Patent ID: 7938003
Filing Date: 2011-05-10
Classification: G01V

Abstract:
1. A gravity gradiometer for measuring components of the gravity gradient tensor, comprising: an external platform for mounting a Dewar for relative rotation about three orthogonal axes; a sensor arranged in the Dewar for a cryogenic operation for measuring the components of the gravity gradient tensor, the sensor comprising first and second bars; an internal mounting for mounting the sensor for relative rotation about the three orthogonal axes in the Dewar, each of the first bar and the second bar arranged on a respective end of, and external to, the internal mounting and orthogonal to one another; a first feedback controller for monitoring a disturbance of the external platform and producing a force to counteract movement of the external platform to stabilize the external platform; and an internal feedback controller for monitoring a disturbance of the internal mounting caused by any movement of the external platform after stabilization of the external platform to counteract movement of the internal mounting and stabilize the sensor.