Effects of Automated Scanning in a Search and Rescue Detection Task

Abstract

Traditionally, search and rescue (SAR) technicians have conducted search by directly viewing the terrain below the aircraft. Defence R&D Canada is developing a multi-sensor imaging system for SAR that would replace this direct “out-the-window” inspection under low visibility conditions. The system could be designed to automate the sweep of the sensor across the terrain in order to minimize operator workload and to ensure that the sensor covers all of the area to be searched. In a previous prototype, the operator controlled the sweep of the sensor through the use of a joystick, adjusting the speed and direction of the sensor in real time. That interface permitted the operator to both cover the terrain and maximize the detection potential targets by moving the sensor more slowly over portions of the display that was more complex or contained cues to the potential presence of a target. The present study was designed to determine whether automation of the sweep function would compromise detection performance by preventing the operator from adjusting the motion of the sensor to make use of the visual information contained in the scene. The results demonstrate that detection is indeed superior when the sensor sweep is controlled by the operator, and that this effect is modulated by the detectability (contrast) of the target. Additionally, it was observed that the terrain could be more effectively covered under operator control, such that the operator was able to adjust the motion of the sensor to match changes in the visibility of the terrain.