Integrated navigation based on pulsars and sun observation including clock error correction

In order to improve the accuracy of navigation and clock correction of a deep space probe during cruise phase, an integrated navigation method was advanced. By combining the X-ray pulsar based navigation(XPNAV) with the sun line-of-sight vector, and the radial velocity of the probe relative to the sun, an integrated navigation system was advanced by using information fusion, based on extended kalman filter(EKF). The state of atomic clock error was considered in the system model. The UD factorization algorithm was applied to control the rounding error. The simulation results demonstrate that this method can control the divergence rendered by the clock error in EKF. Compared with XPNAV, this method can provide a higher navigation precision and more effectively control the clock error.