Development of aberration measurement program using curvature sensing technique

The aberration measurement program has been developed for improving the optical quality of ground-based telescopes. This program is based on the Curvature Sensing Technique (CST) and aberrations are estimated from two defocused stellar images. We used iterative algorithm that simulates closed-loop wave-front compensation in optics. It has been applied to the telescope of Bohyunsan Optical Astronomy Observatory (BOAO) in Korea. The most frequently encountered aberration by misalignment was coma. As a result, the image quality of telescope was improved after adjustment the alignment of secondary mirror.