# Methodology for Conceptual Navigational 3D Chart Assessment Based on Eye Tracking Measures
## 1 Introduction
### Background and Aim of the Study  
The genesis of the research undertaken in this thesis was the need to test conceptual 3D navigation maps. This was due to the complexity of their construction and the testing process. The complexity of testing nautical charts is related to the necessity of testing the map more extensively in a complete operational environment. This is related to the fact that the chart is a component of the ECDIS system [51; 52], which integrates various ship data in addition to the chart. In this system, the navigational chart also has an interface, and the ECDIS system itself is one component of the entire navigation bridge. The navigator, at an operational level, uses de facto not the map itself but the entire system on which the various elements of the ship's control are situated. In addition, the navigation process is shared with the visual observation and information provided by the various elements of the system. Another aspect is the evolution of navigational charts due to the development of the new S-100 data model [53], which will create further challenges for the visualisation of different navigational information. Therefore, we can distinguish four levels of modes of ENC map visualisation (Figure 1). The first is the basic cartographic development, resulting from the accepted editorial principles of maps. For ENC maps, these principles are included in the IHO standards. The first level of visualisation includes the essential content of the map, that is, the topographic and cartographic model of the data. The second level stems from the functionality of ENC maps as part of the ECDIS system. This level additionally includes the interface and functionalities related to the use of the map at the operational level (e.g., visualisation of safe depths, route planning, display of various ship data or integration of data coming from other navigation devices, such as AIS or radar). The third level includes the visualisation of the ENC map as part of the navigation bridge. Information at this stage is shared with other navigation devices. Perceptually, it may be partially disturbed by additional information or posited by other navigation devices (e.g., radar). The final stage of visualisation includes the full operational environment, in which the navigator uses all available sources of information, additionally performs visual observation, and makes a real-time assessment of the navigation situation. This stage is the most complex, as it is based on the analysis of available navigational data and is related to making decisions based on them (e.g., making a manoeuvre, changing course to correct the ship's position). Exemplary research analysing the behaviour of watch officers on the bridge and taking into account an ECDIS device is presented in [54]. We can also find research in other types of navigation, like aviation, where eye tracking was used for projecting the pilot's cockpit [55]. Currently, there is a lack of formal methods to evaluate new ENC products, including 3D studies. This does not mean that such maps do not exist. In the case of non-standardised products such as Electronic Chart Systems, there are solutions on the market with 3D visualisation of navigation information [56; 57]. In this case, it is difficult to say how much they improved the navigation process. If we consider the analysed literature on 2D and 3D map visualisation research, it is not necessarily the latter that can benefit. If we only take into account the increased cognitive load of performing tasks using a 3D map, this can negatively affect the navigation process, in which the time for analysing navigation information should be as short as possible. Therefore, the motivation of the research process was to develop a methodology for assessing the effectiveness of conceptual 3D maps that could form a solid basis for further  
Figure 1: Levels of ENC visualisation. research--both in terms of integration into the interface and as part of the navigation bridge. They should be at least better than standardised 2D charts.