A Fractal Denoising Method for Astronomical Spectral Signal
HAN Jin-shu1,2,3, LUO A-li1, ZHAO Yong-heng1
1. Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China 2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China 3. Department of Computer Science and Technology, Dezhou University, Dezhou 253020, China
Abstract：To restore the continuum and the spectral lines from a noisy astronomical spectrum, then to measure the equivalent widths of the spectral lines, the fractal denoising method was firstly used in astronomical spectra in the present paper. The method is based on the distinguishing features, that is the local self-similarities exist in an astronomical spectrum, while not in a random white noise signal. The experimental results show that the fractal denoising method is efficient in parameter measurements, such as equivalent widths for spectral lines, redshift of galaxies, and so on. In addition, the method can achieve data compression. The fractal method can be used in the mass spectra of LAMOST.
[1] Adelman-McCarthy J K, Agüeros M A, Allam S S, et al. Astrophysical Journal Supplement Series，2008, 175: 297. [2] Mucciarelli A. Astronomy & Astrophysics，2011, 528: 44. [3] Wende S, Reiners A, Ludwig H G. Astronomy and Astrophysics，2009, 508: 1429. [4] Connolly A J, Szalay A S. Astronomical Journal，1999, 117: 2052. [5] Pizurica A, Philips W, Lemahieu I, et al. IEEE Trans. on IP, 2002, 11(5): 545. [6] Balster E J, Zheng Y F, Ewing R L. IEEE Trans. on IP, 2005, 14(12): 2024. [7] Baraniuk R G. IEEE Signal Processing Magazine，2007, 24(4): 118. [8] Liu Teng, Wang Junxian. The Astrophysical Journal，2010, 725: 2381. [9] Lara-López M A, Cepa J, Castaeda H, et al. Publications of the Astronomical Society of the Pacific，2010, 122: 1495. [10] Abazajian K N, Adelman-McCarthy J K, Agüeros M A, et al. The Astrophysical Journal Supplement，2009, 182: 154. [11] Trager S C, Worthey Guy, Faber S M, et al. Astrophysical Journal Supplement Series, 1998, 116: 1. [12] Barnsley M F, Demko S. Proc. R. Soc. London, 1985, A399: 243. [13] Jacquin A. IEEE Trans. Image Processing，1992, 1: 18. [14] Ghazel M, Freeman G H, Vrscay E R. IEEE Transaction on Image Processing, 2003, 12: 1560.
