The celestial navigation using the difference between the direct and reflected solar light is emerging, as the difference can remove the conjoint bias caused by the instability and unpredictability of sunlight. These navigation methods include the solar Doppler difference and the solar TDOA (time difference of arrival). The solar TDOA measurement has a high positioning accuracy. However, the solar flare is unpredictable, which leads to the instability and randomness of the positioning performance in the approach phase. Fortunately, the solar Doppler difference navigation is stable. However, this navigation system is unobservable. To utilize their advantages and avoid their disadvantages, we combine them and propose the solar TDOA/Doppler difference joint observation. Due to its unobservability, we integrate it with the Mars angle navigation, and develop the solar light joint observation/Mars angle integrated navigation that is completely observable. The simulation results demonstrate the stability and robustness of the solar TDOA/Doppler difference joint observation navigation method. Compared with the celestial navigation using one solar difference observation such as the TDOA or the Doppler, the solar light joint observation/Mars angle integrated navigation can provide higher and more stable navigation accuracy.

中文翻译：

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火星探测接近阶段的太阳TDOA/多普勒差分联合观测导航

利用太阳直射光和反射光之间的差异的天文导航正在兴起，因为这种差异可以消除由太阳光的不稳定性和不可预测性引起的联合偏差。这些导航方法包括太阳多普勒差和太阳 TDOA（到达时间差）。太阳能TDOA测量具有较高的定位精度。然而，太阳耀斑是不可预测的，导致接近阶段定位性能的不稳定和随机性。幸运的是，太阳多普勒差分导航是稳定的。然而，这个导航系统是不可观察的。为了发挥它们的优点，避免它们的缺点，我们将它们结合起来，提出了太阳TDOA/多普勒差分联合观测。由于其不可观测性，我们将其与火星角度导航相结合，发展完全可观测的太阳光联合观测/火星角综合导航。仿真结果证明了太阳TDOA/多普勒差分联合观测导航方法的稳定性和鲁棒性。与使用TDOA或多普勒等单一太阳差观测的天文导航相比，太阳光联合观测/火星角组合导航可以提供更高、更稳定的导航精度。