Performance Analysis of In-flight Alignment Using UKF for Trajectory

In this paper, GPS aided in-flight alignment algorithm using UKF(Unscented Kalman Filter) is presented for an SDINS under large initial heading error and different trajectory. For this task, the EKF that approximates the propagation of mean and covariance accurate to first-order only is generally used. To overcome the EKF limitation, the various unscented transformations that achieve second order approximation are applied to the in-flight alignment. With a low cost MEMS IMU, the simulations are carried out at S-type and Circle-type trajectory for analyzing the performance of the proposed method. The results show that performance of UKF has a better than EKF for large initial heading error. And using S-type trajectory increase the performance of error estimates