High-precision spot centroid positioning of high-frame-rate short-wave infrared images for satellite laser communication

The accuracy of spot centroid positioning has a significant impact on the tracking accuracy of the system and the stability of the laser link construction. In satellite laser communication systems, the use of short-wave infrared wavelengths as beacon light can reduce atmospheric absorption and signal attenuation. However, there are strong non-uniformity and blind pixels in the short-wave infrared image, which makes the image distorted and leads to the decrease of spot centroid positioning accuracy. Therefore, the high-precision localization of the spot centroid of the short-wave infrared images is of great research significance. A high-precision spot centroid positioning model for short-wave infrared is proposed to correct for non-uniformity and blind pixels in short-wave infrared images and quantify the localization errors caused by the two, further model-based localization error simulations are performed, and a novel spot centroid positioning payload for satellite laser communications has been designed using the latest 640x512 planar array InGaAs shortwave infrared detector. The experimental results show that the non-uniformity of the corrected image is reduced from 7% to 0.6%, the blind pixels rejection rate reaches 100%, the frame rate can be up to 2000 Hz, and the spot centroid localization accuracy is as high as 0.1 pixel point, which realizes high-precision spot centroid localization of high-frame-frequency short-wave infrared images.