Relative Effectiveness of Four Color Coding Techniques for Intensity Coding onSimulated Advanced Mine Detection System (AMDS) Displays

摘要

Four methods of color coding the intensity levels of sonar returns on theAdvanced Mine Detection System displays, currently under development, were studied to determine how the added use of color could enhance operability. The target detection and identification performance of seven experienced observers was measured using the following schemes for coding signal intensity into eight discrete steps: levels of green (the original coding method), levels of white, colors approximating specifications supplied by the Naval Undersea Warfare Center (NUWC), and colors arranged according to lightness, from dark to light. A portion of a static AMDS display 726 pixels wide by 323 pixels high was simulated on a computer controlled color display system. A single target simulating six sonar pings, or histories, was six pixels wide (10.2 arc min visual angle) by one pixel high, and was present on 50% of the trials. It could be located anywhere in the background. Four target signal strengths were used. The randomized distributions of the background noise levels and the target levels were specified by NUWC and considered to be representative of those expected at sea. Each observer ran on two 100-trial sessions of each of the 16 conditions, combinations of one of the four target strengths and one of the four color coding schemes. In a signal detection paradigm, for each trial the observer signalled, by key press, confidence in the presence or absence of a target on a four-point scale, and indicated the location of the target, when present, by means of a trackball cursor. The hit rates (percentage of trials Decision making, Tactical displays, Human subjects, Visual sonar displays, Performance.