Research on autonomous navigation method of deep space cruise phase based on the Sun observation

In this paper, two types of autonomous navigation method based on the Sun observation are proposed for the problem of orbit determination during the deep space cruise phase. The radial velocity of the spacecraft relative to the Sun is measured by a spectrometer, and the line-of-sight vector of the reference celestial body relative to the spacecraft is measured by the onboard camera. Then, two kinds of observation scheme, one is based on the Sun information and the other is based on line-of-sight information, are constructed combined with the line-of-sight vector from the spacecraft to the Sun. The fundamental of the observation schemes is analyzed and the measurement equations are educed in detail. The orbit parameters of the spacecraft are estimated in real time by utilizing extended Kalman filter. Finally, the autonomous navigation methods presented are verified by the practical data of deep impact mission. The estimation accuracy of the orbit is demonstrated to meet the requirement of the deep space cruise phase.