Deterministic EKF-like estimator for spacecraft attitude estimation

A filter for estimating spacecraft attitude quaternion and gyro drift bias vector is developed. The point of view taken in this paper is deterministic in that the underlying system and the measurement process are assumed to be both deterministic, while the uncertainties considered are assumed to be unmeasurable deterministic functions of time. The approach taken is motivated largely by some recent work that has been done in the area of nonlinear H/sub /spl infin// control and estimation.