基于轮廓特征的X射线脉冲星信号多普勒估计

探测器速度引起的多普勒效应会影响脉冲星信号累积轮廓特征,反之,这种轮廓特征改变可用于多普勒估计。提出了一种基于轮廓特征的X射线脉冲星信号多普勒估计方法。通过建立累积轮廓非齐次泊松模型,获得多普勒效应对累积轮廓的影响。构造轮廓特征函数对该影响进行度量,并利用函数值与周期误差的关系搜索信号周期。在搜索过程中,将离散观测数据转换为连续能量密度函数,消除相位间隔对累积周期的限制。根据周期搜索结果,结合脉冲星先验知识完成多普勒估计。仿真实验验证了该方法的有效性,其多普勒估计精度优于频域方法。

Doppler Estimation of X-Ray Pulsar Signals Based on Profile Feature

The distortion of cumulative profile feature caused by detector movement can be used for pulsar signal Doppler estimation.In this paper,a Doppler estimation method based on profile feature is proposed.Firstly,a nonhomogeneous Poisson model is developed to characterize the cumulative profile,and the influence of Doppler Effect on cumulative profile is presented.Secondly,a profile feature function is defined to measure cumulative profile distortion.Then according to the relationship between function value and period error,the signal period is recognized by a search method.In the search process,restriction on cumulative period is eliminated by transforming observation data into energy density.At last,the Doppler estimation is realized by comparing search period with signal standard period.The simulation result verifies the effectiveness of the suggested method,and the suggested method has higher accuracy in Doppler estimation compared with frequency domain method.