Astronomical spectral lines auto-extraction based on framelet transform

The important astrophysical information is hidden in spectral lines of astronomical spectra. This paper presents a method in detail extraction of spectral lines and splitting. The method consists of four main steps: First, fitting the continuum of the observed spectra by a combined method of framelet transform and spline fitting. After removing the continuum, the spectral signal is transformed by framelet with 4 (th) scale. Then, estimate the noise with high frequency coefficients; the noise with coefficients of the 4 (th) scale is eliminated by soft thresholding. At last, extract the spectral lines. Experimental results show that the algorithm can improve the fitting accuracy and extract spectral lines effectively.