GRAVITY GRADIOMETER SYSTEM WITH SPHERICAL AIR BEARING BASED PLATFORM

摘要

A non-contacting spherical air bearing-based stable platform for use by a gravity gradiometer instrument (GGI) is provided by attaching a spherical ball-shaped bearing to a rotational stage of the GGI and integrating a concave spherical cup in the linear stage and mounting base assembly of the GGI which is fixedly attached to a host vehicle or platform. The spherical cup supports the spherical ball-shaped bearing on a thin cushion of air provided by a source of compressed air or gas at the concave surface of the spherical cup. The spherical ball-shaped bearing is supported, providing three degrees of rotational freedom of motion without the need for slip rings, flex capsules, races, or mechanical bearings, thereby reducing or eliminating gradient disturbance signals owing to parasitic torques and jitter in the output of the accelerometers of the GGI.

主权项

1. A gravity gradient instrument (GGI) comprising:
a linear stage and mounting base assembly fixedly attached to a host vehicle or platform; a rotational stage; and a spherical air bearing comprising an upper half comprising a spherical ball-shaped bearing of said rotational stage, and a lower half comprising a spherical cup of said linear stage, wherein said spherical ball-shaped bearing is supported by said spherical cup by a thin cushion of air such that said rotational stage rotates relative to said linear stage without contacting said linear stage and is rotationally decoupled from the linear stage.