In X-ray pulsar-based navigation (XPNAV), the appearance of Doppler effects caused by the dynamic motion of the spacecraft would severely degrade the navigation accuracy. In this paper, we develop a new XPNAV method based on a two-stage estimation method of Doppler frequency and phase delay to overcome the Doppler effects. Based on the pre-established phase model of the pulsar at the SSB and the predicted states of the spacecraft, the real-time phase model at the spacecraft is modeled with respect to the initial position and velocity errors of the spacecraft. It turns out that within an observation interval, a constant Doppler frequency can be estimated to overcome the effect of the initial velocity error, and then the phase delay caused by the initial position error can be estimated by using the computationally efficient methods based on epoch folding. Under this frame, the H-test for uniformity, which needs no prior knowledge of the light curve, is used to estimate the Doppler frequency and the fast maximum likelihood method is used to estimate the phase delay. The dynamic model and measurement model of the proposed navigation method are also given. Photon-level simulation results obtained by using the ground-based semi-physical simulation system for X-ray pulsar signals show a significant improvement over the traditional XPNAV method.

在基于X射线脉冲星的导航（XPNAV）中，由航天器的动态运动引起的多普勒效应的出现将严重降低导航精度。在本文中，我们基于多普勒频率和相位延迟的两阶段估计方法开发了一种新的XPNAV方法，以克服多普勒效应。基于SSB处脉冲星的预先建立的相位模型和航天器的预测状态，针对航天器的初始位置和速度误差对航天器的实时相位模型进行建模。事实证明，在一个观察间隔内，可以估算出恒定的多普勒频率以克服初始速度误差的影响，然后可以使用基于历元折叠的高效计算方法来估计由初始位置误差引起的相位延迟。在此框架下，不需要先验光曲线的均匀性H检验可用于估计多普勒频率，而快速最大似然法则可用于估计相位延迟。给出了所提出的导航方法的动力学模型和测量模型。通过使用基于地面的半物理模拟系统对X射线脉冲星信号进行的光子级模拟结果显示，与传统XPNAV方法相比有显着改进。使用“估计多普勒频率”和“快速最大似然法”估计相位延迟。给出了所提出的导航方法的动力学模型和测量模型。通过使用基于地面的半物理模拟系统对X射线脉冲星信号进行的光子级模拟结果显示，与传统XPNAV方法相比有显着改进。使用“估计多普勒频率”和“快速最大似然法”估计相位延迟。给出了所提出的导航方法的动力学模型和测量模型。通过使用基于地面的半物理模拟系统对X射线脉冲星信号进行的光子级模拟结果显示，与传统XPNAV方法相比有显着改进。