VEHICLE POSITION ESTIMATION SYSTEM

A system (100) and a method (700) for estimating a position (510) of an object (170). The object (170) includes a gradiometer (110). The method (700) includes calculating a gravity vector (270) using a gravity spatial derivative (210) generated by the gradiometer (110) and a plurality of body velocities (220) generated by a body velocity source (120), calculating a gravity potential (430) based on the gravity vector (270), and estimating an inertial measurement unit (IMU)-based position (250) of the object (170) using the gravity vector (270), a body acceleration (230), and a body attitude (240). The IMU (130) generates the body acceleration (230) and the body attitude (240). The method (700) includes estimating a gravity vector-based position (310) of the object (170) using the gravity vector (270) and estimating a gravity map-based position (410) of the object (170) using the gravity potential (430) and one or more gravitational maps (440). The method (700) estimating a position (510) of the object (170) based on the IMU-based position (250), the gravity vector-based position (310), and the gravity map-based position (410). The method (700) includes outputting the position (510) of the object (170) to an output device (150).