摘要
脉冲星信号具有极低信噪比,传统降噪算法难以在抑制噪声的同时保留微脉冲等细节信息。为此,提出一种基于改进小波空域相关滤波的脉冲星极弱信号降噪算法。从小波阈值和空域相关算法在极弱信号降噪中的缺陷出发,以保留细节信息和提高信噪比为目标,结合脉冲星辐射信号的严格周期性、相邻周期间的相关性、极低信噪比和窗口辐射等特性,改进了小波空域相关滤波算法。采用Parks射电天文台和罗希(Rossi)X射线时变探测器的脉冲星观测数据进行实验。结果表明,改进小波空域相关滤波算法可以保留更多微脉冲等细节信息,在提高信号的信噪比方面优于现有算法。
Because of the extremely low signal-to-noise ratio（SNR） of pulsar signals,it is difficult for the traditional denoise algorithms to suppress noise while preserving details such as micro-pulses.Therefore a new denoising algorithm which is based on the improved wavelet spatial correlation filtering is proposed.Firstly,the defects of the wavelet threshold and spatial correlation denoising algorithms in the extremely weak pulsar signals＇ processing are analysed.Then,the wavelet spatial correlation filtering algorithm is improved according to the characteristics of pulsar signals,such as strict periodicity,correlation of adjacent periods,low SNR,radiation in the window and so on.Finally,the experiments are made with the pulsar signal observed by the Parks observatory and Rossi X-ray timing explorer.The results show that the proposed algorithm can preserve more details and provide a notable improvement in SNR.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2010年第12期2500-2505,共6页
Systems Engineering and Electronics
基金
国家自然科学基金(60772139)
国家高技术研究发展计划(863计划)(2007AA12Z323)
中国科学院精密导航定位与定时技术重点实验室开放基金(2009PNTT09)资助课题
关键词
脉冲星
降噪
小波空域相关滤波
微脉冲
pulsar
denoise
wavelet spatial correlation filtering
micro-pulse
