Patent ID: 7406390
Filing Date: 2008-07-29
Classification: G01V

Abstract:
1. A method of obtaining gravity information having an accuracy comparable to absolute gravity information by using an array of relative gravimeters to obtain gravity information for determining characteristics of a subsurface structure located beneath the surface of the earth, comprising: positioning each of the relative gravimeters in the array at predetermined stationary locations at the surface of the earth; moving an absolute gravimeter to each of the predetermined locations of each of the relative gravimeters; making absolute gravity measurements using the absolute gravimeter and making relative gravity measurements using the relative gravimeter, while the absolute gravimeter is positioned at the predetermined position of each relative gravimeter; processing the absolute and relative gravity measurements obtained when the absolute gravimeter is at the position of each relative gravimeter to determine an error value for each relative gravimeter; and applying the error value to alter subsequent relative gravity measurements supplied by each relative gravimeter into calibrated relative gravity measurements which closely approximate absolute gravity at the predetermined location of each relative gravimeter in the array.