A Signal Processor for Focal Plane Detector Arrays

Abstract

This paper discusses a signal processing unit developed for 2D Cadmium Mercury Telluride - Silicon hybrid (CMT-Si) photovoltaic detector arrays. It overcomes the severe fixed pattern noise problems associated with these detectors by performing the required nonuniformity removal in the analogue domain without the use of Digital Signal Processing (DSP) or fast, high resolution Analogue to Digital Convertors (ADC's). The reasons for the adoption of this approach stem from the need for a compact, high speed IR imaging system for use in automatic weapon guidance and homing systems particularly in the anti-armour role. A prototype system using this approach has been developed and used to operate a 32 x 32 element Random Access Line Scanned Array (RALSA) at frame rates in excess of 200Hz with measured NETD of less than 0.1°C. This same system, without further modification, will be capable of operating 64 x 64 element detector arrays with frame rates in excess of 400Hz if required.