Interpretation of FTG data using Tensor Axis Realignment

Abstract

Full Tensor Gravity Gradiometry (FTG) data measures the 5 independent tensor components, providing us with a measurement of the complete gravity field; standard visualisation techniques do not always allow us to extract the best from this dataset. Tensor axis realignment allows us to visualise the data in an alternative reference frame, rather than the typical East-North-Down system used for gravity gradiometry which is chosen because it conforms to mapping conventions rather than for any geological reason. With axis realignment, the coordinates are rotated about the z-axis, so we are effectively visualising the potential field from a different orientation. In doing this we highlight different geological trends which were not so prominently visualised in the typical END coordinate frame. By using tensor axis realignment we are able to draw out further geological information from FTG data and hence produce a better interpretation of the dataset. Tensor axis realignment provides a way to visualise the three-dimensionality of FTG data and gain more geological insight into the survey area.