Human Efficiency for Visual Detection of Targets on CRT Displays Using a Two-Level Multiple Channel Time History Format
Abstract
Human observers were tested for their ability to detect targets on visual displays. The displays simulated the multiple channel time history format of sonar displays, using two levels of intensity encoding. A target was presented on 50% of the trails and appeared as a vertical line at a fixed position. Observers indicated their judgment as to whether a target was present by using a four-category rating scale. Receiver-operating characteristics (ROCs) were generated from the rating data and compared to ROCs for an optimal detector. Data were collected for two signal-to-noise ratios and for 32, 64, and 128 lines of data. Results indicated that observers were 3-5 dB less sensitive than an optimal detector. Performance improved as the number of lines increased, but not to the extent predicted by optimal integration of information across lines of the display. Human inefficiency with this display is possibly due to the inability to focus on a single column of data or to the use of a suboptimal decision rule for judging the presence of the target.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 02, 1987
- Accession Number
- ADA188419
Entities
People
- Joseph Divita
- Thomas Hanna
Organizations
- Naval Submarine Medical Research Laboratory