Abstract
Adaptive optics is widely used in astronomy. Recently, most of newly built telescopes have adaptive optical systems. In
order to apply adaptive optics into astronomical telescope, high-speed wavefront sensing is required. In high-speed
operation, exposure time per frame of a sensor is quite short. In this case, optical intensity of one-frame image is pretty
low. Thus signal-to-noise ratio of the wavefront sensor is also low. Therefore, in this case, noises such as readout noise
and photon noise greatly influence the accuracy of wavefront sensing. The center of mass method is widely used due to
its low computational cost. However it is very weak to noise. The correlation method is robust to noise. But the
computational cost is expensive. In this paper, Multi-Resolution Correlation method is proposed. This method, by
employing multi-resolution images, considerably reduces the computation time when compared to the FFT correlation
method. Also the accuracy of Shack-Hartmann wavefront sensor using the proposed algorithm is proved to be almost
same as that of the conventional correlation method. The verification is done through the simulation.
