Study on uncertainty evaluation methods of aerodynamic parameter estimation for aircraft

In order to make effective use of aerodynamic parameter estimation results for an aircraft, it is necessary to provide at the same time an aerodynamic parameter uncertainty interval, for which the uncertainty evaluation methods are studied in this paper. If test runs are sufficient in number, the sample standard deviation has a clear statistical significance. Therefore it is a good criterion for uncertainty evaluation. The C-R (Cramer-Rao) bound based on the uncertainty ellipsoid is the best theoretical prediction of uncertainty for a single flight test, but C-R bound is different from the sample standard deviation due to colored residuals. A correction method by constructing the Gauss noises based on colored noises is proposed, and the accuracy of the corrected C-R bound is validated through comparing it the with sample standard deviation. Finally the correction method of C-R bound is applied to flight test data, and the corrected C-R bound is found to be close to the sample standard deviation, which demonstrates that the uncertainty evaluation method is valid.