Upward continuation with topographic datuming operator: the integrated wave equation datuming scheme revised
Kai Yang, Yu-Zhu Liu, Jian-Hua Geng and Zai-Tian Ma
Journal name: Geophysical Prospecting
Issue: Vol 57, No 6, November 2009 pp. 943 - 956
Info: Article, PDF ( 1.4Mb )
The integrated wave equation datuming scheme is an integrated datuming method to implement the wave equation velocity replacement with a one-way extrapolator for overthrust data. The integrated wave equation datuming scheme is accomplished by downward continuing the data from the topography to a non-planar base of the weathering layer, followed by an upward continuation from the base of the weathering layer to a final planar datum. Both the downward and the upward continuation are accomplished by a one-way extrapolator by a classical 'two-step' implementation. The topographic datuming operator is a distinctive technique by which the shots and receivers are downward continued simultaneously. Although its inadaptability to non-planar datum and the strong lateral variation of the near-surface structure constrains its application to the downward continuation of the overthrust data, we found that the 'one-step' feature of the topographic datuming operator is extremely suitable for the upward continuation. In this paper, the topographic datuming operator is incorporated into the integrated wave equation datuming scheme to perform upward continuation instead of a one-way extrapolator – thus a revised integrated wave equation datuming scheme is constructed. Compared with the previous scheme, the computatiol cost of the revised integrated wave equation datuming scheme is greatly reduced, thus the applicability of the integrated wave equation datuming scheme is further improved. The synthetic and real data examples demonstrate its effectiveness and efficiency.