The present disclosure provides a method of processing gravity gradient data indicative of an output generated by an airborne gravity gradiometer that is moving along a flight path over a terrain. The method comprises the step of providing the gravity gradient data. The gravity gradient data comprising gravity gradient data elements that are associated with respective flight path segments of the airborne gravity gradiometer. Further, the method comprises providing terrain data indicative of a topography and a density or a density distribution of the terrain above a datum that is below the surface of the terrain over which the airborne gravity gradiometer is moved. The method also comprises providing information concerning the flight path of the airborne gravity gradiometer in three dimensions. In addition, the method comprises calculating the gravity gradient response of the terrain using the provided terrain data and the provided information concerning the flight path. The gravity gradient terrain response data is calculated for a plurality of locations of the gravity gradiometer along at least some of the flight path segment. In addition, the method comprises correcting the gravity gradient data by forming a difference between the calculated gravity gradient terrain response of the terrain topography and the gravity gradient data.