Compound image stabilization for coupled disturbance in ship-borne imaging system

For the lever arm translational motion and equivalent coning rotation of a ship-borne optical detection system under a great hull attitude, a compound Electronic Image Stabilization(EIS) method which brought inertial information was proposed to compensate the coupled disturbance. Firstly, the equivalent coning rotation existed in the LOS (Line Of Sight) stabilization process was analyzed based on a pitch-yaw optical stabilization system, and the relationship between LOS rotation angle and platform roll angle was deduced. Then, the influence of lever arm disturbance on weak spots was analyzed and a coupled disturbance model combined with the equivalent coning rotation was built. On the basis of the model, a compound image stabilization method by combing inertial information and the EIS method was proposed to realize the image stabilization under a low characteristic environment. Finally, the image stabilization and real time ability of the proposed method were verified through hardware-in-the-loop simulation under the low characteristic environment. The results demonstrate that the method compensates the coupled disturbance from the lever arm translational motion and equivalent coning rotation. It has higher image stabilization and real time ability, and motion estimation is at a sub-pixel level. After compensation, the peak signal-to-noise ratio (PSNR) of image stabilization improves by 4 dB on average. It satisfies the requirements of ship-borne optical imaging systems for strong instantaneity, high precision, strong anti-interference and stable and reliable characteristics.