高稳定度X射线脉冲星信号模拟

X射线脉冲星导航是一种完全自主的导航方式, 在深空乃至行星际空间具有潜在的工程应用价值.由于空间飞行试验系统复杂, 成本巨大, 在实验室环境下高精度地模拟X射线脉冲星信号对数据处理方法和导航方案的验证具有重要意义. 针对当前机械转盘式模拟系统中时间稳定度和轮廓精度的不足, 提出了一种通过产生的轮廓电压信号直接控制可见光光源, 再利用衰减获得光子流, 最后经单光子探测和处理电路输出光子到达时间序列的模拟新方法.该方法实现成本低, 支持任意X射线脉冲星信号的模拟, 且具有高时间稳定度和轮廓精度. 详细地讨论了该方法的原理和涉及的关键技术, 搭建了X射线脉冲星信号模拟系统, 并进行了实验. 实验结果表明: 该系统大幅提高了X射线脉冲星信号的模拟效果, 将模拟脉冲星自转周期的稳定度从现有的10^-4提高到10^-9; 当探测器面积为1 m², 探测能谱范围为2–10 keV, 积分时间为1200 s时, 模拟的PSR B1509-58 观测脉冲轮廓与标准脉冲轮廓的相关系数达到了0.993. 关键词： X 射线光子信号 时间稳定度 观测脉冲轮廓 导航算法

A simulation technique of X-ray pulsar signals with high timing stability

A simulation experiment system is required presently, for the space flight experiment of X-ray pulsar based navigation is very costly. To solve the crucial issues of the timing stability and the profile precision in existing simulation techniques of pulsar signal, a new simulation technique which utilizes visible light is proposed. The simulation experiment system is set up based on the proposed technique. And some experiments are carried out to test the proposed technique. The results demonstrate that the proposed technique can be used to simulate any of known pulsars. The timing stability of simulated X-ray pulsars is raised from 10^-4 to 10^-9. And the accuracy of pulsar profile simulation is noticeably improved. Within the X-ray band 1-10 keV, when the observation time reaches 1200 s, and the area of the X-ray detector is 1 m², the Pearson correlation coefficient of pulsar's observation profile with the standard template profile arrives at 0.993. And the simulation experiment system can be realized with high flexibility and low cost. On the basis of the simulation experiment system, the signal characteristic of X-ray pulsar can be investigated. On the other hand, the performances of X-ray pulsar signal processing algorithms and navigation algorithms can be surveyed in detail.
Keywords： X-ray pulsar signal timing stability observation profile navigation algorithms