The aim of this research was to conduct a comparative analysis of the precision of ground geodetic data versus the three-dimensional (3D) measurements from unmanned aerial vehicles (UAV), while establishing the impact of herbaceous vegetation on the UAV 3D model. Low (up to 0.5 m high) herbaceous vegetation can impede the establishment of the anthropogenic roughness of the surface. The identification of minor surface alterations, which enables the determination of their anthropogenic origin, is of utmost importance in archaeological investigations. Vegetation cover is regarded as one of the factors influencing the identification of such minor forms of relief. The research was conducted on the Lepelionys Mound (Prienai District Municipality, Lithuania). Ground measurements were obtained using Trimble GPS, and UAV “Inspire 1” was used for taking aerial photographs. Following the data from the ground measurements and aerial photographs, large scale surface maps were drawn and the errors in the measurement of the position of the isolines were compared. The results showed that the largest errors in the positional measurements of fixed objects were conditioned by the height of grass. Grass with a height of up to 0.1 m resulted in discrepancies of up to 0.5 m, whereas grass that was up to 0.5 m high led to discrepancies up to 1.3 m high.
National atlases provide comprehensive information about nature, population, social and economic situation of the country. In 2017 the process of compiling and publishing the National Atlas of Lithuania (Lietuvos Nationalinis Atlasas) was finished. The goal of the authors is: in the context of the whole National Atlas to present a thorough analysis of the structure of content and cartographic visualization methods of Volume III. This volume focusses on social and economic phenomena in Lithuania. The authors discuss the principles of compiling the whole National Atlas of Lithuania and presents its structure in a concise manner. Following the classification of traditional mapping methods, specific examples of mapping in Volume III are presented, advantages of mapping techniques are discussed and the structural analysis of mapping methods is also conducted. The conclusions and the discussion part present the problems encountered while compiling Volume III as well as solutions to them.