国防科技大学学报
國防科技大學學報
국방과기대학학보
JOURNAL OF NATIONAL UNIVERSITY OF DEFENSE TECHNOLOGY
2015年
2期
143-148
,共6页
X 射线脉冲星%泊松分布%信号重构%卡方拟合优度检验%模拟算法
X 射線脈遲星%泊鬆分佈%信號重構%卡方擬閤優度檢驗%模擬算法
X 사선맥충성%박송분포%신호중구%잡방의합우도검험%모의산법
X-ray pulsar%poisson distribution%signal reconstruction%chi-square goodness-of-fit-test%simulation algorithm
基于 X 射线脉冲星的导航技术，无论技术研究还是实验验证，都是以 X 射线脉冲星信号为基础。但是实际的观测数据无法确定其精确值，不便于进行导航算法的分析验证。因此，通过模拟算法重构 X 射线脉冲星信号十分必要。基于泊松分布建立 X 射线脉冲星信号模型，介绍脉冲轮廓的构建方法；介绍了两种纯数值的脉冲星信号模拟算法。针对这两种算法因近似导致信号模拟不精确的问题，提出一种基于精确光子流量函数的纯数值 X 射线脉冲星信号的模拟算法，该算法采用分段线性函数拟合的脉冲轮廓函数，基于分布函数及其反函数导出。模拟算法重构 PSR B0531＋21脉冲星的信号，并利用χ2拟合优度检验验证模拟算法生成的光子到达时间服从泊松分布。将提出的算法与两种已有的算法进行比较，仿真结果表明从光子数目和脉冲轮廓误差来看，提出的算法都优于其他两种算法，更接近实际信号。由新算法重构的脉冲星信号进行历元折叠得到观测脉冲轮廓，并将其与标准脉冲轮廓比较，发现随着观测时间的增长，观测脉冲轮廓趋近于标准脉冲轮廓，验证了模拟算法是有效可行的。
基于 X 射線脈遲星的導航技術，無論技術研究還是實驗驗證，都是以 X 射線脈遲星信號為基礎。但是實際的觀測數據無法確定其精確值，不便于進行導航算法的分析驗證。因此，通過模擬算法重構 X 射線脈遲星信號十分必要。基于泊鬆分佈建立 X 射線脈遲星信號模型，介紹脈遲輪廓的構建方法；介紹瞭兩種純數值的脈遲星信號模擬算法。針對這兩種算法因近似導緻信號模擬不精確的問題，提齣一種基于精確光子流量函數的純數值 X 射線脈遲星信號的模擬算法，該算法採用分段線性函數擬閤的脈遲輪廓函數，基于分佈函數及其反函數導齣。模擬算法重構 PSR B0531＋21脈遲星的信號，併利用χ2擬閤優度檢驗驗證模擬算法生成的光子到達時間服從泊鬆分佈。將提齣的算法與兩種已有的算法進行比較，倣真結果錶明從光子數目和脈遲輪廓誤差來看，提齣的算法都優于其他兩種算法，更接近實際信號。由新算法重構的脈遲星信號進行歷元摺疊得到觀測脈遲輪廓，併將其與標準脈遲輪廓比較，髮現隨著觀測時間的增長，觀測脈遲輪廓趨近于標準脈遲輪廓，驗證瞭模擬算法是有效可行的。
기우 X 사선맥충성적도항기술，무론기술연구환시실험험증，도시이 X 사선맥충성신호위기출。단시실제적관측수거무법학정기정학치，불편우진행도항산법적분석험증。인차，통과모의산법중구 X 사선맥충성신호십분필요。기우박송분포건립 X 사선맥충성신호모형，개소맥충륜곽적구건방법；개소료량충순수치적맥충성신호모의산법。침대저량충산법인근사도치신호모의불정학적문제，제출일충기우정학광자류량함수적순수치 X 사선맥충성신호적모의산법，해산법채용분단선성함수의합적맥충륜곽함수，기우분포함수급기반함수도출。모의산법중구 PSR B0531＋21맥충성적신호，병이용χ2의합우도검험험증모의산법생성적광자도체시간복종박송분포。장제출적산법여량충이유적산법진행비교，방진결과표명종광자수목화맥충륜곽오차래간，제출적산법도우우기타량충산법，경접근실제신호。유신산법중구적맥충성신호진행역원절첩득도관측맥충륜곽，병장기여표준맥충륜곽비교，발현수착관측시간적증장，관측맥충륜곽추근우표준맥충륜곽，험증료모의산법시유효가행적。
For navigation using X-ray pulsars,both technique investigation and simulation were based on the X-ray pulsar signal.But practically,the observation data was unable to confirm the exact value or the analysis of validation of navigation algorithm.Therefore,it was necessary for simulation algorithms to reconstruct X-ray pulsars.Based on the fact that the arrival of photons possess non-homogeneous poisson random process,the model of the signal of X-ray pulsars was built,and the epoch folding algorithm for pulse profile construction was presented. Two existed simulation algorithms were presented.A new numerical simulation algorithm based on the reconstruction of photon TOAs (time of arrivals)was derivated from distributive function and its inverse function.To avoid approximating in the two algorithms,the derivated algorithm employed the pulse profile fitted by piecewise linear function.The signal of pulsar PSR B0531 +21 was simulated,and chi-square goodness-of-fit-test was utilized to demonstrate that the simulated TOAs complied with the poisson distribution.Comparison was implemented among the new algorithm and the existed two algorithms.Simulation result indicates that the new algorithm is superior to the existed two algorithms in photon counts and pulse profile error.Observed pulse profiles approaches to the standard template profile as observation time increases,which demonstrate that the simulation algorithm is feasible,and the X-ray pulsar signal can be reconstructed effectively.
