Fuzzy based decision system for estimation of operator’s situation awareness index while surveillance during low ambient lighting conditions

Abstract

Surveillance during low ambient lighting conditions is a challenging task due to hampered perception of the scene while using only visible range cameras. As a solution to this, surveillance using fusion of visible and infrared image has been proposed to provide comprehensive information of the scene instantaneously. Fusion of multispectral sensor information leads to enhancement of information for the operator. However, enhancement of information presented to user not always lead to enhancement of situation awareness (SA) level. This study focuses on SA estimation of operator during ground surveillance tasks while used visible-infrared fused imagery. The original reference image and fused image outputs are compared statistically using different image quality parameters like target to background entropy, correlation and structural similarity index. A fuzzy based decision model is developed to give a quantitative and qualitative estimate of operator’s SA during surveillance carried out in low ambient lighting conditions. The fuzzy based decision model gives a qualitative estimate of SA as: poor, low, moderate & high, and, quantitative index in range of 1–10 indicating SA level and thus provides alert about the level of details perceivable from the fused image, thereby, helping operator to take decision based on SA index instantaneously.