Microscanning is an optical technique used principally to enhance the resolution of cameras using 2-D arrays of detectors. It provides small (typically half pixel pitch) movements of the image across the detector array so that a high-resolution image can be built up by interlacing a number of fields. Microscanning may also be used to provide information to allow non-uniformity correction of the image. Microscanning is frequently used in thermal cameras, where detector resolutions are limited, and where uniformity correction is critical because of the low contrast of the image. In this paper we look at the consequences of microscanning by lateral motions of a lens. It is found that in general the motion of the image caused by motion of the lens varies with position in the field of view, and is different in the radial and tangential directions. This difference is what we refer to here as microscan distortion. This paper describes how to minimise or completely eliminate distortions in the microscan pattern. Eliminating this distortion is particularly useful where the microscan is used to support scene-based uniformity correction.

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Robert Craig and Nick Thompson, "Optical correction of microscan distortion," Proc. SPIE 13200, Electro-Optical and Infrared Systems: Technology and Applications XXI, 132000L (Presented at Security + Defence: September 17, 2024; Published: 1 November 2024); https://doi.org/10.1117/12.3031698.