Weighting Logic Design of Hybrid Database Referenced Navigation Algorithm Using Multiple Geophysical Information

This paper presents the hybrid database referenced navigation algorithm using terrain height and gravity anomaly information together. Geophysical information database can be used for navigation with inertial sensors on the GPS denied environment. Terrain height is the most commonly used as secondary navigation information with INS. However, the terrain referenced navigation is sometimes impossible to estimate the position because of the lack of uniqueness on the flat terrain. Therefore, we propose the hybrid database referenced navigation technique which utilizes a gravity anomaly information along with terrain height. In this paper, the point mass filter is used for estimation of the vehicle's position. And weighting logic for hybrid database referenced navigation is designed based on the kurtosis of posteriori pdf (probability density function) because that of posteriori pdf has a proportional relationship to the estimation accuracy. Each estimation result is mixed together according to the kurtosis. As a result, it is shown by the numerical simulation that the proposed method has a better performance than the navigation result obtained from individual database.