VTS operators' eye movements

This study clarifies the characteristics of Vessel Traffic Services (VTS) Operators' eye movements during their regular tasks. Experimental studies are carried out at the Istanbul Strait VTS Head Center in TURKEY for the general aim of the authors as maximising integrated human reliability on board during the passage of congested waterways. The safe passing through the Istanbul Strait is a critical issue not only for VTS Operators (VTS-Os) but also for Ship Masters, ship owners, major oil companies and so on for saving lives, keeping clean seas and also economic aspects. The objective of this study is to define eye movements of VTS-Os who have a long-term experience as a Ship Master. For this purpose, Eye Mark Recorder (EMR) is utilized as physiological index to evaluate fixation points, fixation durations and changes in viewpoints of VTS-Os. Three experimental studies are carried out in different conditions of watch keeping times and sectors in the VTS area. VTS-Os' eye movements were recorded by the EMR-8 that provided by Istanbul Technical University Maritime Faculty. In the analysing part, the visual field is categorized to determine the fixation points of VTS-Os and to understand of what is the mainly information and its significance for their decision-making. Then, the data was analysed by using "Frame by Frame" method. The results are also compared among the VTS Sectors. The visual field of the operator consists of two computer screens, two monitors for displaying of cameras in the Istanbul Strait and cameras' control unit, VHF communication unit and paper work area. Computer screens of the VTS System can spread from one display to other and VTS-Os generally used the function of picture in picture on the display. There are some sharing behaviours for the VTS-Os' fixation durations and some differences based on their individual characteristics. Generally, their eye movements have similar pattern for operating VTS System and for the information. However, the order of information changed among the fixation points, and the fixation durations changed based on the operating display as individual choosing. On the other hand, moving of viewpoints was over 60 deg/sec, so saccade of eye movements has significant ratio, because of quick eye movements through the categories.