In this article, we develop an algorithm for the estimation of a full six degree of freedom position, navigation, and timing solution in deep space by measuring the time and angle of arrival of x-rays photons from pulsars and other bright stars. We show that for pulsar navigation, the position and attitude determination problems are coupled. This is due in part to the small signal-to-noise ratio of pulsar signals and the fact that x-ray photons emanating from various pulsars and bright stars have no unique identifier that can be used to associate them with their source. To address this challenge, a joint probabilistic data association filter is developed. The filter fuses angular rate measurements from a three-axis rate gyro with time-of-arrival and angle-of-arrival measurements from an x-ray detector. The performance of the filter is validated in simulation, and the tradeoffs associated with detector size and initial conditions are evaluated. Additional validation of the algorithm is performed by playback of data from x-ray detectors on the Chandra spacecraft. The results show that positioning accuracy on the order of 1000 km and attitude accuracies on the order of 5 arcseconds can be achieved.

中文翻译：

---

使用 X 射线脉冲星估算深空位置和姿态

在本文中，我们开发了一种算法，通过测量来自脉冲星和其他明亮恒星的 X 射线光子的到达时间和角度，来估计深空中完整的六自由度位置、导航和定时解决方案。我们表明，对于脉冲星导航，位置和姿态确定问题是耦合的。部分原因是脉冲星信号的信噪比很小，而且从各种脉冲星和明亮恒星发出的 X 射线光子没有唯一的标识符可用于将它们与其来源联系起来。为了应对这一挑战，开发了联合概率数据关联过滤器。该滤波器将来自三轴速率陀螺的角速率测量值与来自 X 射线探测器的到达时间和到达角测量值融合在一起。在仿真中验证了滤波器的性能，并评估了与探测器尺寸和初始条件相关的权衡。该算法的额外验证是通过回放来自 X 射线探测器的数据来执行的。钱德拉飞船。结果表明，可以实现1000公里量级的定位精度和5弧秒量级的姿态精度。