Determining spacecraft orientation by using an astronavigation system

The problem of determining spacecraft orientation by using an astronavigation system is considered. А quaternion determining the rotation of the spacecraft axes is calculated based on a sequence of starry sky images obtained by the instrument’s camera. The rotation quaternion is calculated by solving a geometric problem based on determining the dependencies of celestial object coordinates specified in different reference systems. The effect of the error in determining celestial object coordinates from starry sky images on the accuracy of attitude parameter estimation is studied. The simulation results demonstrated the fundamental applicability of the approach considered for determining the spacecraft’s attitude quaternion by using a series of starry sky images.