Atmospheric refraction effect and its correction in LAMOST

摘要

Atmospheric dispersion and differential refraction will lead to a non-neglectable light loss varying with wavelength across the field of view during the integral time of multi-fiber spectral observation. These effects will be more severe in telescopes with large field of view such as the Large sky Area Multi-Object Fiber Spectro-scopic Telescope(LAMOST). We have calculated the light loss due to atmospheric refraction for LAMOST. To improve the efficiency, we could move individual fiber to correct its 5000A monochromatic displacement during observation, the best number of this kind of track should be balanced between the displacement correction and the fiber positioner error. We have calculated the best track number by monte-carlo simulation for different declination field and different position of the field. Also we have derived the fiber positioner error tolerance from simulation.