Experimental Evaluation of Cursors for B-2 Synthetic Aperture Radar (SAR) Application

Abstract : The purpose of the current study was to evaluate the current and two alternative cursors for B-2 Synthetic, Aperture Radar (SAR) imagery application and to recommend an alternative design. This study was conducted in response to problems crewmembers are experiencing with the current cursor on the B-2 SAR display. In particular, the design of the current radar cursor (i.e., the width of the cursor bars) makes it difficult to accomplish fine cursor positioning (i. e., accurate placement of the cursor within the desired one pixel of the target. ) This affects the accuracy of radar updates and impacts the precision of the navigation and bombing solutions. The experiment evaluated the current cursor and two alternative designs in terms of designation speed and accuracy. Eighteen subjects completed experimental trials in which they performed a SAR radar update procedure (i.e., identified and designated specified aim points). This procedure was conducted using simulated SAR imagery presented on a multipurpose display unit (MDU) within the Computer-Assisted Procedures Trainer (CAPT) resident at Armstrong Laboratory. The results indicated that one of the alternative cursor designs elicited significantly higher designation accuracy (mean error = 1.94 pixels) than the current cursor (mean error = 2.36 pixels) or the second alternative cursor (mean error = 2.28 pixels). Designation speed did not vary significantly across cursors. Subjective data and comments gathered from subjects supported these findings, with the most accurate alternative cursor being rated as very effective and the current cursor being rated as "somewhat ineffective".