A Novel Non-Coaxial Image Motion Compensation Method for Airborne Infrared Area-Array Whisk-Broom Camera Under Backward Squint Conditions

Three-dimensional (3D) imaging technology enables simultaneously capturing two-dimensional surface features, depth information, and the spatial structure of the target area, offering broad applications in airborne imaging. Airborne area-array whisk-broom cameras are widely used at low-to-medium altitudes, providing high-speed height ratio airborne imaging due to their ability to achieve wide-field imaging through scanning. Currently, most airborne area-array whisk-broom imaging systems employ a vertical downward view, which limits their ability to fully capture the 3D characteristics of the target area. To overcome this limitation, this study proposes a backward-squint area-array wide-field whisk-broom imaging scheme. However, under such whisk-broom scanning conditions, a misalignment exists between the equivalent rotation axis of the image motion compensation mirror after optical path deflection and the roll scanning axis of the camera. To resolve this problem, we propose an accurate calculation model for non-coaxial image motion compensation. We conducted theoretical analysis and simulation experiments to validate the proposed method, achieving a stabilization accuracy better than 0.65 μrad per compensation cycle during a 45° backward squint and a 90° scanning width. Our research advances airborne area-array whisk-broom imaging technology by proposing a novel backward-squint imaging scheme and an innovative non-coaxial image motion compensation model, which significantly enhance in wide-field squint imaging and 3D modeling.