X射线脉冲星光子序列频域加权测相方法
发布时间：2018-09-02 09:13
【摘要】：针对X射线脉冲星信号累积轮廓位相测量误差大的问题,提出了一种直接位相测量的频域加权方法。首先,直接对X射线探测器捕获和采样形成的光子序列进行频域变换得到幅度谱,分别提取幅度谱各个成分的相位,再用幅度对相位变量加权平均,得到位相测量结果;进一步采取分段加权的策略,解决序列过长引起的内存溢出问题;最后对所提出方法的计算复杂度进行了理论分析。仿真结果表明:在观测时长和采样间隔相同的条件下,与平均法相比,加权法的测相精度提高了10%以上;与最大似然(ML)和非线性最小均方误差(NLS)法相比,加权法的比相精度提升了1倍以上,计算速度处于ML法和NLS法之间;分段情况下性能会随着分段数增加有所改善。
[Abstract]:Aiming at the problem of large error in the phase measurement of the cumulative profile of X-ray pulsars, a frequency domain weighting method for direct phase measurement is proposed. Firstly, the amplitude spectrum is obtained by the frequency domain transformation of the photon sequence captured and sampled by the X-ray detector, and the phase measurement results are obtained by weighted average of the phase variables by the amplitudes of each component of the spectrum. Furthermore, the strategy of piecewise weighting is adopted to solve the problem of memory overflow caused by long sequence. Finally, the computational complexity of the proposed method is analyzed theoretically. The simulation results show that under the condition of the same observation time and sampling interval, the phase measurement accuracy of the weighted method is improved by more than 10% compared with the average method, and compared with the maximum likelihood (ML) and the nonlinear minimum mean square error (NLS) method. The phase contrast accuracy of the weighted method is more than twice as high as that of the ML method and the NLS method, and the performance of the weighted method is improved with the increase of the number of segments.
【作者单位】： 西安电子科技大学空间科学与技术学院;
【基金】：国家自然科学基金资助项目(61172138,61401340)
【分类号】：P128.4
，
本文编号：2218909
[Abstract]:Aiming at the problem of large error in the phase measurement of the cumulative profile of X-ray pulsars, a frequency domain weighting method for direct phase measurement is proposed. Firstly, the amplitude spectrum is obtained by the frequency domain transformation of the photon sequence captured and sampled by the X-ray detector, and the phase measurement results are obtained by weighted average of the phase variables by the amplitudes of each component of the spectrum. Furthermore, the strategy of piecewise weighting is adopted to solve the problem of memory overflow caused by long sequence. Finally, the computational complexity of the proposed method is analyzed theoretically. The simulation results show that under the condition of the same observation time and sampling interval, the phase measurement accuracy of the weighted method is improved by more than 10% compared with the average method, and compared with the maximum likelihood (ML) and the nonlinear minimum mean square error (NLS) method. The phase contrast accuracy of the weighted method is more than twice as high as that of the ML method and the NLS method, and the performance of the weighted method is improved with the increase of the number of segments.
【作者单位】： 西安电子科技大学空间科学与技术学院;
【基金】：国家自然科学基金资助项目(61172138,61401340)
【分类号】：P128.4
，
本文编号：2218909
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