Abstract: A method and device for processing a seismic survey data set including: an actual source location, an actual receiver location, and an actual reflection event location is provided. The actual source location and actual receiver location are over a first layer having a first layer velocity and a first layer ray parameter, and over a second layer having a second layer velocity different from the first layer velocity and a second layer ray parameter different from the first layer ray parameter. The actual reflection event location is located below the first layer. The method comprises: providing the first layer velocity; providing the second layer velocity; providing the first layer ray parameter; providing the second layer ray parameter; determining a correction factor for the position of a ray path end dependant upon the first and second layer velocities and the first and second layer ray parameters; and applying the correction factor to the ray path end, wherein a ray path-corrected ray path end is provided.

Abstract: The invention disclosed is a drive assembly for acoustic sources having sound emitting surfaces (1) adapted to be excited into vibrational motions. The invention is especially for use in seismic surveys. The drive assembly includes an electric rotational motor with at least one associated axle comprising at least an axle part (18) and a number of rods (21, 22) arranged radially in relation to the axle. The inner ends of the rods (21, 22) are influenced by the axle part (18) and the outer ends of the rods (21, 22) are adapted to excite the sound emitting surfaces (1) into vibrational motion. The inner ends of the rods (21, 22) are connected to the axle part (18) and the connection is adapted to perform both push and pull forces upon the rods. One or more spring elements (23) are provided between at least one of the rods (21, 22) and the sound emitting surfaces (1).