DMO on irregularly spaced seismic data (dip moveout)
Gardner, Gerald H. F.
Master of Arts
Irregularly spaced seismic data have uneven distribution of trace midpoint density on the half-offset (h) versus common-midpoint (y) space. The deviation from uniformity disrupts the cancellation and reinforcement processes of dip moveout (DMO) operators, hence artificial amplitude anomalies are produced on the DMO output. A pre-DMO weighting method is devised to weight each trace based on the trace midpoint density on the (y,h) space. Using the Voronoi Diagram concept, the method is designed to calculate the Voronoi polygon areas associated with mid-points of seismic traces on the (y,h) space. The area of a polygon is inversely proportional to the trace density on the (y,h) space. Scaling each trace by its Voronoi polygon area prior to applying DMO, the undesirable effects caused by irregular spatial sampling can be largely overcome. The method is called the Voronoi weighting method in this thesis. It can be efficiently implemented on vector or parallel computers.
Geophysics; Geology; Computer science