Patent ID: 7814790
Filing Date: 2010-10-19
Classification: G01V

Abstract:
1. A gravity gradiometer for measuring components of the gravity gradient tensor, the gravity gradiometer comprising: a housing; at least one sensor mass being positioned in the housing and being arranged for movement in response to a gravity gradient; a gimballed support structure for supporting the housing and rotating the housing about an axis at an angular frequency that approximately equals half the resonance frequency of the at least one sensor mass, the support structure comprising an actuator; a pivotal coupling enabling the movement of the at least one sensor mass about an axis and suspending the at least one sensor mass in the housing so that a gravity gradient will result in an oscillation of that at least one sensor mass during rotation of the housing with the at least one sensor mass; a transducer arranged so that the movement of the at least one sensor mass relative to a portion of the transducer generates a transducer signal; and an electrical feedback loop arranged to direct an electrical signal to the actuator of the support structure, the electrical signal being associated with the transducer signal; wherein the gravity gradiometer is arranged so that an influence of an external angular acceleration on the rotation of the housing is reduced by the actuator when the transducer generates the transducer signal effected by the external angular acceleration on the gravity gradiometer.