Autonomous navigation method research of two spacecraft system based on relative line of sight vector

Autonomous orbit determination of two satellites system in near earth orbit was considered based on the relative line-of-sight vector measurements between two satellites. In this program, the relative line-of-sight vector between the two satellites was obtained by the navigation camera on board; then, the vector was converted into the pixel and line in the camera coordinates, which is the measurement model in the navigation system. After that, the orbit states including position and velocity of satellites of a total of twelve components in inertial frame were achieved accurately through the extended Kalman filter arithmetic with the combination of the orbit dynamical equations. The feasibility of this method has been demonstrated by numerical simulations.