The invention relates to a square root
cubature Kalman filter-based aircraft attitude
estimation method which comprises the steps of setting an initial value and a Rodriguez parameter when calculating time updating, calculating a volume point value, calculating a
quaternion error point, calculating a
quaternion volume point, calculating an iteration
quaternion and an iteration quaternion error, calculating an iteration volume point, estimating a one-step prediction state, estimating a square root factor prediction error
covariance matrix, calculating a volume point in measurement updating, calculating an iteration volume point value, calculating prediction measurement
estimation, calculating square root factor innovation
covariance matrix estimation, calculating a
cross covariance matrix, carrying out Kalman
gain, estimating state updating, calculating an estimated error
covariance matrix and a corresponding square root factor, updating the quaternion, and calculating a corresponding estimated error euler angle. According to the square root
cubature Kalman filter-based aircraft attitude
estimation method, the precision and the stability of aircraft attitude can be improved.