光学学报, 2013, 33 (3): 0304002, 网络出版: 2013-02-26
提升小波的X射线脉冲星信号降噪
X-Ray Pulsar Signal De-noising Using Lifting Scheme Wavelet
摘要
对于短时间内X射线脉冲星信号形成的脉冲轮廓的信噪比低,提出基于提升小波的X射线脉冲星信号的降噪方法。分析了基于提升小波的信号降噪理论模型。在周期叠加的基础上,利用探测设备及空间环境的先验信息建立预降噪模型,并对X射线脉冲星的脉冲轮廓做降噪预处理。通过选择小波和自适应的阈值函数,利用提升小波对脉冲轮廓降噪。通过对多组罗西X射线计时探测器(RXTE)卫星探测的实测X射线脉冲星数据的仿真分析,结果表明,降噪后的脉冲轮廓信噪比得到提高,且算法有更快的处理速度。
Abstract
As the pulsar profile obtained through the folding of X-ray signal in a short time has low signal-to-noise ratio, a de-noising method based on lifting scheme is proposed for the X-ray pulsar signal. The model of noise reduction based lifting scheme is analyzed. And the pulsar profile is preprocessed by using the pre-denoising model. The noise of the pulsar profile is reduced based on the lifting scheme with wavelet and the adaptive thresholding function. Some groups of measure data explored by Rossi X-ray timing explorer (RXTE) are applied for simulation analysis. The simulation results show that the signal-to-noise ratio of pulse profile can be improved, and that the proposed method has fast computational speed.
刘秀平, 李小平, 孙海峰. 提升小波的X射线脉冲星信号降噪[J]. 光学学报, 2013, 33(3): 0304002. Liu Xiuping, Li Xiaoping, Sun Haifeng. X-Ray Pulsar Signal De-noising Using Lifting Scheme Wavelet[J]. Acta Optica Sinica, 2013, 33(3): 0304002.