ESOQ-2 single-point algorithm for fast optimal spacecraft attitude determination Academic Article uri icon


  • The ESOQ-2 algorithm for the optimal attitude estimation based on vector observations is presented in this paper. Starting from the q-Method solution equation, the procedure leads to the computation of the optimal Euler axis as a cross product between two row vectors of a symmetric 3×3 matrix. The optimal quaternion is then immediately computed. The introduced singularity is optimally avoided by employing only one sequential rotation. The resulting proposed algorithm is reliable, non singular, easy to code, and able to identify the quasi-parallel condition when the attitude computation is impossible. Numerical tests in computational speed demonstrated ESOQ-2 to be the fastest available optimal attitude estimation algorithm. Therefore, it can be considered quite suitable when a fast optimal attitude estimation is required.

author list (cited authors)

  • Mortari, D.

publication date

  • January 1, 1997 11:11 AM