Asymptotically Ecient Estimation of Pulse Time Delay For X-ray Pulsar Based Relative Navigation
Asymptotically Ecient Estimation of Pulse Time Delay For X-ray Pulsar Based Relative Navigation
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DOI：
10.2514/6.2009-5974
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发表时间：
2009-08
期刊：
影响因子：
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通讯作者：
A. A. Emadzadeh-A.;J. Speyer;A. Golshan
中科院分区：
文献类型：
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作者：
A. A. Emadzadeh-A.;J. Speyer;A. Golshan
研究了基于X射线脉冲星测量的航天器间相对位置估计问题。建立了在每个航天器上观测到的脉冲星强度的数学模型。将光子到达时间(TOA)模型化为泊松过程，给出了相应的概率密度函数。基于对探测信号之间脉冲时延的估计，提出了相对导航问题的解决方案。建立了脉冲时延估计问题的数学模型，给出了脉冲时延估计的Cram er-Rao下界。基于光子到达时间的概率分布，建立了一个极大似然估计(MLE)问题，提出了脉冲时延估计器。证明了所提出的估计量是渐近独立的。利用计算机模拟对分析结果进行了数值验证。
The problem of relative position estimation between two spacecraft based on X-ray pulsar measurements is addressed. A mathematical model is developed for the pulsar’s intensity as observed at each spacecraft. The time of arrival (TOA) of photons is modeled as a Poisson point process, and the relevant probability density functions are provided. A solution to the relative navigation problem is suggested based on estimation of the pulse delay between the detected signals. The problem of pulse time delay estimation is formulated and the Cram er-Rao lower bound (CRLB) is presented. Based on probability distribution of photon time of arrivals, a maximum likelihood estimation (MLE) problem is formulated and the pulse delay estimator is proposed. It is proven that the proposed estimator is asymptotically ecient. The analytical results are veried numerically employing computer simulations.