Barnaby W. Smith

Multiframe enchancement of FLIR and infrared seeker images

In many IR imagers the resolution is determined by the finite size of the detector elements rather than inherent optical limitations, resulting in undersampled images. If a number of frames are collected in which the sharply-focused image of an object has moved across the detectors, the sequence of frames will contain more information on the object than any single frame. Over the past few years there have been a number of papers reporting success at producing a single high-resolution frame from such lower-resolution image sequences. In the current study techniques are described for the real-time enhancement of aircraft images during air-to-air combat. Of particular interest is the early identification of the target aircraft during a merge: in this situation the aircraft image expands on closure and produces a relative motion across the detector elements in addition to the jitter normally experienced. Issues covered include the need for accurate determination of the target movement against the background and the handling of rotation and aspect changes of the target. One novel suggestion is the use of the intensity weighted centroid of the aircraft target for frame-to-frame matching. Examples of enhanced images are provided, including some synthesized air-combat scenarios.