SLERP-based optimal TRIAD algorithm

TRIAD algorithm, simple and easy to use by serving two vectors, is widely applied to attitude determination. Through selecting the different vector as anchor, this algorithm may be acquired two distinct attitude matrices with error covariance, respectively. To improve the accuracy of the attitude matrices, we propose an optimal TRIAD algorithm utilizing the spherical linear interpolation (SLERP) method in this paper. The proposed algorithm is fused the two distinct matrices to achieve an optimal result by minimizing the error covariance of quaternion representation of attitude. We verify the correctness by simulations, and finally, two experiments are demonstrated.