RESOLUTION PERFORMANCE IMPROVEMENTS IN STARING IMAGING SYSTEMS USING MICRO - SCANNING AND A RETICULATED , SELECTABLE FILL FACTOR InSb FPA

As staring focal plane array (FPA) detectors continue to mature, FPA based IR imaging systems are available in more compact packages that are lighter and consume less power than first or second generation scanning IR sensor packages. However, standard IR analysis models indicate that staring FPA based cameras, while having excellent sensitivity, will have reduced resolution when compared to scanning systems with similar sized detector elements and optics. This apparent resolution limitation is created by the fixed sampling of the active pixel size native to staring FPA systems. Micro-scanning, a technique which moves the image in sub-pixel steps on the focal plane, can provide some over-sampling and reduce this limitation. Standard attempts at micro-scanning using 2-dimensional starring arrays with near 100% fill factor produce only marginal improvements in resolution in these systems. We will present here a new concept in micro-scanning using an InSb FPA with reticulated detector elements and active area masking to provide a well defined, selectable fill factor. A compact micro-scanned imaging system design that weighs less than 8 pounds and consumes less than 15 watts is presented here. MRTD (Minimum Resolvable Temperature Difference) analyses demonstrating a 2X improvement in resolution in both vertical and horizontal directions over non-micro-scanned systems has been measured, a performance level which micro-scanned systems with non-reticulated FPAs cannot approach. Test data from this system will also be presented including NETD and MRTD performance.