Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 170391, 5 pages
Letter to the Editor

Comment on “Highly Efficient Sigma Point Filter for Spacecraft Attitude and Rate Estimation”

Department of Navigation Engineering, Naval University of Engineering, Wuhan 430033, China

Received 13 September 2011; Accepted 3 January 2012

Copyright © 2012 Baiqing Hu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In light of the intuition that a better symmetrical structure can further increase the numerical accuracy, the paper by Fan and Zeng (2009) developed a new sigma point construction strategy for the unscented Kalman filter (UKF), namely, geometric simplex sigma points (GSSP). This comment presents a different perspective from the standpoint of the numerical integration. In this respect, the GSSP constitutes an integration formula of degree 2 with equal weights. Then, we demonstrate that the GSSP can be derived through the orthogonal transformation from the basic points set of degree 2. Moreover, the method presented in this comment can be used to construct more accurate sigma points set for certain dynamic problems.