A real-time compensation technique for nonuniformities of infrared imaging arrays

TLDR: In this article, a real-time digital compensation technique that corrects for the non-uniformities in both dark currents and responsivities of solid-state electro-optical imaging arrays is presented.

Abstract: Present solid-state infrared staring imagers are characterized by large element-to-element nonuniformities in both dark currents and responsivities. These nonuniformities result in "fixed pattern" noise which can exceed the amplitude of the desired signal by more than 500 times. For solid-state infrared staring imagers to be a viable alternative to other infrared imaging systems, real-time nonuniformity compensation must be developed. This paper presents a real-time digital compensation technique that corrects for the non-uniformities in both dark currents and responsivities of solid-state electro-optical imaging arrays. Experimental results yielded a measured net gain in the signal to fixed pattern noise ratio of 46 dB. Hardware is described and results demonstrated for a 32 by 32 CID (charge injection device) visible imaging array using a simulated infrared image and background. Basic MTI (moving target indication) and target correlation features as well as extrapolation to 128 by 128-element staring arrays are also discussed.