基于四象限叠加的海底节点高精度二次定位OA

In ocean bottom node(OBN)seismic exploration,significant discrepancies often exist between the actual node positions and the initial surveyed locations due to factors such as ocean currents,tides,topographic variations,and fishing vessel dragging,necessitating secondary positioning.To address this,a high-precision secondary positioning method based on four-quadrant stacking is proposed.Specifically,within a relative coordi-nate system,shot points are divided into four quadrants according to their azimuth.Linear moveout correction and common receiver point stacking are performed separately for shot points in each quadrant.Subsequently,the displacement of the node from the surveyed position to the actual position is decomposed into two mutually per-pendicular components.These two components are determined by analyzing the first arrival time differences from the common receiver points in each quadrant,which thereby enables precise estimation of the node's actual coordinates.Application to field data demonstrates that this method achieves high-precision secondary position-ing of nodes.Moreover,the four-quadrant stacking strategy significantly improves the reliability of first arrival picking.Compared with traditional methods,this approach offers higher positioning accuracy and efficiency,showing excellent engineering applicability and promising potential for broader adoption.