Method for navigation positioning by using gravitation vector and gradient tensor

Abstract

The invention discloses a method for navigation positioning by using a gravitation vector and gradient tensor. The method comprises the following steps: firstly, establishing a background field three-dimensional information databank of a target area according to beforehand observation, wherein basic elements comprise position coordinates of different points, gravitation vector invariants and gravitation gradient tensor invariants, subsequently observing and calculating according to the gravitation and the gravitation gradient in real time so as to obtain three invariants, judging whether navigation positioning can be performed directly or not by judging whether a resolving matrix is of full rank, if navigation positioning can be performed directly, performing iterative computation to obtain the position of a point to be positioned according to a least squares algorithm, if navigation positioning cannot be performed directly, performing matching search with the combination of an inertial navigation positioning technique, and performing iterative search for multiple times so as to obtain the position of the point to be positioned. The method has the outstanding characteristics that the gravitation vector invariants and gravitation gradient tensor invariants are adopted, and not only is contribution of all components of gravitation field information considered, but also the components are not related to the posture, so that compared with a conventional algorithm, the method can greatly reduce the influence of posture errors.

Description

technical field [0001] The invention relates to a method for navigation and positioning by using gravity vector and gradient tensor, which is especially suitable for gravity-assisted navigation and positioning under the condition of large attitude error observation. Background technique [0002] Compared with the current popular navigation methods (such as satellite navigation, radio navigation, etc.), gravity-assisted inertial navigation has the characteristics of autonomy and passiveness, which determines that this navigation method has certain advantages in certain situations. Since the concept of gravity-assisted inertial navigation was proposed in 1975, it has attracted the attention of many scholars, for example: Metzger and Jircitano (Journal of Spacecraft and Rockets, 1976.13 (6): 323-324), Affeck and Jircitano (Proceedings of IEEE's Position Location and Navigation Symposium (PLANS), 1990, 60-66) have studied how to use the gravity gradient to improve the accuracy o...

AI Technical Summary

Problems solved by technology

In the currently widely used method of using gravity or gravity gradient to assist inertial navigation, the matching quantity used also needs direction information, because the gravitational vector and gravitational gradient tensor have different component values ​​in different coordinate systems. Significant differences

Therefore, the method of using traditional gravity or gravity gradient to assist inertial navigation will not be able to effectively eliminate the part of inertial navigation positioning error that originates from attitude error

Images