Practical Evaluation of EKF^1 and UKF^2 Filters for Terrain Aided Navigation

This article deals with batch and recursive methods used in terrain navigation systems. These systems have a lot of disadvantages. That is why researchers have studied various methods of aided navigation for many years and have introduced different types of aided navigation systems with practical and theoretical advantages and disadvantages. One of the main ideas related to aided navigation is integration of extended Kalman filter and INS3. This integration method has a significant weakness in practice that has caused it not to be highly valued as an aided navigation method. Hence, in this article, the authors introduce a more accurate filter (UKF) to be integrated with INS and other sensors such as barometers and radar systems. Then, the use of the aided EKF and UKF navigation schemes are justified, their respective algorithms are developed and performed for the needed applications and the simulation results are presented and compared. Finally, the advantages of the proposed method are compared with those of other batch and recursive methods. The most significant idea of the present article is related to its practical application on a UAV that was tested in 2010.