## 1 Introduction  
The purpose of using cartographic projections and creating maps is to present a convex surface approximating to the shape of the Earth (sphere or rotational ellipsoid) on a flat two-dimensional surface [1]. The mapping functions enable the transition from angular coordinates of longitude and latitude to orthogonal coordinates on the plane [2]. Attributes containing selected spatial information such as the course of borders, height in the adopted reference system, or the manner of land use are assigned to the planar coordinates [3]. A key feature of cartographic mapping is the mutual assignment of points on the Earth's surface and the map's surface [4]. As a result, a unique assignment of each point on the surface of the original to exactly one point on the surface of the image is obtained [5]. An inherent feature of all mapping is the occurrence of mapping distortions. Hence, when creating maps, the available projections are analyzed and the mapping is carefully selected, which in turn represents the desired region of the Earth in the least disturbed manner [6, 7]. Maps, due to various content and purpose, are divided according to various criteria. Thanks to mathematical properties, mappings dedicated to the needs of specific areas of human activity are known, e.g., navigation [8, 9], or land surveying [10]. In turn, in order to present local and global processes, thematic maps are created [11]. The catalog of thematic map applications is constantly growing alongside the development of technology and human needs [12]. An important theoretical aspect of creating maps is spatial visualization semiotics [13]. Semantic, syntactic, and pragmatic components determine how to build and connect cartographic elements on the map and their relationship with the recipient. Technological development over the past few decades has largely eliminated the use of classic paper maps. Currently, the standard use of maps is electronic imaging, often available on-line [14]. The first signals of a diametrical change in cartography were noticed as early as the 1990s [15]. Rapid technological development observed in recent years is also reflected in measurement technologies used to obtain source data for creating maps. Particularly noteworthy are the measurement methods that implement mass data acquisition in a short time, such as laser scanning [16], bathymetric surveys [17], satellite GNSS measurements [18] or photogrammetric flight missions by unmanned aerial vehicles [19]. The large amount of data collected during these measurement methods calls for generalization, e.g., in the form of three-dimensional models [20]. Nevertheless, even after applying cartographic generalization procedures, the presentation of all objects at once is a complex problem. This especially applies to areas with a high degree of urbanization, where significant infrastructure facilities are located at points with the same horizontal coordinates, but at different heights. Generally, maps differ in both the content and component parts. Simple maps consist of several elements, while more complex maps (e.g., topographical) contain more elements. Every map is a set of strictly defined graphical elements. Some of the signs are subordinated to cartographic rules and depict some real world objects. Other elements of the map are not cartographic and are thus subject to different rules or do not represent any real life objects. Ref. [21] mentions an example of the map title and legend. Those descriptive elements are controlled by natural language rules, and their location on the map is controlled by aesthetic rules of the map creator. Thematic maps belong to the group of geographical maps. [PERSON] [22] states that they are effective in discovering and exploring spatial data. The theme is related to the chosen phenomena (e.g., economic, demographical or cultural). According to [PERSON] et al. [12] and [PERSON] [7], in many cases thematic maps are defined by the special technique used for the map's creation.