Celestial Doppler Difference/Pulsar for Formation Flying and Its Integrated Navigation

In order to improve the spacecraft capability of autonomous celestial navigation,a celestial Doppler difference/pulsar for formation flying and its integrated navigation method is proposed. The Sun light is strong,and the accuracy of the Sun Doppler difference navigation is high,but it is difficult to provide multi-directional velocity information. Star light is weak,and the accuracy of star Doppler difference navigation is low,but it can provide multi-directional velocity information. The Sun Doppler difference navigation and the star Doppler difference navigation are complementary,but which cannot be fully observable. Using three or more pulsar navigation is completely observable,but the filtering period is longer,and it is difficult to obtain continuous navigation information. The three navigation methods are complementary and can be used for integrated navigation. The extended Kalman filter is used as a navigation filter to fuse the difference and arrival time of the astronomical Doppler,and can provide absolute and relative navigation information for formation flying. Simulation results show that the integrated navigation method for formation flight can provide absolute and relative highly-accurate navigation information.