Weighted Self-Threshold Local Contrast Method for Daytime Shortwave Infrared Adaptive Optics

To achieve high-resolution imaging during daytime, we designed a short-wave infrared adaptive optics (SWIR AO) system utilizing the Shack-Hartmann wavefront sensor (SHWS). A weighted self-thresholding local contrast algorithm is proposed to minimize complex background and pixel-sized noise with high brightness (PNHB) in real-time applications. The algorithm effectively suppresses interference while enhancing the signal-to-noise ratio (SNR). The simulations show a higher robustness and lower centroid estimation error, than the traditional algorithm. Further, field experiments were also carried out. Deployed on our SWIR AO of a 4-m telescope, the proposed algorithm yielded a 30-fold peak SNR boost for HIP11698 (6.2Mv), from below 0.28 to 8.49, when the elevation angle of the sun was 37.1°.