Gravity gradiometer
AssigneeTechnological Resources Pty. Limited
InventorFrank Joachim Van Kann
Life of this patent
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Abstract
The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass.
Claims13
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.
Dependencies are inferred from the claim text.