Determination of the Wavelenth Position in A Spectrum

The wavelength calibration is most important in the spectroscopic research. In this paper, several ways are discussed which include the use of the intrinsic spectral lines of a celestial body itself, the night sky emission lines or terrestrial atmospherical absorption lines as well. Especially, the way to use spectral lines of a standard spectral lamp in another spectral order to do wavelength calibration in a given spectral order is introduced and discussed.