Concept for image intensifier with CMOS imager output interface

Abstract

A concept is described for the detection and location of transient objects, in which a "pixel-binary" CMOS imager is used to give a very high effective frame rate for the imager. The sensitivity to incoming photons is enhanced by the use of an image intensifier in front of the imager. For faint signals and a high enough frame rate, a single "image" typically contains only a few photon or noise events. Only the event locations need be stored, rather than the full image. The processing of many such "fast frames" allows a composite image to be created. In the composite image, isolated noise events can be removed, photon shot noise effects can be spatially smoothed and moving objects can be de-blurred and assigned a velocity vector. Expected objects can be masked or removed by differencing methods. In this work, the concept of a combined image intensifier/CMOS imager is modeled. Sensitivity, location precision and other performance factors are assessed. Benchmark measurements are used to validate aspects of the model. Options for a custom CMOS imager design concept are identified within the context of the benefits and drawbacks of commercially available night vision devices and CMOS imagers.