Patent ID: 10620332

Abstract:
A method for rotating recorded seismic data. The method includes receiving raw seismic data recorded with a particle motion sensor located along a streamer; receiving vibrational data recorded by a gravity sensing sensor also located along the streamer; calculating an angle β(t), defined by a Z axis of the particle motion sensor and a Z0 axis of a global orthogonal system of coordinates, based on (1) an angle α(t), defined by a Zt axis of the gravity sensing sensor and the Z0 axis, and (2) an angle θ(t) defined by the Zt axis and the Z axis, wherein the Z axis is part of a first local orthogonal system of coordinates attached to the particle motion sensor, the Z0 axis is part of a global orthogonal system of coordinates attached to the earth, and the Zt axis is part of a second local orthogonal system of coordinates attached to the gravity sensing sensor; and correcting the raw seismic data by rotating the raw seismic data, recorded in the first local orthogonal system of coordinates, with the angle β(t), to obtain corrected seismic data in the global orthogonal system of coordinates. The first and second local system of coordinates share a same X axis but the other two axes of each of the first and second local systems are offset from each other by angle θ(t) while the streamer moves in water and records the raw seismic data and the vibrational data. The global orthogonal system of coordinates share the same X axis with the first and second local systems, and the global orthogonal system is fixed to the earth while the first and second local systems rotate with the streamer.