Unified attitude determination problem from vector observations and hand-eye measurements

The hand-eye measurements have recently been proven to be very efficient for spacecraft attitude determination relative to an ellipsoidal asteroid. However, the recent method does not guarantee full attitude observability for all conditions. This article refines this problem by taking the vector observations into account so that the accuracy and robustness of the spacecraft attitude estimation can be improved. The vector observations come from many sources including visual perspective geometry, optical navigation, and point clouds that frequently occur in aerospace electronic systems. Completely closed-form solutions along with their uncertainty descriptions are presented for the proposed problem. Experiments using our simulated dataset and real-world spacecraft measurements from National Aeronautics and Space Administration's Dawn spacecraft verify the effectiveness and superiority of the derived solution.