To improve the autonomous navigation ability during interplanetary cruise, we designed an autonomous navigation system based on observing pulsars and asteroids. The X-ray pulsars were observed by an X-ray detector, and the images of asteroids were taken by the navigation camera. Thus the times of pulsars' pulse arrival and the pixels of asteroids were obtained through signal processing. The centralized Kalman filter was used to estimate the system's state. The onboard atomic clock error was corrected. The orbit in the Deep Space I mission was adopted to validate this navigation method. The numerical simulation results show that this method is very feasible in the interplanetary cruise phase. Moreover, this integrated navigation system can solve the problem of atomic clock error divergence when the optical navigation based on asteroids is applied independently. This method can improve the orbit determination accuracy by 57.18%.%针对三频载波模糊度解算TCAR法因电离层、观测噪声等误差影响而导致长基线模糊度解算可靠性较低的问题,提出了一种改进的适用于长基线网络RTK的TCAR方法.该方法继承了传统TCAR法逐级固定整周模糊度的思想,充分根据模糊度解算中每一步骤不同特点及不同目的选择最优组合观测值.首先,利用组合限制条件确定超宽巷模糊度解算最优组合；然后,引入平滑思想提高电离层残差估计精度,同时结合求解窄巷模糊度的WL/NL最优组合快速获得窄巷模糊度；最后,通过线性无关宽巷与窄巷组合模糊度实现基础载波模糊度准确解算.算例分析表明,基于最优组合的改进TCAR法有效提高了模糊度解算的成功率,实现了长基线网络RTK三频载波模糊度的快速解算.
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