一种基于最优频段的X射线脉冲星累积轮廓时延估计方法

发布时间：2018-07-02 14:34

  本文选题：X射线脉冲星导航 + 时间延迟估计　； 参考：《物理学报》2016年11期

【摘要】：为提高X射线脉冲星导航中累积脉冲轮廓的时间延迟估计精度,分析了X射线脉冲星累积脉冲轮廓的频谱特性和现有Taylor快速傅里叶变换时延估计算法的缺陷,提出了一种基于最优频段的累积轮廓时延估计算法,并通过建立不同信噪比下时延估计误差与所采用频段之间的关系以确定最优频段.数值及实测数据实验结果表明:在短时观测或光子流量较小时,该算法优于常用的近似最大似然(FAML)、相关(CC)、最小二乘(NLS)及加权最小二乘(WNLS)方法;在观测时间较长或光子流量较大时,该算法的估计精度与CC及NLS方法相当,但其运算量低于NLS,FAML及WNLS方法.本文所提算法适用于短时观测脉冲轮廓或低流量脉冲星的高精度时延估计.
[Abstract]:In order to improve the accuracy of time delay estimation of cumulative pulse profile in X-ray pulsar navigation, the spectral characteristics of cumulative pulse profile of X-ray pulsar and the defects of existing Taylor fast Fourier transform (FFT) time-delay estimation algorithms are analyzed. A cumulative contour time delay estimation algorithm based on optimal frequency band is proposed, and the optimal frequency band is determined by establishing the relationship between the delay estimation error and the frequency band under different SNR. The experimental results show that the proposed algorithm is superior to the approximate maximum likelihood (FAML), correlation (CC), least squares (NLS) and weighted least squares (WNLS) methods for short time observation or small photon flux. When the observation time is longer or the photon flux is larger, the estimation accuracy of this algorithm is similar to that of CC and NLS methods, but its computational complexity is lower than that of NLSS-FAML and WNLS methods. The algorithm proposed in this paper is suitable for high precision time delay estimation of short-time observed pulse profiles or low-flow pulsars.
【作者单位】： 西安电子科技大学空间科学与技术学院;
【分类号】：P128.4
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本文编号：2090431