Abstract
To maintain situation awareness (SA) when exposed to emergencies during pilotage, a pilot needs to selectively allocate attentional resources to perceive critical status information about ships and environments. Although it is important to continuously monitor a pilot's SA, its relationship with attention is still not fully understood in ship pilotage. This study performs bridge simulation experiments that include vessel departure, navigation in the fairway, encounters, poor visibility, and anchoring scenes with 13 pilots (mean = 11.3 and standard deviation = 1.4 of experience). Individuals were divided into two SA group levels based on the Situation Awareness Rating Technology (SART-2) score (mean = 20.13 and standard deviation = 5.83) after the experiments. The visual patterns using different SA groups were examined using heat maps and scan paths based on pilots' fixations and saccade data. The preliminary visual analyses of the heat maps and scan paths indicate that the pilots' attentional distribution is modulated by the SA level. That is, the most concerning areas of interest (AOIs) for pilots in the high and low SA groups are outside the window (AOI-2) and electronic charts (AOI-1), respectively. Subsequently, permutation simulations were utilized to identify statistical differences between the pilots' eye-tracking metrics and SA. The results of the statistical analyses show that the fixation and saccade metrics are affected by the SA level in different AOIs across the five scenes, which confirms the findings of previous studies. In encounter scenes, the pilots' SA level is correlated with the fixation and saccade metrics: fixation count (p = 0.034 < 0.05 in AOI-1 and p = 0.032 < 0.05 in AOI-2), fixation duration (p = 0.043 < 0.05 in AOI-1 and p = 0.014 < 0.05 in AOI-2), and saccade count (p = 0.086 < 0.1 in AOI-1 and p = 0.054 < 0.1 in AOI-2). This was determined by the fixation count (p = 0.024 < 0.05 in AOI-1 and p = 0.034 < 0.05 in AOI-2), fixation duration (p = 0.036 < 0.05 in AOI-1 and p = 0.047 < 0.05 in AOI-2), and saccade duration (p = 0.05 ≤ 0.05 in AOI-1 and p = 0.042 < 0.05 in AOI-2) in poor-visibility scenes. In the remaining scenes, the SA could not be measured using eye movements alone. This study lays a foundation for the cognitive mechanism recognition of pilots based on SA via eye-tracking technology, which provides a reference to establish cognitive competency standards in preliminary pilot screenings.
Highlights
Improvements to pilots’ situation awareness (SA) in maritime navigation are critical to reducing human errors, which have caused 75% to 96% of marine accidents over the last few years [1]
Taking the gaze data during departure as an example, the discrete degree in the high SA group was greater than that in the low SA group, indicating pilots in the high group may scan more areas (Figure 8). us, the relatively static fixation segment with a certain time continuity is defined as the “background” subview, and colors ranging from green to red were used to represent how much an individual attended different areas of interest (AOIs) in a scene based on the heat map
Discussion e AOIs account for at least 90% of the 13 pilots’ visual areas, where AOI-3 and AOI-4 together occupy less than 5% of the simulation experiment duration. e pilots’ visual features were extracted using eye-tracking technology to calculate the proportion of the cumulative time for these visual behaviors in the AOIs to the total effective time. e mean saccade counts in the low SA group for AOI-1 and AOI-2 are both higher than the high SA group
Summary
Improvements to pilots’ situation awareness (SA) in maritime navigation are critical to reducing human errors, which have caused 75% to 96% of marine accidents over the last few years [1]. Growth in traffic densities, ship speeds, and ship sizes have led to the need to improve pilots’ operational safety [2, 3]. To evaluate unsafe behaviors in ship pilotage more effectively and practically, it is essential to investigate SA from a cognitive perspective. Before improving SA, the first problem to solve is how to accurately measure it in pilotage operations. Some direct (questioning and/or observations) and indirect (user behaviors, physiological responses, and/or task performances) assessment methods have been proposed to measure an operator’s SA based on three-level frameworks [6]. Probe-based methods are common direct measurements, such as the SA Global Assessment Technique
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
