The Measurement and Correction of Atmospheric Dispersion in 4-Meter Telescope With Adaptive Optical System

Atmospheric dispersion is a wavelength-dependent effect that affects astronomical observations performed using ground-based telescopes. The effect of atmospheric dispersion for a 4-meter telescope is analyzed and an atmospheric dispersion corrector (ADC) system was designed for its adaptive optical system. With the help of adaptive optical system and a line fit method, the science images can be conveniently used to measure the atmospheric dispersion and to control ADC to correct the dispersion, and thus the full-width at half-maximum of the final images can approach the diffraction limit of the telescope.