep Tracked Vehicle Performance Model (NTVPM) for assessing the cross-country performance of military tracked vehicles. The NRMM can be used strictly for the tactical level of planning. Such detailed data is not available across the whole Supreme Commanders of Allied Powers in Europe's (SACEURs) area of interest (AOI). The AOI is an extended area beyond the territory of NATO nations where NATO can operate [16; 17]. Global availability of high-detail elevation models is limited; therefore, other simplified CCM models must be considered. Future requirements of NATO towards CCM analyses are defined in [18], emphasising the ongoing important position of passability analyses in military planning. The research of the CCM model in the Czech Republic at the University of Defence at the Department of Military Geography and Meteorology focuses on creating a system of coefficients representing various land features and conditions. Their analyses and implementations defining soil impact are in [19; 20], refs. [21; 22; 23] focused on forest passability, refs. [24; 25] describing problematics of microrelief obstacles and [26; 27; 28; 29] consist of all environmental elements in one complex study. This approach was also partially included in the evaluation of data in the article. It is mainly in a form that considers which level of detail is required for data usability in the Czech military CCM model. [PERSON] analysed the spatial database quality influence on the modelling of movement of vehicles in terrain in [30]. This general assessment of the quality of geospatial data can serve as a template for how to compare various datasets, including elevation models. A similar approach as that found in the Czech Republic can be found among authors from other nations. Raster analysis is the main method used in the Polish CCM cartographic model [31; 32]. This form was also assumed for the results of the article. The research introduced in [33] was specifically taken into consideration. It defines variances between elevation models with a focus on high-detail models (0.5 m, 1.0 m, 2.5 m, 5.0 m). It shows that the passable area of a smaller tested location is larger with higher detail terrain models.