Effects of TEL Confusers on Operator Target Acquisition Performance with SAR Imagery

Abstract : The present study examined the effects of the number of M-548 confuser vehicles (from zero to four) on TEL target acquisition performance with simulated synthetic aperture radar imagery at 2 ft and 4 ft resolutions. The vehicles were positioned at orientations of 0 degrees (head-on), 45 degrees, 90 degrees (broadside), 135 degrees, and 180 degrees (tail-on) in low, medium, or high clutter backgrounds. Upon viewing each of 1560 images, ten operators determined whether the TEL target appeared in the scene, rated their confidence, and identified the TEL's location if they thought it was present. The results revealed that decision making time was slower and operator confidence was poorer at the 4 It image resolution as compared to 2 ft. Further, perceptual sensitivity, reaction time, and confidence were all degraded in high clutter scenes and when the TEL was positioned at 0 degrees and 180 degrees as compared to oblique and broadside orientations. Finally, number of confusers had no effect on operators' hits, false alarms, perceptual sensitivity, response bias, or confidence; however, reaction times were slower when two or three confusers appeared in the image. The radar return of the M-548 cargo truck may have been sufficiently different from the TEL target so as not to be particularly confusing.